Clarke Energy (Australia) Pty Ltd v Alinta Energy Transmission (Roy Hill)... [2026] NSWSC 1124 | Case summary

Clarke Energy (Australia) Pty Ltd v Alinta Energy Transmission (Roy Hill)... [2026] NSWSC 1124 | Case summary | Zoe

At a glance

Source facts

Court

Supreme Court of NSW

Decision date

2026-09-21

Before

Rees J

Catchwords

CONSTRUCTION — contractor engaged to engineer, procure and construct power station in remote WA for $78 million — small site nestled between two existing power stations operated by Alinta and BHP — principal says it will move existing underground services before the contractor starts, to avoid problems with neighbours — extensive delay until underground services are removed, ultimately with the assistance of the contractor — contractor serves extension of time (EOT) claim on principal but omits to copy superintendent — contractor required to undertake work on Alinta’s existing power station — principal obliged to, but fails to, perform electrical isolations for the contractor to undertake works — contractor asked to perform work near live cables — refuses — delay while isolations done — COVID-19 border restrictions and quarantine interrupt interstate fly-in fly-out (FIFO) workers getting to remote site — local labour hired but less productive, causing delay — complex commissioning and testing process for new power station — principal required to, but fails to, make electricity network available during this process, causing delay — when was practical completion achieved — is contractor entitled to EOTs and delay costs — yes. SUPERINTENDENTS — parties agree that superintendent’s determinations may be challenged in Court — how Court to approach its task at [12]-[18] — principal to ensure superintendent “acts honestly, fairly and reasonably and arrives at reasonable determinations” — role of superintendent at [19]-[21] — superintendent “overwhelmed” and makes no determination —replaced — second superintendent privately indicates to principal that inclined to issue certificate of practical completion — superintendent immediately replaced — private communications between superintendent and one contracting party undermines role of superintendent — removing a superintendent to stop them giving a determination that you do not want effectively destroys the role. EXTENSIONS OF TIME — time impacted analysis at [407]-[408] — programs — who ‘owns’ the float at [130]-[134] — whether change of logic in subsequent program may indicate baseline program should not be used — yes, at [832] — whether it matters that the work was ultimately done differently — no, at [834] — whether EOT should include loss of ‘activity float’ — no, at [524]-[526]. DELAY COSTS — “reasonable additional costs and expenses directly incurred … as a result of that delay” includes usual margin — contractor not obliged to provide goods and services without gain, absent clear words at [536]-[538] — contractor entitled to overheads and profit margin, at [544]-[547] — whether delay costs include lost days of ‘activity float’ — no, at [528]. VARIATIONS — was an email a variation order — consideration at [289]-[291]. CONTRACTS — proper construction, at [84]-[85] — resolving inconsistencies, at [399] — whether removal of underground services formed part of contractor’s scope of work — no — whether contractor’s acceptance of Site Conditions included the site as later excavated by the principal to remove underground services — no — whether principal obliged to backfill and compact the land disturbed by removal of such services to Site Conditions as at the date of the contract — yes. IMPLIED TERM — duty to cooperate — principles at [270] — principal had “sole discretion” to give a notice to proceed — issue of notice fixed Date for Practical Completion and commencement of contractual provisions for liquidated damages — principal obliged to give contractor access to site “to perform the Work” within 10 business days of the notice — duty to cooperate obliged principal to be satisfied that it would be in such a position when issuing the notice. ‘PREVENTION PRINCIPLE’ — implied obligation to cooperate — whether contract excluded prevention principle — case law review at [259], [867]-[871] — Growthbuilt Pty Ltd v Modern Touch Marble & Granite Pty Ltd [2021] NSWSC 290 considered — prevention principle not excluded. WAIVER — principles at [761] — impact of ‘no waiver’ clause at [762] — case law review at [763]-[766] — principal relies on contractor’s failure to provide EOT claim to superintendent in time as basis to reject claim entirely — process for determination of EOTs not followed — principal later content for third superintendent to determine claim substantively — principal chooses between inconsistent rights — principal waives reliance on failure to comply with conditions precedent. AUSTRALIAN CONSUMER LAW — whether representation made, principles at [63] — implications of entire agreement and no reliance clauses at [73] — representation as to future matter — whether misleading or deceptive, at [882]-[883] — had proper basis when made. ESTOPPEL — whether representation made, principles at [64] — principal represented that it would remove underground services prior to contractor arriving on site — whether principal should be estopped from denying entitlement to EOT — elements of estoppel at [294] — principal did not represent that it would not rely on contractual regime in respect of EOTs — estoppel not made out.

Source

Original judgment source is linked above.

Catchwords

CONSTRUCTION — contractor engaged to engineer, procure and construct power station in remote WA for $78 million — small site nestled between two existing power stations operated by Alinta and BHP — principal says it will move existing underground services before the contractor starts, to avoid problems with neighbours — extensive delay until underground services are removed, ultimately with the assistance of the contractor — contractor serves extension of time (EOT) claim on principal but omits to copy superintendent — contractor required to undertake work on Alinta’s existing power station — principal obliged to, but fails to, perform electrical isolations for the contractor to undertake works — contractor asked to perform work near live cables — refuses — delay while isolations done — COVID-19 border restrictions and quarantine interrupt interstate fly-in fly-out (FIFO) workers getting to remote site — local labour hired but less productive, causing delay — complex commissioning and testing process for new power station — principal required to, but fails to, make electricity network available during this process, causing delay — when was practical completion achieved — is contractor entitled to EOTs and delay costs — yes. SUPERINTENDENTS — parties agree that superintendent’s determinations may be challenged in Court — how Court to approach its task at [12]-[18] — principal to ensure superintendent “acts honestly, fairly and reasonably and arrives at reasonable determinations” — role of superintendent at [19]-[21] — superintendent “overwhelmed” and makes no determination —replaced — second superintendent privately indicates to principal that inclined to issue certificate of practical completion — superintendent immediately replaced — private communications between superintendent and one contracting party undermines role of superintendent — removing a superintendent to stop them giving a determination that you do not want effectively destroys the role. EXTENSIONS OF TIME — time impacted analysis at [407]-[408] — programs — who ‘owns’ the float at [130]-[134] — whether change of logic in subsequent program may indicate baseline program should not be used — yes, at [832] — whether it matters that the work was ultimately done differently — no, at [834] — whether EOT should include loss of ‘activity float’ — no, at [524]-[526]. DELAY COSTS — “reasonable additional costs and expenses directly incurred … as a result of that delay” includes usual margin — contractor not obliged to provide goods and services without gain, absent clear words at [536]-[538] — contractor entitled to overheads and profit margin, at [544]-[547] — whether delay costs include lost days of ‘activity float’ — no, at [528]. VARIATIONS — was an email a variation order — consideration at [289]-[291]. CONTRACTS — proper construction, at [84]-[85] — resolving inconsistencies, at [399] — whether removal of underground services formed part of contractor’s scope of work — no — whether contractor’s acceptance of Site Conditions included the site as later excavated by the principal to remove underground services — no — whether principal obliged to backfill and compact the land disturbed by removal of such services to Site Conditions as at the date of the contract — yes. IMPLIED TERM — duty to cooperate — principles at [270] — principal had “sole discretion” to give a notice to proceed — issue of notice fixed Date for Practical Completion and commencement of contractual provisions for liquidated damages — principal obliged to give contractor access to site “to perform the Work” within 10 business days of the notice — duty to cooperate obliged principal to be satisfied that it would be in such a position when issuing the notice. ‘PREVENTION PRINCIPLE’ — implied obligation to cooperate — whether contract excluded prevention principle — case law review at [259], [867]-[871] — Growthbuilt Pty Ltd v Modern Touch Marble & Granite Pty Ltd [2021] NSWSC 290 considered — prevention principle not excluded. WAIVER — principles at [761] — impact of ‘no waiver’ clause at [762] — case law review at [763]-[766] — principal relies on contractor’s failure to provide EOT claim to superintendent in time as basis to reject claim entirely — process for determination of EOTs not followed — principal later content for third superintendent to determine claim substantively — principal chooses between inconsistent rights — principal waives reliance on failure to comply with conditions precedent. AUSTRALIAN CONSUMER LAW — whether representation made, principles at [63] — implications of entire agreement and no reliance clauses at [73] — representation as to future matter — whether misleading or deceptive, at [882]-[883] — had proper basis when made. ESTOPPEL — whether representation made, principles at [64] — principal represented that it would remove underground services prior to contractor arriving on site — whether principal should be estopped from denying entitlement to EOT — elements of estoppel at [294] — principal did not represent that it would not rely on contractual regime in respect of EOTs — estoppel not made out.

Judgment

Source: NSW Caselaw (www.caselaw.nsw.gov.au). Converted to plain text by ZoeLaw. Not the official version.

Medium Neutral Citation: Clarke Energy (Australia) Pty Ltd v Alinta Energy Transmission (Roy Hill) Pty Ltd [2026] NSWSC 1124

Hearing dates: 13-24, 28-30 April; 12-14, 21 May 2026

Date of orders: 21 September 2026

Decision date: 21 September 2026

Jurisdiction: Equity - Technology and Construction List

Before: Rees J

Decision: Judgment for the plaintiff

Catchwords: CONSTRUCTION — contractor engaged to engineer, procure and construct power station in remote WA for $78 million — small site nestled between two existing power stations operated by Alinta and BHP — principal says it will move existing underground services before the contractor starts, to avoid problems with neighbours — extensive delay until underground services are removed, ultimately with the assistance of the contractor — contractor serves extension of time (EOT) claim on principal but omits to copy superintendent — contractor required to undertake work on Alinta’s existing power station — principal obliged to, but fails to, perform electrical isolations for the contractor to undertake works — contractor asked to perform work near live cables — refuses — delay while isolations done — COVID-19 border restrictions and quarantine interrupt interstate fly-in fly-out (FIFO) workers getting to remote site — local labour hired but less productive, causing delay — complex commissioning and testing process for new power station — principal required to, but fails to, make electricity network available during this process, causing delay — when was practical completion achieved — is contractor entitled to EOTs and delay costs — yes.
SUPERINTENDENTS — parties agree that superintendent’s determinations may be challenged in Court — how Court to approach its task at [12]-[18] — principal to ensure superintendent “acts honestly, fairly and reasonably and arrives at reasonable determinations” — role of superintendent at [19]-[21] — superintendent “overwhelmed” and makes no determination —replaced — second superintendent privately indicates to principal that inclined to issue certificate of practical completion — superintendent immediately replaced — private communications between superintendent and one contracting party undermines role of superintendent — removing a superintendent to stop them giving a determination that you do not want effectively destroys the role. EXTENSIONS OF TIME — time impacted analysis at [407]-[408] — programs — who ‘owns’ the float at [130]-[134] — whether change of logic in subsequent program may indicate baseline program should not be used — yes, at [832] — whether it matters that the work was ultimately done differently — no, at [834] — whether EOT should include loss of ‘activity float’ — no, at [524]-[526]. DELAY COSTS — “reasonable additional costs and expenses directly incurred … as a result of that delay” includes usual margin — contractor not obliged to provide goods and services without gain, absent clear words at [536]-[538] — contractor entitled to overheads and profit margin, at [544]-[547] — whether delay costs include lost days of ‘activity float’ — no, at [528]. VARIATIONS — was an email a variation order — consideration at [289]-[291]. CONTRACTS — proper construction, at [84]-[85] — resolving inconsistencies, at [399] — whether removal of underground services formed part of contractor’s scope of work — no — whether contractor’s acceptance of Site Conditions included the site as later excavated by the principal to remove underground services — no — whether principal obliged to backfill and compact the land disturbed by removal of such services to Site Conditions as at the date of the contract — yes. IMPLIED TERM — duty to cooperate — principles at [270] — principal had “sole discretion” to give a notice to proceed — issue of notice fixed Date for Practical Completion and commencement of contractual provisions for liquidated damages — principal obliged to give contractor access to site “to perform the Work” within 10 business days of the notice — duty to cooperate obliged principal to be satisfied that it would be in such a position when issuing the notice. ‘PREVENTION PRINCIPLE’ — implied obligation to cooperate — whether contract excluded prevention principle — case law review at [259], [867]-[871] — Growthbuilt Pty Ltd v Modern Touch Marble & Granite Pty Ltd [2021] NSWSC 290 considered — prevention principle not excluded. WAIVER — principles at [761] — impact of ‘no waiver’ clause at [762] — case law review at [763]-[766] — principal relies on contractor’s failure to provide EOT claim to superintendent in time as basis to reject claim entirely — process for determination of EOTs not followed — principal later content for third superintendent to determine claim substantively — principal chooses between inconsistent rights — principal waives reliance on failure to comply with conditions precedent. AUSTRALIAN CONSUMER LAW — whether representation made, principles at [63] — implications of entire agreement and no reliance clauses at [73] — representation as to future matter — whether misleading or deceptive, at [882]-[883] — had proper basis when made. ESTOPPEL — whether representation made, principles at [64] — principal represented that it would remove underground services prior to contractor arriving on site — whether principal should be estopped from denying entitlement to EOT — elements of estoppel at [294] — principal did not represent that it would not rely on contractual regime in respect of EOTs — estoppel not made out.

Parties

Applicant/Plaintiff:

Clarke Energy (Australia) Pty Ltd

Respondent/Defendant:

Alinta Energy Transmission (Roy Hill) Pty Ltd

Legislation Cited (8)

Electricity (Licensing) Regulations 1991(WA)

Emergency Management Act 2004(SA)

Emergency Management Act 2005(WA)

Evidence Act 1995(NSW)

Work Health and Safety Act 2020(WA)

Management Act 2005

Management Act 2004

Health and Safety Act 2020

Cases Cited (105)

[2021] NSWSC 290

[2017] NSWCA 11

Cases Cited: Abergeldie Contractors Pty Ltd v Fairfield City Council [2017] NSWCA 11
Agricultural and Rural Finance Pty Ltd v Gardiner (2008) 238 CLR 570; [2008] HCA 57
Alstom Ltd v Yokogawa Australia Pty Ltd (No 7) [2012] SASC 49
Aquatec-Maxcon Pty Ltd v Barwon Region Water Authority (No 2) [2006] VSC 117
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Australian Competition and Consumer Commission v Coles Supermarkets Australia Pty Ltd [2014] FCA 634
Australian Competition and Consumer Commission v Telstra Corporation Ltd [2007] FCA 1904
Australian Competition and Consumer Commission v TPG Internet Pty Ltd (2013) 250 CLR 640; [2013] HCA 54
Australian Competition and Consumer Commission v Woolworths Ltd [2019] FCA 1039
Banco de Portugal v Waterlow & Sons Ltd [1932] AC 452
Beerens v Bluescope Distribution Pty Ltd (2012) 39 VR 1; [2012] VSCA 209
Bensons Property Group Pty Ltd v Key Infrastructure Australia Pty Ltd [2021] VSCA 69
Brighton Australia Pty Ltd v Multiplex Constructions Pty Ltd (2018) 56 VR 557; [2018] VSC 246
Briginshaw v Briginshaw [1938] HCA 34; (1938) 60 CLR 336
Built Qld Pty Ltd v Pro-Invest Australian Hospitality Opportunity (ST) Pty Ltd (2022) 13 QR 148; [2022] QCA 266
Butcher v Lachlan Elder Realty Pty Ltd (2004) 218 CLR 592; [2004] HCA 60
Butt v M’Donald (1896) 7 QLJ 68
Campbell v Backoffice Investments Pty Ltd (2009) 238 CLR 304; [2009] HCA 25
Campomar Sociedad Limitada v Nike International Ltd (2000) 202 CLR 45; [2000] HCA 12
Carbone atf S and N Carbone Family Trust v Mills [2019] NSWCA 15
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CPB Contractors Pty Ltd v Rizzani De Eccher Australia Pty Ltd [2017] NSWSC 1798
Commonwealth v Verwayen (1990) 170 CLR 394; [1990] HCA 39
Construction, Forestry, Maritime, Mining and Energy Union v Personnel Contracting Pty Ltd (2022) 275 CLR 165; [2022] HCA 1
Corbett Court Pty Ltd v Quasar Constructions (NSW) Pty Ltd [2008] NSWSC 1163
Crossman v Sheahan [2016] NSWCA 200
Crown Melbourne Ltd v Cosmopolitan Hotel (Vic) Pty Ltd (2016) 260 CLR 1; [2016] HCA 26
DIF III - Global Co-Investment Fund LP v Babcock & Brown International Pty Ltd [2019] NSWSC 527
Evans v Evans [2011] NSWCA 92
GEC Marconi Systems Pty Ltd v BHP Information Technology Pty Ltd (2003) 128 FCR 1; [2003] FCA 50
Girchow Enterprises Pty Ltd v Ultimate Franchising Group Pty Ltd (Final Hearing) [2023] FCA 420
Global Sportsman Pty Ltd v Mirror Newspapers Pty Ltd (1984) 2 FCR 82
Golden Mile Property Investments Pty Ltd (in liq) v Cudgegong Australia Pty Ltd [2016] NSWCA 224
Growthbuilt Pty Ltd v Modern Touch Marble & Granite Pty Ltd [2021] NSWSC 290
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Ireland v WG Riverview Pty Ltd (2019) 101 NSWLR 658; [2019] NSWCA 307
Karacominakis v Big Country Developments Pty Ltd [2000] NSWCA 313
Kramer v Stone (2024) 281 CLR 484; [2024] HCA 48
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Mallonland Pty Ltd v Advanta Seeds Pty Ltd (2024) 283 CLR 507; [2024] HCA 25
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Pamplin v Irwin [2024] NSWCA 213
Parkdale Custom Built Furniture Pty Ltd v Puxu Pty Ltd (1982) 149 CLR 191; [1982] HCA 44
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Peninsula Balmain Pty Ltd v Abigroup Contractors Pty Ltd [2002] NSWCA 211
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HER HONOUR: The plaintiff, Clarke Energy (Australia) Pty Ltd, was engaged to engineer and construct a gas-fired power station in remote Western Australia. The principal was Alinta Energy Transmission (Roy Hill) Pty Ltd, being the first defendant. The parties signed a complex and exacting contract. It took two years. Neither party adhered to the contract precisely. But now that the project is complete, the principal seeks to rely on the contract exactly, while the contractor seeks to ameliorate the harshness of that result by calling in aid equitable remedies and the Australian Consumer Law.
The Engineering, Procurement and Construction (EPC) contract ‘capped’ liquidated damages at 10% of the contract sum. Alinta now seeks this ‘capped’ amount, being some $7.8 million, while Clarke claims to be entitled to four extensions of time (EOTs) which may mean that it need pay no liquidated damages at all. There is also a disputed variation (VO 05) and delay costs associated with the EOT claims.
The first EOT claim concerned protracted delays in starting work at all. The project site should not be thought to be in the middle of nowhere. It was nestled between two existing power stations, one operated by Alinta and the other by BHP. The APA Group Newman Lateral high pressure natural gas transmission pipeline ran along its boundary. To avoid problems with its neighbours, Alinta said that it would remove existing underground services before Clarke arrived on site. Alinta said this without knowing exactly what that would involve. Alinta gave Clarke a notice to proceed before any underground services had been removed. Time began to run to complete the works.
While Alinta tried to organise the removal of underground services, Clarke could not actually begin, where the first activity on site was bulk earthworks. When the complexities involved in removing underground services became apparent, Alinta asked Clarke to submit a variation to undertake the task instead. But Clarke’s variation was thought too expensive. Alinta hired a contractor to do it for a fraction of the price. This proved to be false economy. Clarke’s bulk earthworks subcontractor refused to start work until it had access to the whole site and was protected in respect of the fairly obviously inadequate compaction undertaken by Alinta’s contractor. Alinta considered this to be Clarke’s problem, as it had to compact the site anyway. Ultimately, Clarke engaged Alinta’s contractor to return to the site and re-do its compaction.
Clarke’s bulk earthworks subcontractor then commenced work. Clarke sought an extension of time (EOT 1) but omitted to copy the superintendent on its claim. This omission was promptly remedied. Although the superintendent was to determine the claim within 15 business days, EOT 1 was ultimately determined almost two years later, when no extension was allowed. Clarke now seeks an extension of 116 days.
Second, the project was undertaken during the COVID-19 pandemic. The Western Australia and South Australia borders were closed from time to time, and quarantine periods imposed. The ability of Clarke and its subcontractor to get fly-in fly-out (FIFO) workers to site was thrown into disarray, prompting the subcontractor to embark on a “google rampage of calling people” in an effort to hire local labour instead. Clarke sought an extension of time (EOT 4). The claim was refused six months later, perhaps ironically, for Clarke’s failure to make the claim in time. Clarke now seeks an extension of 27.5 days.
Third, part of the project involved connecting the existing Alinta power station (referred to as NPS1) to the new power station (referred to as NPS2). This involved work on a relay panel at NPS1. Clarke was obliged to liaise with Alinta’s staff at NPS1 (referred to as "Alinta Operations”), who were the font of knowledge as to precisely how the 25 year old panel was wired. But Alinta Operations was busy. Alinta asked Clarke’s subcontractor to prepare a list of electrical isolations to be performed on the panel instead. Alinta did so without knowing exactly what that would involve. Alinta proved difficult to engage in finalising the isolation list. Clarke pressed for its subcontractor to come to site to perform the work, albeit it on relatively short notice. Alinta Operations was still busy. On arrival, Alinta Operations issued a permit to work to Clarke’s subcontractor, even though the isolations had not been done. Alinta Operations suggested that the subcontractor do the work close to live cabling. The subcontractor refused. Alinta Operations then focused on the isolations needed, but it took some time to work it out. Clarke sought an extension of time (EOT 11), which was refused at the time and for which Clarke now seeks an extension of 17 days.
Fourth, as the project neared completion, Alinta was obliged to make the electricity network available to enable Clarke to test and commission NPS2. This did not always happen; Alinta called no evidence as to why not. Clarke sought an extension of time (EOT 12), which was refused at the time and for which Clarke now seeks an extension of eight days.
It is also necessary to determine what the date of practical completion was. The ‘cornerstone’ of Clarke’s delivery of the NPS2 project was the INNIO Jenbacher gas engine from Austria. According to the manufacturer, the engines would ‘de-rate’, that is, reduce output above air temperatures of 46oC. Where the temperature at the project site ranged from -2°C to 46°C, Alinta was concerned that alarms and ‘de-rates’ encountered during the commissioning process indicated that the new power station was not dealing with local conditions. Clarke’s commissioning technicians said these events were typical for a power facility during the final stages of optimisation and fine-tuning for local operating conditions. This issue is resolved by the contract’s detailed provisions in respect of Guarantee Tests and the requirements for Practical Completion, as opposed to Design Criteria which Alinta’s personnel focused on at the time.
A subsidiary question is whether Clarke’s applications for EOTs and a Certificate of Practical Completion were properly dealt with by the superintendent at the time. There were three superintendents over the life of the project. The first superintendent, Anthony Ravi (the second defendant), was an Alinta employee who had never been a superintendent before. He felt “overwhelmed” by the task and made no determinations at all. Mr Ravi was replaced by Hamish Marshall (the third defendant), an Alinta employee but had been a superintendent once before. As the project neared completion, Mr Marshall privately indicated to Alinta that he was thinking of issuing a Certificate of Practical Completion. Alinta promptly replaced him with the last superintendent, Brett Anderson (the fourth defendant), who was not an Alinta employee. At Alinta’s request, Mr Anderson also belatedly determined EOT 1.

The parties agreed that the superintendents’ determinations were not final or binding. The contract provided that either party may commence legal proceedings to resolve a Dispute, where “Dispute” was defined as “any dispute, difference or disagreement … arising out of or in connection with this agreement or the performance of it (including in relation to a determination of the Superintendent)”: cll 1.1, 35.3(a). As such, it is convenient to resolve the Disputes and defer any consideration of the superintendents’ actions until later.
As to how the Court may go about this task, the Court is not bound to determine the question only on the basis of the material which could have been known to the superintendent: Built Qld Pty Ltd v Pro-Invest Australian Hospitality Opportunity (ST) Pty Ltd (2022) 13 QR 148; [2022] QCA 266 at [115] (Morrison, Dalton JJA and Bradley J). Further, while the superintendent may have had no option but to assess delay on a prospective basis because of time limitations in the contract, it is open to the Court to make its assessment on a retrospective basis even though that course would not have been available to the superintendent: Built Qld at [116]-[117], citing V601 Developments Pty Ltd v Probuild Constructions (Aust) Pty Ltd [2021] VSC 849 at [623], [627] (Digby J).
In V601, Digby J considered “it to be more practical and more accurate and sensible to analyse delay and the effect of delay retrospectively, with the benefit of hindsight, and the higher level of assurance now achievable from a retrospective delay analysis utilising the ‘as build’ facts to ascertain how the [Works Under Contract] were actually constructed and actually delayed”: at [587]. A retrospective analysis was “not only the most appropriate method of identifying the actual delay which occurred, but is also likely the only practical way of doing so and satisfying the real intent of … the Contract and also doing justice as between the parties”: at [623]. Further, at [627]:

Similarly, in Republic of Turkey v Mackie Pty Ltd [2019] VSC 103, Bell J noted that, by its very nature, contractual review of a superintendent’s exercise of power was not to be confined to facts and circumstances existing at that time or known by the superintendent; where the dispute becomes justiciable before a court, “The evidence may extend to facts and circumstances that the superintendent did not know or which happened subsequently. … the issue is live at all times up until the determination of the dispute by the court”: at [102].
The language of this contract may require a different approach, at least in respect of determining the date of practical completion. The contract provided that this depended on NPS1 completing a Guarantee Test “conditional upon only a satisfactory level of alarms, standing alarms and warnings occurring during the tests. The level shall be determined by the Principal”: cl 7 of Sch 3A. Where the contract indicates that it was for Alinta to determine whether the level of alarms and warnings during the test was “satisfactory”, is it the end of the matter if Alinta’s personnel formed the contrary view at the time? This turns on the proper construction of the contract: for example, Abergeldie Contractors Pty Ltd v Fairfield City Council [2017] NSWCA 113 at [37]-[42] (Basten JA considering a similar clause, Beazley ACJ and Meagher JA agreeing).
Here, the contract provided that Clarke must give Alinta and the Superintendent 10 Business Days’ notice of the date the Contractor reasonably believes Practical Completion will be achieved, and notice when the Contractor reasonably believes that Practical Completion has been achieved: cl 18.1. The clause envisages that the Contractor can and will form a view as to when Practical Completion will and has been achieved. If the Principal’s view as to a satisfactory level of alarms points in the other direction, then there would be no basis for the Contractor to form such a view.
Once the Contractor has given a notice that it reasonably believes that Practical Completion has been achieved, together with a draft Punch List, then the Superintendent must determine whether Practical Completion has been achieved. The Superintendent must give the Contractor and the Principal either a Certificate of Practical Completion or, otherwise, a list of outstanding Work which must be carried out and Defects that must be rectified before Practical Completion is achieved: cl 18.2(a). This clause also presupposes that the Superintendent is in a position to form a view as to whether Practical Completion has been achieved, having regard to the Contractor's notice and the enclosed Punch List. If it be the case that the Principal’s view that the level of warnings and alarms during the test was not satisfactory is determinative, then there is really nothing for the Superintendent to turn their mind to.
The parties have also agreed that either party may commence legal proceedings to resolve a Dispute, including in relation to a determination of the Superintendent: cl 34.3; cl 1.1 (definition of Dispute). All of these contractual provisions would be rendered otiose if the Principal’s view on the level of alarms during tests, and whether that level was satisfactory, was dispositive. Having regard to the contractual regime as a whole, I consider that the parties have agreed that the Court is to consider the underlying facts as to when Practical Completion was achieved, including whether the level of alarms during the Guarantee Tests was in fact satisfactory: Abergeldie at [37]. In light of the authorities referred to above, I conclude that the role of the Court in determining whether Practical Completion was achieved on a given date involves considering the matter on a retrospective basis, including having regard to all of the evidence now before the Court.
The role of the superintendent remains relevant to resolution of some of the Disputes. The learned author of A Cullen, Building Contracts Australia (Looseleaf, 2024, LexisNexis) describes the role of a superintendent at [202,500]:

Clarke relied on the evidence of director Gregory Columbus, regional sales manager for Western Australia and the Northern Territory David Jose, construction site superintendent Jeffrey Stevens, senior projects manager Samuel Vickery, planning and controls engineer Emad Viliani, senior mechanical engineer Michael Nielsen, mechanical engineer Benjamin Schofer, electrical engineer Pavel Bohacik, commissioning manager Cameron Cole and subcontractor Luke Albone of Fredon (WA) Electrical Pty Ltd.
Alinta relied on the evidence of project development engineer Joshua Wozniuk, project manager Jack Shuker, construction manager Chris Anderson and senior mechanical engineer Scott List.
Each of the superintendents, Anthony Ravi (the second defendant), Hamish Marshall (the third defendant) and Brett Anderson (the fourth defendant) gave evidence.
Alinta personnel that I did not hear from, and would have been interested to hear from, were its first representative under the contract, Clive Blowers, senior electrical engineer Nik Walker and General Manager, Power Generation, Scott Thomas. I draw no adverse inference in this regard, given the number of witnesses who were called. It just meant that I had to decide what happened without the benefit of what they might have said.
The absence of Mr Blowers made resolving EOT 1 and VO 05 a little more difficult, as I was reliant on the contemporaneous documents as to what he said and did at the time. Mr Walker was a strident critic of Clarke in respect of EOT 11 and Clarke’s efforts to commission the new plant. Mr Walker made an affidavit but did not give evidence (Clarke tendered a portion of his affidavit). I have attached less weight to the criticisms he voiced at the time, where those criticisms were not tested at trial, including in light of further information and expert evidence then at hand. Mr Thomas decided to replace Mr Marshall immediately after he indicated that he was minded to issue a Certificate of Practical Completion. The absence of Mr Thomas made resolving the issue of waiver more difficult. I was largely reliant on the contemporaneous documents as to why Alinta chose to appoint Mr Anderson as Superintendent at that time and what exactly he was asked to do.
The following experts were relied upon:
On bulk earthworks, mechanical engineer Mark Griffith (for Clarke) and civil engineer Nagamuttu Narendra Nathan (for Alinta).
On electrical installation, Paul Egan (for Clarke) and Dale West (for Alinta).
On the tests involved in commissioning NPS2, power systems expert John Harvey (for Clarke).
On practical completion, mechanical engineer Steve Haddon (for Clarke) and technical adviser Andrew Maynard (for Alinta).
On delay, Mr Griffith (for Clarke) and Dominique Halloran (for Alinta).
On quantum, Mike Cox (for Clarke) and Ms Halloran (for Alinta).
On superintendents, Brent Jones (for Clarke) and Ian Maxted (for the fourth defendant).
The parties relied on an enormous amount of evidentiary material, including 38,000 pages of documents, 21 lay witnesses, 24 expert reports and five conclaves. Where extensive discovery was given the week before the trial, roughly a third of the documentary exhibits were tendered during the trial and separately from the 40-volume Court Book. This had the consequence, I think, that the significance of some of the documents may not have been appreciated at the time, or not until the witness who could have been asked about a particular document had come and gone.

Clarke almost did not tender for this project at all, given “the impossibly small area they have allotted for the project”. But Clarke submitted an expression of interest. Alinta invited tenderers to inspect the site. What happened at the site visit is relevant to the disputed variation VO 05, in respect of the relocation of site amenities, and the largest EOT, being EOT 1. Alinta is said to have indicated where it wanted the site amenities to be and also represented that it would remove existing underground services.
Alinta’s Mr Wozniuk ran the site visit. He is a mechanical engineer who, at the time, was the project development engineer during the tender phase. Mr Wozniuk was responsible for preparing the technical requirements for the project and the interface design requirements (that is, how the proposed works would intersect with NPS1) and undertaking the procurement process.
On Friday, 26 July 2019, Clarke’s David Jose attended the site visit “from Sales” together with Jeffrey Stevens, a construction site superintendent in the EPC section of Clarke. Mr Stevens’ role was to review the documents issued as part of the request for tender, including the scope of works. He then estimated the cost of the civil and mechanical work involved, for inclusion in the tender.
At the site visit, after leaving the main gate of NPS1 and walking onto the access road, Mr Stevens said that Mr Wozniuk pointed to the left of the main gate to NPS1 and said that would be a good laydown area for construction offices and amenities. Mr Stevens took photographs of the proposed site laydown area, including this photo:
Mr Stevens explained that the photograph was of the gate into the “Alinta Non-Operational Area”. The area pointed to by Mr Wozniuk was through the gates and diagonally to the right (marked on the earlier site photograph with an “X”). Mr Stevens thought that the area was suitable as it was flat and level and appeared to be compacted; no earthworks would be needed before the area could be used for site offices or the laydown area.
Mr Stevens said he had actually recalled the conversation, “I just remember a conversation as we were walking out the gate. Josh saying, ‘that’s … a good laydown area’ … obviously the equipment will be removed. … He said, ‘if … you walk in that gate there there’s diesel tanks … a truck can turn around in there … you can have all that area to the north of that … non-operational area if you like … all that equipment will be removed. But just remember there’ll be trucks coming and going filling those diesel tanks so as long as you sort of mark out a circle … in that area so you can make sure there’s nothing there’.” Mr Stevens said the fact that Mr Wozniuk talked about a truck turning circle made it clear what part of the site he was talking about.
Mr Wozniuk and the tenderers then walked down the access road towards the Contractor Site. Mr Stevens saw some concrete stormwater drains, a bollard and a sewerage cover. Mr Stevens took some photographs of the existing services, including:
Mr Stevens said that it was important for Clarke to understand whether it needed to remove these services prior to submitting its tender proposal, as this would need to be incorporated into the scope of works and would affect both time and cost. He recalled that Mr Wozniuk said words to the effect, “All existing underground services will be removed prior to the successful contractor’s arrival on site.”
Mr Wozniuk did not recall the conversation described by Mr Stevens. Mr Wozniuk was first asked to think back to these events in August 2025, that is, six years later. He had no file note. Mr Wozniuk had no recollection, one way or the other, as to whether he had turned his mind to whether underground services should be removed before work commenced on the site. Notwithstanding his lack of recollection, Mr Wozniuk did not accept that it was possible that he said that all existing underground services would be removed.
In his first affidavit, Mr Jose simply said that he relied on Mr Stevens to address matters of a technical nature at the site visit; Mr Jose was more focused on the other tenderers. In his second affidavit, Mr Jose went into more detail. He recalled that one of the stops on the tour was a position standing on the access road, looking down on the proposed site for NPS2. A ‘question and answer’ session took place amongst the group. Mr Wozniuk pointed out the approximate location of underground services and said, “some services run through the site and will be relocated”. In his third affidavit, Mr Jose added that he understood that the underground services were a shared resource between Alinta and “Yarnima”. Mr Wozniuk indicated that Alinta did not want to create any issues with BHP or risk disrupting BHP operations on account of site works.
In cross-examination, Mr Jose agreed that he had set out, to the best of his recollection, his memory of the events that occurred at the site visit in his first affidavit. That was the level of detail that he was then able to give. Mr Jose agreed that he had had many conversations, and exchanged many emails, with Mr Wozniuk during the tender process and negotiation of the contract. Mr Jose accepted that, sometimes, the contents of conversations can become intermingled in one’s mind. But Mr Jose maintained that he remembered the site visit, and clearly. Mr Jose did not accept that his recollection had been affected by reading emails or updating his recollection ahead of preparing affidavits, “No, I remember specific bits clearly.”
On the next working day, Monday, 29 July 2019, Mr Wozniuk emailed Mr Jose an addendum to the invitation to tender, being an interface schedule. This listed drawings where the proposed works would intersect with existing works. When shown photographs taken during the site visit, Mr Wozniuk agreed, “There was indications that there were services there.” Mr Wozniuk agreed that, having seen the photographs and given that he sent Mr Jose details of the potential intersection between the works and underground services, he was then of the understanding that there were some underground services on the site.
And that is clearly the case. At the time, Alinta had engaged CMW Geosciences to undertake a geotechnical investigation of the area. A surveyor, McMullen Nolan Group Pty Ltd, had been engaged by CMW Geosciences to locate underground services so that CMW Geosciences could commence its work. Mr Wozniuk was dealing with CMW Geosciences in relation to the survey. On Tuesday, 30 July 2019, McMullen Nolan Group issued “Utility Locating Plan Rev G”. (A copy of the survey as it existed at that date is not in evidence, but a subsequent version of the document on which Telstra, water and sewer services are identified: see [52].)
The provision of the interface schedule to Clarke and the production of the survey, in the days immediately following the site visit, indicate that the existence of underground services was on Mr Wozniuk’s mind at the time, albeit not necessarily who was going to remove those services.
Clarke proceeded to prepare a tender. On 17 August 2019, Clarke prepared a “Risk / Hazard Register”, which was assessed by Mr Stevens. A construction risk included “Existing services”, which was regarded as “Serious”. These services were “To be relocated prior to [Clarke] mobilisation to avoid delays”. A “Controlling Action” was recorded as “[Alinta] to relocate, progress meetings, RFIs”. This suggests that Mr Stevens then understood that Alinta was going to relocate the existing services prior to Clarke’s mobilisation.
As part of the tender, Clarke was required to provide details of proposed design concepts for civil and structural work, including assumed underground conditions for construction. On 11 September 2019, Mr Stevens was asked by a colleague to comment on draft assumptions, including:

This suggests that Mr Stevens had passed on his understanding of Clarke’s scope of works to Wallbridge Gilbert Aztec. The civil engineer prepared a site plan and concept earthworks and drainage plan, but did not go into any further detail on existing underground services. Mr Stevens said the removal of existing services was not included in Wallbridge Gilbert Aztec’s report or drawings, as he understood that it was not within Clarke’s scope of works.
On 13 May 2020, shortly before the contract was signed, Mr Jose participated in a Microsoft Teams meeting with Mr Wozniuk and others. Underground services were discussed towards the end of the meeting. Mr Jose could not recall who raised the issue, or the words used, but understood from Mr Wozniuk that there had been no change regarding Alinta’s responsibility to remove underground services prior to work commencing. But Mr Wozniuk did not clearly describe how Alinta was going to do this. That made Mr Jose nervous.
After the meeting, Mr Jose had a telephone call with Mr Wozniuk and questioned whether relocation of the underground services was going to remain within Alinta’s scope of works or be a variation to the contract. Mr Jose asked, “Are you sure that you don’t want the underground services to be a part of the contracted scope? I don’t want Clarke to sign the contract and then have to sign a variation on day one.” Mr Wozniuk replied, “Alinta will relocate the services and it will remain within our scope.” When Mr Jose asked why, Mr Wozniuk explained, “There are sensitivities and risks around interrupting any supply to the BHP Yarnima Power Station and Alinta doesn’t want to risk getting BHP off-side.”
Although this conversation was not mentioned until Mr Jose’s second affidavit, he maintained that he remembered the conversation clearly. Mr Jose agreed that he knew that, if Clarke wanted to exclude the existing services from its scope of works, it needed to do so expressly in the contract. But while Mr Jose attended meetings where the terms of the contract were negotiated with Mr Wozniuk, Mr Jose appears to have left the detail of any drafting to the lawyers. Mr Jose recalled later being disappointed to learn that Alinta had approached Clarke for a variation regarding the underground works once the project had commenced.
Mr Wozniuk was first asked to recall the telephone call with Mr Jose more than five years later. Mr Wozniuk attended two meetings with Clarke that day and refreshed his recollection by reference to his file notes. Those notes did not include a conversation with Mr Jose after the Microsoft Teams meeting. Mr Wozniuk did not recall, one way or the other, whether the conversation took place. Nor did he deny it.

Clarke relies on representations said to have been made by Mr Wozniuk as part of its estoppel and Australian Consumer Law claims. It is convenient to consider whether the alleged representations were made, and defer for later consideration whether the representations can be relied upon or have the consequences asserted by Clarke. Clarke contended that Mr Wozniuk represented at the site visit on 26 July 2019 that all services within Clarke’s footprint would be removed prior to Clarke arriving at the site. At the meeting before the contract was signed, Mr Wozniuk represented that Alinta would relocate the services and that would remain within its scope of work. Alinta denied these representations.
Under the Australian Consumer Law, the question is whether the representation would have been conveyed to a reasonable person in the plaintiff’s position, viewing the defendant’s conduct as a whole and in context: Parkdale Custom Built Furniture Pty Ltd v Puxu Pty Ltd (1982) 149 CLR 191 at 199 (Gibbs CJ); [1982] HCA 44; Butcher v Lachlan Elder Realty Pty Ltd (2004) 218 CLR 592; [2004] HCA 60 at [109] (McHugh J). Where the representation was oral, “it is necessary that the words spoken be proved with a degree of precision sufficient to enable the court to be reasonably satisfied that they were in fact misleading in the proved circumstances. In many cases … the question whether spoken words were misleading may depend upon what, if examined at the time, may have been seen to be relatively subtle nuances flowing from the use of one word, phrase or grammatical construction rather than another, or the presence or absence of some qualifying word or phrase, or condition”: Watson v Foxman (1995) 49 NSWLR 315 at 318 (McClelland CJ in Eq).
In equity, a representation which “engenders the expectation of the party asserting an estoppel must possess some level of clarity”: Wantagong Farms Pty Ltd atf Bulle Family Trust v Bulle [2015] NSWSC 1603 at [63] (Ball J); Crown Melbourne Ltd v Cosmopolitan Hotel (Vic) Pty Ltd (2016) 260 CLR 1; [2016] HCA 26 at [142] (Keane J). In Wantagong, Ball J relied on the formulation of Hoffman LJ in Walton v Walton (Court of Appeal of England and Wales, 14 April 1994, unrep), “The promise must be unambiguous and must appear to have been intended to be taken seriously. Taken in its context, it must have been a promise which one might reasonably expect to be relied upon by the person to whom it was made”: at [63].
I accept Mr Stevens’ evidence as to the conversation with Mr Wozniuk during the site visit on 26 July 2019, as to where would be a good laydown area for construction offices and amenities. Mr Stevens’ role was to estimate the costs of the work, for the purpose of submitting a tender. The fact that the identified area was suitable without spending much money was likely to have been of interest to Mr Stevens at the time. Mr Stevens took a photograph of the spot. Mr Wozniuk had no recollection.
As to the removal of underground services, the fact that Mr Wozniuk was – at the time of the site meeting – involved in investigating underground services and preparing an interface schedule indicates that he had some knowledge about the existence of underground services at the time; it was something that he was thinking about. This makes it more likely that Mr Wozniuk said something on that subject.
There is contemporaneous evidence that Alinta was concerned not to annoy its neighbours: see [32], [51]. As will be seen, BHP and APA had elaborate procedures and protocols for those who wished to access their sites or perform works alongside. For example, Clarke and its subcontractors had to complete a nine-page registration form with BHP and complete BHP’s induction process before using the Mt Whaleback access road: cl 15.3(a); Sch 7, cl 2.4; see other examples at [95], [186], [330]. As the project development engineer, Mr Wozniuk was likely to have gained some familiarity with such matters. Mr Jose’s evidence that Mr Wozniuk was concerned not to risk getting Alinta’s neighbours “off-side” is plausible.
But I have no doubt that Mr Wozniuk said that Alinta would remove existing underground services before the successful tenderer arrived on site. As will be seen, Alinta re-stated this repeatedly in the months leading up to Clarke mobilising to the site and thereafter, in minutes of meetings and correspondence which Alinta prepared, including Alinta’s initial response to EOT 1: see [313]. And Alinta proceeded to remove such services. I am less confident as to whether Mr Wozniuk said Alinta would remove “all” underground services. Nor do I think it matters whether he uttered that word. It was implicit that Alinta’s removal of “existing” underground services meant whatever underground services were there.
The purpose of the site visit was for tenderers to be appraised of the practicalities of the proposed project, with a view to preparing tenders to undertake the work. Those visiting the site would be likely to act on what they were told, both in deciding whether to submit a tender at all, and the price for which the tenderer was prepared to undertake the work. Whether the tenderer would have to factor in the cost of removing existing underground services or not was likely to have been a subject of interest to those attending the site visit. Mr Wozniuk presumably expected those present to rely on what he told them when formulating their tenders. Mr Wozniuk’s remarks were clear. He could expect that the tenderers would proceed on the basis that Alinta would remove existing underground services before they got to site.
I accept Mr Jose’s evidence of his telephone conversation with Mr Wozniuk shortly before the contract was signed. Where executing the contract was imminent, Mr Jose sought confirmation and assurance that Alinta did not want Clarke to add the removal of underground services to the scope of work. I am satisfied that he was given that assurance. Mr Wozniuk was emphatic; Alinta would do this itself. I find that this representation was made too.

On 15 May 2020, Clarke and Alinta executed the contract. The details of this contract will be considered elsewhere in this judgment. Suffice to note that the contractor’s representative was Mr Vickery. The principal’s representative was Mr Blowers and the superintendent was Mr Ravi, both of Alinta. (The contract permitted the superintendent to be an employee or contractor of Alinta: cl 38.1(b).) The contract price was some $78 million. The Date for Practical Completion was 567 days after the Commencement Date. Liquidated damages for delay were $60,000 per day, capped at 10% of the contract price. The governing law was that of Western Australia.
Mr Columbus said that, when he signed the contract, he understood that Alinta was going to remove the underground services at the proposed location of the NPS2 site and that this was not part of the work that Clarke had to perform under the contract. Mr Columbus was informed of this by one of Clarke’s employees during the tender phase. Mr Columbus was not required for cross-examination. I accept his evidence.
But the contract contained an entire agreement clause (cl 43.5) and provided that Clarke had not relied on any statement made by or on behalf of Alinta that was not expressly included in the contract: cl 43.6. These clauses do not exclude the operation of the Australian Consumer Law but may be evidence of non-reliance and of the want of a causal link between the representation and entry into the contract: Butcher v Lachlan Elder Realty at [150]-[152] (McHugh J); Campbell v Backoffice Investments Pty Ltd (2009) 238 CLR 304; [2009] HCA 25 at [31] (French CJ), [130] (Gummow, Hayne, Heydon and Kiefel JJ). As such, the representations made by Mr Wozniuk may still provide a basis for a remedy under the Australian Consumer Law when the circumstances are viewed as a whole and where these clauses form part of those circumstances. I will return to this at [876].
It is necessary to consider the content of the parties’ respective obligations under the contract in respect of the removal of existing underground services. Further, what were the parties’ obligations, if any, as to the state in which the site was to be left after the removal of such services? This debate focused on the parties’ obligations under cl 15.1 and 16.1 of the contract. Clause 15.1 provided:

The Works appear to be listed in a roughly chronological sequence. While “Site clearance and preparation” is a broad description, the fact that “In-ground services” are specifically detailed in a subsequent work item suggests that dealing with such services was not included in “Site clearance and preparation”. Similar drafting may be seen in Sch 3B in respect of “Civil and Structural Works”: Sch 3B, cl 1.12.
Schedule 9 to the contract contained the initial construction program, assuming that the Commencement Date was 15 May 2020. Civil works were expected to begin on 16 October 2020. The first activity noted was “Site Mobilisation and Preparation” (one week), followed by bulk earthworks commencing on 23 October 2020 (four weeks), followed by “Conduits and Underground Services” (four weeks). Practical completion was 2 December 2021. Again, Underground Services were specifically mentioned in the activity following bulk earthworks but was not specifically mentioned in the preceding activity (“Site Mobilisation and Preparation”). This indicates that Site Preparation did not include dealing with existing Underground Services.
“Site clearance and preparation”, as referred to in Clarke’s scope of works, are words of broad generality and could well include the removal of existing underground services. The principles of construing commercial contract are notorious. An entire agreement clause does not prevent regard being had to context: Mainteck Services Pty Ltd v Stein Heurtey SA (2014) 89 NSWLR 633; [2014] NSWCA 184 at [130] (Leeming JA, Ward and Emmett JJA agreeing). The commercial context has been described. When the broad and general words “Site clearance and preparation” are read together with specific and subsequent reference to in-ground or underground services, I consider that dealing with such services was not intended, by the contracting parties, to form part of the contractor’s initial task.
If I am wrong about this, and the language is thought to be ambiguous or susceptible of more than one meaning, the commercial context may assist in determining the proper construction where there is a constructional choice: Codelfa Construction Pty Ltd v State Rail Authority (NSW) (1982) 149 CLR 337 at 352 (Mason J); [1982] HCA 24; Mount Bruce Mining Pty Ltd v Wright Prospecting Pty Ltd (2015) 256 CLR 104; [2015] HCA 37 at [48]-[49] (French CJ, Nettle and Gordon JJ).
Here, the commercial context includes the conversations at the site visit, which were reflected in the assumptions recorded in Clarke’s tender submitted to Alinta, and conversations in the days before the contract was signed. Each of these surrounding circumstances were known to both parties. By reference to this context, any constructional choice can be resolved in construing “Site clearance and preparation” as involving tasks other than removing existing underground services, where that activity would be undertaken by Alinta before Clarke began work.
Clarke further contended that, on the proper interpretation of the contract, the removal of existing underground services included any consequential backfilling of trenches and / or compaction to the parts of the site disturbed following the removal of services, so as to enable Clarke to perform the Works. This construction was said to arise from the absence of any contractual requirement for Clarke to backfill or compact surfaces which Alinta had disturbed after entry into the contract. Further, there was said to be an implied term that Alinta would do what was reasonable or necessary on its part to allow Clarke to have the benefit of the contract, if it disturbed the site after the time it was required to provide access under cl 15.1. Further, the interpretation was said to arise from the fact that backfilling and compaction was an inherent component of the removal of such services. Alinta was said to have impliedly agreed and undertaken to compact the land disturbed by these works to a degree consistent with the state of the land before the works were performed.
Alinta denied that it was obliged to undertake backfilling or compaction at all, or to any particular value, level or standard. Clarke was said to be estopped from asserting otherwise, where Clarke was aware that Alinta was undertaking backfilling and compaction but did not tell Alinta of any particular value, level or standard of compaction. (The estoppel argument can be put to one side. As will be seen, Clarke was keen to discuss compaction requirements with Alinta at the time. Alinta resisted this, maintaining that it would attend to compaction itself: for example, at [250].) Further, under the contract, Clarke was responsible for compaction of the site as a whole.
Clarke’s contention relied, in part, on the fact that Alinta engaged a contractor to undertake “Trenching and Backfill Works” when the removing existing underground services. Alinta’s Mr Shuker agreed that, if someone was tasked to remove a service, to fill in the trench and compact it was “part and parcel” of that job. Mr Shuker agreed that, in his experience, “it’s good practice for any excavation … when the material is placed back into the trench, for it to be compacted, yes”.
Mr Shuker’s evidence does not really add to the parties’ contractual obligations. Whilst Clarke accepted the Site Conditions which existed as at the date of the contract, Clarke did not accept the site in any condition in which it may be left after Alinta had removed underground services. Alinta was also obliged to give Clarke access to the site sufficient for Clarke “to perform the Work”. It follows that Alinta was obliged to remove the existing underground services and return the site to the condition that it was in before such services were removed, and to attend to this in a manner such that Clarke’s access to the site enabled it “to perform the Work”. It also follows that Alinta was obliged to backfill and compact the land disturbed by its works to a level consistent with the state of the land before those works were performed.

These actions were not allocated to either party in the minutes. But, fairly clearly, Alinta was taking responsibility for this task. The next day, on 7 August 2020, Mr Wozniuk spoke to and then emailed Mr Vickery in respect of the relocation of existing services on the NPS2 site, seeking his input on the proposed relocation of the Telstra line, water and sewer pipes, to ensure that this was suitable to Clarke. Mr Vickery enlisted Clarke’s principal mechanical engineer, Ben Schofer, to review and respond.
On 12 August 2020, Mr Schofer provided Mr Vickery with a site plan, marking existing services (including some not identified by Alinta), together with a proposed “service corridor” for re-routed services. He set out some suggestions to align with Clarke’s intended design. Mr Schofer said the existing services identified on the site came partly from the survey provided by Alinta and the Reliance Information.
Mr Schofer’s drawing of existing services was more detailed than those depicted in McMullen Nolan Group’s survey. There were more underground services, and those services were more extensive across the site. There was an existing above ground poly pipe and an existing overflow service water. The water pipes were “fire water”, that is, supplying fire protection systems. Presumably, the details obtained by Mr Schofer from the Reliance Information were more comprehensive than the As-built drawings provided by Alinta to the surveyor (see [52]-[53]), or what the surveyor was able to divine from its test pits and bore holes. Mr Schofer’s drawing also suggests that it was not simply a case of “no big items to move”. Alinta may have been underestimating the task ahead, even though the Reliance Information on which Mr Schofer’s drawing was based came from Alinta.
A Newman Expansion Project Weekly Meeting was held on 13 August 2020. The minutes noted that a purchase order had been raised for relocation of the Telstra fibre, with markups on the preferred route issued to Mr Wozniuk.

The significance of the notice to proceed is that it fixed the Commencement Date and thus the Date for Practical Completion. On 19 August 2020, Alinta issued a notice to proceed. The Date for Practical Completion became 9 March 2022.
On 20 August 2020, a further Newman Expansion Project Weekly Meeting was held. The minutes record that a kick off meeting with Telstra would take place that day. On 27 August 2020, a further Newman Expansion Project Weekly Meeting was held. Telstra was mobilising that weekend and services should be ready by 7 September 2020. Mr Wozniuk was to provide an update. Alinta was also progressing the relocation of other existing services. In respect of “fire water”, a quote had been received from FRC Group Pty Ltd (FRC) and Alinta was looking to finalise the contract; Alinta would follow up with Mr Wozniuk. As for “water services”, a plumbing contractor had been organised and attended site that day. An additional “xxx” was added to the minutes, apparently apprehending that other existing services may have to be addressed. On 1 September 2020, Mr Schofer emailed Mr Wozniuk, providing dimensions to assist in relocating the Telstra line.
Where Alinta had issued a notice to proceed on 19 August 2020, Alinta was obliged to ensure that Clarke had non-exclusive access to the site to perform the Work on and from 10 Business Days after the Commencement Date, that is, 2 September 2020: cl 15.1(a). On 3 September 2020, a further Newman Expansion Project Weekly Meeting was held. The minutes record that subcontractors had been on site to progress relocation of the Telstra fibre, “No delays”. Other subcontractors had been on site to scope two other mechanical services. On 10 September 2020, a further Newman Expansion Project Weekly Meeting was held. Relocation of the Telstra fibre was scheduled to complete that week, with cutover on 14 September 2020. Mr Wozniuk remained responsible for this action. For other mechanical services, these were on track for the end of September 2020, “No issues”. The action remained allocated to Alinta.
Clarke was obliged to provide a monthly progress report: Sch 3C, cl 6.1. On 8 September 2020, Clarke issued its first report, including an updated program. While the program attached to the contract had assumed that the Commencement Date was 15 May 2020, the date of the notice to proceed now became the ‘start’ date on the program. For civil works, the activities remained the same: Site Mobilisation and Preparation (one week), followed by bulk earthworks beginning on 19 October 2020 (four weeks), then Conduits and Underground Services.
On 16 September 2020, Clarke and Alinta held their first weekly engineering meeting. Mr Wozniuk was listed against the following item:

One of Mr Stevens’ tasks was to create a layout of the site offices and amenities. He planned to install the site offices in the area pointed out by Mr Wozniuk during the first site visit, now more than a year ago. On 16 September 2020, Mr Vickery emailed Mr Blowers an “Unofficial draft layout … for your review on site next week. Once we get your feedback we will submit formally”. Mr Stevens said the drawings were broadly in line with where he understood Mr Wozniuk had pointed out the location for site offices.
On 17 September 2020, a further Newman Expansion Project Weekly Meeting was held. The minutes record, “Site Layout Plan - intent for diesel area availability for B Double truck (~turnaround area)”. Mr Blowers was marked against this item for action. I take it that Mr Blowers had some concerns about the proposed layout for site offices and amenities, given the required turning circle for large trucks near the diesel tanks.
As for the relocation of services, the minutes record that the new Telstra service had been activated and confirmed as operational. Mechanical services remained on track for the end of September with “No issues”. Then bulk earthworks were ongoing until mid-October.
After the meeting, Mr Stevens received a call from Mr Blowers, who said that he would be making some changes to the layout area to accommodate the needs of Alinta Operations. On 23 September 2020, Mr Blowers emailed proposed changes to the site layout to Mr Vickery, Mr Stevens and Clarke’s site manager, Tony Whelan, which were thought to be safer for personnel and to work better with truck deliveries for Clarke and Alinta Operations. Mr Blowers noted that Alinta’s preferred location “would need to be levelled and a[n] inverted culvert and drain installed … the proposed location of the walkway will be required to be built up to a level and fencing either side installed to protect the pedestrians.” One advantage of this was said to be that personnel would not be required to walk across the road up to where the cars were parked.
On 24 September 2020, Mr Blowers provided some photographs of the proposed site laydown area. Mr Stevens replied, “Yes agree this looks like a good plan”. He advised that Mr Whelan would investigate what needed to happen when on site. A few minutes later, Mr Stevens forwarded his email to Mr Whelan, noting “not sure on the costs here though – can you discuss with Ahrens when on site next week”.
Mr Stevens said that, while he thought that Alinta’s proposal made sense, he needed to review the pricing associated with it. Had Mr Stevens known about this before Clarke entered into the contract, he would have submitted a different price because of the work that Clarke would need to do to make the area proposed by Mr Blowers suitable. For example, there would need to be additional bulk earthworks to make the area level. For his part, Mr Vickery said the revised placement of site amenities did not reduce labour costs by reason of the reduced walk from the site. The original 80 m walk was not unusual nor something that Clarke would quantify or factor into pricing as it was not significant enough to have an impact on cost.

Clarke’s Mr Stevens was involved in liaising with potential contractors. On 31 July 2020, Clarke had produced drawings for bulk earthworks, including compaction details. On 7 August 2020, Mr Stevens sent a Request for Quotation (RFQ) for bulk earthworks to potential subcontractors. The task of removing underground services was not included in the RFQ. Contractors were asked to submit a price breakdown against a list of items, relevantly, “Devege / stripping topsoil / preparation of subgrade”. Mr Stevens explained that he prepared the RFQ based on the drawings prepared by Wallbridge Gilbert Aztec. As earlier explained, these drawings did not include existing services, as he did not consider this to be part of Clarke’s scope of work.
On 9 September 2020, Ahrens Group Pty Ltd had submitted a tender proposal for bulk earthworks, being a fixed lump sum. The quote was expressed to be dependent on “Site access to all areas shall be 100% any delays due to operational matters or other work groups will be charged at rates for all personnel and equipment.” When asked whether Ahrens could start on site by 10 October 2020, Ahrens advised, on 16 September 2020, that it could “organise a team for mobilisation pending receipt of purchase order”.
On 29 September 2020, the first Newman Expansion Project Mobilisation Meeting took place. According to the minutes, Clarke’s Mr Whelan had had an initial look at the laydown area with Alinta’s Mr Baikie. Mr Vickery had issued an updated site layout plan to Mr Blowers, Mr Baikie and Mr Whelan to finalise. As for existing services locations, Mr Wozniuk reported that they should be able to commence removing or moving existing services that week, with two weeks required to complete work. A purchase order was to be issued to FRC.
After the meeting, Mr Blowers spoke to Mr Vickery about issues that Alinta was having finding contractors to remove the underground services. Mr Blowers asked if Clarke could ask Ahrens whether it could provide a quote in the event that FRC was not able to complete the work. After the meeting, Mr Vickery amended the minutes to note, “due to FRC availability difficulties, [Clarke] to provide proposal to take on this scope using Ahrens, pending Ahrens availability.”
On 30 September 2020, Clarke’s Mr Schofer issued a Request for Information (RFI), to Alinta’s Mr Wozniuk in respect of the “existing pipeline impacted by bulk earthworks”. There was an existing above ground poly pipe running along the south-eastern boundary of the project site. Clarke’s civil design proposed a batter slope on that boundary, which would bury the pipe. Mr Wozniuk was asked to confirm if this was acceptable “and/or any requirements to do so (eg BHP approvals)”.
Mr Whelan also asked Mr Vickery to request details of the scope of work from Mr Wozniuk “regarding the new / additional pre-works underground scope” to speed up discussions with Ahrens, “I recall from yesterday’s mobilisation meeting [that Mr Wozniuk] seemed to be the person responsible / dealing with this”. On 1 October 2020, Mr Vickery replied that he had spoken to Mr Wozniuk and “Alinta have not done a scope. [Mr Wozniuk] had arranged for FRC to do a site visit to scope it out with [Mr] Baikie and they were going to provide details of the scope within their quote.” That is, Alinta did not have a clear idea of the amount of work involved in removing the existing underground services, but was leaving it to the contractor to prepare a scope of works itself.
On 1 October 2020, Clarke issued a purchase order to Ahrens, “With the Contract negotiations all but completed and on the assumption everything is now in order with the contract”. Mr Vickery forwarded Alinta’s process for site induction. Ahrens’ operations manager, Tyler Fuller, replied, “Once we have final sign off, our on boarding team will be in contact … to commence required inductions”. Mr Fuller was confident that the team in head office would have all contract terms completed and closed out shortly. On 2 October 2020, Clarke provided Ahrens with a site roster. Mr Fuller advised that he would have a look at it over the weekend.
Ahrens’ willingness to prepare to start work on the basis of a purchase order is relevant to Alinta’s contention, in respect of EOT 1, that there was no delay as Ahrens was not prepared to start work without a signed contract. Mr Stevens said that, in his experience, it was not unusual for a contractor to issue a purchase order to a subcontractor before a formal contract was signed. This was because there was often pressure to commence works quickly, even though the parties were still in the process of negotiating a contract. In such cases, a contractor would issue a purchase order so that the subcontractor could rely upon the order for payment. Usually, on receipt of a purchase order, the subcontractor would commence works or prepare for the works and incur the costs involved. Mr Stevens understood that, by sending Ahrens a purchase order, they would be committing to the project and begin to incur costs. As will be seen, Alinta took the same approach: see [184].
On 7 October 2020, the second Newman Expansion Project Mobilisation Meeting took place. As to existing services locations, Mr Whelan and Mr Baikie had walked around with Alinta’s operations and maintenance supervisor of NPS1, Andrew Primer, and discussed the differences from the drawings. Information was to be collated and a RFQ provided to Ahrens, “Potentially more than 2 weeks work and effect start of civil works.” This is the first reference to the fact that a delay in relocating underground services may delay the commencement of civil works.
After the meeting, Clarke asked Ahrens for a quote to perform the additional work needed to follow Mr Blower’s changes to the drawings for the site amenities area. A revised drawing for construction of the site amenities was attached, in accordance with the comments provided by Mr Blowers. On 8 October 2020, Ahrens provided Clarke with Variation 001 for site establishment. (Noteworthy, the absence of a signed contract did not stop Ahrens issuing a variation.)
On 9 October 2020, Clarke provided its monthly report for September 2020. The “Key Issues List” now included “Existing services relocation” as follows:

On 13 October 2020, the third Newman Expansion Project Mobilisation Meeting was held. Mr Whelan was working on a scope of works to price the relocation of services. The sewerage looked like it was on BHP’s land. Services now included service water, fire water and fire tank drainage and overflow. Mr Blowers was to discuss the “commercials” with, apparently, someone from BHP. Specifically, BHP water lines clashed with a spoondrain pit discharge point. Mr Blowers and Mr Whelan were to check this. The minutes note that there was “[p]otentially more than 2 weeks work” related to existing services, which would “effect start of civil works”.
That is, the extent and complexity of underground services was more than Alinta appears to have appreciated. Consistently with this, Clarke director, Mr Columbus, participated in an Alinta “steering meeting” on 15 October 2020. According to Mr Columbus, while discussing Alinta’s progress in removing underground services, Alinta’s Head of Construction, Mr Knill said, “This is a greater scope than what we thought”. Mr Columbus’ handwritten note of the meeting records, “Greater scope than [Alinta] believed!! More complication”.
After the Newman Expansion Project Mobilisation Meeting, Mr Stevens emailed Mr Vickery, noting that the site mobilisation date for Ahrens was to be 11 October 2020, “So potentially they can also put in a delay claim here and obviously their PC date will be pushed back accordingly. I will go back to them and confirm no costs?” On 13 October 2020, Mr Stevens emailed Ahrens, “As we work through the mobilisation start on site / set up offices / removal of existing services etc – there will obviously be a delay to start the civil works”. Ahrens was asked to confirm that there would be no additional cost for this delay at site. Obviously enough, as Clarke was expecting delay in commencement of the bulk earthworks, it was seeking to manage this delay ‘downstream’ with its subcontractor, Ahrens. (By way of explanation, the significant detail in what follows in respect of Ahrens is relevant to Alinta’s contention that the delay reflected in EOT 1 was caused by Clarke’s problems with Ahrens and Clarke’s failure to mitigate those problems.)
Ahrens replied that, once they had “priced up” the variation to remove or relocate existing services, they would provide a forecast delay “and issue an EOT as per contract. … we are more than likely looking at a possible 4-5 week delay”. Ahrens advised that it may look at delaying the mobilisation of plant and equipment and operators. Noteworthy, notwithstanding that Ahrens had not signed a contract with Clarke at that time, it was preparing to “issue an EOT as per contract”.
On 14 October 2020, Mr Stevens replied to Ahrens regarding the proposed EOT, “there is no signed contract in place as yet”. A separate purchase order would be issued for the relocation of existing services. Ahrens had a purchase order for the extra works to do with site setup, “When we sign cont[r]act we will slip in new programme with correct start date … Ok?” Again, Mr Stevens appears to have been using the absence of a formal contract with Ahrens to manage ‘downstream’ delay risk. Ahrens was untroubled. Ahrens advised Mr Stevens that they were following up on the contract, “Once we have a clear plan re the in ground services variation and lead times, this will then form the new program and indicate delays to start in the bulk earthworks and civil works.”
On 14 October 2020, Mr Vickery spoke to Mr Blowers about the relocation of site amenities. Mr Vickery reported to his colleagues:

The next day, on 15 October 2020, a further Newman Expansion Project Weekly Meeting was held. Mr Blowers and Mr Vickery were in attendance. In respect of relocation of existing services, Telstra still had to provide As-built drawings for its services. Mr Whelan was to issue a scope of works on other existing services for Ahrens’ pricing and Mr Blowers was to discuss this with Alinta.
The minutes also record that an initial scope of works for the site laydown plan had been provided on 9 October 2020, together with pad levels and services relocations. Ahrens would be on site to commence the laydown area on 19 October 2020. In a portion of the minutes concerning “commercial” matters, Trevor Lombard was “to issue letters RE: Variation proposal for services relocations & laydown area” (emphasis added). Mr Lombard was a Commercial Manager engaged by Engenium Resources to provide administrative support for Alinta on the NPS2 project; he was responsible for contract and commercial management correspondence.
Immediately after the meeting on 15 October 2020, Clarke issued a purchase order to Ahrens for site establishment. Later that evening, Alinta issued a Request for Variation Proposal to Clarke in respect of site services relocation. But while the minutes of the Newman Expansion Project Weekly Meeting anticipated that Mr Lombard would issue “letters”, no letter appears to have been issued requesting a variation proposal for the laydown area.
Whether this is what happened and, if so, whether it was an oversight or intentional, is unclear. The minutes of the next Newman Expansion Project Weekly Meeting on 22 October 2020 record, “[Trevor Lombard] issued letters RE: Variation request for services relocations & laydown area”. The same entry appears in subsequent minutes for 29 October 2020 and 5 November 2020. According to the minutes, at least, a variation request for the laydown area was issued. By 11 November 2020, Clarke had noticed that the request had not been provided: see [163]. Likely, this was an oversight by Mr Lombard, which initially went unnoticed.
On 16 October 2020, Mr Vickery served a notice of mobilisation to the Facility Land under cl 15.2(a) of the contract, noting that Ahrens was due to commence mobilisation activities on 19 October 2020. Mr Whelan circulated some sketches, plans and options to relocate underground services. Mr Blowers asked Mr Stevens whether there was anything that could be done on site while Clarke was preparing a variation proposal to remove underground services. Mr Stevens suggested that “potholing” of the site, to locate the existing underground services, could be done regardless of who would eventually carry out the works. Mr Schofer explained that non-destructive excavation methods, such as vacuum excavation or ‘potholing’, were used to verify the precise horizontal and vertical location, type, material, size and condition of subsurface utilities.
On 19 October 2020, Ahrens started on site, undertaking work associated with the site amenities and laydown area. According to Clarke’s Weekly Project Status Report, Mr Blowers had visited the site. Mr Whelan had walked through the underground service relocation scopes and alternative APA access route, assisting with the development of information packs for Mr Blowers. High-level scope documents for each service, describing existing underground services, likely relocation routes and potential issues to be resolved and mitigated had been further revised; these were now with Clarke for further development and engineering input for RFQ submission.
On 20 October 2020, the fourth Newman Expansion Project Mobilisation Meeting was held. Mr Blowers and Mr Whelan were to check whether the BHP water lines clashed with the spoondrain pit discharge point but were “waiting on BHP contact”. At the Newman Expansion Project Weekly Meeting on 22 October 2020, Mr Blowers advised that he was still chasing Telstra for As-builts for its fibre and would get clarification on working around / building up on the area of where the new fibre had been installed. Ahrens had completed 90% of the temporary pad and 80% of the LV (light vehicle) carpark for the site laydown plan.
Clause 12.5(a) required Clarke to give Alinta written notice “promptly after becoming aware that Work is likely to be delayed (whether by an Extension Event or otherwise)”. On 23 October 2020, Clarke issued a notice of likely delay under cl 12.5 of the contract, due to the presence of existing services on the site which were preventing the commencement of bulk earthworks. The existing services were to be relocated by Alinta prior to Clarke mobilising to site but service water, fire water, overflow drainage and sewer services had not been relocated. The duration of delay was unknown but expected to be in the order of four weeks.
It was noted that Alinta had issued a variation request in relation to the relocation of the services. As to steps which may avoid or mitigate the delay, Clarke advised, “Pending the final agreed scope of the Variation Clarke will determine the most time effective methodology to complete the services relocation on behalf of the Principal. This may include temporary measures to isolate and ‘cap’ services to allow bulk earthworks to commence while the relocations are completed.” (This possibility was not repeated in subsequent delay notices.)
The contract also provided that Alinta “must give the Contractor written notice promptly after becoming aware of a delay to any act or thing the Principal is required to do or provide under this agreement which is likely to delay the Work”: cl 12.5(c). This did not happen, although it obviously should have. Further, cl 9.3 provided:

Confirmation was sought as to the location of the Telstra lines, as it was within Ahrens’ footprint and may give rise to restrictions when working around or near Telstra’s lines “and if current location will require relocating”. If the lines were to remain in their current location, “this will require the pits heights to be adjusted to suit the pad. This has to be completed by Telstra themselves.”
Later that evening, Ahrens gave Clarke an EOT claim of eight weeks, “due to the delays posed by Alinta with the existing services”. The “Reasons of delay” were, “Princip[al] Client were to have existing services removed and redirected by a contractor prior to princip[al] contractor & sub-contractor’s mobilisation.” Noteworthy, Ahrens did not feel constrained by the absence of a formal contract with Clarke from submitting an EOT claim. Mr Vickery forwarded Ahren’s EOT notice to Mr Viliani, who updated the program accordingly.
On 3 November 2020, the sixth Newman Expansion Project Mobilisation Meeting took place. The laydown area and site offices were expected to be completed by 9 November 2020, with clearing and grubbing to commence on about 6 November 2020. Telstra As-builts had been received. As for the relocation of existing services, BHP did not seem concerned about sewerage being moved but a BHP licensed plumber would confirm this. BHP was happy to relocate raw water lines off Alinta’s tenure. A temporary water line had been put in place, stopping short of APA road access; a purchase order had been raised in BHP’s system.
Mr Blowers provided the As-built data received from Telstra to Clarke, which forwarded the As-built data to Ahrens. As Mr Stevens understood it, Clarke required this confirmation – as did Ahrens – before Ahrens could commence the bulk earthworks. On 6 November 2020, Clarke also provided Ahrens with the McMullen Nolan Group survey, showing in-ground services within the area to be cleared of vegetation. Mr Whelan emailed Ahrens and Alinta, “As discuss[ed] all trees are to be left undisturbed as they sit near or over existing services”.
On 6 November 2020, Clarke issued a second notice of delay under cl 12.6 of the contract, given the presence of existing services on the site. A third notice of delay was also issued given the presence of BHP’s above ground poly pipe services on the site. The bulk earthworks design included a batter where the section of the BHP services were located. Alinta had advised that BHP approval was required prior to burying or moving these services. This was preventing finalisation of the civil design and commencement of bulk earthworks. On 7 November 2020, Ahrens commenced clearing vegetation. The vegetation and topsoil had been removed by 10 November 2020, save for three trees located near existing services.
On 9 November 2020, Mr Stevens emailed Ahrens, advising that Clarke “can’t accept the EOT as we have not started the works not to mention no contract signed as yet”. Mr Stevens suggested that, once the additional works had been completed for Alinta, being works that were not within the current scope of works tendered on, then they could set a new start date that would be referenced in the contract, “We don’t believe there should be any reason for the duration to be extended but rather the start date and finish date will move in unison”. That is, Mr Stevens was continuing to use the absence of a formal contract with Ahrens to resist an EOT claim.
On 11 November 2020, Mr Vickery circulated Clarke’s monthly report for October. The monthly report contained a section “Contractual Items”. This included a table listing potential variation items that had been requested formally or by way of RFI and were under review by Clarke. An entry in the table for relocation of services now noted that a formal request had been received. No like notation was made in respect of the item, “Additional site preparation works required due to change in location of site amenities area”. That is, by now, Clarke had noticed that Mr Lombard had issued one but not two letters. This item remained in the table for subsequent monthly reports.
The executive summary of the October report noted that civil works had been delayed due to existing services on the site, including two BHP water lines, which required relocation prior to commencement of bulk earthworks. Alinta had provided a Request for Variation Proposal for Clarke to perform the services relocation works. The “Key Issues List” now included an expanded entry in respect of “Existing services relocation”. The implications for the project more broadly were outlined. The scope of works to relocate the services was “complex in terms of routing and interfaces with BHP.” Clarke was working with Ahrens to provide a cost estimate for approval, with the aim of commencing relocation of services in November 2020. A hydro-vac truck was being sourced as first priority to verify the location of existing service lines. The section of the report on “Potential Delays” was similarly expanded.
The target schedule had been updated. Mr Viliani made changes to the program, which resulted in bulk earthworks becoming a critical path activity. He explained that this was because line items were added for work that Alinta should have carried out in removing the existing services. Additional activities were added to the program as follows:

Mr Viliani also amended the logic between “Cladding of the Powerhouse and Insulation” and powerhouse electrical installation, from ‘Start to Start’ to ‘Finish to Start’. Mr Viliani made this change following discussions with Mr Vickery and Clarke’s Electrical Construction Superintendent, Michael Weinel, from which he understood that the relevant contractors could not start the electrical installation until the cladding was complete. (This change in logic was relevant to the delay experts in respect of EOT 1.)
The contemporaneous documents provide, I think, a more accurate indication as to why Mr Viliani made this logic change. On 13 October 2020, Clarke and Ahrens signed a contract for the supply of services relating to the delivery and installation of the powerhouse steel works. The minutes for the Newman Expansion Project Weekly Meetings on 22 October 2020, 29 October 2020 and 5 November 2020 record that “Incident / Injury Free” workshops were being held with the site team, Ahrens and Alinta “around installation Powerhouse” and “[I]nstallation Powerhouse / Mechanical & Electrical / Commissioning”. At the Newman Expansion Project Weekly Meeting which took place the day after the updated program was circulated, Mr Vickery reported that a civil and powerhouse contract had been issued to Ahrens and an electrical subcontract was on track for award as per Clarke’s project schedule.
That is, when Mr Viliani amended the logic, Clarke was discussing the sequence of work with Ahrens and Alinta, apparently with a view to minimising the risk of incident or injury. I infer that it was thought that it would be safer not to start powerhouse electrical installation until the cladding was complete, and the logic change reflected this thinking as to how best to sequence the works. I defer to the contemporaneous documents to the extent that Mr Viliani’s recollection differs.
On 12 November 2020, a further Newman Expansion Project Weekly Meeting was held. Clarke was awaiting a quote for relocation of services “before any civil works can commence”. From 14 to 19 November 2020, hydro-vac works were completed by Ahrens to identify underground services, in order to provide Clarke with an estimate of the cost and scope to remove those services. On 16 November 2020, Mr Vickery provided Mr Blowers with a “Weekly Project Status Report”, noting:

At about this time, Jack Shuker became involved in the project for Alinta, to take over from Mr Blowers. During the handover by Mr Blowers and Mr Knill, Mr Shuker was told that there were services that needed to be removed and Alinta was waiting for Clarke to provide a variation proposal. He understood from what he was told that Alinta had earlier agreed to remove the services on site. He understood that the additional works that Clarke would be asked to do under the variation was beyond its scope of works.
On 24 November 2020, Mr Vickery submitted a variation proposal to Alinta for all works associated with the relocation of fire water, services water, sewerage, fire tank drain and overflow services. The quote included trench compaction and reinstatement of surface, “Reinstate grade surface as per existing with power station compound, (spray seal or similar). External grade surface per existing … Support all in ground piping with correct bedding, padding and backfill materials.” It was proposed that Milestone Amounts would be increased by $1,562,650. If approvals to commence the work were received by 1 December 2020, the commencement of bulk earthworks would be delayed by some 16 weeks, causing a 10 week delay to practical completion.
On 26 November 2020, Clarke’s Mr Columbus participated in a Teams meeting urgently requested by Alinta’s General Manager, Power Generation, Scott Thomas. According to Mr Columbus, Mr Thomas said that Clarke’s variation proposal to relocate underground services was “way too expensive for what we need and so we will do it ourselves”. Mr Shuker said that the decision was predominantly “based on my experience and prior engagement of a competent contractor could … get it done quicker”.
Later that day, Clarke’s Mr Schofer advised Mechanical Design Draftsperson, Shane Gosling, that Alinta “have decided to undertake relocation of services at another time. At best the existing services will be abandoned rather than removed”. This meant that Clarke’s design would sit over the existing services. Mr Gosling was asked to overlay the existing services in a model to determine clashes and potential issues. Mr Schofer was concerned about Alinta’s decision to leave some of the underground services in place, as this may require further design works.
Also on 26 November 2020, Mr Stevens asked for a meeting with Ahrens’ Mr Fuller later that day:

On 26 November 2020, Clarke’s Mr Stevens and Mr Whelan met with Ahrens’ Mr Fuller. Ahrens advised that Holcim was returning after the Christmas break on 11 January 2021 and would not be starting to deliver bulk fill any earlier than that. Ahrens could not start bulk earthworks this side of Christmas as it would “bake” during the Christmas period and be required to be re-worked or conditioned on return in the New Year, negating the benefit of starting this side of Christmas. Ahrens would send through an email showing why it was not a good idea to do bulk earthworks in two stages.
On 27 November 2020, Mr Stevens sought further details from Ahrens, “Can you please respond with your concerns here and perhaps a bit more theory on why we shouldn’t start Bulk Earthworks”. It appears that Clarke was seeking information from Ahrens to support Clarke’s position vis a vis Alinta. Ahrens obliged. In addition to difficulties with obtaining bulk fill from Holcim, Ahrens noted that any bulk earthworks would depend on Alinta organising other works prior, “We would require execution dates for the works and a completion date commitment to enable us to schedule a remobilisation and kick of[f] date.” The time remaining before Christmas would only see “a couple of lifts go in at best”. Leaving the material unfinished for two weeks would see the moisture drawn out, due to extreme weather in the Pilbara, “Upwards of 50 degrees some days”. On return in the New Year, the material would have to be reworked to get moisture back into the materials to enable further lifts. The materials would require re-testing to ensure that they met specifications. There would be a cost impact of plant and equipment sitting idle over the Christmas break, as well as the cost of any re-works and testing. Holcim could not guarantee supply before Christmas, but any material that came in would be “without an even flow [which] would not be productive. This would also pose costs impacts.”
On 1 December 2020, Alinta’s representative under the contract officially became Mr Shuker. On 3 December 2020, a further Newman Expansion Project Weekly Meeting was held. The parties discussed difficulties with commencing bulk earthworks. According to the minutes, Clarke was “awaiting confirmation of access to start bulk earth works and have put on hold any further mobilisation”. Construction activities were noted as pending a variation outcome on service relocation, APA access and BHP pipe clearance.
After the meeting, Alinta received a quote from FRC to undertake trenching and backfill works in respect of site services relocation for $50,400. Obviously, this was a mere fraction of Clarke’s variation proposal. Fairly obviously also, Ahrens and FRC were quoting on different tasks.
On 4 December 2020, Clarke issued a fifth notice of continuing delay to bulk earthworks, noting that the delay to each work activity and practical completion could not be estimated at that time, “Based on current advice from Alinta … temporary works will be completed by others to enable bulk earthworks to commence.” Clarke understood that Alinta would not be engaging Clarke for these works but would advise Clarke when the site could be accessed for bulk earthworks to commence, however, Alinta had not provided formal notification in that regard. If temporary works were completed in December 2020, bulk earthworks could commence in January 2021, which would delay the commencement of bulk earthworks by 12 weeks and cause a six week delay to practical completion.
Mr Vickery said that, after Alinta confirmed that it would be completing the relocation of the existing underground services with its own contractors, most Clarke personnel demobilised to mitigate the costs of the delay. Mr Shuker accepted that, in late 2020, he knew that bulk earthworks could not be undertaken on the site by Clarke until the services had been removed by Alinta.
On 10 December 2020, a further Newman Expansion Project Weekly Meeting was held. Alinta confirmed that a subcontractor was planned to be on site for the week of 14 December 2020, to start works on the sewer and service water services relocation. It was planned to handover the main site to Clarke on 21 December 2020.
After the meeting, Alinta issued a purchase order to FRC for “Trenching and Backfill Works … Site Services Relocation”. Mr Shuker said the purchase order was essentially the contract and the means by which the contractor was engaged at the time. Mr Shuker said it was common practice to use purchase orders, regardless of the urgency of the work. Contracts were needed for high value contracts but otherwise a purchase order and its standard terms and conditions was used. Mr Shuker agreed that this was a common way to engage a subcontractor, and FRC commenced work on the basis of the purchase order.
After the Newman Expansion Project Weekly Meeting that day, Clarke staff shared concerns about the state of play. Mr Stevens noted that at least two weeks were needed to mobilise Ahrens and “due to the delay we now need to reschedule the delivery of the bulk fill”. Clarke’s General Manager – Engineering Procurement and Construction, Vincent Kain, encouraged his colleagues to be “proactive on this one please. What can Ahrens do now? Will it really be clear for us to start works? … How does th[is] work [given] that we do not have site ownership and no site handover? What is the impact in regards to contract as Site Access will still be delayed … So we work around them at no cost to us. Really???”
Alinta had also issued an RFI to Clarke, to assess the impact of construction activities on the Alinta gas yard. Clarke was required to provide a compaction methodology, including details of the types of equipment to be used for bulk earthworks and the vibration or oscillation levels produced. Clarke had sought this information from Ahrens, and followed up its request several times. But Ahrens needed more information to prepare a compaction methodology and was somewhat reluctant to go further, given the unclear state of contractual arrangements. On 10 December 2020, Ahrens’ project manager, Brad Rice, advised Clarke that Ahrens “would definitely be prepared to provide you with the [compaction] methodology, but ultimately our hands are tied without this essential information, alongside a [purchase order] to provide our services on works that [are] not within the [scope of works] and have been deemed [a] variation”. Ahrens did provide Clarke with details of the vibration created by its machinery, together with APA’s extensive requirements to assess proposed encroachments on the easement for the APA Newman Lateral high pressure natural gas transmission pipeline.
Later that day, Clarke advised Ahrens that Alinta had given a verbal indication that site access would be provided for Clarke on 20 December 2020. Further:

Mr Stevens supplied a photograph of the site to Ahrens, with the “bowl” and balance of the site marked. Mr Stevens suggested that handing over the “bowl” was “a reasonable request / solution to move forward”. He acknowledged that Ahrens should not have to work over the Christmas period. Mr Stevens agreed to meet to “look at what obstacles we (Ahrens and Clarke) have due to Alinta not removing the existing services”.
On 15 December 2020, FRC began “Trenching and Backfill Works” on site. Mr Shuker did not recall FRC’s scope of works in relation to compaction, “the engagement of the contractor to do the work was on the basis that … they’re experts enough to do the required compaction for finishing the job”. Mr Shuker said, “there was a level of compaction done by FRC”. Mr Shuker’s guarded responses indicate that Alinta just left backfilling and compaction to FRC.
On 17 December 2020, Mr Whelan attended site to see how FRC was going. He reported to Mr Stevens and Mr Vickery that Alinta’s Mr Baikie said, “he has the FRC guys until the 23 Dec and they will remove as much of the sewer and pits as they can and as much of the service water line if they have time”. A Newman Expansion Project Monthly EPC Meeting was also held. A key issue to be discussed was existing services relocation. Participants discussed Clarke’s concerns that some of the underground services clashed with its design. Alinta wanted to explore the impact of leaving the underground services in the ground. After the meeting, Mr Schofer circulated an Underground Services Impact Report, showing the interference between Clarke’s design and existing underground services, to quantify any impact from Alinta’s change in approach to leave existing services in situ.
The issues caused by the underground services being left in place were discussed at a Design Review Meeting on 18 December 2020. On 18 December 2020, Clarke also gave a sixth notice of continuing delay to bulk earthworks. Alinta had advised that access would be provided to the APA yard via NPS1 and, thus, this was no longer preventing commencement of works. But the existing services and BHP water lines continued to do so.
According to photographs taken by a site camera, work to remove underground services began on 20 December 2020. An L-shaped trench was dug through the middle of the site, presumably to remove the fire water line. On 21 December 2020, Mr Stevens asked Mr Whelan and Clarke site manager, Daniel Elliott, to verify progress by speaking to Alinta’s personnel on site. Mr Stevens could see from the site camera that work was ongoing; he wanted to let Ahrens know when they may be able to commence works.
On 22 December 2020, FRC finished up for Christmas. But the works were not complete. FRC proposed to return in early January 2021 for another three or four days. Alinta’s Mr Primer asked FRC for a formal quote “to finish with services removal” and to restart on 2 January 2021 noting, “3 days would see us right when Clarke would be remobilising”. On 26 December 2020, Alinta placed a purchase order with FRC for additional trenching and backfilling.
On 22 December 2020, Mr Vickery also sought clarification from Alinta on progress, “in order to plan for commencement of works in the new year”.” Confirmation was sought for site access and handover. Mr Stevens also provided Ahrens with the questions Clarke had raised with Alinta regarding FRC’s works. Clarke asked for Ahrens’ construction methodology as “this will help us support our argument of having the site handed over in its entirety at the start and not piece meal as Alinta has suggested will happen”. Ahrens obliged.
On 23 December 2020, Mr Stevens advised Ahrens that, whilst Alinta had made a good start with the relocation of existing services, “it is becoming increasingly obvious that we may still have a couple of hurdles when we arrive on the 4th Jan … I understand Ahrens would like 100% of the site handed over at the start and it makes obvious sense – but fact is this may not be a choice for us”. If the BHP lines were not removed in time, how close could Ahrens complete the bulk earthworks up to those lines if they stayed where they were, and what would it cost to remobilise at a later date once the works had been removed? While Alinta had relocated the service water line, FRC had run out of materials and the line was still within the project site. If the line was not removed by 4 January 2021, how would this impact the bulk earthworks and what would the costs be? Similar questions were raised in respect of other services.
At noon on Christmas Eve, 24 December 2020, Alinta emailed a letter to Clarke advising that, pursuant to cl 15.1(a) of the contract, non-exclusive access to the Contractor Site within the Facility Land would be made available from 23 December 2020 (that is, the prior day). However, the 1/66kV main transformer excavation works could not commence until the underground fire ring main beneath that area was decommissioned. Alinta would notify Clarke once this was done. By issuing this letter, Alinta may be taken to have accepted that it had not provided the Contractor with non-exclusive access to the land to perform the Work within 10 business days of the notice to proceed issued on 19 August 2020.
Shortly afterwards, Mr Shuker responded to Clarke’s queries regarding the work undertaken by FRC, and the work that remained. Mr Shuker did not accept that the BHP water lines would cause delay to the commencement of bulk earthworks, where the lines were outside the site. On a without prejudice basis, Mr Shuker advised that Alinta had engaged with BHP to relocate the pipes. Mr Shuker advised “works are ongoing to provide [Clarke] access to the area that currently has the fire ring main beneath”. The service water line had been removed but a temporary connection would remain until works commenced on the fire ring main removal.
Mr Vickery said that, although Alinta had just issued a notice of non-exclusive access to the site, within a couple of hours Mr Shuker was saying that Alinta was still performing work. Mr Vickery could also see from the site camera that Alinta’s works to remove the existing underground services on the NPS2 site were ongoing. Excavation works appeared to be in progress, with relevant personnel engaged by Alinta present on site.
For his part, Mr Shuker understood that Alinta had now removed all existing services from the southern construction area. The underground fire ring main remained in the northern construction area. Nor did he think, at the time he wrote the letter, that additional compaction would need to be undertaken, “the assumption was that the whole site needed to be compacted and the material was to be brought on”.
On 3 January 2021, FRC resumed work on site. On 4 January 2021, Clarke’s Mr Whelan attended site and prepared a Project Status Report, with photographs and “what information I could extract from [Mr] Primer today”. Mr Whelan’s photographs show the extent to which underground services had been removed, or remained to be removed, and the extent to which trenches had yet to be backfilled. The task does appear to have had some way to go. Photographs taken by the site camera indicate that the L-shaped trench was now partially backfilled.
Mr Whelan also reported that Ahrens’ team was back in Newman (five people) but advised that their workforce would not remobilise until they got a date for when the site would be ready to commence. Mr Whelan was told that there would be new recruits and new onboarding / inductions activities to complete. The Ahrens’ project manager had been moved to another project and a new project manager would commence later that week after onboarding / induction.
On 4 January 2021, Mr Whelan also spoke to Alinta’s Scott List and “advised him we had many questions and need answers, as we have a bit of a chicken and eggs situation going on”. On 5 January 2021, Mr Whelan spoke with Mr Primer, who had “NO knowledge of when [fire water] line and [s]ewer line will be removed/relocated … I believe these to be as big an issue as the 2 x water lines and need to happen ASAP”. Mr Vickery was asked to raise these issues with Alinta. Photographs from the site camera record that the L-shaped trench had now been completely backfilled.
Based on the photographs in Mr Whelan’s report, Mr Vickery did not think that bulk earthworks could be safely commenced or carried out by Clarke while Alinta continued to remove underground services. (From looking at the photographs taken by the site camera, I agree: see [222].) Mr Vickery began to discuss the matter with his colleagues, including Mr Columbus, as to the impact that this would have on the project and how Clarke should respond. Later on 5 January 2021, Ahrens provided Clarke with the costs incurred due to delays in the start of the project, then totalling $180,041.38.
On 6 January 2021, Ahrens and Clarke personnel met, following which Ahrens provided reasons why the existing services needed to be relocated to allow Ahrens to effectively complete its scope of works. Various tasks needed to be attended to before work could begin, and it could not be completed in stages. Further:

On 7 January 2021, Mr Whelan sent a Project Status Photo Report to his colleagues, showing the state of the site after FRC had removed their equipment that morning. The job does appear to have been done in something of a rough and ready fashion. Trenches which had been backfilled were obvious, with the soil in the trench below ground level. Pieces of underground services infrastructure remained on site. Mr Stevens reviewed the report, based on which he believed that Clarke and its subcontractors were not able to commence bulk earthworks. Until these issues were resolved satisfactorily, there would be continued delays.
On 8 January 2021, Clarke provided the December monthly report. Despite the notice for site access issued on 24 December 2020, “the site remains occupied with open trenches, barricading, plant and equipment. The fire water line and BHP water lines have not been relocated. It is not possible for the bulk earthworks to commence at the end of the month.”
The updated program now included 22 days for line 597, “Resolve Fire Water Line (By Others) – TBC”. Mr Viliani agreed that this was longer than the seven days he had been asked to add to the program by Mr Vickery on 16 December 2020. He explained that the task was estimated to take seven days but, in fact, took 22 days. Mr Viliani said that this was not a Clarke activity but an Alinta activity, “They have to remove … the fire water and … underground system, to be ready for us … this 22 days is based on our information from them at that time”. That seemed to be a perfectly reasonable explanation, which I accept.
On 11 January 2021, Mr Vickery and Mr Stevens emailed back and forth as to whether, in light of Ahrens’ input, work could start now or not until the entire site was available. For Mr Stevens’ part, he considered, “We could make a start on site now” if the fire line, a post inside the fence line and the sewer in the northern construction area were relocated within a week of Clarke starting on site. Other things, such as relocation of BHP lines “would be a nicety” but could be deferred. There were clearly a number of views on the subject.
Mr Stevens said this was a draft email in which he was trying to put pressure on Ahrens to get to site. He sent this draft email to his boss to see whether it was okay to send. Mr Stevens thought that handover of the site in two stages was a way forward, given that Clarke had been trying to get onto the site for four months. Mr Stevens explained that he was trying to do anything that he could to get the contractor on site to mitigate. But Ahrens were persistent that the works needed to be complete so they had a “clean slate” to get on with the bulk earthworks.
Mr Whelan had earlier asked Ahrens whether they had any fully inducted personnel available, to remove existing Alinta fencing. On 11 January 2021, Ahrens advised that it did not, due to reallocation of personnel onto other projects. The operators were currently in Perth on extended leave as Ahrens did not require them yet. As I understand it, Alinta relied on this email as evidence that Ahrens was not available to commence work in any event. That submission significantly understates the full complexities of the position in which Clarke and Ahrens found themselves as a result of Alinta’s inability to remove underground services in a timely manner.
On 12 January 2021, consultation continued between Clarke personnel as to whether, and how, Clarke could commence on site given the incomplete removal of underground services. Mr Stevens suggested that Clarke should propose to Alinta and then Ahrens that the whole site should be handed over to Ahrens on 18 January 2021 and, once bulk earthworks were finished in the northern construction area, then Clarke could hand that section of the site back to Alinta for two weeks whilst they dealt with the remaining sewer and fire line relocation. Separately, Mr Stevens assured Ahrens that Clarke was continuing to work closely with Alinta to make site access available without any obstacles; Clarke was confident that they could start works as early as 18 January 2021 on site.
Mr Stevens and Ahrens had been going back and forth over a quote to install a new fire line. Also on 12 January 2021, Ahrens’ Mr Meldrum repeated his concerns with the project. The quote was to be fixed priced “as we are already in dispute with a number of claims and currently as I see it need to make continued justification of such claims”. Mr Meldrum reiterated his comments in the meeting held before Christmas prior to any further works or mobilisation, Ahrens needed inter alia*,* “Removal of existing services by others with site report detailing final RL’s, condition of site and any QA documents to provide to Ahrens for review”. The contract between Ahrens and Clarke must be in place with correct details about site access, start date and the practical completion date. Further:

Mr Stevens agreed that Ahrens were “starting to get a bit firm with us about the contract … whereas previously they were happy to start on the [purchase order]”. The fact that the contract had not been signed had worked to Clarke’s advantage somewhat, because if there were variation works, then Clarke could include those works within the contract too. Clarke had the opportunity to delay the signing of the contract “because we couldn’t access the site”. Mr Stevens explained, “if you delay the contract being signed you can include the scope of works that are still being designed so you don’t have a variation come through later after the contract is signed. … I like [to] try and get as much in the contract scope of works so that I have less variations to deal with at a later date”.
On 13 January 2021, Clarke provided a Project Status Report to Alinta, detailing remaining services and possible options. For each remaining underground service, or parts of that service left on the ground, Clarke provided options, such as leaving the service buried – with Alinta to accept responsibility if there were any adverse effects in the future – or for either Alinta or Clarke to remove the items, when this needed to be completed and at whose cost. Clarke proposed that Ahrens prepare the subgrade in accordance with the civil drawings, “If there are soft spots after correct subgrade preparation, this would be cause for delay / costs to rectify.” Otherwise, Alinta could compact the backfilled areas and provide QA. Similar options were presented in respect of the BHP water lines, which were currently within the footprint of the bulk earthworks, in particular, the batter.
Clarke’s report noted that trenches where services had been removed “appears to have subsided due to lack of compaction”. (That does appear to be the case from the photographs.) Mr Shuker said, “it did look to me at the time that there was [subsidence] and that it was for Clarke to deal with it given that [it] had to compact the site at the time”. He did not accept that Alinta should properly compact the land from which it had removed the services to ensure that the foundations for the power island were properly maintained, as “there was always a level of compaction that’s required for that site as part of the broader scope of work”. As earlier noted, Mr Shuker’s view does not accord with the contract.
Mr Columbus was in regular communication with Alinta’s Mr Thomas, trying to find a way forward in respect of the removal of underground services. On 15 January 2021, Mr Columbus provided a chronology on the history of the problems with underground services to Mr Thomas, “Not the best start as we should have had site possession and commence [with] Civil work on or around 1st October per program. We continue to try and mitigate these delays best I can and appreciate your involvement in getting [Alinta] works moved along please as this has clearly dragged on and on now.”
Mr Columbus sent a further “PS”, advising Mr Thomas that Alinta had advised by letter on 24 December 2020 “that we could now have the site … and this is what the site was like when we turned [up] on 4th January 202[1] to start works – Alinta Energy’s contractor still occupying the site - ??”. The photograph forwarded by Mr Columbus, and another taken by the site camera on 5 January 2021 showed:
Mr Stevens shared another photograph taken on site on 4 January 2021 with Mr Columbus and Mr Vickery, “how would we start on site … when this is [Alinta] contractors at work on site”. There was a water truck, an excavator and a bobcat. There was an open trench running across the site, which was being worked on. There was a water pipe on the ground, which Mr Stevens believed to be in service. Based on his experience, Mr Stevens did not believe that it would be possible for Ahrens to commence bulk earthworks with the site in this condition, as FRC was still in the process of removing and relocating underground services. FRC’s equipment was on site. This meant that Ahrens could not bring its own equipment on site and there would be a greater occupational health and safety risk in commencing bulk earthworks in the circumstances.
Mr Vickery held the same view. In order for Ahrens to complete the bulk earthworks, they first needed to ‘rip’ the entire site for conditioning, then bring heavy vehicles to deliver fill, which would be spread out in layers and ‘keyed in’ so that it had a uniform consistency and could be built upon. This process involved building up the pad in layers across the entire area. In Mr Vickery’s experience, this could not be done in a piecemeal fashion, as this created the risk that the surface may subside and be unsuitable for building on. Even if it was possible for the earthworks to be completed in sections, there was also significant safety issues that would arise if there were different sets of contractors working with others on the site. It would also lead to inefficiencies in performing the works and cause further delay and incur further costs.
Through these conversations, and reviewing the photograph of the site, Mr Columbus believed there were practical difficulties with Clarke being able to commence its work, as well as safety issues. Alinta’s contractor was still working on site and there was unfinished work, including open trenches. As Mr Columbus understood it, Clarke could not have bulk earthworks machinery, such as B-double trucks, enter and turn around in the area where there were open trenches and services still present.
Alinta’s Mr Knill arranged a meeting on 18 January 2021, to discuss and resolve each of the items in the Project Status Report. Mr Stevens also requested a meeting with Ahrens, to go through each point in the Project Status Report in advance of a meeting with Alinta, “I would also like to explore the possibility of handing over the site in 2 stages”, where most of the site was ready for Clarke to move in and start, but for a few minor items, and “I doubt Alinta … will have the [remaining] section … ready for another 4-6 weeks … and this is far too late for us to start. I think a clean approach for all involved would be to hand over the site in these 2 stages and provide a cost variation for this.”
I take this to be an attempt by Mr Stevens to persuade Ahrens to start earlier. Mr Stevens agreed that there was an opportunity to hand over the site in stages, as the southern construction area was lower. When undertaking bulk earthworks, work started at the lowest point and worked upwards. Whilst Alinta was removing their services in the northern construction area, there was an opportunity to potentially start in the lower southern construction area, as long as Alinta could complete the remaining works within a certain timeframe.
On 18 January 2021, Alinta and Clarke participated in a “Site Services Meeting”. Each of the items on the Project Status Report of 12 January 2021 was reviewed. In particular, the section of sewer pipe underneath the APA access road would be removed by Ahrens during bulk earthworks at Alinta’s expense. Ahrens would remove and dispose of the sewer pits at Alinta’s expense. The minutes also record, “Location of temporary water supply impedes on the driveway to main transformer and bulk storage area.” Alinta would confirm action to be completed with the redundant sewer water line and active fire water main, which ran under the location of the new main transformer, prior to handover. As for service removal trenching, the minutes record, “[Alinta] doesn’t warrant the condition of the site. [Clarke / Ahrens] to address site”. Alinta’s attitude ignored the fact that, while Clarke accepted the Site Conditions, it only did so for the site as at the date of the contract, being before Alinta began digging things up: see [80].
On 19 January 2021, Clarke advised Ahrens that the status of the site had been reviewed with Alinta and agreement reached on how the site would be handed over, “With some additional works to be completed, [w]e believe there is a clear path forward”. Ahrens’ review was sought as soon as possible and to “look at remobilising to site asap to start works”. Mr Meldrum was unmoved, “There will be no mobilisation until the items [in his previous email] have been addressed.”
On 20 January 2021, Mr Stevens pressed on, noting that while “Ahrens are stating they won’t start until Cont[r]act is signed”, the way to sign the contract was to address two remaining items. Further, “We need to make a start on the site asap as Alinta … [are] now providing site Access to Clarke … thus we are now potentially losing days in our own programme and need Ahrens to support us in making a start on site”. Clarke provided Ahrens with a contract for final checks, to be updated with new program dates. Clarke also issued a purchase order to Ahrens for the installation of the fire line. Ahrens advised that they expected to have approval to proceed by 26 January 2021, which would have Ahrens remobilising on 9 February 2021.
Also on 20 January 2021, Alinta sent a letter rejecting the assertions contained in Clarke’s delay notices. In particular, Alinta rejected the notion that work by its contractors prevented Clarke from commencing bulk earthworks in unaffected areas. Clarke was only entitled to “non-exclusive” access. By notifying the contractor of the availability of non-exclusive access to the site from 23 December 2020, Alinta was said to have instigated the process for Clarke to assume the management and control of the Contractor Site, with the reasonable expectation that any services remaining to be relocated would be coordinated by Clarke under its own work, health and safety management plan. Mr Shuker agreed that, despite this letter, he understood that the obligation to remove underground services remained with Alinta.
On 21 January 2021, Mr Stevens pressed Ahrens to “look at getting [a] small crew as a minimum to start next week”, where a number of tasks could be done whilst waiting “for the bigger equipment to arrive”. This included installing construction fencing, backfilling potholes, and removing redundant pits and sewer pipe. Ahrens replied that it “will not be mobili[s]ing to site until the final [variation] scope is confirmed and the contract agreed and signed”. Ahrens’ projected dates remained firm.
Mr Stevens then approached FRC, as he was “in a little bit of a situation” at Newman. There were a few items that needed work before Ahrens could start their “contract works”, and they could not start until 9 February 2021, “by the look of their programme … it will take another 4 weeks to complete [which] will put us further behind our own schedule with which we are already 12 weeks late”. Mr Stevens said he was looking at a “Plan B” and knew that FRC had a working relationship with Alinta and inducted people; assistance was sought. Alinta also contacted FRC, looking to have some further work done at Newman, including removal of the fire ring main and removal, backfilling and compaction of a camera pole and sewer pits.
That evening, Clarke gave an eighth notice of continuing delay to bulk earthworks, noting that direction had been provided by Alinta on each remaining site service. Clarke was expediting review and action of these items, including variation items to enable bulk earthworks to commence. Delay to the commencement of bulk earthworks was now some 17 weeks, causing some 12 weeks’ delay to practical completion.
On 22 January 2021, Mr Stevens updated his colleagues on his progress with “Plan B”, noting that he had been given the “green light to engage with another civil contractor to complete the Pre-works on site”. He was speaking with FRC and hoped to have them on site by 1 February 2021 at the latest. He proposed that FRC “rework the areas and then we get compaction testing complete – I cant see Ahrens taking the site possession until they have this QA”. Mr Stevens suggested that FRC could be used to complete other minor works, take down the fence and install construction fencing and anything else they could think of, “I want [Alinta] to hand the whole site to us and then we are in control of all works – we can still hand back the ‘northern area’ if required to [Alinta] to complete some works there.”
FRC was happy to assist. Mr Stevens went back to Ahrens, accepting their start date of 9 February 2021. Ahrens provided its comments on the contract.
On 23 January 2021, Mr Whelan circulated a scope of works to be completed by FRC, including re-excavation of all trenches in the southern construction area, compaction to specifications and compaction testing. Mr Whelan used the compaction value in note 6 on the drawings in Ahrens’ contract. Mr Stevens queried whether it was necessary to ask FRC to re-excavate and re-compact trenches to those specifications. FRC was instructed to compact the trenches to meet the level of compaction of the site before the underground services had been removed, leaving it to Ahrens to achieve the compaction level specified in its contract. Meanwhile, Ahrens followed up Clarke for its review of Ahrens’ comments on the contract, “Critical to our team locking in material delivery and labour is contract execution.”
On 28 January 2021, a further Newman Expansion Project Weekly Meeting was held. Clarke confirmed that FRC had been engaged to complete site clearance, commencing on 1 February 2021 and finishing by 8 February 2021. Ahrens’ mobilisation was planned for 9 February 2021. Clarke confirmed that the first delivery of fill material would be 12 February 2021, subject to the quarry re-opening.
After the meeting, Mr Stevens responded to Ahrens’ comments on the contract, querying why it was necessary to change particular wording, “The service[s] that have been removed and thus areas “disturbed” – the intention is that these areas will be handed over at [the] same / or better compaction than the current natural surrounding ground is. Clarke … will provide compaction test results to demonstrate this. It is up to the contractor to carry out the ground surface treatment as per note 6 on the drawings prior to introducing fill”.
Clarke and Ahrens spoke. Ahrens wanted Clarke to be responsible for any re-work required during the ground surface treatment works that were associated with the services that had been removed. Mr Stevens remained of the view that there was no need to change the contract wording, “If there are any ‘soft spots’ … where the existing services were removed … then this would need reworking and be cause for a variation – the contract allows this”.
Meanwhile, Mr Whelan had been asking Ahrens for a manning forecast for its remobilisation from 9 February 2021 on, but was having no joy. Ahrens said the forecast would be available once there was a clear direction with respect to signing the contract. Mr Stevens pressed Mr Meldrum on the evening of 28 January 2021, noting that they were both doing everything they could to get the contract signed. Regardless of the contract being signed, Mr Stevens did not consider that this should be holding up the type of paperwork that Clarke required for its client, including other onboarding paperwork needed to get a start on site. Support was sought to meet Clarke’s requirements. Mr Stevens and Mr Meldrum spoke, to resolve remaining drafting issues in respect of areas on the site which had been disturbed, where underground services were once located.
On 29 January 2021, Ahrens provided Mr Stevens with its delay costs. FRC also provided a quote, noting that the crew’s paperwork had been finalised. Mr Vickery advised that a purchase order would be raised and instructed FRC to proceed with inductions and mobilisation as soon as possible. Separately, Alinta issued a purchase order to FRC for the work which it had commissioned.
On 2 February 2021, Mr Vickery circulated the Weekly Project Status Report, noting that Alinta had engaged FRC to remove the fire water line, the remaining sewer line and pit and the camera pole and pit from the construction area. Clarke had also engaged FRC to perform remediation works within the construction area, with works to commence on 3 February 2021. Bulk earthworks had been delayed while removal of these services and pits from the construction area was being arranged.
On 4 February 2021, Clarke gave a ninth notice of continuing delay to bulk earthworks. Clarke advised that it had engaged FRC to complete the designated actions including variation items to enable bulk earthworks to commence. Commencement had been delayed due to the current COVID-19 lockdown in Western Australia. FRC would mobilise for the remediation work as soon as practicable after the lockdown ceased. The delay to practical completion was now thought to be 14 weeks.
On 5 February 2021, Mr Stevens pressed Ahrens for an updated program to be used in the contract, where wording was now agreed, “we note we were looking at getting the tester on Monday next week to start with the areas that are not being worked”. On Saturday, 6 February 2021, Clarke sent Ahrens proposed compaction test locations. On Sunday, 7 February 2021, FRC arrived but was required to isolate until negative COVID-19 test results were received.
On Monday, 8 February 2021, Alinta requested Clarke to provide a variation proposal for the removal of the remaining items, in accordance with Alinta’s comments on the Project Status Report of 12 January 2021. FRC mobilised to site on 9 February 2021 for inductions and personal protective equipment (PPE) checks and commenced earthworks and excavations on 10 February 2021.
On 10 February 2021, Alinta’s Mr Primer contacted Clarke in respect of the re-excavation of the water, sewerage and Telstra trenches which had been completed in late 2020. While Clarke had been authorised to remove 300 mm of material from the Telstra trench and refill and compact, Mr Primer was concerned that the next 300 mm below was not clean fill and asked whether all of the material in the Telstra trench could be removed and refilled correctly with clean fill and compacted, to avoid problems in the future.
Separately Clarke sought to clarify FRC’s scope of works with Alinta, including how Alinta would confirm / document the compaction value for the subgrade once FRC had completed removing the fire ring main section, sewer, CCTV service and bollards. Clarke also advised Alinta that its intention for the Telstra service was to reinstate the top 300 mm to 400 mm of material to an acceptable density for handover to Ahrens but, “On inspection of the potholing indicates no bedding material has been used during the install and the backfill material is questionable due to the excessive amount of rocks removed from the trenching.” Alinta’s intentions for the Telstra service were sought, so as not to cause delays to Clarke’s works.
A Newman Expansion Project Weekly Meeting held on 11 February 2021. Clarke confirmed that FRC had begun. Ahrens’ mobilisation was now planned for 22 February 2021. Potholing had been completed to confirm the accuracy of Telstra’s “As-builts”. Backfill from previous relocation works was inadequate.
On 12 February 2021, Alinta advised Clarke that confirming the compaction value for the subgrade was not Clarke’s scope and Alinta would deal with this. On Saturday, 13 February 2021, Alinta issued an amended purchase order to FRC to include additional scope, being fire system upgrade works. Clarke pressed Alinta for consent to complete the works to the Telstra service trench, noting that Clarke had advised FRC to complete works in other areas until Alinta could provide its approval.
On 18 February 2021, Clarke gave a tenth notice of continuing delay to bulk earthworks. The remediation work being conducted by FRC was expected to be completed by 26 February 2021. The delay to commencement of bulk earthworks was 133 calendar days and the delay to practical completion would be 103 calendar days. Clarke estimated that the cost incurred was $641,470.
Clarke and Ahrens had executed a contract on 12 February 2021. On 18 February 2021, Ahrens confirmed that they would be on site on 23 February 2021 to carry out the works. Ahrens advised that it was amenable to FRC still being on site completing the removal of underground services. But, on 22 February 2021, Ahrens advised that they were unable to access the site the next day due to hinderance by other contractors, “We will now park up the plant until we have clear access to site.” Ahrens warned that this may have significant delay costs as their plant may have to be hired to other projects and other plant re-hired from other suppliers (if available) at higher costs. Operators may not be able to return to site once they return to Perth and other personnel may need to be engaged with additional onboarding. Ahrens gave notice of delay with a possible claim and an EOT claim. The site camera indicates that the L-shaped trench was now partially open as it had to be correctly backfilled prior to commencement of bulk earthworks. Underground services continued to be removed at the same time.
On 23 February 2021, Mr Stevens spoke to Ahrens, noting that some initial delays had been caused on site due to weather, which had held up FRC’s site works. FRC looked likely to finish a few days later, on 26 February 2021. Ahrens advised that its surveyor was on site but could only carry out control checking. Grids could not be set out until the pad was cleared of other contractors. The Ahrens project manager added, “our site is other contractors working space”. Clarke and Ahrens turned their attention to safety management plans. On 26 February 2021, Ahrens issued a notice of delay to Clarke in respect of earthworks due to other contractors working within the footprint. Six standard shifts had been lost.

As EOT 1 was not determined by the Superintendent until November 2022, it is necessary to defer consideration of the issues in relation to that claim. Before moving on, it is convenient to consider Clarke’s contention that Alinta breached its contractual obligations in this initial phase of the project. This goes to Clarke’s argument that, by reason of these ‘acts of prevention’, Alinta is not entitled to rely on Clarke’s failure to provide EOT 1 to the Superintendent as a bar.
The ‘prevention principle’ is that “a party cannot insist on the performance of a contractual obligation by the other party if it itself is the cause of the other party's non-performance”; the principle may be regarded as a particular manifestation of the duty to cooperate implied by law in all contracts: Spiers Earthworks Pty Ltd v Landtec Projects Corporation Pty Ltd (No 2) [2012] WASCA 53 at [47] (McLure P, Newnes JA agreeing); cited with approval in Probuild Constructions (Aust) Pty Ltd v DDI Group Pty Ltd (2017) 95 NSWLR 82; [2017] NSWCA 151 at [114] (McColl JA, Beazley ACJ and Macfarlan JA agreeing). It is a breach of the contractual terms that gives rise to the potential application of the principle: Bensons Property Group Pty Ltd v Key Infrastructure Australia Pty Ltd [2021] VSCA 69 at [114].
There were two suggested breaches of contract by the principal.
First, Clarke contended that, on the true construction of cll 2.3 and 15.1, and by reference to an implied term of the contract that Alinta would do what was necessary on its part to comply with its contractual obligations, Alinta should not have given the notice to proceed unless, within the 10 Business Days stipulated in cl 15.1, Alinta actually provided non-exclusive access to the site. Alinta was not in that position on 19 August 2020, as it had not relocated the services. Without this, Clarke was not able to undertake the Work, being bulk earthworks. Alinta was said to have thereby breached cl 2.3 of the contract.
Clarke further contended that Alinta did not have a reasonable basis to believe that it could give non-exclusive access to the site within 10 Business Days of the notice. Where cl 2.1(b) provided that cl 12 of the contract did not come into force or effect until the Commencement Date, pursuant to the principle of construction that Alinta could not take advantage of its own breach of contract, Alinta was not entitled to invoke the provisions of cll 12.1(b), 12.6 and 12.8 of the contract to bar EOT 1 where, had Alinta not acted in breach of contract, those provisions would not have been in force. The contract envisaged that it would have 567 days to complete the Works after the Commencement Date. In these circumstances, the proper construction of the contract was that Alinta could not give a notice under cl 2.3 which prevented Clarke from achieving Practical Completion within that timeframe, by issuing a notice to proceed where the underground services would not be removed in time for Clarke to start the Works.
Alinta submitted that, when the notice to proceed was issued on 19 August 2020, there was then thought to be two weeks of work involved in removing underground services. That left plenty of time before Clarke was expected on site, according to its then program. There was a reasonable basis for the issuing the notice. It was not until 7 October 2020, after Clarke had identified that the BHP water lines would be impacted by its design, that the parties began recording that there was “[p]otentially more than 2 weeks work and effect start to civil works”. It was not until sometime between 13 October 2020 and 15 October 2020 that Clarke identified that Clarke’s design might clash with the fire water main in the northern construction area. It was at this stage when Mr Columbus of Clarke attended a meeting with Alinta in which Mr Columbus recorded that the scope of the services relocation works was now “greater … than AE believed!!”. Despite this, Clarke issued a notice of mobilisation to the Facility Land on 16 October 2020 under cl 15.2(a) “to carry out pre-mobilisation and mobilisation activities”. Had Clarke considered that the notice to proceed issued on 19 August 2020 was issued in breach of the contract then, presumably, Clarke would have stated as such and reserved its rights to mobilise to the Facility Land at a later date.
As to the submission that the “complication” referred to at the steering meeting on 15 October 2020 arose from Clarke’s design circulated on 30 September 2020, proposing to bury the BHP pipe on the boundary, that appears to have been part, but a small part, of the complication which was then beginning to be appreciated.
I can understand why Alinta would have wanted to issue the notice to proceed when it did. There was a Commencement Deadline, being 28 August 2020: cl 1.1; item 3 of Sch 1. If the Commencement Date had not occurred by the Commencement Deadline, then Alinta would have re-negotiate with Clarke in respect of price and time. Within 5 Business Days after the Commencement Deadline, Alinta would be obliged to either request an extension from the Contractor or advise that it did not want an extension: cl 2.4(a). If Alinta requested an extension, then the parties were obliged, acting in good faith, to endeavour to agree on a range of matters, including amendments to the Milestone Amounts, Date for Practical Completion and the program in Sch 9: cl 2.4(b). If these matters could not be agreed within 20 Business Days after a request for an extension, then either party could terminate the contract, in which case “the rights and obligations of the Parties which accrued before the date of termination are not excluded or reduced": cl 2.5(b)(c).
The Principal was entitled to consider issuing the notice, as “the Conditions Precedent ha[d] been satisfied …”: cl 2.3(1). Clause 2.3(a) provided that, in those circumstances, “the Principal may (at its sole discretion) give the Contractor a written notice to proceed …”. That is, Alinta had a discretion whether to give the notice (denoted by “may”). That the notice may be given “at its sole discretion” indicated that the decision was vested in Alinta alone: Topfelt Pty Ltd v State Bank of New South Wales Ltd (1993) 6 BPR 13,209 at 13,216 (Sheller JA, Priestley and Cripps JJA agreeing).
As mentioned, the significance of the notice to proceed is that it fixed the Commencement Date and thus the Date for Practical Completion. The Commencement Date was the date on which the Principal gave the Contractor a notice to proceed under cl 2.3(a): cl 1.1. The Date for Practical Completion was the date that is 567 days after the Commencement Date, as adjusted in accordance with the agreement: cl 1.1; Sch 1, item 8. Further, it was not until the Commencement Date that the bulk of the contract came into force and effect, specifically, the obligation to achieve Practical Completion by the Date for Practical Completion (cl 3.2(b)), the EOT provisions (cl 12), the Principal’s obligation to provide access (cl 15.1) and the liquidated damages regime (cl 19): cl 2.1.
It will be recalled that, under cl 2.3(b), “The Principal must regularly update the Contractor regarding when the Principal believes it will issue a notice to proceed”. The reason why Alinta was obliged to regularly update Clarke as to when it expected to issue a notice to proceed is made plain by cl 15. Clause 15.1 has already been considered, obliging Alinta to give Clarke non-exclusive access to the site to perform the Work in 10 Business Days after the Commencement Date. Further, cl 15.2 contained detailed requirements for mobilisation, obliging Clarke to give Alinta at least 10 Business Days prior written notice before mobilising to the Facility Land: cl 15.2(a). Clarke was not entitled to access the Facility Land absent compiling a variety of materials including health, safety and environmental plans, providing Performance Securities and guarantees and obtaining insurance: cl 15.2(b).
As such, it was necessary for Alinta to give Clarke fair warning as to when Alinta proposed to issue a notice to proceed, so that Clarke was in a position to promptly mobilise to site if it wished, having attended to the necessary prerequisites for so doing. All of this was presumably intended to ensure a seamless commencement of work, where the Date for Practical Completion would be fixed by the issue of the notice to proceed and time would now be ticking.
Alinta accepted that it had a duty to cooperate. The implied obligation to cooperate is subject to the express terms of the contract: Campbell v Backoffice Investments at [168]. If the implied obligation survives the express terms of the contract, then the duty of cooperation “is a duty to afford the other party the benefit of what [they have] contracted for … [T]he duty of cooperation does not extend to being nice”: Beerens v Bluescope Distribution Pty Ltd (2012) 39 VR 1; [2012] VSCA 209 at [54].
What is the content of the implied duty of cooperation when issuing a notice to proceed, given the express terms of the contract? The interaction between cl 2.3 and cl 15 corroborates, rather than excludes, any duty to cooperate. The parties are to liaise and ensure a prompt and seamless commencement of the Work, where any delay in the Work after the Commencement Date is now to be dealt with under the EOT or liquidated damages regimes. While Alinta’s duty to cooperate did not extend to making sure that Clarke would be ready to start, its duty to cooperate did oblige Alinta to be satisfied that it would be in a position to give the Contractor non-exclusive access to the site “to perform the Work” within 10 Business Days of giving the notice.
Was Alinta in a position, on 19 August 2020, to be satisfied that it would be able to give the Contractor non-exclusive access to the site “to perform the Work” within 10 Business Days of giving the notice? At that time, despite having been in discussions with Telstra for two months, the Telstra fibre had yet to be moved. What Alinta had presumably learnt from the preceding two months is that it had taken a lot longer to arrange the relocation of the Telstra service than had been initially anticipated and, indeed, a purchase order had only just been issued.
Alinta then thought that there was only the Telstra service, water and sewerage to relocate, with “no big items to move”. But while Mr Wozniuk had been liaising with Clarke’s Mr Schofer as to where to relocate the underground services to, there is no indication that Alinta had undertaken any step to engage a contractor to relocate those services. Alinta reported on 27 August 2020 that a quote had been received from FRC, this being six Business Days after the notice to proceed was issued and four Business Days before Alinta was obliged to give Clarke access to the site “to perform the Work”.
Nor had Alinta prepared a scope of works for whoever was engaged to undertake this task. The metes and bounds of the water and sewerage pipes, as then depicted on the McMullen Nolan Group survey, indicated that these services involved more than half of the Contractor’s site, assuming that was all that was there on excavation. The survey also warned that there may well be more underground services, given the “very ineffective” radar scanning of the area.
The focus must be, I think, on what was “the Work” for which Clarke would need non-exclusive access to the site within 10 Business Days of issue of the notice to proceed? A key piece of information in this regard was the program. At that time, the only program was the one attached to the contract. Many activities were listed after “Contract Award” on 15 May 2020 and, according to the minutes of meetings, were underway, including procuring equipment and progressing engineering design. According to that program, the date for “Site Access Available (construction)” was 15 October 2020.
When considering whether to issue a notice to proceed, Alinta was entitled to proceed on the basis that it did not require site access to be available for construction for another two months. Until then, Clarke’s access to the site was likely to be for the purposes of taking measurements or site investigations for the purposes of procuring equipment or engineering and design work. If Alinta’s contractor was in the process of removing underground services when Clarke personnel attended site for that purpose, Clarke would have had access to the site “to perform the Work” which was planned during that time. I consider that Alinta had a reasonable basis to think that it would be in a position to give Clarke non-exclusive access to the site “to perform the Work” within 10 Business Days of giving the notice to proceed.
Further, Alinta had a reasonable basis to think that, within the next two months, it would be able to engage a contractor to remove existing underground services and complete that task before Clarke needed access to the site for construction, specifically, for bulk earthworks. Consistent with its duty to cooperate, I consider that the Principal did not breach its implied obligation by issuing the notice to proceed when it did.
Second, Clarke contended that Alinta should have issued a notice of delay on 15 October 2020, where it was guilty of delay as it had not removed the underground services and this was likely to delay the works. The same could be said as at 20 October 2020, between 24 November 2020 and 4 December 2020 and as at 4 January 2021. Alinta contended that whether it gave notice of delay was neither here nor there.
As mentioned, the contract provided that Alinta “must give the Contractor written notice promptly after becoming aware of a delay to any act or thing the Principal is required to do or provide under this agreement which is likely to delay the Work”: cl 12.5(c). The removal of existing underground services was not within Clarke’s scope of works. Alinta was to do this work. Alinta was having trouble getting this work done and it was likely to delay Clarke’s work. Alinta was obliged to give a notice of delay and was in breach of contract by failing to do so.

On 12 April 2021, Clarke submitted a variation proposal under cl 14.1(c) of the contract, for additional site preparation works for site amenities, being VO 05. Clarke noted that the works had been completed by Ahrens. Clarke proposed that the Milestone Amount be amended to add the cost of the variation, being $83,314.36. The benefits associated with the variation were said to be uninhibited access to the diesel fill area adjacent to the originally proposed amenities area and better delineation of pedestrian access to the project site. The proposal was open for acceptance for 20 Business Days from the date of the letter.
On 6 May 2021, Alinta rejected variation proposal VO 05. It was said that Clarke did not provide any proposal for Alinta’s consideration in respect of the works but, contrary to cl 14.3, was said to have unilaterally decided to proceed with the works without giving a variation order. Further, such site preparations were said to form part of the Work. Clarke should have reasonably made sufficient allowance for site establishment to optimise the execution of the work. Where Mr Stevens had agreed in his email that the proposed location was “a good plan”, it was said to be evident that the proximity of the site offices to the site was intended to optimise the execution of the work by Clarke, as contemplated by the Principal’s Project Requirements. Alinta considered the matter closed.
On 3 June 2021, Clarke disputed the basis on which VO 05 was rejected. Mr Vickery explained that the matter had been discussed verbally with Mr Blowers. While a variation proposal was not provided prior to the work, the change in scope was in response to Mr Blowers’ direction to change the location of the site offices. Clarke had flagged that there would be additional costs, both verbally and in monthly reports. The reason for the variation request was that the site chosen for the site office by Clarke was on a suitable surface, while the location to which Mr Blowers directed that Clarke locate the site offices required considerable earthworks for bringing in the site offices.

I have found that, during the site visit on 26 July 2019, Mr Wozniuk pointed out where would be a good laydown area for construction offices and amenities. Whether Mr Wozniuk made this representation does not actually matter, as Clarke was entitled to put the laydown area where it wanted. But Clarke put forward a site layout with site amenities in that location. There was good reason to do so. Putting site amenities there could be achieved with minimal time and cost.
But Mr Blowers proposed changes on 23 September 2020, to suit Alinta Operations and its access to the diesel tanks. It is evident from Mr Blowers’ email that he appreciated that the change to the proposed site layout would involve additional works. Mr Vickery broached the subject of who would bear the additional costs on 14 October 2020: see [141]. Mr Vickery’s email after their conversation indicates that Mr Blowers expected that the costs associated with the “new spot” would form the basis of a variation.
It appears from the Newman Expansion Project Weekly Meeting minutes of 15 October 2020 that Mr Blowers was going to deal with the additional costs associated with relocating site amenities by requesting Clarke to provide a proposal for a variation under cl 14.1(a): see [143]. By Alinta’s oversight, the request was not sent. Nor did Clarke wait for Alinta’s request to provide a variation proposal. Immediately after the meeting, Clarke issued a purchase order to Ahrens for site establishment. As Mr Vickery indicated to his colleagues at the time, “This needs to commence … Ahrens are set to mobilise on [19 October 2020]”. But I think that Clarke was entitled to expect that a request to provide a proposal for a Variation under cl 14.1(a) would be forthcoming. Where Mr Blowers wanted the site amenities in the “new spot”, Clarke was also entitled to expect that, on providing a Variation proposal, Alinta would issue a Variation Order.
Clarke could also expect that there would be negotiation with Mr Blowers about whether all of the costs associated with the “new spot” could be recovered from Alinta, where Clarke was going to spend some money on site amenities in the original location in any event. Given the limited time between the meeting and when Ahrens was due to arrive on site – to commence the works associated with the new site amenities area – it was reasonable for Clarke to issue a purchase order to Ahrens when it did. In doing so, Clarke was also taking a risk that Alinta may not ultimately accept that all of Ahrens' charges were “reasonable additional costs … which arise out of the Variation": cl 14.4.
Ahrens undertook the work from 19 October 2020 until about 9 November 2020. Alinta omitted to request a Variation proposal under cl 14.1(a), as it had indicated that it would. Soon afterwards, Mr Shuker took over from Mr Blowers. What may not have been imparted to Mr Shuker in the handover is what had happened in respect of the change of the site layout. This appears to have resulted in a ‘loss of corporate memory’. When Clarke belatedly submitted a proposal for a Variation under cl 14.1(c) instead, Mr Shuker rejected it.
I consider that Clarke was entitled to assume that Alinta would do as its representative, Mr Blowers, had said. Clarke proceeded on that basis, commissioning additional work which Clarke did not want for itself. Mr Blowers likely intended that Clarke would do so, so that the site amenities were located in the location which he wanted, and promptly. But Alinta did not fulfill Clarke’s expectation as Alinta did not issue a request for a Variation proposal, most likely by reason of Alinta’s oversight. Alinta now seeks to rely on cl 14.3(f). If Alinta is permitted to do so, then Clarke will suffer a detriment, being its inability to recover reasonable additional costs arising from a Variation done at Alinta’s request. I am satisfied that the elements of promissory estoppel have been established.

While the contractual provisions are complex, in short, if the Principal directs the Contractor to perform a Variation pursuant to a Variation Order, then the Contractor is entitled to “the reasonable additional costs … which will arise out of the Variation” plus the Profit and Overheads Margin (being 15%): cll 1.1, 14.2(a)(1)-(5), 14.4(b); Sch 2, cl 5.
Ahrens’ price for the revised site amenities location was $141,576.84, of which Clarke had claimed only $71,689.10 from Alinta. Clarke’s quantity surveyor, Mr Cox, arrived at a figure of $80,328.31.
Ms Halloran assessed the variation at $42,122. Given the terms of cl 14.4, Ms Halloran considered that the reasonable additional costs should be measured by the actual costs of the variation works. Ms Halloran noted that Clarke had never submitted a price for the original location of the site amenities. Ms Halloran reviewed the drawings for the original and revised location of site amenities and site photographs showing the completed site office complex and services. From this, Ms Halloran assumed that the additional work involved in the revised location was imported fill for the installation of the office complex, amenities and parking area, and associated plant, equipment and labour. Ms Halloran assumed that it would always have been necessary to have supervision, site vehicles, a crane and consumables when installing the amenities in the original location. Ms Halloran calculated the final area of the site office and car park from aerial photographs, which was slightly smaller than the area used by Mr Cox in his calculations. As a consequence, the volume and tonnage associated with the fill material was less in Ms Halloran’s calculations. Ms Halloran reduced the time taken to construct the site amenities to allow for the time that would have always been needed to construct the site amenities in their original location. Site records indicated that smaller and less equipment was used than that assumed by Mr Cox. Ms Halloran used equipment hire rates accordingly.
Mr Cox saw no reason to revise his assessment in light of Ms Halloran's view. Given Mr Stevens’ evidence, Mr Cox understood that the total costs passed on to Alinta were directly related to the performance of bulk earthworks which were required in order to place the site amenities. This suggested that the scope had more complexity than could be derived from site photographs. Where neither expert knew precisely what equipment had been used, Mr Cox considered that his assessment of plant costs was in the low to mid–range and was more reasonable.
The amount in issue is small. Mr Cox's approach is, I think, fair and reasonable. The missing piece of information is what Clarke would have spent on site amenities in its original location. I note from Mr Vickery's email to his colleagues on 14 October 2020 that Clarke’s original budget for equipment mobilisation, demobilising and site cleanup was $22,680. Doing the best I can, I will deduct half of the original budget from Mr Cox's figure (in an effort to exclude the budgeted amount for demobilisation and site cleanup*,* where site cleanup is presumably a reference to site cleanup on demobilisation*)*. Clarke is entitled to $69,000 for VO 05.

As earlier mentioned, Clarke made EOT 1 on 26 March 2021. Clause 12.8(a) provided, “The Contractor must give the Principal and the Superintendent” an EOT claim within 20 Business Days of becoming aware that the delay event was no longer continuing to delay Practical Completion. While the EOT claim was made on time to the Principal, it had not been given to the Superintendent. Nor was Mr Ravi copied to the earlier notices of likely or actual delay, or delay updates.
Having received EOT 1 on 26 March 2021, Mr Shuker emailed Clarke three weeks later, on 19 April 2021, acknowledging receipt and seeking confirmation that EOT 1 had also been given to the Superintendent, as required under cl 12.8(a) of the contract.
Clarke promptly re-sent its correspondence to Mr Ravi, “For completeness … as your name was missing from the list of recipients”. Clarke attached the previous notices of continuing delay, presumably recognising that none of this material had previously been provided to Mr Ravi either. Clarke received an automatic reply from Mr Ravi, advising that he was on annual leave, returning on 27 April 2021 and would respond to the email on his return. Clarke enquired of Mr Shuker, “is there another person to contact?” Mr Shuker advised that the Superintendent was contactable by mobile phone for urgent matters.
After receipt of a claim under cl 12.8, the Superintendent had 15 Business Days to respond: cl 12.9. The response must either grant the extension of time to the Date for Practical Completion which Clarke was entitled to (if any), specify the delay costs under cl 12.4 to which Clarke was entitled (if any) and, if the extension of time or amounts under cl 12.4 differed from those claimed, state the reasons for the difference.
On 10 May 2021, Mr Ravi wrote to Clarke in respect of EOT 1, copied to Mr Shuker. Whilst the superintendent responded to the EOT claim within 15 Business Days of receipt, he did not determine EOT 1. Rather, Mr Ravi referred to cl 12.6 (requiring Clarke to provide written notice of delay within 10 Business Days of first becoming aware of the commencement of the delay) and cl 12.7 (requiring Clarke to provide an update on delay to the Superintendent at least every 10 Business Days), noting that the earliest notice of delay received by the Principal was 6 November 2020, “It is noted that the Contractor did not provide any notices of delay to the Superintendent.” Clarke was asked to “provide justification for not complying with the EPC Contract requirements”. Further particulars of the claim were also sought.
On 4 June 2021, Clarke responded to the Superintendent’s request, copied to Alinta. Clarke explained that it had first issued a notice in respect of the delay on 23 October 2020 under cl 12.5. An extensive reply was given.
On 24 June 2021, Alinta sent a letter and supporting material to Clarke and the Superintendent regarding EOT 1. (Clarke objected to Alinta making submissions in respect of EOTs, where the contract did not provide for this; nor did the timeframes within which the Superintendent was to determine EOTs envisage such a step in the process.) Alinta noted at the outset:

Since 15 March 2020, that is, before the contract was signed, a state of emergency had been declared in Western Australia in respect of the pandemic caused by COVID-19, under s 56 of the Emergency Management Act 2005 (WA). The Commissioner of Police and State Emergency Coordinator had also issued directions under the Act for the purpose of preventing COVID-19 coming into Western Australia and limiting the spread of COVID-19 in that state: Controlled Border for Western Australia Directions. The state of emergency had been extended from time to time. The directions were amended from time to time. On 22 March 2020, a major emergency had also been declared by the State Coordinator for the State of South Australia under s 23(1) of the Emergency Management Act 2004 (SA), and that declaration was extended from time to time too.
Mr Vickery said that the COVID-19 pandemic, and state government responses to the rise or fall in the number of cases, was unpredictable and created a real challenge for Clarke and its subcontractors in making arrangements for crews to mobilise and demobilise from the site. The NPS2 site was in a remote area of Western Australia, which meant that it took considerable planning to arrange for work crews to physically travel to the site, whilst also ensuring that all necessary testing and quarantine conditions were met. I accept this.
On 28 June 2021, Mr Stevens advised Mr Vickery, “WA have shut the border to Queensland … Qld now categorised as “low risk” – so this means you can enter WA but must quarantine for 14 days”. On 29 June 2021, Ahrens advised Clarke, “we have been halted in bringing personnel on site … due to Covid 19 BHP conditions and regulations”.
On 30 June 2021, Clarke gave notice to Alinta of a force majeure event in respect of the COVID-19 lockdown in Western Australia, under cl 12.5 (notice of likely delay). The latest notice of extension of the Western Australia state of emergency and amended direction were attached. A link was provided to a government website. Mr Vickery advised that, according to this material, the Perth metropolitan area and the Peel region would enter a minimum four day lockdown, during which people would be required to stay at home unless they were an “essential worker”. But the definition of “essential worker” now excluded FIFO workers, who had historically been able to fly in and out of remote workplaces during a lockdown. The known duration of the delay was four days. The force majeure event had affected the mobilisation of resources to the site for works shown in the current program. Where it was possible to do so, shifts for personnel already at the site had been extended; progress was being made on work fronts where there was an existing workforce.
The program dated 30 June 2021 then showed that the steel erection works in Powerhouse Building 2 were on the critical path. The works were to commence that day and be completed on 11 August 2021 (43 days). (The delay experts agreed that this was the relevant program for the purposes of EOT 4.)
On 13 July 2021, Clarke gave a second notice of a force majeure event in respect of “COVID-19 Lockdown and border restrictions in WA”. This was a notice of actual delay (cl 12.6) and an update on delay (cl 12.7). The most recent extension of the Western Australia state of emergency was enclosed, dated 12 July 2021. The four day lockdown in Perth and the Peel region ended on 3 July 2021 and from midnight on 12 July 2021, all restrictions on those residing in Western Australia were lifted. But the state was incrementally imposing COVID-19 related border restrictions. These restrictions were continuing for travellers from Queensland and New South Wales. These restrictions did not allow persons to enter Western Australia from Queensland or New South Wales unless they were an exempt traveller, and workers did not qualify. The force majeure event had affected the program, now including installation of Powerhouse buildings and civil footings for switch rooms. Clarke was monitoring the shifts for personnel already on site in accordance with fatigue policies. Clarke was seeking to mobilise staff from non-restricted states as an alternative to those residing in those states impacted by border restrictions.
On 20 July 2021, Clarke gave a third notice of a force majeure event in respect of “COVID-19 lockdown in SA”. This was a notice of actual delay (cl 12.6) and an update on delay (cl 12.7). The most recent extension of the major emergency was enclosed, dated 24 June 2021. Under this declaration, from 6 pm that day, and for the next seven days, the only reasons to leave home in South Australia would be limited, including for essential work. The Works were not considered essential work under the Declaration. The known duration of the lockdown was seven days but “Western Australia has already announced that arrivals from South Australia will have to quarantine for 14 days. The nature and duration of the border restrictions are unknown [but] continuing”. The force majeure event had now also affected fabrication works of structural steel.
On 23 July 2021, Ahrens issued a notice of delay, noting that South Australia went into a hard seven day lockdown on 21 July 2021 due to COVID-19. This had affected Ahrens’ capacity to fabricate materials, receive materials and galvanise steelworks. Ahrens could not send any labour to site from South Australia. Ahrens was trying to seek local labour in Western Australia and get them mobilised to reduce delay. On 27 July 2021, Ahrens tried to engage labour elsewhere, noting, “Due to the lockdown, our install team from SA cannot get back to site and I have been spending the last week desperately trying to find labour to continue the install.”
On 28 July 2021, Clarke gave a fourth notice of a force majeure event in respect of “COVID-19 Lockdown SA”. This was an update under cl 12.7. While the seven day lockdown in South Australia had ended at midnight, Western Australia required all arrivals from South Australia to quarantine for 14 days. The notice of delay from Ahrens was attached.
At the same time, Ahrens advised Clarke that Ahrens was experiencing difficulties on site, as it was running out of work fronts, “we are currently in disarray having additional number of personnel on site to complete the works promptly but we are hampered as there is nowhere to go”. Clarke disagreed, noting that the other personnel on site were also from Ahrens and they should work together. Clarke sought an update from Ahrens “on the additional WA labour that you were looking at” and any other details “other than your programme that shows a long delay currently”. Ahrens replied that they had contacted “Complete Projects” to assist with steel erection and the installation of cladding “and they provided the most positive feedback regarding having labour available to help us out until our own guys can return”.
Ahrens asked Complete Projects to provide a crew of four men for a full 21 day swing, to be extended for another one or two swings “depending on what the borders do and how much we need to accelerate our program”. A four to five man cladding crew was also sought, “This is dependant on the borders and us getting our cladders over to site however there would be no harm in having a 2nd crew on site.” On 29 July 2021, Ahrens advised Clarke that they were looking at getting another team out of Perth “to keep this moving and then looking [at] our own guys out of SA (when we can travel) to double up with an afternoon/night shift to try [to] pull this back on track”.
On 30 July 2021, Ahrens updated Clarke, advising, “we still cannot get our crew on site from across the border from SA into WA”. Some labour would be provided by Complete Projects from 6 August 2021 but Ahrens was pushing for an earlier arrival. Clarke was asked to write a letter to assist Ahrens’ drivers “getting across the border with steel deliveries”. Ahrens assured Clarke that they were doing their “absolute best to mitigate and provide a solution that can get us back on track and deliver this project successfully”. Ahrens issued a second notice of delay.
On 4 August 2021, Ahrens advised Clarke, “I am not planning around the borders opening at all as it is so uncertain.” Feedback was sought from Clarke on running a day and night shift. On 9 August 2021, Ahrens’ project manager, Jayden Bell, updated Clarke on his efforts to hire labour, which were proving unsuccessful notwithstanding Ahrens’ “google rampage of calling people. … we ideally need a good crew that have experience and will do the job to a high standard and also safely. They need to underst[an]d the BHP rules and abide by them”.
Ahrens’ project manager updated Clarke later that day about a potential second crew who could be on site from 17 or 18 August 2021, “however they will need the guidance of one of the guys he has there already with reading drawings etc. This doesn’t give me too much confidence but we may be able to make it work. … they don’t have rigging tickets which I believe is a must have for us.”
Ahrens continued to provide updates to Clarke on its ability to source available labour, which Clarke provided to Mr Viliani to feed into Clarke’s program. On 10 August 2021, Clarke circulated the monthly progress report for July 2021. The updated program now included lines 601-602 regarding the Western Australia border closure, which appeared as a 12 day event between 20 and 31 July 2021.
On 11 August 2021, Clarke gave a fifth notice of a force majeure event in respect of “COVID-19 continued border closure between SA and WA”, being an update on delay under cl 12.7. While the seven day lockdown in South Australia had ended, the impact of the lockdown continued due to Western Australia’s classification of South Australia as a “medium risk” jurisdiction. As a consequence, there was a continuing hard border closure to those attempting to enter Western Australia from South Australia. Workers were not considered exempt travellers. Ahrens’ workers had been affected by the Western Australian hard border closure to South Australia, “Ahrens’ crew of 5 steel erectors are affected as well as the 5-6 man crew of cladders that were schedule to mobilise to Site. It has also affected the install date of the precast and overhead crane which together is another 7-8 people.”
Details of the 10 companies that Ahrens had approached in Western Australia were provided. Most had no capacity. Complete Projects had sought to assist by advertising for riggers and cladders. Orbital Welding had “2-3 resources which Ahrens have accepted and have commenced the onboarding process”. This crew would be supplemented by resources from Cosa Cranes but “this work involves high risk activities and requires a suitable level of experience to be able to perform the job safely and to the required quality standards”. Ahrens was endeavouring to get an external crew on site as soon as possible, “Ahrens are not relying on the borders opening up again given the current uncertainty around the delta variant of COVID-19. If / when Ahrens are able to get their internal (SA) crew to Site, they plan on running the Ahrens crew along with the external crew in order to have more hands on deck.” Clarke was investigating the possibility of running night shifts to recover some of the schedule and sought Alinta’s input on this option.
On 13 August 2021, Ahrens provided Clarke with an updated program and manning schedule, “Luckily the 3 from Orbital Welding are already mobilised … The 5 from Complete [P]rojects have been delayed on another project and need their tools to come back.” The remaining steel for Powerhouse Building 2 was to be installed commencing on 18 August 2021 and finishing on 20 August 2021 (three days). Precast installation was then to follow immediately, from 20 to 24 August 2021 (five days). This indicated a significant lack of progress from Clarke’s 30 June 2021 program. The attached manning schedule showed a crew of three from Orbital Welding plus a crane operator from Cosa Cranes starting from 18 August 2021, with another crew from Complete Projects starting 19 August 2021. Another crew of four from Complete Projects were to arrive on 24 August 2021.
On 18 August 2021, a Newman Expansion Project Weekly Meeting was held. The minutes record “Structural steel crew from SA unable to travel. May be allowed to travel towards end of the month, if no further [COVID-19] case in SA. Orbital working under Ahrens.” Structural steel erection was to recommence on 20 or 21 August 2021, “Once SA resources are re-mobilised, [Clarke] will look into increasing workforce, afternoon shift and multiple work fronts.”
On 25 August 2021, Clarke gave a sixth force majeure notice in respect of “COVID-19 continued border restrictions between SA and WA”, being an update under cl 12.7. Western Australia had recently revised South Australia to a “low risk” jurisdiction but there were continuing restrictions “including a mandatory requirement of 14-day self-quarantine to persons entering Western Australia from South Australia”. Orbital Welding and Cosa Cranes had restarted erection works on site from 19 August 2021, while Complete Projects had commenced onboarding for mobilisation. Ahrens had recommenced works with the external local crew now on site.
Later that day, Mr Vickery sought an update from Ahrens on its program and manning where the Western Australian border was open to South Australia from midnight that night, “Please advise on additional manning from SA and any program improvement this is likely to make.” Ahrens obliged. When compared with Ahrens’ manning schedule of 13 August 2021, it appears that not all of the alternate local labour had, in fact, been available. Nor was the Ahrens’ crew now expected to return to site until 30 August 2021 (three people for cladding) and 31 August 2021 (a further three crew for installing using the overhead crane). By 1 September 2021, Ahrens’ crew was expected back. Mr Vickery provided Ahrens’ program and manning schedule to Mr Viliani. On 9 September 2021, Mr Vickery circulated the monthly report for August 2021. The program detailed a 29 day delay as a result of the Western Australia border closure.
On 22 September 2021, Clarke submitted an extension of time claim to Alinta and Mr Ravi in respect of “COVID Restrictions SA”, being EOT 4. The duration of delay to the works and Practical Completion was calculated to be 36 calendar days from 20 July 2021 to 25 August 2021. The for**ce majeure event was said to have affected the mobilisation of resources to site for installation of Powerhouse buildings. Ahrens’ steel erection crew could not travel to Western Australia from South Australia, due to border restrictions which came into force from midnight on 20 July 2021. On 18 August 2021, as a mitigation measure, a small local crew resumed the installation of the structural steel. On 31 August 2021, site returned to full capacity when personnel from South Australia, including Ahrens’ site supervisor, mobilised to site following relaxation of border restrictions on 26 August 2021. Limited progress was made between 20 July 2021 and 18 August 2021, as the local crew had to familiarise themselves with the work and the required replanning. Clarke calculated a loss of seven days of the 14-day period due to inefficiencies resulting from the force majeure. As this delay occurred during the Powerhouse 2 structural steel installation, which was on the critical path, Practical Completion was delayed by 36 days.

On 14 October 2021, Alinta wrote to Clarke in respect of EOT 1, advising that Clarke’s letter of 22 July 2021 had not caused Alinta to change its position. Alinta considered that an exercise of its discretion to extend time (cl 12.2(a)) was unwarranted, where Clarke had failed to satisfy the conditions precedent to an EOT as stipulated in cll 12.1(b) and 12.6. Without prejudice, and on a strict reservation of rights basis, Alinta maintained that the claim must be no more than 20 calendar days and delay costs should not be in excess of $123,218.12.
On 22 October 2021, the Superintendent wrote to Mr Vickery, copying Mr Shuker, in respect of EOT 4. Mr Ravi noted that the claim was complex as it related to extensions of time arising out of various government orders over a period of time; further information may be needed from the contractor and / or the principal in order to properly assess the claim. Alinta “may also wish to provide submissions in response to the Claim and I invite the Principal to do so within 14 days”. The Superintendent advised that he would reasonably require 30 calendar days in order to assess and respond to Alinta’s submissions. On 29 October 2021, Alinta made submissions in respect of EOT 4.
On 2 November 2021, the Superintendent wrote to Mr Vickery in respect of EOT 1, noting that Clarke had not responded to Alinta’s response of 14 October 2021. Clarke was asked to confirm that it did not intend to make any further submissions on the matter. On 8 November 2021, Clarke replied to the Superintendent, noting that Clarke did not agree with Alinta’s position and reserved all of its rights. Shortly afterwards, Mr Vickery emailed again, advising that Clarke intended to correspond further with the Superintendent and the Principal “in due course”.
On 26 November 2021, Clarke served a notice of claim on Alinta pursuant to cl 34.7 (“Notice of claims”) in respect of Alinta’s failure to grant EOT 1 or EOT 4, where cl 38.2 of the contract provided:

On 11 May 2020, before the contract was executed, Mr Wozniuk had provided Clarke with Alinta’s “Major Hazard Standard Electrical”. This was listed in Item 7(f) of Sch 1 to the contract as “Available Site information”. The standard stated that isolation was the preferred means to manage the hazards of electricity and render electrical equipment safe to be worked upon: cl 7.1.8. Work on electrical apparatus that was not isolated, being "Live Work", had to be approved in writing by five company officers, including Alinta's chief executive officer.
Clarke subcontracted this work to Fredon, which subcontracted the work to Universal Energy Australia Pty Ltd. Universal worked at NPS1 from time to time and thus had some familiarity with Alinta Operations and its facility. On 3 June 2021, Alinta's construction manager, Chris Anderson, provided Clarke with Alinta's procedures for NPS1, “for your reference and Subcontractor Compliance". Mr Anderson’s role was to facilitate coordination between operational and project personnel. Whilst Mr Anderson managed and coordinated the work, he was not involved in operations or electrical engineering issues; those issues were dealt with by separate teams.
Mr Anderson provided Clarke with two procedures. The first procedure was Alinta's “Isolation Procedure". Clause 5.2.1, “When must Isolations be applied?", provided that isolations must be applied for any operation or maintenance task where an individual was potentially exposed to a hazardous energy source.
The second procedure was Alinta's “Permit to Work Procedure", which required contractors to be issued with a General Work Permit before carrying out work. Before issuing a General Work Permit, all potential sources of energy which could impact on the work were to be identified and isolated in accordance with Alinta's “Isolation Procedure", so that work could be conducted safely: cl 4.1.11. It was the responsibility of the Alinta Approved Person (AAP) – being as an Alinta employee trained and competent to conduct isolations – to correctly identify, apply and prove all isolations and correctly document them on the General Work Permit. Further, the AAP “shall … Ensure all required Isolations are in place and correct".
Unsurprisingly, Alinta’s “Major Hazard Standard Electrical”, “Isolation Procedure” and “Permit to Work Procedure” reflected the law of Western Australia. Alinta had overall control of the site, being NPS1. The Work Health and Safety Act 2020 (WA) imposes a primary duty of care on “a person conducting a business or undertaking” to “ensure, so far as is reasonably practicable” the health and safety of those working in the business or undertaking, including providing a safe work environment and safe systems of work: s 19. (Clarke and its subcontractor owed the same duty.)
Further, cl 55(1) of Electricity (Licensing) Regulations 1991 (WA) provides that a person may only carry out electrical work, or cause electrical work to be carried out, on or near an energised part of an electrical installation if certain requirements are fulfilled, otherwise it is an offence. A person carries out electrical work near an energised part of an electrical installation if they may make direct or indirect contact with an uninsulated energised part of the electrical installation in carrying out the work: cl 54A(2). The requirements include a risk assessment undertaken by a competent person, where the risks have been reduced to as low as reasonably practicable, and the work can be carried out safety: cl 55(2). There are some exceptions, but no one suggested that the exceptions applied to this work.
As Clarke’s electrical installation expert, Mr Egan, summarised the position, given that Alinta had management and control of the site, Clarke and its subcontractor did not have authority to carry out any isolations within the relay panel. Both were reliant on Alinta to carry out isolations to the panel and make the area safe. Clarke would be working under Alinta’s supervision and its “Permit to Work Procedure”. Alinta had a primary duty of care to ensure that the electrical systems were isolated and the relay panel was safe to work on.
On 6 August 2021, Clarke, Alinta and Fredon held a “CRAW” meeting. (Mr Egan explained that CRAW means Critical / Constructive Risk Assessment Workshop, where all persons involved walk through the project and identify all potential risks so that control measures can be implemented to eliminate the risk, or reduce the risk to as low as practically possible.) The minutes record:

Mr Egan explained that 110VDC is extra low voltage, in a range which carries a low risk of dangerous electrical shock. For extra low voltage, covers are considered to be adequate risk protection. From the minutes, it appeared to Mr Egan that the only electrical risk identified in this CRAW was the 110VDC at the bottom of the protection panels.
Following the CRAW meeting, on 18 August 2021, Alinta performed various isolations in respect of Relay Panel 7405 and the relay room. A “Group Isolation List” was implemented by Alinta’s Ben Cope under Permit to Work No 49445. I take these to be the “secondary isolations” referred to in the minutes.
Fredon’s Mr Albone then prepared a methodology for the works, together with Darryl Wade of Universal, entitled “Methodology for secondary wiring of new protection relays in NPS1 66kV relay house and termination of new control cabling in the relay house and field”. The first version of the methodology was circulated in September 2021 for comment.
For some months, Clarke and Fredon then communicated about the scope of works and the methodology. It is apparent from the numerous emails that precisely what needed to be done was a little unknown, where the works involved an existing facility. The up to date configuration of the facility appears not to have been well documented. None of the people preparing to do the work were on site during the course of their preparations, to check exactly what they were dealing with.
Alinta had provided Clarke with drawings in the Reliance Information. But Clarke’s electrical engineer, Pavel Bohacik, said that, in his experience, Clarke would not be able to identify the necessary isolations from the drawings alone. It was necessary to conduct a physical inspection to confirm the accuracy of what was shown in the drawings, especially for works that were to be performed on potentially live electrical components. This was because sometimes relevant drawings were not provided or were not kept up to date.
Mr Egan wholeheartedly agreed. Given the age of the panel, Mr Egan said “you’ll find that lots of things were put in there that may not have been on the drawings. They would have had to go into those panels … and actually verify it by use of a … multimeter to verify there’s voltage there”. Clarke would have to get a Permit to Work from Alinta and would have to be under supervision going into the panels, “These panels actually fed a number of different supplies and [it] wouldn’t be difficult … if you caused a failure and a trip, you’d actually lose power supplies out to some of the mines which is a fairly expensive proposition if that were to occur.”

On 17 February 2022, Clarke provided Alinta’s Mr Anderson with a SWMS prepared by Universal to remove and replace relays. Clarke’s Electrical Construction Superintendent, Mr Weinel, added further comments on the SWMS and Revision 1 of the methodology, noting that it did not address decommissioning. Mr Albone replied, “What about decommissioning? … As they are not currently energised and cannot be energised due to the Alinta [high voltage] isolation. Please clarify.” It would appear that Mr Albone understood that, as a consequence of the isolations performed by Alinta on 18 August 2021, that Relay Panel 7405 was completely isolated. Mr Weinel forwarded the CRAW minutes and noted, “Terminal protection related to the live 110V DC in the bottom of the panel.” Mr Albone met with Clarke’s Mr Weinel and Mr Bohacik, who pushed for additional detail in the methodology. Fredon asked Universal to review and update the methodology.
On 19 February 2022, Alinta’s Mr Anderson also provided comments on Universal’s SWMS. Alinta suggested that Universal consider whether the relays had been incorrectly installed, including considering the latest For Construction drawings. Universal was asked whether insulated mats would be used to protect against the bottom of the panel. On 26 February 2022, Alinta also provided comments on Revision 2 of the methodology including “Identifying live equipment in the panel once isolations are applied, isolation list will need to be prepared.” Alinta’s comment suggested that the isolations performed on 18 August 2021 had not completely isolated Relay Panel 7405.
On 27 February 2022, Clarke’s Mr Weinel asked his colleagues to arrange an engineer to be present for the relay room works, where Universal was due to mobilise to site on 7 March 2022 and had “requested engineering assistance due to the complex nature of the works”. Clarke arranged for its principal electrical engineer, Brian Ghorbanian, to check the settings at the relay house.
On 2 March 2022, Alinta’s Mr Anderson circulated Alinta’s comments on Revision 2 of the methodology, noting that the SWMS was suitable. In respect of the proposed sequence of works in the methodology, Alinta suggested for step 7, before inspecting access to the work area, “Ensure insulation barriers are in place for any potential live components.” For step 8, “test for dead at the panel”, Alinta suggested, “[Clarke] to identify required isolation.” Clarke promptly provided an updated version of the document, addressing Alinta’s comments.
As to Alinta’s comment on the methodology – that Clarke was “to identify required isolation” – Mr Egan said that it was unusual that Clarke or its subcontractor Fredon was asked to prepare an isolation list required for this work, due to the complexity of relay room electrical systems, particularly in a power station. The electrical control systems in power stations were highly complex and required a deep understanding, which should be held by the persons operating and managing the powerhouse and transmission schemes. The relay panel, and the systems within the relay room, were highly complex systems. Alinta was familiar with those systems, while Clarke’s subcontractor had only restricted access to the relay room and panel. Mr Egan added, “I have never seen it on a job where the contractor was left to their own devices, it’s always been managed by the overall owner. This is a very expensive plant and Alinta overall should be managing all of that with all of them together.” The contemporaneous records indicate that Alinta may have taken this unusual step because Alinta Operations was “busy”: see [384].
On 3 March 2022, Clarke provided Fredon with Alinta’s comments, noting, “It has been made clear by [Alinta] today that no corners will be cut in the relay room works due to the high risk and outcomes if there is an accidental trip.” Mr Albone forwarded Alinta’s comments to Universal for prompt attention. Universal immediately obliged.
A ‘walk-down’ was then had with Clarke’s Mr Ghorbanian, Alinta’s Mr Anderson and Fredon’s Mr Albone. Mr Albone explained that the purpose of a ‘walk-down’ is to inspect the existing facility so as to properly design and plan the works to be performed. Mr Anderson said that walk-downs had an operational person present if available. Apparently, no one from Alinta Operations was available. Later that evening, Mr Albone reported to Mr Vickery and Mr Weinel:

It is not entirely clear from Mr Albone’s email whether he reassured Mr Anderson “that there is no risk of electric shock as the panel is completely isolated from other parts of the relay house” or whether that assurance was given by Mr Anderson. As Mr Albone recalled it, during the ‘walk-down’ he told Mr Anderson, “this is the relay panel we will be working on and we need everything in the relay panel to be isolated”. (Mr Anderson accepted that Mr Albone may have said that, but he could not recall.) According to Mr Albone, Mr Anderson said, “That’s fine … yeah that panel can all be isolated” and, further, that Relay Panel 7405 was isolated from other supplies in the Relay House. But within the next few days, Mr Anderson told him that the fuse holders in the relay panel were unable to be de-energised, as they contained live wiring that linked between Relay Panels 7400 to 7409, that is, other panels in the relay room.
Mr Anderson did not recall making the statements attributed to him. Nor did he turn his mind to these events until four years later. Mr Anderson said that such statements would have been inconsistent with his role at the time, as he did not have the technical knowledge or authority to confirm whether the relay panel could be fully isolated. As a construction manager, he had little to no understanding of what equipment was in any particular relay panel, the extent to which that equipment could be isolated without affecting the equipment in the relay room, or the extent to which such equipment could be isolated without requiring a plant shutdown.
I prefer Mr Anderson’s evidence on this subject, as it is corroborated by the contemporaneous documents: see [366], [378]. Both before and after the ‘walk down’, Mr Albone appears to have been of the view that Alinta’s isolations performed on 18 August 2021 had completely isolated Relay Panel 7405, as a consequence of which the methodology was adequate and works could proceed. Alinta’s comments on the SWMS and methodology indicated that it was not so sure. Mr Anderson was in no position to say one way or the other.
Mr Albone also recalled that, during the ‘walk down’, Mr Ghorbanian “opened a couple of relay panel doors and then wasn’t allowed in there after that”. This is corroborated by the contemporaneous documents. Mr Bohacik later jested with Mr Albone by email as to whether Mr Ghorbanian was “still opening panels” to which Mr Albone replied, “Look it’s been hairy in the relay room when we were looking at the works but Alinta aren’t wigging out anymore and realise we know what we are doing. [Mr Ghorbanian] isn’t allowed in the relay room anymore [at] Alinta request …”. What was also decided on the ‘walk down’ was that the best way to install the new relays would be to attach a new fixed hinge door to store the relays, as there was not enough room in the existing panel.
In giving his opinion, Mr Egan did not know whether Clarke had actually inspected the relay panel but presumed that they would have had some look at the system, albeit fairly limited, when compiling information for their methodology. That does appear to have been the case. What was not revealed on this limited inspection was that some of the supplies that fed into Relay Panel 7405 came from the adjacent panels. As Mr Egan described it, “They go through what they call a daisy chain of loops of the same cabling so it loops in and loops out of that particular panel. They didn’t have access to [other panels than panel 7405, with the consequence that] they wouldn’t have been able to tell which cables were actually feeding in there and which ones weren’t.” Mr Egan added, “It’s a quite complex interlinked system and Clarke Energy and Fredon only really had access to [Panel] 7405, they didn’t have access to the rest of the … panels in the room [of] which there are numerous panels. So these were all interlinked, interconnected.”
On 4 March 2022, Mr Albone emailed Universal, “Can you also add a note [to the methodology] that there is no access to live parts as the relay house panel has barriers over any potentially live parts”. Mr Albone further emailed Universal in respect of Alinta’s comments, adding “I’ve walked the route with Alinta and [Clarke] to prove that there is no access to anything potentially live. And they now understand what we are doing I think the biggest issue is they don’t understand what we are doing and what we are [not] doing. Now they do I’m hoping we can continue once we re-submit …”
Later that day, Mr Albone provided an updated methodology to Clarke, addressing Alinta’s comments. As to the proposed sequence of works, Alinta’s comment is italicised and Mr Albone’s response is underlined:

Permit to Work No 49445 referred to the isolations performed on 18 August 2021. Again, Fredon and, thus, Clarke were proceeding on the basis that the isolations completed after the CRAW in August 2021 sufficed.
On 5 March 2022, Clarke provided the updated methodology to Alinta’s Mr Anderson, together with the spreadsheet setting out how each of Alinta’s comments had been addressed. Mr Albone sought direction from his manager as to how to proceed, given delays in the issue of a General Work Permit for the relay house works, adding “This morning we were advised that when we pull the new cabling in to go to the relay house … we cannot install the cabling into the panels in the relay house until Alinta Engineering approve. (Operations are [not] sure what is happening with this)”. He informed Clarke likewise. Mr Albone later updated his manager, “After talking with [Alinta] [O]perations they will not raise a permit until [Alinta] projects have a site engineer check the works over prior to commencement which … will take a few weeks to action.” It appears from Mr Albone’s updates that it was unclear whether Alinta Operations or Alinta “projects” would be checking the proposed works.
On 6 March 2022, Clarke’s Mr Weinel returned the methodology to Fredon for further work, describing the document as “substandard”. Mr Albone replied, “Noted, Chris [Anderson] seems to think these works won’t be proceeding for a couple of weeks? … [O]perations … have said projects need a project engineer to monitor the works ([Alinta] projects have deemed the works high risk) [and] [O]perations are busy with other works within the power station”. Alinta’s Mr Anderson also provided further comments on Universal’s SWMS, relevantly:
for risk control measures in respect of “Preparation of work area and task”, Alinta added, “Confirm Isolations with Alinta Operations …”; and
for risk control measures in respect of “Removal and Installation of Relays”, Alinta commented “No risks mentioned of potential live components in cabinet and controls”.
On 7 March 2022, Clarke provided Alinta’s comments to Fredon, noting that, as Universal was now on site, “it will be the ideal opportunity to close out these items”. Mr Albone asked Universal to action Alinta’s comments as soon as possible. Alinta’s Mr Shuker also provided comments on Revision 3 of the methodology, noting that it was important to clearly document the demolition scope “so we can assess any disruption risk on the operating power station”. Clarke was asked to finalise the methodology, SMWS and Job Hazard Assessment (Risk Assessment) (JHA), with “Alinta to implement required isolation and issue [Permit to Work] (2-3 days from final methodology/SWMS and JHA)”.
It will be recalled that 9 March 2022 was the Date for Practical Completion. Although Clarke had submitted EOT claims, Mr Ravi had not determined these claims. The day came and went. Clarke’s Mr Ghorbanian provided an update to his colleagues from site, reporting that Alinta had signed off the permit for the relay replacement inspections and checking. The permit from Alinta to start replacing the relays was awaited. Universal was soon to leave the site. Photos were supplied of the relay panel, including a photograph of the isolations already performed, “under isolation now”. I take this to be a photograph of the isolations that had been performed in August 2021. Mr Ghorbanian explained the need for a new door.
On 9 March 2022, Mr Albone provided Clarke with an isolation list, “we have worked on this with the Alinta engineers so we shouldn’t get any push back with this!” Mr Albone also circulated a revised methodology, “[Clarke] will need to get the isolations approved by Alinta … If this methodology gets knocked back then I have no idea what they want …” Presumably, Universal had been able to progress this whilst on site and the isolation list and revised methodology reflected its engagement with Alinta. Where Mr Anderson had asked Universal to “Confirm isolations with Alinta Operations …” and Universal was then on site, it is likely that the isolation list provided by Mr Albone had been “worked on” with Alinta Operations’ engineers.
On 18 March 2022, Clarke’s Mr Weinel circulated the revised methodology and isolation list for review, noting that Mr Bohacik had said there were some incorrectly referenced drawings and isolations to be checked. Mr Bohacik advised that he had checked the documents and “all seems OK”. Clarke updated the program, now noting that the relay house installation works by Fredon and Universal would start on 11 April 2022 and finish on 17 April 2022 (seven days).
On 21 March 2022, Clarke provided the revised methodology (now Revision 5) and isolation list to Alinta for review. The documents and comment sheet was provided to Alinta’s Mr Shuker, senior electrical engineers Kirk Reeve and Nik Walker, senior mechanical engineer Mr List and senior electrical and instrumentation engineer Yadi Kaler. Comments were sought by 28 March 2022. The “Proposed Sequence” was as follows (amendments underlined):

Alinta contended that the conditions precedent in cl 12.1(b)(2) and (3) had not been met. The Western Australian border closure was for four days. The South Australian border closure was for seven days. Each border closure was a separate and distinct event. (This contention was not mentioned in Alinta’s closing submissions and I take it not to be pressed.) Alinta submitted that the “hard border closure” referred to in Clarke’s letter of 11 August 2021 followed an announcement of a Western Australian Government Agency which, although not referred to in Clarke’s letter, was publicly available and published on 22 July 2021. Clarke did not issue a cl 12.6 notice in respect of this announcement within 15 Business Days of the announcement (that is, on or before, 11 August 2021) and, as such, Clarke did not comply with the condition precedent contained in clause 12.1(b)(2) of the Contract. The delay caused by that announcement ceased on 18 August 2021. That being so, the letter dated 22 September 2021 was not sent within the time required by cl 12.8, where 20 Business Days after 18 August 2021 was 15 September 2021. It was said to follow that Clarke did not comply with cl 12.1(b)(3) either.
Here, Alinta focused on one government announcement amongst many, which may have the consequence that the fifth of six delay notices was given out of time. But the announcement of a Western Australian Government Agency referred to by Alinta is not in evidence. Alinta provided a link to the announcement in its written submissions. I can take judicial notice of matters set out in s 143(1) of the Evidence Act 1995 (NSW), including an Act, regulation, rule, by-law, proclamation, order or instrument of legislative character made under an Act. To see whether the announcement met this description, I followed the link to find an announcement by the Western Australian Department of the Premier and Cabinet. This does not fall within s 143(1) of the Evidence Act. Nor can I be sure that this is what Mr Vickery had in mind when drafting his letter of 11 August 2021. He does not refer to this announcement in the letter. Nor was Mr Vickery asked about this in cross-examination. The suggested non-compliance with cl 12.1(b)(2) fails for want of evidence. For completeness, the fifth notice was an update on delay under cl 12.7. Service of such a notice within a particular timeframe was not a condition precedent under cl 12.1 in any event.
Nor has Alinta proved when the delay caused by that announcement (which is not in evidence) ceased. The suggestion that the delay caused by the COVID-19 measures referred to in Clarke’s six notices ceased on 18 August 2021 is not made out either. The fact that Ahrens’ structural steel crew was then unable to travel from South Australia was recorded in the minutes of the Newman Expansion Project Weekly Meeting on 18 August 2021. Clarke and Ahrens’ efforts to keep things moving using local labour are well documented. Mr Vickery noted, in his letter of 22 September 2021, that the site returned to full capacity on 31 August 2021. That accords with Ahrens’ manning schedules. The EOT claim was made well within the 20 Business Days required by cl 12.8. The conditions precedent are satisfied.

The next question is the duration of the delay. Clarke claimed to be entitled to an extension of time to the Date for Practical Completion of 27.5 days. Alinta contended that the Works were not delayed during some or all of the period of alleged delay. Works were able to and did progress using local Western Australian resources. Workers returned to site and worked on and from 18 August 2021.
Mr Griffith was Clarke’s delay expert and Ms Halloran was Alinta’s delay expert. They agreed on the calculations. The only difference was the assumptions each made. It is sufficient to set out how Mr Griffith approached the task, and to note where Ms Halloran disagreed with that approach.
Mr Griffith noted that cl 12.1(b)(1) required that the Extension Event must delay one or more activities on the critical path to Practical Completion. In his opinion, it was not necessary for the activities to be on the critical path prior to the Extension Event. The activity must either be on the critical path or become critical as a result of the Extension Event. Mr Griffith explained that the critical path is the longest path that connects a series of activities from commencement to Practical Completion. Any delay to an activity that is on the critical path will cause a delay in achieving Practical Completion. There are other paths that connect activities that are not on the critical path, which may be delayed for a period of time before their completion is critical to achieving Practical Completion. This amount of time is known as “Total Float”. Once the Total Float has been consumed, the delay event becomes critical and commences delaying Practical Completion.
The first step was to choose a baseline program. Mr Griffith explained that, by adopting a program updated to account for actual progress just prior to the commencement of the Extension Event as a baseline, any prior delay is accounted for in the analysis. He confirmed that the baseline program was an accurate representation of Clarke’s actual progress at the time of the delay and that planning for future works was reasonable and achievable, and that the baseline program was otherwise suitable for use in his analysis.
The second step was to introduce the delay event into the baseline program. Mr Griffith added delay events which represented the effects of the Extension Event to the baseline program to create an impacted program. Where necessary, he added additional logic to the delay activity which he considered necessary to correctly and accurately model the impact of the delay event on Practical Completion. He then determined the extent of delay to Practical Completion by comparing the forecast date of Practical Completion in the baseline program as compared with the impacted program.
Third, where Mr Griffith’s assessment showed that concurrent delay had occurred, he deducted any period over which critical delay to Practical Completion would have occurred in any event. Fourth, he assessed whether Clarke had complied with its obligations to mitigate in cl 12.12.
Mr Griffith’s time impacted analysis indicated that Practical Completion was delayed by 29 days due to the events associated with EOT 4, but he reduced the delay to 27.5 days in light of Ms Halloran’s analysis. Mr Griffith split the periods of critical delay into two delay periods. Delay Period 1 was from 20 July 2021 to 17 August 2021, being 21 days of critical delay. (Ms Halloran agreed with his assessment in respect of this period.) Delay Period 2 was a further seven days from 18 to 31 August 2021, being 6.5 days of critical delay, on the assumption that the temporary crew arranged for this period was about half as productive as Ahrens’ specialist structural steel crew would have been if available.
For Delay Period 2, Ms Halloran considered that there were nil days of delay if the temporary crew had the same productivity as the Ahrens crew. If the temporary crew was half as productive as the Ahrens crew, then she calculated 5.5 days, as it appeared that Ahrens’ structural crew returned to site on 30 and 31 August 2021.
Alinta’s Daily Site Reports for 30 and 31 August 2021 recorded six Ahrens personnel on site each day for “Structural Scope”. Mr Griffith was unable to confirm whether the Ahrens’ crew were steel erecters or the cladding crew. In any event, his assessment was based on an assessed average productivity of approximately half over the full period of delay. This assessment was not affected if it was found that an Ahrens structural steel erection crew mobilised to site on 30 and 31 August 2021.
Alinta submitted that there was insufficient evidence of lower productivity. According to Alinta’s Daily Site Reports for 30 and 31 August 2021, installation of structural steel was ongoing for Powerhouse 1 and Powerhouse 2. This was ahead of schedule for Powerhouse 1. It was said to be unhelpful to point to the percentage of work completed in Powerhouse 2 as an indicator of productivity, where work was occurring in both powerhouses. But this submission relied on a subsequent program, for September 2021, and items relating to cladding, not structural steel.
Further, Alinta submitted that any lack of productivity may be explained by delays in the procurement of the steel and defects in the steel for Powerhouse 2, which had to be re-worked. Alinta relied on an email of 30 July 2021 from Mr Viliani to Mr Kain, reporting that steel for Powerhouse 2 (P5 steel) was being held for “re-work”. But while Alinta focused on Mr Viliani’s comment, “We are holding P5 for re-work to the stairs”, his email as a whole detailed extensive delay on the critical path then being encountered. Mr Kain had asked for “any update on the additional WA labour that you are looking?” Mr Viliani advised that Complete Projects had provided the most positive feedback on having labour for steel erection and cladding install “to help us out until our own guys can return. I am expecting an email any minute on their capacity.” When read as a whole, the contribution of a “re-work to the stairs” on P5 to the problems being encountered appears de minimis.
I think Ms Halloran’s ‘nil’ assessment for Delay Period 2 can be put to one side. Ahrens’ experienced work teams would surely erect structural steel on a project of this complexity and scale more efficiently than the local workers that Ahrens was able to secure. The contemporaneous emails from Ahrens’ project manager indicate that the local labour was less than ideal, but Ahrens made do with what they had: see [330].
This leaves me with a debate about whether Delay Period 2 should be 5.5 days or 6.5 days. Ahrens’ manning schedule of 26 August 2021 suggests that the crew to arrive on 30 August 2021 were for cladding. A further three crew to arrive on 31 August 2021 were to work on installation using the overhead crane. The contemporaneous records do not reveal whether Ahrens’ crew who got to site on 30 and 31 August 2021 were from Ahrens’ structural steel erection crew or not. It does not matter on Mr Griffith’s analysis. His assessment seems fair and reasonable. Clarke is entitled to an extension of 27.5 days. No delay costs were sought.

As earlier mentioned, Clarke had updated the program on 18 March 2022, with Fredon and Universal to commence the relay house installation works on 11 April 2022. On 6 April 2022, Clarke’s Mr Weinel sent Revision 6 of the methodology to Alinta’s Mr Shuker and Mr Reeve again, noting that the methodology would need to be updated “to cover the I/O locations when drawings issued and [Alinta] approved”. I take this to be a polite follow up.
Clarke was also waiting on the new door**.** On 12 April 2022, Clarke’s Commissioning Manager – EPC, Steven Granger, pressed Mr Weinel as to when the relay house works were scheduled to commence. It was hoped that Fredon would be completed by 4 May 2022, when another activity was scheduled to commence, being pre-commissioning the new power station. On 13 April 2022, Mr Vickery replied that the new door would be ready by the end of the next week, “Allow a week to site, it should be there by end of April. Suggest booking Universal in for first week of May. 3 days work. Is cutting it fine but I don’t think its realistic to book any earlier.” Mr Weinel provided Fredon with Revision 7 of the methodology and requested that Universal attend site in the first week of May 2022.
On 26 April 2022, Clarke’s team had a site catch up. The notes of the meeting record that most of the preparation for the relay room works had been done. The door had been received, “works now urgent to be completed”. Clarke’s Mr Weinel arranged for relay room gear in Adelaide to be couriered to site.
On Wednesday, 27 April 2022, a Newman Expansion Project Weekly Meeting was held. Alinta’s Mr Anderson was an apology for this meeting. But other Alinta personnel who had been copied on Clarke’s previous emails in respect of these works and the methodology were present: Mr List, Mr Kelly, Mr Kaler and Mr Reeve. Alinta’s Head of Construction, Mr Knill, was also in attendance. Clarke’s Mr Weinel reported that the panel for the relay room work had left Adelaide. Further, “Universal planned to be on site next week, to be confirmed. Alinta may require 2 weeks’ notice to arrange a permit. Universal has a small window, otherwise work will be delayed. [Mr Weinel] to send an email today to Alinta after Universal visit is confirmed with all documentation for the work”.
The minutes appear to record a ‘to and fro’ between Clarke and Alinta in respect of these works, with Clarke wishing to proceed as soon as possible and Alinta suggesting that more time was needed to arrange a permit. The “2 weeks’ notice to arrange a permit” was obviously much longer than the “2-3 days” earlier indicated by Mr Shuker: see [385]. Clarke pressed the point, where Universal had limited availability and the works would otherwise be delayed. The meeting appears to have concluded on the basis that Mr Weinel would confirm Universal’s availability and provide Alinta with “all documentation” for the work. Another problem was that, despite Clarke having circulated the methodology and responded to Alinta’s comments on it some time earlier, and despite a polite follow up, Alinta had not responded further on the documentation.
After the meeting, Fredon confirmed that Universal could be available for the relay house works from 2 to 6 May 2022. Mr Weinel advised Mr Reeve accordingly. Mr Bohacik would be on site “to supervise works in line with the methodology submitted (rev 7)”. Mr Weinel sought “to ensure all parties are aware and the issuing of [Alinta] permits is not held up”. Beyond referring to the current version of the methodology, Mr Weinel did not attach any documents to his email.
On 28 April 2022, Fredon communicated with Clarke as to who was bringing what materials to site. On 29 April 2022, Fredon advised that some of the material, such as labelling, would not be able to be obtained in time, where the labels had changed since the original tender.
At 5.09 pm on Sunday, 1 May 2022, Alinta’s Mr Anderson provided upcoming work methodologies to his colleagues, Mr Primer and Alinta’s Operations & Maintenance Supervisor, Glen McGovern, copied to Mr Knill, for upcoming works that week. These included relay house works by Universal on 2 May 2022, that is, the next day. The attached Revision 7 of the methodology included the isolation list (referred to as Attachment 1, albeit not well labelled) and the SWMS. The Proposed Sequence remained the same.
Early on Monday, 2 May 2022, Alinta’s Mr McGovern emailed Mr Anderson and Mr Primer, copied to Mr Knill, “Can you please advise who is the approving project engineer for the methodology and which project engineer will be overseeing the works in a QA/QC & technical capacity?” Mr Anderson asked Mr Kaler to assist if Operations required assistance in a QA / QC and technical capacity but noted, “This has already been reviewed by Projects to date …” Mr Knill also forwarded the methodology to Alinta’s senior electrical engineer, Mr Walker, suggesting that he have a chat with Mr Anderson about Fredon’s proposed timing.
So far as the evidence reveals, Alinta’s Mr Kaler did not provide assistance. Nor did Alinta’s Mr Walker speak to Mr Anderson about Fredon’s proposed timing. Rather, at 11 am on 2 May 2022, Alinta’s Mr McGovern issued a General Work Permit for “Bay 7405 – relay house relay replacement – cabling terminations”. Universal’s SWMS was attached to the permit. The General Work Permit noted that an isolation list was not attached. Mr McGovern apparently did not appreciate that the isolation list was included in the methodology.
Mr Egan said that, by issuing the Permit to Work, Alinta advised that all isolations had been carried out and the area was safe to work in, complying with Electricity (Licensing) Regulations, cll 49(1)(d), 54A and 55. Alinta was obliged to reduce the risk to as low as reasonably practicable by isolating low voltage electrical components and conductors. Mr Egan was of the view that Alinta had not complied with all relevant legislative requirements at the time. And that was clearly the case. Alinta had not completed any further isolations in Relay Panel 7405 since August 2021, nor checked the isolation list, nor implemented the isolations in that list. Nor did the AAP even think that they had the isolation list when issuing the Permit to Work.
At the time, Mr Bohacik understood from the methodology that the relay panel would be dead, that is, there would not be any electrical current flowing through it, except for the live cabling which was protected by a physical barrier. Mr Egan agreed that Point 13 of the methodology confirmed this.
Mr Albone did a ‘walk-through’ of the relay room with Alinta’s Mr McGovern and Universal’s Mr Wade, to inspect the isolations. According to Mr Albone, Mr McGovern said that Alinta had not performed all of the isolations in the isolation list, and there was live cabling in the relay panel. (As I understand it, no isolations had been performed since August 2021.) Further, Alinta would not perform the remaining isolations as they would cause an issue elsewhere in the relay room. Alinta needed more time and potentially a shutdown or outage to effect these isolations. Fredon was asked to proceed to perform the work with live cabling in the work area. Mr McGovern showed them which cables were still live in the panel (being the blue cables in the earlier photograph).
Mr Albone refused to perform the work without all of the isolations being completed. He said that it would have been dangerous as they could easily have come into contact with the live cabling, given how small the panel was and how close the live cables were. Mr Albone believed at the time that this would have been contrary to the regulations; there was a high potential that they would be exposed to an electric shock. The live cabling included cables which were in Fredon’s work area and above where the protection barrier was to be placed above the fuse holders.
There was some debate between the experts as to whether Mr Albone should have acted as he did. Alinta’s electrical installation expert, Dale West, considered that Clarke was in a position, on 2 May 2022, to employ further engineering measures to reduce the hazards to their personal satisfaction and did not require access to any switchgear or other locations outside Replay Panel 7405, nor tools or PPE that was not readily available to an electrician working on an industrial site. Mr West said that Mr Albone “could have used a school wooden ruler”. Although Mr West said the panels were “very narrow”, and most of the wiring in the panel was single insulated, a lot of electricians would do the job with no tape at all. He did accept, however, that if Mr Albone decided not to proceed with the work then “it’s up to them to then decide, ‘I don’t like it. I’m going to cover that’, and that’s perfectly fine. … You can’t force them to do the job, … on their risk assessment they then determine what they can do”.
Mr Egan considered that Fredon’s decision to stop work showed that they knew what they were doing. If Fredon had proceeded to carry out the work, an offence would have been committed. There was a large number of live low voltage electrical conductors and components in the panel. The probability of contact with these live conductors and components while carrying out electrical installation was extremely high. The clearances and space between the exposed terminals and single insulated cables was extremely close. Contact with these items would be unavoidable. That could have resulted in a fatal electric shock. I strongly preferred Mr Egan to Mr West where their views differed, given his obviously greater expertise and objectivity. I note that Alinta did not refer to Mr West in its closing submissions.
Soon afterwards, Mr Albone’s manager emailed Mr Weinel:

Further, Mr Anderson stated that carrying out electrical work on or near energised electrical installations was standard in industry practice in an operational setting with appropriate safety and risk mitigation in place. Clarke was asked to ensure that it had a representative attending the pre-start meeting to ensure that contractors and Clarke were adequately informed of daily operations and safety discussions.
Mr Weinel replied, advising that Alinta “have not yet completed the secondary isolations as per the CRAW”. Further, “While not a Fredon task they have produced an isolation list which was submitted as part of the methodology. As you will see from the isolation list Fredon have provided solutions for the isolations.” But Fredon had not been able to move past step one on the approved methodology, nor could work commence until the secondary isolations were in place “and from my understanding the isolations are not able to be put in place due to [Alinta] resource[s] not being available. There will be no electrical work carried out in live panels.”
Alinta resisted Clarke’s approach, also noting “Currently works cannot be conducted without materials on site.” Mr Anderson suggested that Fredon had revisited the methodology, where there was said to be inconsistences between Revision 2 and Revision 7. Clarke was said to have made no reasonable attempt to ensure that the relay board was in an acceptable state for their contractor. Steps 12 and 13 in the Proposed Sequence were said to be contradictory, as was Clarke’s statement that there would be no electrical work carried on in live panels. Alinta’s Permit to Work was suspended until Clarke and Alinta came up with a way forward. Mr Weinel replied that Fredon was complying with the regulations in Western Australia, specifically, cl 55(5) of the Electricity (Licensing) Regulations. Mr Anderson rejoined that he had no concerns with Fredon complying with the regulations or raising a safety concern, but Alinta would provide feedback. Further, “Please advise when all materials are on site to conduct the works.”
More constructively, that afternoon, Alinta’s Mr Walker began to provide comments on his review of Universal’s methodology, noting that some methods could not be used. In particular, removing and replacing test blocks could not be done unless Alinta isolated the “Protection” VTs in the switchyard, “More work required to determine what systems need to be bypassed to achieve this.” Clarke also incorrectly proposed to use test block terminals 13 and 14 for a Current Transformer but the OEM (Original Equipment Manufacturer) “clearly states that these terminals must not be used for current transformers”. A design issue was noticed, “with power supply to the remote IO units that will need to be rectified”.
On the morning of 4 May 2022, Mr Walker reported the results of his further investigations to his colleagues, suggesting that it was likely that Alinta needed to turn off the BSS for a couple of hours to make the VT [voltage transformer] wiring disconnection within Relay Panel 7405. Diesel generators would need to be used to cover the majority of the load. Alinta’s Mr Anderson passed the comments from Alinta’s engineering team onto Mr Bohacik, ahead of a collaborative walk through the next day.
Mr Albone said that these design comments should have been raised by Alinta much earlier during the design phase. (I agree.) To the extent that Mr Walker suggested that some isolations in the isolation list were unable to be undertaken, Mr Albone said that the list was prepared based on Alinta’s drawings and Mr Anderson’s comments. If there was some issue with Alinta’s ability to perform any of these isolations, he would have expected Alinta to raise this before 2 May 2022. (I agree.)
On 5 May 2022, the courier delivered the new panel door to Newman. Alinta’s Mr Anderson conducted a ‘walk-through’ of the “Relay Room Isolations Concerns”, following which he emailed the parties identifying the agreed next steps:

Mr Egan said that Mr Albone should probably have attended the collaborative ‘walk-through’, where the relay room isolation concerns were discussed, “They probably should’ve been there, yes. … I couldn’t understand why they just walked off the job. I would have expected them to help contribute and help sort this out. That didn’t happen.” To be fair to Mr Albone, Fredon did not “just walk off the job”; he sought instructions from Clarke (twice) as to whether to remain on site or demobilise.
On 6 May 2022, Alinta’s AAP Kurt Wilson signed an isolation list, confirming that various connections in Bay 7405 had been permanently disconnected. Mr Vickery confirmed agreement with Mr Anderson on the next steps for the “Relay Room Isolations Concerns”, noting that further isolations to be applied by Alinta were in progress and aimed to be completed over the weekend. The critical issue now was the availability of Universal, which apparently had no resources available until the end of the month but had significant resources working for Alinta. Mr Vickery enquired whether it was possible to secure at least one technician “as this will impact the project critical path”.
Mr Anderson said that he would look into it and, on Saturday, 7 May 2022, sought confirmation from Mr Vickery that, if Universal were to provide a technician the following week, then the works would be achievable in the desired timeframe. Mr Vickery confirmed that that was his understanding. Fredon had confirmed that they would relocate Mr Albone and another back to site to assist, “Looking at the program this has already hit critical path but I need to work through with [Mr Granger] to see if we can pull back anything else to maintain the engine commissioning dates.”
On Monday morning, 9 May 2022, Alinta’s Mr Anderson advised Clarke’s Site Manager (Electrical), Tony Marchant, of further isolations and non-conductive barriers to be installed by Alinta, to prevent inadvertent contact or access to live equipment. Clarke was asked to advise whether that was acceptable to Fredon so that Alinta could plan to execute the works. Mr Marchant asked Mr Albone to review and advise if this satisfied his concerns with working in the panel.
But Fredon was not amenable to what Alinta had done, or proposed to do, as there was still live power in the relay panel. Fredon advised that, as there was still live cabling in the panel that they could potentially come into contact with, it could not complete the works until this was resolved, providing the relevant guidelines from the Department of Mines, Industry Regulation and Safety. Mr Albone did not believe that the work would fall under any of the categories that would deem working in the live panel acceptable.
Alinta’s Mr Anderson promptly arranged an online meeting at 7 am on 10 May 2022 to discuss Relay Panel 7405. Following the meeting, Alinta’s Mr Walker criticised Clarke to his colleagues, suggesting that Clarke was simply passing on Fredon’s concerns rather than engaging with the problem. Clarke’s initial design was said to have been deficient, as Clarke did not consider modifying equipment built pre-1996 nor methodically review the design and construction of the existing equipment. Mr Walker considered that Clarke’s design was “still wrong” and Clarke’s reliance on “a one-liner in a CRAW [was] poor form”. All of Mr Walker’s observations, if apt, would have been more useful if conveyed earlier in the design process, but his view does appear to have infused Alinta’s treatment of Clarke’s EOT claim which followed.
Fredon was not particularly happy either, emailing Clarke after the meeting and setting out what they needed from Alinta so that Fredon’s company directors could decide whether Fredon could proceed with the works safely with confidence that there was zero potential for harm by electrical sources to its workers due to the isolation process and procedures provided by Alinta. Specifically, Fredon needed:

Mr Knill’s “push back” did not have a proper foundation, where Alinta had yet to identify the necessary isolations to make the relay room safe. On 13 May 2022, Alinta’s Mr Walker provided a review of the drawings submitted by Clarke, which he suggested was incomplete. (Mr Bohacik said that most of the drawings had, in fact, been provided to Alinta.) Mr Walker proposed changes to the circuit breaker failure function wiring to allow them to get a functional system, “without having to shut down the Power Station”. But Mr Walker also proposed to provide a reason as to why Alinta needed to propose changes to the design, being the lack of notice by Clarke to prepare isolations. Mr Walker’s view was that Clarke “haven’t submitted a complete design that is ready to be implemented and as a competent EPC contractor, should have been all over these brown-fields integrations activities much earlier in the project”. I have to say that the same comment could be directed at Alinta Operations’ electrical engineers, including Mr Walker.
On 13 May 2022, Mr Vickery embraced Alinta’s offer to release Universal from maintenance work to attend to these works. Fredon readily agreed that Clarke could engage any contractor they wished to complete the work. Emails continued between Clarke in relation to updating the drawings on the methodology, prompting Clarke’s electrical design draftsperson, Scott Freeborn to comment, “What a circus!”, and Mr Vickery to reply, “Yep, no one owning it.” Mr Freeborn rejoined that there were drawings which were “out of date, duplicated, in need of new revision, not on the document register all within their rev 8 methodology”. Mr Vickery noted that the methodology was done by Universal, who did work for Alinta “and I can only guess they may have referenced drawings they got directly from Alinta”.
On Saturday, 14 May 2022, Alinta’s Mr Anderson advised Clarke’s Mr Marchant that they may have some resource support available from Universal in the coming week and asked when Clarke wished to conduct the works in Bay 7405. Mr Anderson attached a six page document describing, with photographs, how each of the sources of electrical energy to Relay Panel 7405 could be isolated or shrouded.
Numerous emails also passed between Clarke and Alinta, proposing numerous amendments to the methodology. On 19 May 2022, Alinta’s Mr Anderson advised his colleagues that he and Mr Walker had walked through and reviewed the methodology, which was acceptable for issue. Works commenced later that day. Industrial electrical contractor, PHE Pty Ltd, performed the work, having been released by Universal from work for Alinta Operations.
On Saturday, 21 May 2022, PHE advised Clarke that panel wiring in the relay house was progressing well, although the latest drawings now had interposing relays which they did not have on site. The required wiring for these relays would be sourced from Brisbane and should be on site on Wednesday, 25 May 2022.
On Sunday, 22 May 2022, Alinta’s Mr Walker and Clarke’s Mr Bohacik discussed the Bay 7405 secondary works. Mr Walker later reported to his colleagues that, as of Sunday afternoon, Clarke did not have the parts to complete the relay panel works. Clarke was missing links for the circuit breaker fail scheme and auxiliary relays for the bay status and auto synchroniser control, “It is unclear to me how they can claim a delay when they don’t have the parts available to complete and commission the works …” (I suppose that one reason might be that the works were now different, since Alinta Operations’ engineers engaged with the methodology.)
On Monday, 23 May 2022, Mr Walker asked Mr Bohacik to advise when the parts were expected. Mr Walker found some of the parts in Alinta’s warehouse and offered to provide these to Clarke to allow progress on the relay panel works. Mr Egan said that at the time, “we’re at the end of COVID, the supply chain was atrocious. … Alinta had the relays in … stock … they were lent to [Clarke] on the basis they replace them when they come in, that’s a common practice in industry … at that time getting anything in and out of the north-west was extremely difficult”.
On 25 May 2022, Clarke provided Alinta and the Superintendent with an update on the delay to the relay room works and its impact to the critical path. Works were able to commence late on 19 May 2022 and were in progress. The estimated duration of the delay was 18 days, with 17 days impact to the critical path. Due to the delay, Fredon was no longer available. Clarke transferred the work to PHE, who were already on site, thus enabling the works to commence expediently and mitigating remobilisation costs, “We thank Alinta Energy for redirecting a Universal Energy resource who was assigned to works for Alinta Operations.” The Extension Event was no longer continuing to delay Practical Completion and a claim would be provided in due course.
On 17 June 2022, Clarke made a claim for extension of time in respect of “Relay room works delay to critical path” for 17 calendar days to Practical Completion (being EOT 11). Delay costs of $201,290 were sought.
By now, the superintendents had not granted Clarke’s various requests for an extension of time. EOT 1, EOT 4 and EOT 11 totalled 185 days of delay. The contractual date for practical completion remained 20 April 2022. Mr Vickery said the superintendent’s failure to give decisions in a timely manner created a challenge from a project management perspective. In the absence of a decision in relation to EOT claims, Clarke needed to make a commercial calculation as to whether it should commit additional resources to the project, at substantial cost, in order to try to make up time, or risk a liquidated damages claim arising out of a delay to practical completion. Mr Vickery took this up with Mr Columbus and others.
Mr Columbus said that he was in regular contact with Alinta’s Mr Thomas, given that the superintendents had not granted the EOTs. Given Clarke’s obligation to mitigate any delay, Mr Columbus was of the view that Clarke needed to accelerate the works in order to bring the project to completion and minimise the risk of potential liquidated damages. With this in mind, he decided that it was necessary to bring on additional resources to accelerate the works. He arranged for commissioning technicians from Clarke Energy UK to attend site and assist with the commissioning phase of the works.

Clarke contended that Alinta was contractually responsible for undertaking these isolations: Sch 3, cl 1.4.5; Alinta’s “Permit to Work Procedure” and “Isolation Procedure”. Alinta was also required, as a matter of law, to ensure that as far as reasonably practicable the health and safety of other persons carrying out work at NSP1 was not put at risk from work carried out (s 19, Work Health and Safety Act), and not to cause electrical works to be carried out on or near an energised part of an electrical installation unless an exception in cl 55(2) of the Electricity (Licensing) Regulations applied.
Clarke contended that, at the CRAW meeting on 6 August 2021 and the ‘walk-down’ on 3 March 2022, Alinta represented that it would undertake the isolations to the relay room; everything in the relay panel could and would be isolated before works began. (I have not found that Mr Anderson made that representation.) Save for advising Fredon shortly after the ‘walk-down’ that the fuse holders in the relay panel were unable to be de-energised, that remained the position. Alinta’s comments on Revision 4 of the methodology asked Clarke to identify on the drawings the boundary of the decommissioning of the existing relays, to allow Alinta to isolate and make safe the panel. Clarke did so in Revision 6 of the methodology, which also stipulated “there will be no live components near our work area” and “place physical barrier above fuse holders at the bottom of panel 7405 as a preventative measure where live cabling exists” to deal with the fuse holders.
In anticipation of carrying out the works, Clarke submitted Revision 7 of the methodology, under which Alinta was to issue all permits and implement all isolations within the relay panel prior to work commencing in the relay room: items 1, 3, 12 and 14. This did not happen. Clarke contended that Alinta’s failure to undertake all necessary isolations prior to work being undertaken in the relay room on 2 May 2022 was a breach of the agreement by Alinta, as well as a negligent act or omission, giving rise to a Compensation Event. Clarke claimed an extension of time of 17 days and delay costs of $400,588.97.
Alinta denied making the representations in the CRAW meeting or the ‘walk-down’ on 3 March 2022. It was Clarke who identified the isolations that Clarke required to be performed in Relay Panel 7405. It was Clarke that failed to comply with the contract: cl 9.1. Each of Clarke, Fredon and Universal were also required to comply with ss 22(1), 26 and 46 of the W**ork H**ealth and S**afety Act. (Clarke accepted this.) Clarke’s methodology was said to be defective, as it did not identify all required isolations. As pleaded, Alinta undertook the isolations required by Revision 7 of the methodology, but those isolations were insufficient. In its closing submissions, Alinta acknowledged that no other isolations were performed by Alinta between 18 August 2021 and 2 May 2022.
Alinta submitted that it was given little notice of the fact that the works were to be performed on 2 May 2022. While Revisions 5 to 7 of the methodology were provided to Alinta on 21 March 2022, 23 March 2022 and 12 April 2022 respectively, those revisions were never returned with comments or otherwise approved by Alinta. Nor did Clarke seek Alinta’s comments before arranging for Fredon to attend site on 2 May 2022. Clarke was said to have breached its obligations under cl 9.1 to coordinate this work with Related Activities: cll 9.1(a), 9.2(b)(3). Notifying Alinta of its intention to perform the relay panel works informally in a site meeting less than a week before the works were scheduled to commence, followed by an informal email that did not attach “all documentation for the work”, was not “planning”, “programming” or “notice” within the meaning of cl 9.1(b).
Further, Alinta contended that Clarke was responsible for the risk assessment of the works. Clarke’s control measures did not require any de-energisation of the existing relay panel. Fredon refused to undertake the works in circumstances where either Clarke’s methodology was deficient or Fredon misconstrued the application of the Electricity (Licensing) Regulations. Any critical delay was caused by Clarke, or there were concurrent delays for which Clarke was responsible and for which it failed to take all reasonable steps to mitigate delay. Alinta further contended that Clarke did not provide panel drawings for the relay room works until 24 May 2022, and had not procured the parts and components to complete the relay room. In particular, the new door did not arrive until after the period of delay. At all times, Clarke’s methodology was said to be defective and incomplete.
Further, Alinta submitted that, after 2 May 2022, there was a need for the parties to collaborate to determine the way forward. But Clarke permitted Fredon to demobilise from the site. As a result, Fredon was not present at the collaborative walk down on 5 May 2022. The parties then agreed on the isolations to be performed but because Fredon was not there, its agreement was yet to be secured. Alinta performed the isolations on 6 May 2022. Fredon rejected the isolations agreed between Clarke and Alinta on 9 May 2022. Clarke arranged for Universal to perform the work instead. This meant that Universal needed to be consulted in respect of, and agree, the isolations that had been performed; this occurred on 14 and 15 May 2022. It was wrong to suggest that further isolations were required to be performed on Relay Panel 7405 on 19 May 2022. The three isolations performed on 19 May 2022 were in the list circulated on 14 May 2022. There was no reason for Alinta to perform these isolations ahead of Clarke being ready to perform the relay room works.
Clarke rejoined that it prepared an isolation list at the request of Alinta. The drawings available to Fredon did not identify the presence of cables running from the adjacent panels. Revisions 3 to 6 were checked and approved by Alinta in circumstances where it alone knew of the cables running from the adjacent panels, or had the means to obtain such knowledge. It was only when Revision 8 was published that the fact that the cables ran into Relay Panel 7405 from adjacent panels was recognised. A breach of cl 9.1 had not been established. The design issue was quickly remedied once raised. (Not really; Clarke did not issue Revision 8 with this amendment to the drawings until 17 May 2022.)
Clarke submitted that cl 12.12 restated the general law test of mitigation: J Edelman, McGregor on Damages (20ed, 2018, Sweet & Maxwell) at p 225 [9-004]. The dangers of retrospectivity were explained by Lord Macmillan in Banco de Portugal v Waterlow & Sons Ltd [1932] AC 452 at 506; see also Karacominakis v Big Country Developments Pty Ltd [2000] NSWCA 313 at [187] (Giles JA, Handley and Stein JJA agreeing). Alinta bore the onus of proof: TCN Channel 9 Pty Ltd v Hayden Enterprises Pty Ltd (1989) 16 NSWLR 130 at 158E (Hope JA, Priestley and Meagher JJA agreeing); Wenkart v Pitman (1998) 46 NSWLR 502 at 504, 520-523, 535 (Powell JA, Mason P and Sheppard AJA agreeing). (Alinta did not suggest otherwise.) Clarke submitted that the onus had not been discharged.

The issue is whether the events in relation to Relay Panel 7405 gave rise to an Extension Event, specifically, a Compensation Event.
As to whether there was a breach of contract by the Principal, the contractual provisions cited by Clarke – being cl 1.4.5 of Sch 3 – imposed obligations on the Contractor. While Alinta’s standards and procedures called for compliance by Alinta (and others), non-compliance with the standards and procedures was not necessarily a breach of the contract. I am not satisfied that there was a Compensation Event by reason of Alinta’s breach of its standards and procedures.
Was there a negligent act or omission of the Principal, giving rise to a Compensation Event?
Alinta’s action in issuing a Permit to Work in the circumstances was, I think, a negligent act or omission. On Sunday afternoon, 1 May 2022, Mr Anderson provided Alinta Operations’ Mr McGovern with the methodology, including the isolation list and SWMS. Mr McGovern does not appear to have appreciated that he had the isolation list. On 2 May 2022, Mr McGovern issued a permit to work nonetheless. According to what Mr McGovern told Mr Albone, Alinta was aware that isolations had not been completed and that there was live cabling in the panel. Mr McGovern suggested that Mr Albone continue to work on the panel anyway. The contemporaneous records support Mr Albone’s recollection of what Mr McGovern said. While Alinta Operations was critical of Mr Albone for declining to work in the relay panel, in light of the expert opinions of Mr Egan and Mr West, those criticisms were ill-founded.
Mr Egan and Mr West ultimately agreed that it was Alinta who was required to isolate the existing board in the relay room before Clarke could undertake the relay house works. Mr Egan considered that, in order to comply with its statutory obligations under the Work Health and Safety Act and Electricity (Licensing) Regulations, Alinta should have reviewed the methodology and inspected the workplace before issuing a permit to work. The document attached to Mr Anderson’s email of 14 May 2022 indicated that 240V and 110V was present within the panel. That level of voltage was unsafe and could cause an electrical shock to an individual. In order to make the workplace safe, these voltages were required to be isolated, that is, “switched off, locked out and danger tagged”. Mr Anderson’s email also showed that there were no issues in isolating the electrical supplies into Relay Panel 7405. But Alinta failed to do so before 2 May 2022, when the relay house works were due to commence. I am satisfied that there was a negligent act or omission by Alinta.
But the real question is whether it was this negligent act or omission which delayed Practical Completion: cl 12.1(a). The fact that Alinta issued a General Work Permit in the circumstances was negligent. When Mr Albone was informed that the isolations had not been completed, he (appropriately) declined to proceed with the works. But even if Alinta had completed the isolation list, the same problem would have resulted. This is because the isolations on that list were insufficient in any event.
And why was that? The isolation list had been prepared by Fredon and Universal based on the drawings they had, and with some consultation with Alinta Operations’ engineers after the initial ‘walk down’ in March 2022: see [387]. But why was Fredon preparing the isolation list at all? Mr Egan said that it was most unusual for a power station to ask a contractor to prepare an isolation list, as opposed to taking responsibility for that task itself. This reflected the complex and expensive nature of the equipment, together with the fact that the relay panel was 25 years old. Subsequent alterations, modifications, repairs and ‘tweaks’ may not be properly documented. That is, Alinta Operations gave a task which it should have done to others where, ultimately, only Alinta Operations was in a position to do it properly.
Whether Alinta’s failure to engage with the isolation list earlier, or at all, was negligent is less obvious. Alinta certainly owed a duty to those coming onto its site to perform electrical work, to ensure that the electrical systems were isolated and that the relay panel was safe to work on. Issuing a Permit to Work on the relay panel without having attended to these matters was a negligent act. But I am not satisfied that Alinta’s duty extended to focusing on that task in any particular timeframe. I am not satisfied that Alinta’s failure to engage with the isolation list before 2 May 2022 was a negligent act or omission within the meaning of the contract.
Was Alinta’s conduct an “act or omission … except to the extent … the Principal … is acting in accordance with this agreement; or … caused or contributed to by the Contractor’s failure to comply with cl 9.1 (if applicable)”? Here, the focus is on Alinta’s engagement with the methodology and isolation list before Fredon and Universal attended site to undertake the work. Alinta delegated the task of preparing the isolation list to Clarke and its subcontractor. Alinta failed to engage with the isolation list earlier, or at all. Clarke’s subcontractor came to site to undertake work, on the basis that the isolations had been implemented. I consider that Alinta’s conduct in this sequence of events falls within the description of an “act or omission”. It was an “act or omission” which delayed the work as, once it became apparent that the isolations had not been done, the work could not be performed. Further, even if the isolations in the list had been implemented, those isolations would have been insufficient to make the area safe to work on, for reasons already given.
The next question is to what extent Clarke caused or contributed to that act or omission by its failure to comply with cl 9.1. Specifically, did Clarke fail to coordinate the performance of the Work with the performance of Related Activities, including by planning and programming the performance of the Work to avoid or minimise any impacts on the performance of the Related Activities (cll 9.1(a)(3), 9.1(b)(3)) or notifying Alinta in writing before performing Work which had the potential to impact on the performance of the Related Activities (cl 9.1(b)(5))?
The experts agreed that all parties had responsibilities for planning the work, and adequate planning did not appear to have occurred, either before or after 2 May 2022. But Clarke had been engaging with Alinta for months in respect of the methodology. Since the ‘walk-down’ on 3 March 2022, Clarke had submitted a number of revisions and isolation lists, addressed Alinta’s comments, and followed up Alinta for its comments. There appears to have been a lack of engagement with these works by Alinta Operations, where Alinta Operations was “busy with other works within the power station”: see [384]. There appears to have been a lack of coordination between Alinta Operations and Alinta’s project team as to who was finalising these documents.
So far as Clarke knew from Mr Shuker’s email of 7 March 2022, Alinta needed two to three days to implement required isolations and issue a Permit to Work “from final methodology / SWMS and JHA”: at [385]. The problem was achieving final documentation, where that depended on Alinta responding to the documentation submitted. Was Clarke to just keep waiting until Alinta Operations had time to have a look at the documents which had been sent their way, repeatedly? There was no mystery that these works had already been delayed. At the Newman Expansion Project Weekly Meeting on Wednesday 27 April 2022, Clarke pressed to proceed with the works. Whilst Mr Anderson was not at the meeting, his colleagues were. They do not appear to have progressed the matter in his absence, nor made him aware of the proposed works until Sunday afternoon.
Nor did Alinta Operations implement the isolation list or tell Clarke that the isolations would not be implemented before the arrival of its subcontractor. Fredon’s trip to site was going to be a waste of time and money, but nobody bothered to tell Clarke. Overall, I consider that Clarke and its subcontractor did enough to encourage Alinta Operations to engage in the methodology and isolation list. In these circumstances, I consider that there was a Compensation Event under para 3 of the definition. I am not satisfied that Clarke failed to comply with cl 9.1. When one works through the interstices of the events in respect of Relay Panel 7405, I think it is Alinta’s acts or omissions which ultimately resulted in the relay panel works being unable to proceed on 2 May 2022.
Alinta submitted that there were concurrent delays. First, Clarke never allowed itself enough time to perform the Relay Room Works. Fredon would be on site from 2 to 6 May 2022. Allowing for travel, that left 4.5 working days. (I agree.) But it took 7 working days to perform the Relay Room Works, between 19 and 25 May 2022. Fredon would always have had to come back to the site to complete that work in the next roster window, being 11 May 2022. There would always have been a delay between 6 and 11 May 2022 (2 Working Days).
I do not accept this submission for three reasons. First, when the relay room works were finally undertaken in late May 2022, the General Work Permit was issued at 3.30 pm on 19 May 2022 and closed at 8.50 am on 25 May 2022. Work was undertaken for two hours on 19 May 2022, all day on 20, 21, 22, 23 and 24 May 2022, with another hour on 25 May 2022. This is 5.5 days, not 7 days. That is one additional working day to the time allocated when the works were originally planned on 2 to 6 May 2022 (4.5 days). But Practical Completion would not have been delayed by the additional working day: cl 12.11(a). Clarke had one day of float left for this activity before the activity came on to the critical path.
Second, Alinta’s submission relied on a site roster dated 8 May 2022, that is, prepared after the works were aborted on 2 May 2022. I think this provides an unsteady foundation for a counterfactual as to how Fredon would have undertaken the work absent the Extension Event. The “next roster window” on this manning schedule shows Mr Albone travelling back to the site on Wednesday 11 May 2022. But those were the dates that Fredon made him available after the events that had previously unfolded.
Third, the Extension Event was Alinta’s failure to engage with the methodology and isolation list in a timely manner, or at all, such that the methodology was not finalised and the necessary isolations had not been implemented before Mr Albone arrived on site on 2 May 2022. The correct counterfactual, I think, is that Fredon would have been aware of the final methodology and allowed enough time to complete it. Given the additional expense and delay in leaving and returning to site, I expect travel arrangements would have been made to enable Mr Albone to stay in Newman and complete the works, if not on the Saturday, then on Monday, 9 May 2022 before returning to Adelaide. Mr Albone was not asked whether, if the works took a day long than planned, he could have stayed on site for a further day.
Alinta further submitted that the methodology contained a defect until Revision 9 issued on 18 May 2022. Clarke designed the new works in the test blocks such that there were terminations for the transformer circuit transformer signals in terminals 13 and 14. The OEM specified that terminals 13 and 14 were not to be used as current transformer signals as, to do so, created a safety hazard. This was raised by Alinta on 4 May 2022.
Clause 12.1(c)(2) provided that the Contractor’s entitlement to an extension of time will be reduced to the extent that a Defect caused or contributed to the delay to Practical Completion or the Extension Event that caused it. As I understood it, the methodology was said to contain such a Defect. Clause 1.1 defined Defect as:

I do not consider that an error in the methodology meets this description. The definition is concerned with a defect in the Facility “or other matter or thing relating to the Facility”. The methodology was a plan for how works would be undertaken on the Facility in a safe manner.
If I am wrong about this, then Clarke accepted that the methodology had design issues and errors, as ultimately identified by Alinta’s Mr Walker. But that was the point of the process of exchanging the methodology and seeking comments. The fact that Alinta Operations did not engage in that process until after Mr Albone found that “this panel is live” meant that these issues could not be resolved until a Compensation Event had occurred. I do not consider that Clarke’s entitlement to an extension of time should be reduced on this account.
The next question is whether Clarke’s entitlement to an extension of time should be reduced to the extent that the delay could have been avoided or mitigated. From his review of the documents, it appeared to Mr Egan that the first time that Clarke or its subcontractor was aware that Relay Panel 7405 was live was on 2 May 2022. Information regarding the correct isolations for the electrical components was only made available on 14 May 2022, “Alinta had no idea what they had and had to deal with, and it took them a number of days to work out what they had to isolate”.
Mr Egan observed that Alinta’s initial emails involved deliberating, “trying how to work out how to get the isolations done … these are extremely complex electrical systems. They’re not the usual run-of-the-mill type of equipment you run into and its fairly specialised in working out what actually feeds the panels. Very complex”. Mr Egan said, “After … they found these additional supplies feeding in there, … there was a lot of deliberation over the following days to try and work out what supplies were going in there. … these were very complex systems and I don’t really think they had a grasp, either Alinta or the guys had a grasp of exactly what was in there”.
It does appear to have taken Alinta some time to work out exactly what isolations needed to be performed, and how. It was not until 14 May 2022 that a comprehensive list of isolations was circulated. Mr Egan explained that, once the final isolation list was at hand, the works would not have been able to be carried out until after the methodology was reissued to Revision 8 on 17 May 2022. Alinta approved this methodology on 19 May 2022 and work began later that day. The contemporaneous documents indicate that Clarke went to considerable lengths to solve the problem, including engaging another subcontractor. The fact that Mr Albone did not stay on site for the collaborative ‘walk-down’ on 5 May 2022 does not change this. I do not see how his presence would have shortened the period of delay. I am not satisfied that Clarke failed to mitigate any delay to the Works.

The delay experts agreed that the relevant program was that of 30 April 2022. The relay house installation works were scheduled to commence on 2 May 2022 and finish on 7 May 2022 (six days). Where Mr Egan and Mr West agreed that it was reasonable for Clarke not to commence work on Relay Panel 7405 until 19 May 2022, the delay experts agreed that there was 16 days critical delay. Both agreed that there was also one day loss of float. (The delay experts differed in their treatment of the loss of float.) Mr Griffith and Ms Halloran agreed that there was insufficient information to allow them to determine what effect, if any, the lack of planning and liaison contributed to delay.
Ms Halloran’s agreement to 16 days critical delay was premised on the assumptions that: works could otherwise have started by 3 May 2022, with any materials obtained from Perth the same day or overnight; the door was delivered on 5 May 2022; and, work on the door would have involved 10 hours of work once it arrived.
Mr Albone said that, if the labels referred to in his email of 29 April 2022 were not available, then Fredon’s workers would have been able to use temporary labels instead and this would not have held up the work. The labels could later be replaced with more permanent labels without any need for isolations to be performed. Mr Egan and Mr West agreed that late delivery of the door would have had little to no impact on the work. Mr Albone also said the missing links ultimately needed for the job were a common ‘off the shelf’ electrical item most likely able to be provided by an electrical wholesaler in Perth. If the links were not on site, they most likely would have been able to have been air freighted the same day or overnight from Perth. As such, the assumptions made by Ms Halloran are supported.
Mr Griffith’s approach to calculating the duration of delay was earlier described at [413]. For EOT 11, Mr Griffith concluded that the baseline program showed that the relay house works activity was forecast to start on 2 May 2022 and had one day total slack, that is, it was one day off the critical path and became critical on 3 May 2022 as a result of delayed commencement of the works. Based on his time impacted analysis, Clarke was entitled to 16 days extension of time due to being delayed in achieving Practical Completion by the events the subject of EOT 11. Ms Halloran agreed with this.
Based on an assumption that Mr Griffith was instructed to make – that any extension to the Date for Practical Completion was to include any amount of float in any Work activity delayed – he concluded that Clarke was entitled to a further one day extension of time as a result of loss of total float on the activity delayed by the Extension Event.
Mr Griffith said there were two types of float in a program, being float (or free float), that is, the amount of time that an activity can be delayed without delaying successor activities, and “Total Float”, being the amount of time that an activity can be delayed without delaying Practical Completion. Mr Griffith determined the reduction in Total Float by comparing the Total Float in the baseline program and the impacted program. Where Total Float existed on an activity which was affected by an Extension Event, then in addition to the extension of time due to the delay to Practical Completion, Mr Griffith allowed an extension of time for any reduction in Total Float.
Ms Halloran did not agree with this. Ms Halloran noted that the contract required, as a condition precedent to an extension of time, that the Extension Event delayed one or more Work activities on the critical path for Practical Completion: cl 12.1(b)(1). It was only when the float on an activity was reduced to zero that the activity would be on, or come on to, the critical path such that Practical Completion would be delayed if the activity was delayed further.
Alinta submitted that the float for this activity was “activity float” and no extension should be allowed on that account given Ms Halloran’s opinion. Until an activity was on the critical path, such that Practical Completion would be delayed if the activity was delayed further, the contractor would be on site for the same length of time as originally planned. A contractor would not incur any additional costs associated with being on site. Allowing an EOT for the loss of “activity float” would, effectively, entitle Clarke to compensation for losses that would never occur. The position was different where there was a loss of “Total Float”, where the contractor’s forecast date for Practical Completion was earlier than the Date for Practical Completion. But there was no such float in this case.
Clarke submitted that when an activity becomes critical and is further delayed, entitling a Contractor to an EOT, the activity float that existed prior to the activity becoming critical is lost to the Contractor as a direct cause of the delay event. Consequently, if the Contractor suffers later delay of whatever cause, for which it is not compensated by way of an EOT, its duration on site is prolonged by the loss of that float through no fault of its own, causing it to incur additional costs and potentially exposing it to liquidated damages. Because Clarke’s time on site was longer than planned, including periods for which it had not claimed an EOT, and that time was extended because of the loss of activity float associated with EOTs, Clarke contended that it suffered increased time related costs as a result of the loss of float.
As to how to deal with the loss of float, I have concluded that Clarke ‘owned’ the float. As such, Clarke is entitled to the benefit of the float which existed from time to time, by reference to the program and the Date for Practical Completion: V601 at [876]. But, as Alinta submitted, Mr Griffith noted that none of the programs which he relied on for his time impacted analysis contained positive Total Float between the forecast date of Practical Completion (as at the time of the Extension Event) and the Date for Practical Completion.
I do not think that the assumption that Mr Griffith was asked to make is supported by the contract. Clause 12.1(a) provided, “if Practical Completion has been delayed by an Extension Event, the Contractor is entitled to an extension of time to the Date for Practical Completion equal to the duration of the delay”. That is, it is only delays to Practical Completion that are relevant. If an activity is delayed but that activity is not on the critical path, then a delay in that activity will not result in a delay to Practical Completion (unless the delay brings that activity on to the critical path and, further, has the consequence of delaying Practical Completion).
Consistently with this, it is a condition precedent to an extension of time that “the Extension Event delayed one or more Work activities on the critical path for Practical Completion”: cl 12.1(b)(1). Likewise, cl 12.10 sets out the principles to be applied “When determining whether and by what period an Extension Event has delayed Practical Completion”. In short, the contract does not apprehend that an extension of time for delay will include additional days to restore any loss of activity float. (In any event, the one day of activity float was probably used rather than lost, as the activity took a little longer than planned.) It follows that Clarke is entitled to an extension of time of 16 days for EOT 11.

Should the contractor be awarded delay costs for lost days of activity float? No. Clause 12.4(a) provides, “if the Date for Practical Completion is extended under clause 12.1 for delay to Practical Completion … the Principal must pay to the Contractor the reasonable additional costs and expenses directly incurred by the Contractor as a result of that delay.” The delay costs are only in respect of the delays to Practical Completion, not costs associated with additional days to restore any loss of activity float.
The delay costs sought by Clarke for EOT 11 were labour costs, flights, accommodation, equipment hire and contracted services, bank guarantee costs, materials and subcontractor margin and subcontractor overhead recovery. Clarke’s quantity surveyor, Mr Cox, assessed this claim at $401,072.31, including one day of float, or $379,445.76 if the day of float was excluded. It is the latter figure that should be considered.
In assessing labour costs, Mr Cox had regard to a spreadsheet prepared by Clarke in support of EOT 11, collating staff who were engaged on each day of the delay period, the portion of their time devoted to the relay room works, hours worked and their hourly rate. Mr Cox reviewed Clarke’s time sheets for the period.
As to the hourly rate used in the spreadsheet, Mr Cox had regard to a schedule of labour rates accompanying EOT 1. In Clarke’s letter in support of EOT 1, Clarke advised, “The rates … represent Clarke Energy’s internal direct costs”. On 4 June 2021, Mr Vickery responded to the Superintendent’s request for further information, “We wish to clarify that due to privacy and confidentiality obligations between Clarke Energy and its employees, we are unable to disclose information relating to employee salaries. The hourly rates for Clarke Energy employees are based on salaries plus direct on-costs.” On 24 June 2021, Alinta submitted that the labour costs were inadequately substantiated. On 22 July 2021, Mr Vickery asked Alinta “to confirm what would work on the understanding that actual wages will not be disclosed – with a view to setting an agreed schedule of rates”.
So far as the evidence reveals, a schedule of rates was never agreed. But Mr Cox considered that the rates for the positions in the schedule appeared reasonable and in line with market expectations, given his experience of the typical day-to-day tender evaluation process that he oversaw in his offices. He calculated labour costs for EOT 11 using the rates in the schedule at $314,919.85.
Ms Halloran agreed with Mr Cox’s calculation of labour costs, but not the premise. Ms Halloran used payroll data and calculated an hourly rate for Clarke staff that included payroll tax, workers compensation insurance and long service leave accrual. She considered that this accorded with cl 12.4. The cost of the time-related resource was not to be changed by applying a rate that was different, or in addition to, the actual cost. Ms Halloran considered that this method provided a better representation of the actual costs incurred by the contractor. Ms Halloran also excluded labour costs where the person was assessed as performing a non time-related or direct work-related role. For EOT 11, Ms Halloran calculated labour costs at $152,626.35 while Mr Cox, using the same approach, arrived at $161,640.65.
Mr Cox considered that his approach to labour costs was more appropriate. Whilst Ms Halloran offered a basic salary reimbursement, all employment benefits needed to be considered in establishing an actual labour cost. A number of further employment benefits would need to be considered in establishing an appropriate cost. Mr Cox listed a number of on-costs, which can add a considerable increase to a base salary without considering other indirect on-costs. He added that the use of an agreed hourly rate for supervisory staff was becoming more common in practice. Mr Cox also included the costs for certain subcontractors engaged in a supervisory role who had also been impacted by the delay and on a time reimbursement basis. In Mr Cox’s opinion, these additional costs were incurred due to delay periods occurring as works could not be completed and return visits and associated costs would be required.
Clarke submitted that all of the costs of employment which Clarke had to bear were a direct and natural consequence of the delay. Alinta submitted that Ms Halloran’s approach aligned with cl 12.4, focusing on “costs and expenses directly incurred”, that is, actual costs. The clause focused on “costs” rather than “price”. There was no evidence from Clarke as to how the schedule of rates was arrived at that would satisfy the Court that the rates represented costs actually “incurred” by Clarke.
As to which approach to adopt, cl 12.4(a) obliges Alinta to pay Clarke “the reasonable additional costs and expenses directly incurred” by Clarke as a result of the delay. Ms Halloran considered this to mean “actual costs” and, for labour costs, calculated these costs on, basically, their wage rather than an hourly rate at which Clarke may charge customers for the services provided by that staff member on a job. I do not think that the contract is so parsimonious.
Delay costs are paid where a delay is caused by a Compensation Event. By definition, a Compensation Event is brought about by someone other than the Contractor, being, generally, the Principal: cl 1.1. The delay is not of the Contractor’s making. To the extent that the Contractor caused or contributed to the delay, or failed to avoid or mitigate the delay, then the extension of time and delay costs are reduced accordingly: cl 12.4(c)(1); para 3(b), definition of Compensation Event: cl 1.1.
If the Contractor incurs costs and expenses as a consequence of a delay which, by definition, it did not cause, could not avoid and was unable to mitigate, then commercial parties would hardly expect the Contractor to pass on its costs to the Principal without enjoying the usual margin or economic rewards inherent in the contractual arrangement. The Contractor would not be expected to now provide goods and services on a non-profit basis, absent clear words. And the contract, I think, reflects this, referring to “reasonable additional costs and expenses … directly incurred”. Where Mr Cox considered that the rates in Clarke’s schedule appeared reasonable and in line with market expectations, I will use those rates.
As to flights and accommodation costs, Mr Cox checked that the costs were supported by invoices. He excluded travel costs for arrivals on 18 May 2022. He gave consideration to including travel costs for flights arriving in Newman from 28 April 2022 on, assuming that site personnel directly affected by the delay may not be able to travel on the specific start or end dates due to limitations around access to the site. This timing allowed for dedicated staff to arrive on site to address the issues around the delay and, when they were impacted by the delay, to stay longer. Mr Cox believed this to be a reasonable approach based on his experience of remote sites and the impact that delays can have to travel around specific dates. Mr Cox noted that certain invoices included nominal allowances for re-issuing tickets and penalties. He considered that these were reasonable due to potential changes around travel arrangements that do occur from time to time.
Mr Cox also included accommodation costs for an additional day on either side of the EOT period. He assumed that site personnel directly affected by the delay may not be able to travel on the specific start or end dates, taking into account the same features of remote work sites as for his assessment of flight costs. Mr Cox checked that equipment hire and contracted services costs were supported by invoices. He assumed that any costs during the delay period should form part of the claim. Mr Cox applied a contractor margin to flights, accommodation and equipment hire. The on-cost of 15% was in line with Item 5 of Sch 2 to the contract. Mr Cox assumed that this was a reasonable inclusion in assessing the costs and expenses relating to Work activities delayed, prolonged or disrupted as a result of a Compensation Event.
Ms Halloran pro-rated flights and accommodation costs by the number of days falling within the delay period and only for personnel in time-related roles. Non-time-related charges such as fare differences and reissue fees due to flight rescheduling and airline penalties were excluded, as these costs did not arise directly from the delay itself, but from changes in personnel, availability, scheduling conflicts, or internal travel management decisions. These expenses were considered not to be directly linked to the delay period caused by the Compensation Event.
Ms Halloran took the same approach to accommodation costs and car hire costs. Site equipment hire and contracted services costs were pro-rated to the days falling within the delay period. Only costs directly attributable to such hire or services were considered, excluding establishment costs, or one-off costs. The costs to extend the bank guarantee were allowed, but not the materials and subcontractor margin and overhead recovery.
Ms Halloran understood that “costs and expenses directly incurred" in cl 12.4(a) referred to actual costs incurred as a result of the prolonged period of the project. The cost of the time-related resource was not to be changed by applying a rate that was different, or in addition to, the actual cost. A profit and / or overheads margin percentage was not applied to the additional costs and expenses directly incurred due to critical delay. This could be compared with the allowance for the Profit and Overheads Margin in cl 14.4 for variations. Mr Cox was not persuaded to change his approach to these cost items in light of Ms Halloran’s approach.
As to flights and accommodation, I consider that Mr Cox’s approach is closer to the contractual language. Clause 12.4(a) provides that “the Principal must pay to the Contractor the reasonable additional costs and expenses directly incurred by the Contractor as a result of that delay.” As Finn J noted in GEC Marconi Systems Pty Ltd v BHP Information Technology Pty Ltd (2003) 128 FCR 1; [2003] FCA 50*,* “direct loss and expense … has been equated with loss and expense which flows naturally from the breach and as such are to be equated with losses and expenses falling within the first limb of the rule in Hadley v Baxendale (1854) 9 Ex 341”: at [1170]. There does not need to be a neat correspondence between the period of delay and the date of flights or accommodation for these costs to be recoverable, as long as these costs were a consequence of the delay.
Alinta submitted that overheads and profit were not “costs [or] expenses directly incurred” by reason of the delay and therefore were not recoverable. Clarke submitted that overhead costs often form a significant part of the delay claim and will only be excluded by clear express language: Built Qld at [172] (Morrison and Dalton JJA and Bradley J). The margin is an integer of the replacement cost of the works: Sopov v Kane Constructions Pty Ltd (No 2) (2009) 24 VR 510; [2009] VSCA 141 at [35] (Maxwell P, Kellam JA and Whelan AJA). Mr Cox was correct to opine that the margin reflected a direct cost to Clarke, arising out of its obligation to pay expenses.
The clause considered in Built Qld was closer to the language inherent in Ms Halloran’s approach. Clause 34.9 of that contract entitled the contractor to “delay damages reasonably and necessarily incurred” being “the actual cost incurred by the Contractor” up to a maximum daily amount: at [145]. The contractor was not entitled to delay damages if the costs of delay had already been included in the value of a variation or other payment under the contract. Where the contractor was entitled to a percentage amount for profit and overheads when pricing variations, the principal argued that delay damages could not include an amount for overheads. It was said to follow that the same allowance for overheads and profits was not payable for delay damages. The Court rejected that submission at [172]:

The Technical Rules were set out in Sch 6: cl 1.1. That schedule contains the North West Interconnected System Electricity Network Access Technical Rules. Under these rules, a “Network Service Provider” must arrange for “management, maintenance and operation of the electricity networks such that in the satisfactory operating state, electricity may be transferred continuously at a connection point up to the agreed capability”: cl 1.8.2(c)(1).
Power systems expert, Mr Harvey, explained that ‘network availability’ meant that Clarke required a load to complete the test, that is, for power to be supplied by NPS2. For a power generation facility to be switched on for the purposes of commissioning, it was necessary for there to be somewhere for the electricity to go. That will be either into the network or to a load bank. Mr Harvey noted, “You can warm your hands on the load bank from a fair distance.” The size of the load needed to complete a test depended on the particular test being carried out and, to some extent, the estimated duration of that test. Mr Harvey estimated the total duration of each test which required network availability and then analysed whether the network was available on each test day. In short, on 10 days, network access was delayed or not made available by Alinta.
On the first day of testing, 20 September 2022, two tests were scheduled. Mr Harvey reviewed the Inspection Test Plans (ITPs) for both tests and estimated the time that each would take. The first test, NPS2 Load Control Commissioning ITP, would take 5¼ hours. The second test, “BPCS PLC & RTU16 Interface ITP” was to be done in coordination with the first test. Mr Harvey noted that some of the activities in the second test were prerequisites for the first test. That did not mean that the tests could be conducted concurrently. Rather, Clarke planned to complete as much interface testing as practical before commencing load control testing.
But the tests were not completed. Although commissioning personnel were available to start at 7 am, Alinta did not issue a permit for the test until 1.45 pm. Testing did not begin until 4.50 pm. Fatigue management led to the suspension of testing at 7 pm. The tests could not be completed on the scheduled date. (Mr Harvey assumed that staff were available to begin testing at 7 am based on his experience and by inference from the fact that the industry standard for fatigue management was 12 hours and the workers ceased at 7 pm because of fatigue.) Mr Harvey concluded that Alinta failed to provide network access by delaying commencement of the test until 4.50 pm and preventing its completion on the scheduled date. One day was lost.
On 22 September 2022, an ITP was issued for a test, “NPS2 Facility Compliance Test Plan”. The ITP included 10 tests. Mr Harvey estimated that the time to complete these tests would be some 8.25 hours. But approval for the test was not received until 4.50 pm. Conditions suitable for testing were available for approximately two hours but all six of the tests could not be completed within that time. If the tests were conducted in numeric sequence, tests 1, 2 and 3 likely would have been completed. Testing was suspended at 7 pm due to fatigue management. Clarke was unable to complete the testing in the available time. Mr Harvey was of the opinion that Alinta failed to provide network access to Clarke as required, preventing commencement of the test plan until 4.50 pm.
Two tests were scheduled on 23 September 2022, being the “NPS2 Facility Compliance” which had not been completed the day before, together with “Gas Generator 01-14 Generator for Load Rejection Performance Testing”. The latter test involved five separate tests, which Mr Harvey estimated would take 4.5 hours. But the two ITPs could not be carried out concurrently.
Approval was received at noon for three hours for the first ITP, which was sufficient to commence the test, but a full load was required to complete four of the 10 tests. Insufficient load was available to complete the test when Clarke suspended the test at 3 pm due to travel commitments. Mr Harvey considered it reasonable for Clarke to suspend testing at 3 pm as there was insufficient load and resources to complete either ITP. Six of the 10 tests in the first ITP could be completed with 50% load, and Clarke may have had the opportunity to continue those tests. The unavailability of a full load meant that neither test could have been completed that day, regardless of travel commitments. Mr Harvey remained of the view that Alinta failed to provide adequate network access for Clarke to complete either ITP.
Clarke issued an ITP, “Generator 01-14 Starting Reliability Performance Testing”, which was scheduled for 26 September 2022. Mr Harvey explained that this test involved demonstrating a minimum of 10 consecutive engine starts without failure. In the event of one failed start, the test must be re-started until 10 successful consecutive starts are achieved. He estimated that this required 9.5 hours per generator based on a 100% success rate. No network access was available until 11.30 am and the available load was restricted to 10MW until 1.30 pm, when 15MW was available.
Mr Harvey was of the view that, with this amount of available load, it would be ambitious to run four generators because of the risk that an unrelated load disruption could have halted the test of the other generators. This would mean that any impacted generators would have to start again. It would, thus, be prudent to test three generators in parallel, with a further two generators able to be tested when a further 5MW became available at 1.30 pm. With fatigue management requirements factored in, only three generators could be tested on that day. Mr Harvey was of the opinion that Alinta failed to provide network access as required.
On 30 September 2022, two tests were scheduled, being emissions testing and vibration testing on all generators. The emissions test took some two hours per generator at varying loads over that timeframe. But there was an efficiency advantage available if generators were tested in parallel, such that four generators could be tested in some three hours. That day, network access was available at 7.30 am for 18MW until 11.05 am, when network availability was restricted to 3MW until 1.15 pm, when 4.4MW became available. With these limitations in mind, Mr Harvey concluded that it would have been feasible to complete emissions testing for seven generators on that date.
Mr Harvey calculated that vibration testing for 14 generators would take 10 hours when sufficient load was available to test all generators in parallel. But there was insufficient load to carry out vibration testing on more than four generators concurrently on that date. It would have been feasible to complete vibration testing on 10 generators on that date but not all 14 generators due to insufficient load availability. He concluded that Alinta failed to provide sufficient network access to Clarke.
On 30 September 2022, Clarke wrote to Alinta and Mr Marshall, providing a notice of likely delay under cl 12.5(a) and notice of actual delay under cl 12.6(a) of the contract, due to Alinta not making the electricity network available which was capable of receiving the electricity that the facility was capable of generating. This became EOT 12.

In respect of Auxiliary Plant, Clarke’s expert mechanical engineer, Steve Haddon, explained that auxiliary systems were installed at NPS2 to support the operation of the gensets, including radiators and fans, water pumps, control systems, transformers, electrical systems and ventilation systems. The generator sets cannot operate without the auxiliary systems operating. The electricity used by the auxiliary systems is called “auxiliary load".
Mr Nielsen explained that, when the Net Heat Rate and Net Power Output tests were conducted, Clarke had to represent operation in the ambient conditions prescribed in the contract, being 37°C as measured at the inlet of the air inlet filter. If the Guarantee Test was conducted on a day where the ambient air temperature was less than 37°C, then Clarke forced higher operating levels for fans and auxiliary load. Manually adjusting the speed of fans and the stages of radiator fans contributed to total auxiliary load to replicate what would have occurred under normal operating conditions at an ambient temperature of 37°C.
Mr Haddon agreed with this approach. He said that it is usually the case that performance tests were completed under conditions that did not match the Guarantee Conditions. There was a lot of coordination and preparation required to complete power output and heat rate tests. It is impossible to predict the weather days in advance of a test. It is more practical to complete the tests as planned, and then adjust the test results to the Guarantee Conditions.
As to the point for air temperature measurement, a temperature datalogger was installed behind weather louvres on the generator hall. Mr Nielsen said that, in his experience, the air inlet temperature was consistently higher than outdoor ambient air temperature, as the air inlet measurement point was subject to heat gains from the ventilation system and other equipment.
Alinta submitted that dry bulb ambient air temperature meant temperature as measured outside or in the Newman area, rather than at the inlet of the air inlet filter. As such, the temperatures measured by the datalogger at the air inlet filter did not prove that the Guarantee Condition as to ambient temperature was met. Alinta submitted that Clarke took the same approach for the second Guarantee Test, where temperatures from the datalogger were considered “erratic and un-suitable”.
What the contract required does not turn on what the Contractor may have done during a particular test, to address a particular problem being encountered with a particular piece of equipment. That is post-contractual conduct, and “it is not legitimate to use as an aid in the construction of [a] contract anything which the parties said or did after it was made”: Agricultural and Rural Finance Pty Ltd v Gardiner (2008) 238 CLR 570; [2008] HCA 57 at [35] (Gummow, Hayne and Kiefel JJ); Construction, Forestry, Maritime, Mining and Energy Union v Personnel Contracting Pty Ltd (2022) 275 CLR 165; [2022] HCA 1 at [45]-[46] (Kiefel, Keane and Edelman JJ).
Alinta further submitted that it was for the Court to interpret the contract, assisted by expert evidence as to the meaning of any specialised technical terms: Quasar Resources Pty Ltd v APG Aus No 3 Pty Ltd [2023] WASCA 171. Alinta’s expert technical adviser, Andrew Maynard, said that in the power-generation industry “ambient temperature refers to the … ambient temperature of the site, the ambient temperature of the day in which it has to operate”. The Court should infer that Mr Haddon agreed.
I accept that the meaning of technical terms may be established by expert evidence. I am prepared to infer that Mr Haddon agreed with Mr Maynard’s view as to what ambient temperature meant, although the experts used the expression interchangeably to refer to the temperature outside and the temperature at the contractually specified point for air temperature measurement. But the contract did not simply refer to ambient air temperature. And Mr Maynard accepted as much, when the transcript relied upon by Alinta is set out in full:

This clause envisaged that there may be some level of alarms, standing alarms and warnings during the Guarantee Test. What level of alarms, standing alarms and warnings is “a satisfactory level” is not further explained, save that that level “shall be determined by the Principal.” There was no documentation or consultation as to what that level should be. It seems to have been left to Mr List’s assessment of the situation.
Clause 7 also refers to the equipment “operating as designed within specification alarm limits”. Where the primary focus of the Guarantee Test was on the Jenbacher gensets, I take cl 7 to be referring to Jenbacher’s specifications and instructions in respect of alarms emitted by the gensets.
As to Jenbacher’s specifications and instructions in respect of alarms, Clarke relied on the Jenbacher Operations Manual. Jenbacher uses an engine management and diagnostics platform called DIA.NE (Diagnostics and Analysis) that keeps records of the engine’s operating parameters. The DIA.NE system stores data recordings for every 100 ms. The DIA.NE system produces event logs which record an engine warning (being either a warning or an alarm), the name of the generator which prompted the warning and an alarm code which identifies the nature of the particular alarm. The Jenbacher Operations Manual explains that messages on the DIA.NE logs appear as “trips, warnings and operational messages”. These trips and warnings are categorised according to a priorities list, being Priority 1 alarms, Priority 2 alarms, Priority 3 alarms and Priority 4 warnings.
To elaborate on the significance of alarms and warnings, Clarke relied on the evidence of Mr Cole, who was the Commissioning and Training Manager for Clarke. He managed the commissioning team, which included three certified commissioners and one commissioner in training. Mr Cole has been a certified commissioning technician for Jenbacher gas engines since 2005 and a fully certified electrical and mechanical trainer for Jenbacher since 2016. He audits all Jenbacher certified technicians in New Zealand and Australia. Mr Cole provides training in Jenbacher equipment to both Clarke and their customers worldwide. He manages the field certification program for Clarke technicians. He is a certified commissioner for all Jenbacher engines in Australia. Mr Cole’s training and accreditation is extensive, supplemented by trips to Jenbacher’s main production facility in Austria every two years to maintain his certifications and receive updated training from Jenbacher engineers.
Mr List accepted that Mr Cole had more knowledge of the operation of the Jenbacher equipment, the generators and the machines than he did. That was clearly the case. From 26 to 29 August 2022, Mr List attended a Jenbacher training course conducted by Mr Cole, which covered a basic understanding of Jenbacher’s documents and structures. Mr Cole was not required for cross-examination. I accept his evidence. Further, to the extent that Mr Cole and Mr List’s disagreed, I preferred Mr Coles’ assessment of the situation.
As to Jenbacher alarms and warnings, Priority 1 alarms cause an immediate engine shutdown. Mr Cole said this alarm could indicate that the engine could sustain damage and was usually associated with an emergency event or a risk to operating personnel. Priority 2 alarms cause an engine shutdown after one second. Mr Cole said this alarm posed a lesser degree of risk to the engine and could occur in a range of circumstances but did not pose a risk to personnel. Priority 3 alarms cause a normal shutdown of the engine, which is an automatic shutdown that occurs over a number of minutes, with no risk of damage to the engine.
Mr Cole explained that an engine shutdown did not, alone, impact the reliability of a power station with 14 engines. When one engine shuts down, the power station is designed so that an engine’s load is redistributed among the remaining operational engines. An engine shutdown will only affect the power station’s overall reliability if the load demand is at or near maximum capacity. Mr List disagreed as he considered that the other engines may be susceptible to the same issue and this could “have a material impact on our network because it is a micro grid so we have much less power stability than, say, the Swiss”. I consider that Mr Cole’s assessment of the situation is to be preferred.
Finally, Priority 4 warnings indicate that the engine is approaching a pre-set limit for a parameter. Warnings do not trigger an engine response and have no impact on an engine’s performance. Mr Cole said that there were thousands of parameters for Jenbacher engines, each of which have certain limits called ‘Set Points’. The Set Point is the limit of the parameter and indicates the point at which any increase from the Set Point requires attention. Priority 4 warnings indicate that the relevant engine is approaching, but has not yet exceeded, the Set Point for a particular parameter. Where a Priority 4 warning appears, the engine is still operating within its set parameters and a warning does not impact an engine’s output or availability to be online to generate output. He did not consider a Priority 4 warning as having any bearing on the reliability of an engine or the facility.
Mr List referred to ‘high’ and ‘low’ priority alarms in his affidavit. He accepted that the Jenbacher Operations Manual had a different description of trips, warnings and alarms, but “as an operator of a power station I’ve applied my own opinion of what I consider low or high priority”. The problem with Mr List’s incomplete understanding of Jenbacher’s warnings and alarms is that he appears to have considered these as more serious and concerning than he probably should have at the time. And the contract directed Mr List to consider whether the equipment was “operating as designed within specification alarm limits”, that is, having regard to the specifications for this particular equipment.
Clause 7.1 of Sch 3A described the tests to measure Net Power Output and Net Heat Rate, including that the Performance Guarantee Tests must be carried out “with all engines at 100% load”. Further, measurement of Net Power Output “must account for all normally running auxiliaries loads and normal losses”. As part of the performance testing plan, Clarke was required to provide a list of normally operating auxiliary loads for approval by Alinta, and further:

Mr Haddon and Mr Maynard (and the parties) agreed that the word “not" was missing from the first bullet point in above text. Mr Haddon explained that the adjustment of the auxiliary load related to loads that were not operating when they should be operating or were operating when they shouldn't be operating. Mr Haddon explained that the “nameplate rating” of a piece of equipment is the size, in kilowatts, of an electric motor. The size of the motor on a piece of equipment is determined by the equipment design engineer. The motor is sized such that the motor will never be overloaded through the equipment operating range plus some safety margin. For example, the nameplate rating of each radiator fan was 7.5 kW, but the estimated power consumption of each fan was 6.4 kW.
Clarke and Alinta had different preferences for how to correct the measure of Net Power Output during performance testing for auxiliary loads that would normally be operating but were not running or vice versa. Mr Nielsen ran the fans at 100% so that Clarke did not need to adjust for “nameplate ratings” values, because the auxiliary loads were as they would be (or higher) for conditions operating at the Guarantee Conditions. He considered that this provided a more accurate and realistic assessment of the facility’s performance under the relevant conditions. Mr Nielsen said substituting nameplate values was a theoretical calculation, as the auxiliary load per fan or set of fans was not measured and recorded at such granular details. Mr Nielsen considered that nameplate adjustments could introduce unnecessary disputes with Alinta.
Mr List preferred to use a nameplate rating for all auxiliary loads, which he understood to be typically higher than measured values. This point of difference is the subject of several emails between Mr List and Clarke at the time. I note that the contract indicates the use of nameplate rating as a secondary method to be used only if normally operating auxiliary loads are not available.
The Guarantee Tests were to be witnessed by Alinta. Copies of the raw test data from the Guarantee Test had to be handed over at the time of testing, with evaluated test results to be submitted to Alinta for approval within seven days of the test: Sch 3A, cl 7. The test data was recorded using the SCADA (Supervisory Control and Data Acquisition) system, the temperature datalogger and logs from the power meter. Mr Nielsen explained that SCADA reads and records the behaviour and performance of the generators during the test and translates this into a numerical record. It was Mr Nielsen’s job to analyse the results of the test and determine whether the requirement set out in Sch 3A of the contract had been met, while Alinta’s Mr List considered the data on behalf of Alinta.
If a Performance Guarantee Test fell short of the Performance Guarantees for Net Power Output or Net Heat Rate, then Clarke could carry out another Performance Guarantee Test within 10 days, with the results of the further Performance Guarantee Test to supersede the previous test.
Upon successful completion of the Guarantee Tests, the reliability of the NPS2 power station was required to be proven during commercial operation for at least 60 consecutive days (Reliability Test): Sch 3A, cl 7.10. During this period, the Facility was to be operated by Alinta’s staff, with supervision provided by Clarke, for the full duration of the Reliability Test. This occurred after Practical Completion, where achievement of Practical Completion was Milestone 13 and Completion of Reliability Period was Milestone 15.
Clause 20, “Guaranteed performance”, provided a complicated regime whereby Clarke could either achieve the Performance Guarantees in accordance with cl 7 of Sch 3A and perform the Guarantee Tests in accordance with the requirements of the agreement (cl 20.1(a) and (b)), rectify any underperformance and repeat a Guarantee Test (cl 20.1(d)), or leave it to Alinta to fix any underperformance and pay liquidated damages instead (cl 20.2). Some of the Performance Guarantees were to be met after Practical Completion (called Post*-Completion Performance Guarantee Tests*) and the same regime applied to those Guarantee Tests: cll 1.1, 20.5. The parties then moved into a two-year Defects Liability Period: cl 21.2; Sch 1, item 20.

Clause 2.6.1 of Sch 3 set out the environmental conditions related to the Site, including, “All combustion, cooling and control air filtration systems must be designed to function reliably without undue impact on power station availability.” A table set out the parameters for the site: ambient air temperature ranged from a minimum of -2oC to a maximum of 46oC, with a mean daily range of 17oC to 31oC.
Accepting that Clarke was obliged to design NPS2 to the Design Criteria, these criteria are not referred to in the requirements for Practical Completion in cl 2 of Sch 8, nor the description of Intended Purpose. Nor are these features referred to in the specific testing and commissioning requirements which are detailed in the contractual requirements for Practical Completion: Sch 8, cl 2(d); Schs 3, 3A. Nor are the environmental conditions included in the Guarantee Conditions, where cl 1.10 of Sch 3A provides, “The Contractor must use the Guarantee Conditions for the design of the Works to meet the Performance Guarantees and Environmental Guarantees”. The Guarantee Conditions refer to a temperature of 37°C.
As will be seen, Mr List and Mr Walker focused on the environmental conditions set out in the Design Criteria rather than the tests specified by the contract for the achievement of Practical Completion. Jenbacher’s Technical Description for the gensets noted that, if combustion air temperature was above 46oC, then output would ‘de-rate’ by 2% per degree. Where the temperature at Newman ranged from a minimum of -2oC to a maximum of 46oC, they were particularly nervous about de-rates which occurred during commissioning and testing on hot days.
As well as preparing for and undertaking Guarantee Tests, Clarke was continuing the commissioning process. Mr Cole said that the first step in this process was to commission the individual engines according to Jenbacher’s factory standards. Clarke’s commissioning team would then conduct testing as required by the contract. The commissioning team would also remain on site after the machines had been commissioned to ‘optimise’ the engines. Parameter changes would be implemented to fine-tune the settings of the engines within the design specifications set by Jenbacher, so that the engines ran at their best achievable output in their environment without impacting the reliability of the engines. A parameter change is an intentional adjustment to a configurable control setting that alters how the engine is controlled. These changes are implemented via Jenbacher’s DIA.NE interface and recorded in the DIA.NE system event logs.
Mr Cole explained that engine optimisation was distinct from engine availability and reliability. Engine availability is the measure of the engine’s ability to start. Engine reliability is the ability of the engine to continue to run as demanded. The optimised point is where overall engine performance is greatest without unacceptable risk of damage to the engine. This is a fine balance; making small changes to increase efficiency in respect of one parameter can have an impact or trade off in respect of others. Optimising engine performance in this way is standard practice and a normal part of the commissioning process.
Event logs produced by the DIA.NE system showed parameter changes made by Clarke in October and November 2022. Mr Cole said that 24 parameter changes were recorded in total, while Mr List tallied up 360 parameter changes. Mr Cole said that was wrong, as Mr List failed to account for the duplication of identical parameter changes across the 14 engines at NPS2. To ensure uniform parameters and thus performance across all engines, a single parameter change was often implemented across the entire fleet but should only be counted as one unique change, not 14 separate ones. Mr List did not agree, “Well, all engines have the same parameter setting file so they’re all susceptible to the same issues.”
Mr Cole also excluded temporary changes where a parameter was changed and then reverted to its original setting on the same day. He said that if a parameter was adjusted but then reversed to its original setting shortly afterwards, effectively testing various parameters as part of the optimisation process, the effect of this process was that there was no parameter changes implemented as the engine was set back to its original setting. For example, a member of the commissioning team conducted a test of Parameter 1189 on 26 October 2022, during which the parameter setting was adjusted nine times before being returned to its initial setting. In Mr Cole’s opinion, these actions did not constitute parameter changes, while Mr List counted each change.
I accept Mr Cole’s analysis as correct. But the effect of Mr List’s incorrect understanding is that he clearly perceived that Clarke was making more changes that it was in an effort to get the generators to work properly.

Turning to the Guarantee Tests, a Guarantee Test was conducted on 7 October 2022. Generator 12 experienced one warning during the test period, being a Priority 4 warning, “Spark plug voltage too low”. Mr Cole said a spark plug on cylinder 24 of the generator momentarily recorded a low voltage, but no misfiring was recorded, which meant that the engine continued to operate.
The temperature datalogger at the inlet of the air inlet filter took a temperature reading every 30 seconds. These temperature readings were averaged over the period of the test, according to which the ambient air temperature was 27.5°C. As such, an adjustment needed to be made to reflect the required Guarantee Conditions of 37°C.
During the test, the auxiliary load was an average of 1,401 kW. Following the test period, Clarke manually increased the auxiliary load to 1,647 kW by operating all the radiator fans at full speed. This simulated the auxiliary load required to operate the power station at a higher ambient temperature, when more airflow through the radiators would be required to provide sufficient cooling. Mr Haddon explained that the measured power output should therefore be reduced by 246 kW, being the difference between the auxiliary load during the test period and the increased auxiliary load simulating operation at a higher ambient temperature.
Mr List thought that the way that Clarke conducted the Guarantee Test resulted in a better outcome for Clarke. “Manipulating” the radiator and ventilator fans to 100% at a temperature of 28°C was likely to result in a lower auxiliary load than if those radiator and ventilation fans were operating at 100% at 37°C. But Mr Haddon explained that the auxiliary load for fans is actually less at higher temperatures. Air density reduces with higher temperatures, so the power consumed to operate the fan is less. The fans would consume 17% more power at -2°C than at 46°C, due to the increased density of the air at low temperature. As such, the auxiliary load would be lower at 34°C than at 27.5°C, due to the 182 fans in the power station using less power. Mr List accepted this in cross examination.
Mr Haddon added that, in fact, by operating all of the auxiliary loads at the Performance Test temperature, Clarke disadvantaged itself as the auxiliary load from the fans was higher at the Performance Test temperature than it would have been at the Guarantee Test temperature. The ventilation fans and radiator fans would consume less power at higher temperatures, so Clarke disadvantaged itself by operating the fans at a lower temperature.
Mr List also thought that Clarke’s way of measuring the auxiliary load would result in a better outcome than adopting the nameplate rating for each piece of equipment as required under the contract. Mr Haddon said there was no technical reason or contractual requirement why Clarke should not operate all equipment to simulate the auxiliary load at a higher operating temperature. Nor did using the nameplate rating necessarily provide an advantage to Clarke. It would depend on the test temperature and the number of loads that needed to be accounted for.
Mr Haddon rejected Mr List’s use of “Maximum Auxiliary Demand” when considering auxiliary load. The Maximum Auxiliary Demand calculation was an estimate of the total auxiliary load for the power station and was used as an input to design the auxiliary switchboards and transformers. These calculations are generally conservative, estimating a higher auxiliary load so that the designer did not install a switchboard or transformer that did not have sufficient capacity. The Maximum Auxiliary Demand calculation also included interruptible loads that may operate simultaneously, such as lights or power points. These interruptible loads would usually not be operating during a net output test, as they were not needed continuously for the operation of the power station.
Mr List continued to express a concern in cross-examination that Clarke was manipulating the auxiliaries for its tests and could be masking ‘de-rates’, “I’d always prefer an unmodified or as is arrangement of the power station, and then you come up with an agreed normally operating auxiliary load that can be used for adjustment”. He was not prepared to take Mr Nielsen’s word for it that the ventilation fans had been run at 100%, as Mr Nielsen did not mention the radiator fans and the data confirming that that is what happened could no longer be accessed.
Nor did Clarke pass the Guarantee Test on this occasion. Clarke did not make the adjustment for the auxiliary load in the Performance Test Report. Having made the required adjustment himself, Mr Haddon concluded that the Net Power Output satisfied the minimum performance requirement (56,000 kW) but not the Performance Guarantee of 58,721 kW.
In fact, four tests were scheduled on 7 October 2022, being emissions testing and vibration testing for Generator 12, Facility Net Power Output and Heat Rate and Facility Part Load Operation. Network access was unavailable until 2 pm, when 9MW was available. Network access was available for 61.67MW from 5.08 pm. After analysing the time taken for each of these tests, and the available load that day, Mr Harvey concluded that Alinta failed to provide network access, preventing the completion of the scheduled tests.
On 9 October 2022, one test was scheduled, being Facility Part Load ITP. The test required a load up to full load of 61.67MW with an estimated duration of 9.25 hours. Clarke requested a load of 30MW at 12.30 pm, which was sufficient to begin testing but insufficient to conclude the test. Approval was granted for 9MW, which was insufficient to complete the test. Mr Harvey considered that Alinta failed to provide adequate network access.
On 13 October 2022, two tests were scheduled to rectify items AE 169 and AE 170 on the Punch List, being a list of the outstanding Work and Defects for the facility: cl 1.1. Both items were Category 5. (According to the key to the Punch List, Category 5 were items which “Must be resolved and signed off before PC”.) Both items had been added to the Punch List that day by Alinta, with Clarke yet to review. Mr Vickery said that the marking of these two items as Category 5 Defects reflected what Alinta had requested be included in the Punch List, not Clarke’s position.
Item AE 169 was “Power System Stabiliser (PSS) Issues” identified by DigSilent on 7 September 2022. (DigSilent were power systems and software engineers.) Mr Vickery explained that, while Alinta may identify an item on a certain date, it may not be sent to Clarke until some time later, when Clarke would add it to the Punch List. Alinta’s comments in the Punch List, to which Clarke had added some responses, were as follows:

On 13 October 2022, Clarke’s Mr Granger circulated a Commissioning Test Schedule and Two Week Lookahead. Clarke asked for NPS2 to operate at loads of up to 61.67MW on 13 and 14 October 2022 for observation and high speed recorder data collection, to assist in resolving the issue of oscillations. But throughout the day, Clarke was limited to 13.2MW (from 7.30 am to 9 am), 8.8MW (from 9 am to 1 pm) and 6.8MW (from 1 pm to 5 pm). Mr Granger then pressed Alinta for network availability, noting that it had not been possible to conduct any of the necessary observations at such limited loads. The data needed to be recorded on DigSilent equipment, which had to be returned on 15 October 2022. Further, in order to address Mr List’s analysis of the first Guarantee Test, Clarke needed to gather additional data while operating at full facility output for 1.5 hours.
Mr Harvey noted that, during testing, the load was curtailed twice due to excessive solar curtailment until the available load progressively increased from 5.50 pm to full load at 6.30 pm. Following a network event at 6.53 pm, Clarke requested 61.67MW but approval was not received and testing was discontinued at 7.17 pm. A high load was required to properly identify defect AE 170 and the available time and load greatly diminished that prospect. Mr Harvey considered that Alinta failed to provide adequate network access, preventing the identification and rectification of these Punch List items.
Later that evening, Mr Granger reported to Jenbacher that a partial test had been carried out on the PSS function. Jenbacher reviewed the data promptly, in advance of further testing the next morning. It appears that Jenbacher was investigating whether this may have something to do with the oscillations.
On 14 October 2022, Clarke tried again but the same problems were encountered. Mr Harvey considered that Alinta failed to provide adequate network access. On 15 October 2022, Clarke tried again but encountered the same problems. Mr Harvey considered that the delay to network access made it difficult for Clarke to rectify these defects.
But Clarke’s Mr Granger did report to his colleagues that the problem with oscillations appeared to have been resolved. More specifically, at 10.43 am on 15 October 2022, Mr Granger provided his colleagues with a comparison from 13 October 2022, when oscillations were observed, and 14 October 2022, when no oscillations were observed in the same operation configuration. With Jenbacher’s assistance, adjustments had been made to compressor bypass settings, which appeared to have settled the oscillation. Mr Vickery advised that there would be more testing that day to determine the implications on compliance tests.
Of this, Mr Harvey said that oscillations depended not only on the generator but on what was happening with the rest of the network and the impedance of the network, “so all we can really say is that there was no oscillations present on that day. If the network conditions change, it’s conceivable they might reappear, it’s because it’s an intermittent fault”. He said that, on 15 October 2022, “Clarke had identified oscillations and made adjustments. … they can be a tricky thing because it depends on what’s happening on the network. … I think for thoroughness, they were still trying to … complete their tests on the basis that, well, what if the load has changed or there is a changing load or changing circumstances? … and that may include interaction with [NPS1]”. But subject to this, Mr Harvey agreed that Alinta provided access to Clarke to identify and rectify the defect. In order to be more confident that oscillations had been eliminated, Mr Harvey added, “you want to test it with a full load”.
On 15 October 2022, Mr Vickery sent a letter to Alinta and the Superintendent providing an update on delay for EOT 12. The event delaying practical completion was said to be Alinta’s failure to make available an electricity network which was capable of providing feedback and receiving the electricity that the facility was capable of generating, as required under cl 17.1(a) of the contract. This included limitations to total generation permitted, availability of load only after normal working hours and constraints imposed during testing.
On 21 October 2022, Clarke conducted further tests on Generator 10. A number of alarms were activated due to engine overload. As Clarke’s Mr Granger advised Alinta, the warm-up and overall testing was aborted shortly after 3.03 pm, when the generator tripped. Alinta and Clarke had recently entered into an agreement to reduce the liquidated damages payable by Clarke for each day that the generators operated prior to Practical Completion (the Early Generation Agreement). To prevent any trip events during Early Generation, Clarke advised Alinta to restrict generator output to 90% at temperatures above 35°C until Clarke was able to assess the position further. Clarke also looked to repeat the test at similar ambient conditions. (On 24 October 2022, Mr Vickery advised Alinta that the 90% limitation for Early Generation could be removed.)
Alinta’s Mr Walker reported to his colleagues that the testing was cancelled by Clarke due to excessive temperatures in the powerhouses. Temperatures reached up to 50°C. Gensets 10 and 11 tripped. The ambient temperature was about 37°C-38°C “and the [Principal’s Project Requirements] is full capacity at ambient conditions of 46°C, interesting to see how that goes”. Of course, the Design Criteria did not require “full capacity” at 46°C but that “the Facility must be reliable” at that temperature. Further, the ambient air temperature in the Guarantee Conditions was 37°C, not 46°C. Mr Walker had in mind the environmental conditions in the Design Criteria. And that does appear to have been what his colleagues were focusing on at the time. Mr List raised three Category 5 Defects for the Punch List, as he thought that there was a defect in Clarke’s ventilation system, indicating that the facility was not reliable for the environmental conditions required by the contract.
Mr Cole reviewed the DIA.NE logs for the 21 October 2022 tests. Mr Cole said that the warning and alarms indicated that the power station required only minor parameter adjustments, which were typical for a power generator facility in the final fine-tuning phase of optimisation. Most of the trips and warnings were Priority 4 warnings, indicating that a parameter was nearing, but had not exceeded, its relevant Set Point. These warnings did not trigger an engine response and had no impact on output or engine performance. Generators 8 and 9 maintained stable output before and after the warning. There was also a Priority 2 alarm text, “Scavenging flap failure”, which was a minor, easily resolved fault, addressed by manually adjusting the temperature switch set point at the scavenging flap from the 80°C factory setting to 90°C. Two engines tripped on this alarm.
On 24 October 2022, Clarke issued a Notice of Practical Completion under cl 18.1(b) of the contract, together with a Punch List. At trial, Clarke accepted that it did not achieve Practical Completion on this date, given its acceptance that the first Guarantee Test was not passed.
On 26 October 2022, Mr List said that Clarke made 30 parameter changes across multiple engines relating to the engine cooling system. Mr Cole reviewed the DIA.NE logs and found that no permanent parameter changes were made. Several parameters were temporarily adjusted and then all were reverted to their original settings. In his experience, this was standard practice when fine-tuning and optimising the machines.

Mr Campbell replied, “no problem, it is a public holiday in WA today, there are still a number of tasks to be completed before PC, the date of the 6th is not achievable let’s discuss this week based on our time to respond”.
This email exchange indicates that the Superintendent was privately consulting with Alinta as to whether to issue a Certificate of Practical Completion, which Mr Marshall appears to have been minded to do. The email also indicates that Mr Marshall was planning to talk to Mr Campbell about this too. Mr Marshall did not recall whether he spoke to Mr Campbell.
Mr Marshall could not recall why he emailed Alinta without copying Clarke, acknowledging that this was at odds with his evidence that he endeavoured to ensure that everything was transparent, with everyone copied in on emails. Private communication between a superintendent and one contracting party on a contentious topic fundamentally undermines the role of a superintendent.
Brett Anderson was then a superintendent for Alinta on another project, the Chichester Solar Gas Hybrid Project. He had been a supervisor on the project since July 2022, in the course of which he had met Alinta’s Mr Thomas. Mr Thomas asked Mr Anderson if he would consider becoming a superintendent on the NPS1 project too. Mr Anderson wanted to look at documents relevant to the project, before deciding whether to take on the role.
On 28 September 2022, Alinta’s Mr Thomas corresponded with a colleague, “I have responded to your comments on the engagement letter for your review. I don’t believe there are any major issues other than … locating the documents for the Superintendent’s review. Can you confirm you are ok for the documents to be attached and sent to [Mr Anderson’s company]?” That is, within two days of Mr Marshall’s email to Mr Campbell, an engagement letter for Mr Anderson had been circulated and commented upon, to which comments Mr Thomas was now responding.
On 29 September 2022, Mr Thomas was asked by his colleague to populate a list of documents he planned to send to Mr Anderson, “e.g. what outstanding payment claims are there, extensions of time granted, or claimed but not granted”. Once this was done, the engagement letter would be sent to Mr Anderson “to confirm he’s happy … We’ll also need to do a letter to Clarke advising of the change in super – but we can cross that bridge when we get to it”. Mr Anderson signed a confidentiality agreement.
On 30 September 2022, Mr Thomas advised Alinta’s project administrator, Kathryn Phillips, “We are looking to engage an independent Superintendent for NPS2.” Ms Phillips was asked to collate the documents to be made available to Mr Anderson. On 4 October 2022, Alinta’s Mr Thomas asked Ms Phillips to provide Brett Anderson access to the documents she had collated, so that Mr Anderson could perform the role of Superintendent.
On 5 October 2022, Mr Anderson confirmed that he had been able to access the documents which he would review “and reach out to Scott [Thomas]”. The documents reviewed are not in evidence and Mr Anderson did not recall what the documents were.
Mr Anderson negotiated the terms of his engagement with Mr Thomas. On 7 October 2022, Mr Anderson signed a consultancy agreement with Alinta, to perform the role of Superintendent under the contract. Mr Thomas emailed Mr Vickery, attaching a notice under cl 38.1(a)(2) that the Superintendent had been replaced with Mr Anderson, effective immediately.
Mr Marshall continued to work for Alinta. Where Mr Marshall had indicated to Alinta that he was proposing to perform his function by determining whether Practical Completion had been achieved, there does not appear to have been the same reason to replace him as there had been for Mr Ravi. Where Mr Marshall had indicated “I’d be seeking to issue the notice”, his speedy replacement was likely because Alinta did not agree with the course that Mr Marshall proposed to take, as indicated by Mr Campbell’s initial response.
Another possible explanation may be gleaned from Mr Thomas’ email of 30 September 2022 to Ms Phillips, that he was looking to engage an “independent Superintendent for NPS2”. It is possible that Mr Thomas was concerned that Mr Marshall had privately contacted Alinta’s Mr Campbell about issuing a Certificate of Practical Completion. Alinta did not suggest this, when advising Clarke that the Superintendent had been replaced. There is no reason to think that Alinta was being nice to Clarke. Most likely, the reference to “independent” was to the fact that the Superintendent would not be an Alinta employee, unlike his two predecessors.
Another reason may have been that Mr Campbell or Mr Thomas formed the view that Mr Marshall was not sufficiently experienced to be the Superintendent for this phase of the project, and that Brett Anderson was better equipped to perform the role given his recent involvement in a similar project.
No one from Alinta came forward to give an explanation for the late change in superintendent. On the balance of probabilities and having regard to the gravity of the matter, I find that Alinta replaced Mr Marshall for a combination of the first and last reasons. Given the speed with which Mr Marshall was replaced after indicating that he was minded to issue a Certificate of Practical Completion, Alinta thought that determination would be incorrect and Mr Anderson was better placed to make that determination. Alinta would not have been in a position to make this swift replacement absent Mr Marshall’s indiscretion, but replacing Mr Marshall as it did had the consequence that a potentially favourable determination in the Contractor’s favour did not eventuate.
Under the contract, the parties had agreed that the Superintendent’s function would be to act honestly, fairly and reasonably and arrive at reasonable determinations: cl 38.2(b). Obviously, Mr Marshall should not have indicated privately to Alinta his inclination as to what his determination would be. But the Principal removing the Superintendent so that its determination could not be made, where the Principal disagreed with that determination, destroyed the parties’ contractual bargain.
Clause 38.1(a)(2) provided, “The Principal … may at any time replace the Superintendent by written notice to the Contractor.” The Principal did not have to give advance warning to the Contractor nor provide a reason for replacing the Superintendent. But the Principal’s discretion (“may”) had to be exercised with the implied duty of cooperation in mind so that, in exercising the discretion, the Contractor was not deprived of the benefit of the contract. That did not include replacing the Superintendent to prevent it giving its “reasonable determination” because that determination favoured the Contractor. Removing a superintendent to prevent them from giving a determination that you do not want also effectively destroys the role of a superintendent: see [19]-[21].
On 12 October 2022, Ms Phillips emailed Brett Anderson, copied to Clarke, noting that the previous Superintendent did not make a determination on EOT 1. Ms Phillips provided a link to the relevant correspondence, “We request you to make a determination on the Contractor’s claim at your earliest convenience.”
On 26 October 2022, Brett Anderson emailed Ms Phillips and Mr Thomas of Alinta (but not copied to Clarke) noting that he was reviewing the assessment of EOT 1:

On 27 October 2022, Clarke conducted a second Guarantee Test. The ambient air temperature over the period of the test was 34°C but the temperature readings taken at the temperature datalogger oscillated wildly from 34.4°C to 42.4°C, according to a graph later prepared by Mr List. Clarke simulated stress conditions, that is, a higher temperature, for the purpose of testing the operation of the generators in a higher heat. To do this, ventilation fans were run at full power throughout the demonstration. After about 40 minutes, some network instability appeared and the demonstration was stopped. The network instability was unrelated to the mechanical functioning of the generators.
Mr Haddon has reviewed the test results. Mr Haddon could see from the data that the radiator fans and other required auxiliaries were operating. As Clarke simulated the operation of the generators at a higher ambient temperature by ensuring all radiator fans were operating at full speed during the test, there was no need to adjust the measured power output due to the ambient temperature not being at the Guarantee Conditions. Mr Haddon concluded that the Net Power Output of 58,735 kW met the Guaranteed Net Power Output requirement. So did the Net Heat Rate. Clarke passed the second Performance Test.
Mr List thought that the facility experienced de-rating, tripping and an unsatisfactory level of alarms during the test. He considered that the demonstration failed to demonstrate reliable operation for the environmental conditions or that the facility was fit for purpose. He thought that the air intake and ventilation system was not providing ambient air temperature to the engine. The air temperature appeared to be pre-heated, which he thought was contributing to the engines exceeding their operational limits. Temperatures taken at the exhaust outlet over the course of the afternoon oscillated considerably and reached almost 44°C, albeit outside the test period.
Mr Walker added another Category 5 item to the Punch List given the high temperature readings at the Facility, “Please demonstrate the Facility is able to continuously operate for the full range of Site conditions including but not limited to ambient temperatures between -2°C and 46°C.” Again, Mr Walker was focusing on the Design Criteria.
Having reviewed the DIA.NE event log, Mr Nielsen said that Generator 8 experienced three warnings and Generator 9 experienced two warnings. One of the Priority 4 warnings caused both generators to ‘de-rate’ temporarily but did not cause the engines to shut down. Mr Cole reviewed the DIA.NE test results and confirmed that the Priority 4 warnings did not affect the operation of Generators 8 or 9, which maintained stable output before and after the warning.
Outside the testing window, Generator 9 had two Priority 2 alarms, which did cause the engine to shut down. Mr Nielsen said this did not of itself affect overall facility reliability and should be considered in context, being the final stages of commissioning and testing on that date. Mr Cole said the Priority 2 alarm for Generator 9 was “Heating water temperature high”, meaning that the heating circuit water exceeded its Set Point. This alarm was typically resolved by fine-tuning the power reduction set points so the engine could produce maximum output without exceeding that Set Point. As only one engine was tripped on this alarm, Mr Cole did not believe that this was an indication that the power station was unreliable. This Priority 2 alarm triggered a second Priority 2 alarm for Generator 5, “Fail safe loop tripped”. This alarm was typical during the optimisation phase and was typically resolved by fine-tuning the power reduction set points. He considered that these events were typical for a power facility during the final stages of optimisation and fine-tuning for local operating conditions.
On 28 October 2022, Clarke provided an update on delay in respect of EOT 12. That evening, Mr List emailed Mr Granger, advising that he had “trended the temperature reading” from the second Guarantee Test with the datalogger, a temperature recorder at NPS1 and the Bureau of Meteorology’s weather station. Mr List provided a graph of the results, “I don’t believe the [datalogger] can be relied on as an accurate representation of the ambient temperature during the test. The source of the additional heat which is giving the high readings on the [datalogger] within the ventilation inlet assembly should also be investigated, e.g. hot air ingestion.”
Clarke analysed the data from the second Guarantee Test, which was extensive. This took some time. Clarke personnel continued to collaborate extensively on changes which could be made to settings, circuitry and butterfly valves to address the high temperatures being encountered during testing. On 29 October 2022, Clarke’s Commissioning Technician, John Ryan, provided some changes for the next test. On 31 October 2022, Clarke contacted the transformer supplier, seeking assistance to determine the cause of temperature issues with the transformer, “With ambient temperatures at 36°C we have seen the OTI and WTI instruments reach 100°C, the [transformer] was operating at less than 80% full load that day. We are concerned that the transformer will not be suitable to operate when the site reaches the design ambient temp (46°C).”
On 1 November 2022, Mr Nielsen, reported to his colleagues that the generator temperature data was “a bit odd” and the datalogger “was highly sensitive to something”. He could also see “considerable” frequency and voltage swings during the day of testing, which Mr Nielsen did not believe were caused by NPS2.
On 4 November 2022, Mr Nielsen suggested throttling the HT system and radiator inlet valve to achieve radiator / engine coolant temperatures closer to Jenbacher’s design, with the intention of reducing the return water emperature and eliminating alarms at high loads or ambient temperatures. Mr Nielsen said that throttling meant restricting the flow of water. He suggested this because there was a difference between Jenbacher’s design and what was being exhibited on site. By restricting the flow in some way, the results might better align with what Jenbacher’s design was intended to achieve.
Mr List counted 65 parameter changes across multiple engines on 4 November 2022. He thought that the parameter changes were aimed at rectifying the unreliable operation of the facility due to temperature-related issues. Mr Cole said seven parameter changes were implemented, of which three parameter changes related to power reduction and de-rate settings. The changes to the parameters demonstrated that those parameters had simply been activated, that is, turned on and a set point entered. These parameters are activated where the ambient temperature is sufficiently high. He considered these to be minor changes, reflecting Clarke’s fine-tuning of the engines to optimise the facility’s output at high ambient temperatures. The other parameter changes were unrelated to power reduction or de-rate tuning, and were minor adjustments as part of the optimisation process.
On 8 November 2022, Mr List counted five parameter changes relating to power reduction and de-rate tuning. He thought that the parameter changes were aimed at rectifying the unreliable operation of the facility due to temperature-related issues. Mr Cole said there were three parameter changes on Generator 9 only. One was a very minor parameter change of 0.5% to optimise engine de-rating. Another was a secondary reduction safety setting for rare events such as multiple fan failures and would only operate in such circumstances. A third parameter change was a minor change of 1°C to optimise engine de-rating capability. He considered these changes to be minor, routine adjustments to de-rating parameters. This fine-tuning to optimise engine output can only be performed when the station is in full operation and on high ambient days. These adjustments were a standard part of facility commissioning.
On 9 November 2022, Mr List counted 66 parameter changes. He thought that the parameter changes were aimed at rectifying the unreliable operation of the facility due to temperature-related issues. Mr Cole said there were five parameter changes but the same parameter change was made across multiple engines. He regarded these as minor changes made to optimise engine performance and to more acutely tune the engines for de-rates. These parameter changes demonstrated the latter stages of engine optimisation to achieve maximum output and optimise operation of the facility under high ambient temperatures. The parameter changes indicated that the technician was bringing the parameters into line with the changes made the previous day.
On 9 November 2022, Clarke also sought approval from Alinta to operate the generators at full load the next day for up to four hours, when the predicted temperature was 38°C, “to demonstrate plant performance at elevated ambient temperatures”.
On 10 November 2022, Mr Nielsen provided the Performance Test Report to Alinta, with the results of both the first and second Guarantee Tests. The report indicated that the Performance Requirements had been met on both occasions. (Mr Nielsen now accepts that it was only the case for the second Guarantee Test.) Having reviewed the data embedded in the Performance Test Report, Mr Nielsen now realises that he did not include the raw SCADA data from the 7 October 2022 test, nor an editable copy of his analysis of the test results. But he noted that Mr Granger had provided Mr List with the data from the first test on 9 October 2022. That said, Mr Nielsen noted that Mr List essentially had the same data in any event, albeit copied and pasted into a spreadsheet. Mr Haddon concluded that, on 10 November 2022, Alinta was provided with sufficient information to assess whether Clarke had passed the second Guarantee Test.
I note also that Clarke accepted Mr List’s concern as to the reliability of the datalogger, noting in the Performance Test Report:

That is, although the ambient air temperature taken at NPS1 was not the dry bulb ambient air temperature as required by the contract, the parties agreed to vary the contract by using the temperature as recorded at NPS1 instead.
Mr List reviewed the Performance Test Report and thought that it contained errors and omissions. He was not satisfied that the Guarantee Tests had conclusively demonstrated that Net Power Output and Net Heat Rate passed at the required environmental conditions. (Again, Mr List is referring to the environmental conditions in the Design Criteria, not the requirements for Practical Completion in Sch 8.) Mr List understood that no adjustment was made for auxiliary load differences or de-rating, nor a power factor adjustment for the difference in the Guarantee Conditions. Mr List did not think that the report included all of the raw test data required by the contract, and appeared to rely on different data to what had earlier been provided to him.
On 10 November 2022, Clarke completed a demonstration of plant performance at elevated ambient air temperature, being 38 C. Mr Nielsen said that this was not a Guarantee Test, but he has reviewed the DIA.NE event log. There were four Priority 4 warnings and two Priority 2 alarms. Whilst two engines were automatically shut down, the remainder of the power station continued production of output as demanded. Further, one of the Priority 2 alarms was a sympathetic alarm, following the first of the Priority 2 alarms, resulting from the same event and occurring within a second of each other. That is, the two alarms were attributable to a single event and not two separate faults.
Mr Cole considered these warnings and alarms to be unremarkable. The warnings were largely based on the impact of ambient air temperature and did not have any correlation to an issue with the engine cooling system. The Priority 2 alarm for Generator 9, “Heating water temperature high”, was readily resolved by adjusting the power reduction return water temperature parameters and did not demonstrate an issue with the external cooling water system or subsequent operation, as the engine performed as designed. This then prompted the second Priority 2 alarm, “Fail safe loop tripped”, and did not reflect an issue with the external cooling system either. The warnings and alarms showed that parameter adjustments were required to optimise engine performance in high ambient conditions, which was a normal part of commissioning a facility like NPS2. Mr Cole said the warnings and alarms were not a sign of unreliable operation of the facility at high ambient temperature. Generator 9 shut down immediately but Generator 10 maintained stable output before and after the warning.
On 11 November 2022, Mr List provided Clarke’s Mr Granger with observations on the demonstration on 10 November 2022, noting that, when the ambient temperature was 36°C, power reduction / de-rate appeared insufficient to prevent generator trip. Power reduction / de-rate occurred prior to 37°C. Clarke had then observed a loud hum coming from the LV switchboard and requested load removal from NPS2 and subsequent de-energisation. Mr Granger circulated Mr List’s comments to his colleagues, noting that they were looking to repeat the test the following week, when ambient temperatures were closer to 37°C. Clarke colleagues conferred in respect of adjustments in de-rate settings to avoid tripping again, and whether they should raise the issue with Jenbacher.
On 11 November 2022, Clarke submitted a claim for an extension of time for 10 days, being EOT 12. The amounts claimed under cl 12.4 were $162,660 excluding GST.
Mr List said there were 15 parameter changes on 13 November 2022. He understood that these changes related to Clarke’s attempts to rectify the unreliable operation of the facility due to temperature-related issues. Mr Cole counted only two changes, both minor in nature, to finely tune the engines to optimise the engines ‘de-rating’ in elevated temperatures. This was a standard part of commissioning and the optimisation process.
On 15 November 2022, Alinta wrote to the Superintendent and Clarke, requesting that Clarke provide the native files of the “Time Impacted Analysis” program that Clarke relied on for EOT 12, advising that Alinta required adequate time to review the claim and provide submissions within seven days of receipt of the native files. The Superintendent also wrote to Clarke and Alinta requesting the native files, inviting Alinta to provide submissions and advising the parties that he required 15 Business Days to assess EOT 12.
On 15 November 2022, Mr List counted 32 parameter changes, which he thought reflected Clarke attempting to rectify the unreliable operation of the facility due to temperature-related issues. Mr Cole said there were no permanent parameter changes made on that date. A temporary adjustment was made to one parameter on all engines, but later reverted to its original setting.
On 16 November 2022, Mr Nielsen suggested that they needed to find ways to get the three-way valve controller to start opening earlier, which would call in additional fans sooner. Further testing was undertaken to try this. Further fine adjustments were suggested. Mr Haddon said adjustments to the butterfly valve were part of Clarke’s efforts to optimise the power station generally. Even once a power plant was commissioned, it was normal to optimise the systems and these changes were, in his view, reasonable and normal.
On 16 November 2022, Mr List counted 46 parameter changes. Mr List thought these changes reflected Clarke attempting to rectify the unreliable operation of the facility due to temperature-related issues. Mr Cole said there were three parameter changes to reflect minor engine cooling system optimisation.
Clarke continued to conduct further testing but was somewhat limited by opportunities to test against high ambient temperatures. Another test was done on 17 November 2022. Radiator fans were progressively turned off. After three of the seven fans were turned off, engines tripped on high engine oil temperature. Mr Haddon said it was not a surprise that engines tripped on a temperature-related alarm on this day, where almost half of the cooling capacity had been turned off. Tripping of engines during this demonstration was not a defect because Clarke was manipulating the configuration of the plant. Mr Nielsen has examined the DIA.NE event log and says there were only two Priority 4 warnings on that day.
Mr Cole added that, based on his review, the decreasing frequency of alarms and warnings between 7 October 2022 and 17 November 2022 indicated that NPS2 was progressing through the final stages of parameter optimisation in response to the rising ambient temperatures at NPS2. None of the warnings or alarms indicated that the facility encountered major defects that would have required the facility to be shut down to be remedied.
Mr Cole said the alarms were largely temperature-related alarms and warnings typical of engines operating in high ambient conditions such as those routinely experienced at NPS2. The warnings reflected the normal behaviour of Jenbacher engines undergoing final optimisation in elevated temperatures. Subsequent parameter changes were minor, routine commissioning adjustments made to tailor the engines’ control settings, including temperature thresholds, reduction rates and fan-staging logic, to the specific ambient conditions at NPS2. Such adjustments were an expected part of fine-tuning and reflected standard optimisation to get the most output possible from the facility at the upper temperature range of the power station’s design.
On 17 November 2022, Clarke wrote to the Superintendent in respect of EOT 12, stating that, as the Superintendent did not make a request pursuant to cl 38.2(3) for the native file, there was no basis to request it.
Mr List said there were 51 parameter changes on 18 November 2022. He continued to think that Clarke was attempting to rectify the unreliable operation of the facility due to temperature-related issues. Mr Cole said there were two parameter changes on all engines. The first change was a “fail-safe” parameter to enhance engine reliability in certain rare events such as unexpected cooling system performance dips or transient high ambient conditions. The second change was a minor adjustment to enhance engine optimisation. The parameter changes reflected oil temperature de-rate parameter changes on all engines, reflecting proactive optimisation for the specific installation and were ordinary commissioning and tooling measures.
On 21 November 2022, Alinta sent a letter demanding liquidated damages of $7,929,384 plus GST, proposing to set-off non-payment of amounts against liquidated damages.
On 22 November 2022, Mr List counted 28 parameter changes made by Clarke. Mr Cole counted two changes, being minor adjustments to optimise performance. Mr List continued to think that these changes reflected Clarke attempting to rectify the unreliable operation of the facility due to temperature-related issues.
On 22 November 2022, the superintendent requested a copy of native files pursuant to cl 38.2(c) of the contract, in respect of EOT 12. Alinta made extensive submissions to the superintendent on EOT 12.
On 23 November 2022, Mr Nielsen suggested some modifications to the directional ventilation louvres directly after the fans inside the powerhouse. There were no observed improvements from varying directional louvre positions and therefore no wholesale modification was performed.
On 24 November 2022, Mr List said there were 22 parameter changes. Mr List continued to think that the parameter changes reflected Clarke’s efforts to rectify the unreliable operation of the facility. He regarded the facility as experiencing a “more acceptable level of alarms, standing alarms and warnings” during this test, with minimal power reduction due to temperature-related issues. Mr Cole said one parameter was changed on one generator but set back to its original value. The parameter changes were made to fine-tune and optimise performance of the engines.
Also on 24 November 2022, Clarke wrote to the Superintendent and Alinta, advising that Clarke disagreed with the Superintendent’s assessment of EOT 1 and advising that it intended to provide a more detailed response “shortly”. Clarke denied liability to pay liquidated damages. Clarke disagreed that it had not achieved Practical Completion. Clarke required further time to consider the Superintendent’s request for native files in respect of EOT 12.
On 25 November 2022, Mr Granger reported to his colleagues that a demonstration of plant performance at elevated ambient air temperature was conducted the previous afternoon “with no warnings, alarms or derates”. On 29 November 2022, Clarke circulated Revision 1 of its Performance Test Report. Alinta advised that, with this report, Clarke had provided evidence of successful completion of the Guarantee Tests and the Facility could commence the Reliability Test.
On 30 November 2022, Clarke wrote to the Superintendent and Alinta, substantively responding to the Superintendent’s assessment of EOT 1, contending that the assessment was an improper exercise of the Superintendent's functions to act honestly, fairly and reasonably as required by cl 38.2(b) of the contract. Clarke also wrote to the Superintendent and Alinta in respect of EOT 12, stating that, until it received further information in response to its request for communications between the Superintendent and Alinta, it would not provide the native file.
On 7 December 2022, Alinta provided a response to Clarke’s Notice of Practical Completion. Alinta maintained that the Facility was only completed on 29 November 2022, except for minor omissions and minor Defects. On 11 December 2022, the Superintendent issued a Certificate of Practical Completion, effective 29 November 2022.
On 22 December 2022, Alinta issued a payment certificate in respect Milestones 12, 13, 14 and 16. Alinta certified $8,564,957.37 as payable for these payment claims but set off liquidated damages of $7,929,384, leaving $635,573.37 payable. (Whether the balance of $635,573.37 was paid is not in evidence.) These proceedings were commenced in April 2023.

Clarke contended that it achieved Practical Completion on 10 November 2022, or alternatively on 24 November 2022, or alternatively on 29 November 2022. Clarke submitted that Practical Completion was achieved on 10 November 2022 as it passed the second Guarantee Test and was only remedying minor defects through parameter changes after that date. The results of the second Guarantee Test were communicated to Alinta on 10 November 2022 in a form that permitted it to determine the Clarke had passed that test. Mr List accepted that he had the relevant test data by 10 November 2022. All items on the Punch List were minor as at this date.
Clarke relied on cll 2(a)-(e) of Sch 8, which indicated that absolute reliability of the generators was not a condition precedent to satisfactory completion of the Guarantee Tests. It was irrelevant that the generators were not fully optimised or free from Defects. Clarke need only demonstrate that it has passed the Performance Tests, notwithstanding the generators not being in a fully optimised state. This produced a commercially sensible conclusion, where Alinta had the right to determine what constituted a satisfactory level of alarms, albeit never did: Sch 3A, cl 7. The very notion that there could be alarms or warnings indicated that there could be a de-rate occurring during the Guarantee Tests.
Alinta contended that Practical Completion was achieved on 29 November 2022 or alternatively on 24 November 2022. Alinta accepted that there could be ‘de-rating’ during a test; the point was whether the output was achieved at the necessary efficiency. But Alinta did not accept that Clarke passed the second Guarantee Test. Alinta pointed out that, on Mr Haddon’s calculations, the Facility only passed the Net Power Output test by 14 kW, being a margin of 0.0002%. But the ambient temperature on that day was 34°C. The Guarantee Conditions were not met during the test window. Clarke relied on the temperatures measured by the “Testo” datalogger mounted at the inlet of the air filter on Powerhouse 1. Those temperatures varied markedly during the test window, between 34°C and 42°C, and rose and fell by multiple degrees within the space of a few minutes at a time. Mr Haddon said that was likely due to “hot air ingestion”.
The significance of this was that later in the afternoon, shortly after the test, one of the engines (Generator 9) overheated and tripped. Mr Haddon’s evidence was that the engine management system was “doing its job”, shutting down because it was exposed to excessive temperatures. That was said to indicate that the Facility was not able to operate for an extended period at full load at the ambient temperature referred to in the Guarantee Conditions. The cooling system was then operating at its highest setting. The fact that the cooling system was not able to prevent the engine tripping at that ambient temperature was said to indicate that the Facility was not ready to go into commercial operation. (Nor, I note, is that the contractual test.) If the ambient temperature was 37°C rather than 34°C, then the performance of the engines would be expected to deteriorate.
Even if the test on 27 October was conducted at 37°C, Alinta submitted that this did not mean that the Guarantee Tests were passed. The commissioning work was to bring the Facility “to a condition where it is ready to … enter commercial operation”: Sch 3A, cl 8.2. (This is not a requirement for Practical Completion in Sch 8.) Clause 7 of Sch 3A required the Guarantee Tests to be completed “with the Facility operated in a mode which is representative of long term operation”, running automatically and with a satisfactory level of alarms and warnings. Further, “Upon successful completion of the Guarantee Tests, the reliability of the NPS2 power station … must be proven during commercial operation, for a period of not less than 60 consecutive days …” and, during this period the Facility was to be operated by Alinta under the supervision of Clarke: cl 7.10, Sch 3A. (I note that the latter period was not a prerequisite to Practical Completion either.) Alinta submitted that Clarke was to handover the site on Practical Completion and demobilise as soon as possible: cl 18.3. All of this suggested that the Facility must be ready to commence commercial operations on Practical Completion, and it was not. The optimisation of the plant described by Mr Cole was said to be a precondition to Practical Completion. This was said to be supported by the program, which scheduled commissioning, then performance tests, then handover, then practical completion.
Alinta submitted that it was not until 14 November 2022 that Clarke changed a parameter for all the engines to set a de-rate if the water coming into an engine from the radiators exceeded 75°C, automatically reducing the engine’s output by 5% per degree. During the test on 27 October 2022, the temperature of the cooling water going into the engines exceeded 77°C. Mr Haddon agreed that the elevated temperature of the water ultimately led to the trip of Generation 9 shortly after the test. Had the de-rate setting been in place, the output from the affected engine would have been lower. A 5% reduction in output for one generation was equivalent to the loss of 220 kW (being 4,400 kW x 0.05). The Facility only passed the Net Power Output test by 14 kW. In any event, it was not possible to conclude that the Facility passed the tests on 27 October or on any other date prior to 29 November 2022.
Alinta contended that the Facility continued to experience significant “tripping”, including on 10 November 2022, when there was said to be “multiple temperature engine alarms and power reductions” at the demonstration. The same was said to be the case on 17 November 2022. These works were said to have been undertaken during a period which included “extensive parameter changes” made by Clarke. On 24 November 2022, Clarke made the final parameter changes and conducted the final test. Practical Completion was not achieved until 29 November 2022, when Revision 1 of the Performance Test Report was received or, alternatively, 24 November 2022, when Clarke performed the final parameter changes and / or the final test.
In reply, Clarke accepted that the second Guarantee Test was conducted at an ambient air temperature of 34°C, but said this made no difference. The contract required auxiliary loads to be adjusted to reflect the Guarantee Conditions and that there be a “satisfactory level” of alarms and warnings. There was no evidence that a de-rate would have been worse at 37°C than at 34°C. Nor did the contract require Clarke to adjust its results for hypothetical de-rates at 37°C. The contract drew a distinction between Guarantee Tests and the Reliability Test. Practical Completion preceded commercial operation. The suggestion that the Facility must have been ready for "commercial operation" on Practical Completion conflated the commissioning language in cl 8.2 of Sch 3A with the post-Practical Completion regime under cl 7.10.
Clarke contended that any tripping at the Facility and any additional testing or works performed to parameter changes on and from 24 October 2022 was work performed to rectify minor Defects or minor omissions which did not prevent the Facility from being used for its Intended Purpose. Alinta could not retrospectively invalidate test results by reference to subsequent optimisation. The contract did not require final optimisation at the time of the Guarantee Tests. While Mr Haddon agreed that, had the 14 November de-rate setting been in place on 27 October, Generator 9 would not have tripped, he also agreed with Mr Maynard that "changing the derate parameters can change the result of a test but only if the conditions for a derate occur during the test". The contract did not require those parameters at the time of the test. Nor should any significance be attached to the trip after the 27 October test, precisely because it occurred after the test’s conclusion.

“Date of Practical Completion” meant the date that Practical Completion was achieved: cl 1.1. I have earlier set out the requirements for Practical Completion: see [565]. It bears repetition that Practical Completion had the meaning given in Sch 8: cl 1.1. It did not have the meaning given in the Design Criteria in Sch 3.
Optimisation of the new power station, including fine-tuning parameters, falls squarely within cl 2(a) of Sch 8: “the Facility is complete in accordance with this agreement, except for minor omissions and minor Defects … which do not prevent the Facility from being used for the Intended Purpose; and … the rectification of which will not adversely affect the convenient use of the Facility for the Intended Purpose.” Clause 1.2 of Sch 3 provides, “The intended purpose of the Facility is the generation and transmission of electricity” in accordance with the contract, with “safe, reliable and efficient operation”. This very general description was met on each of the dates proffered by the parties.
Mr Haddon said the fact that Clarke was in a position to submit Early Generation requests to Alinta from 6 October 2022 on indicated that NPS2 was fulfilling its intended purpose. From 6 October 2022 to 10 November 2022, NPS2 produced approximately 16,090MW hours of electricity. The average output of each engine whilst it was operating during that period was 3.86MW. This showed that the power station was capable of being operated for its intended purpose of generating electricity, where 3.86MW represented approximately 87% of the capacity of each generator. That was reasonably high for intermittently operated generators. The generators were not operating at full capacity at all times and were started and stopped each day, reducing average generating capacity.
It was not in dispute that cl 2(a) of Sch 8 was otherwise met, so far as the Punch List was concerned. Mr Harvey and Mr Haddon reviewed the various Punch Lists and considered that all items which remained open as at 24 October 2022 were minor defects or omissions. Clarke contended at trial that it achieved Practical Completion on 10 November 2022, more than two weeks later.
The real question is whether cl 2(d) of Sch 8 was satisfied, that is, the tests, inspections and commissioning had been carried out, passed and the results provided to Alinta.
Mr Haddon said the second Guarantee Test on 27 October 2022 demonstrated that the facility could produce the required output at 37°C. While an engine trip is undesirable, the chance of a cascading trip of the gas engines or loadshedding due to a single engine trip was low. In the context of the whole power system, a trip of a single 4.4MW engine was minor. Reliability of the facility was an issue which occurred, and was tested, after the completion of the performance testing as required by cl 7.10 of Sch 3A of the Principal's Project Requirements.
Mr Haddon noted that Clarke conducted the second Guarantee Test on 27 October 2022 and not subsequently. He inferred that Alinta accepted those tests when it awarded Practical Completion. Even though one of the engines de-rated momentarily during that test, the facility as a whole still produced sufficient power to pass the test. Clarke made changes to the parameters after that test to improve the operation and reliability of the power station. Whilst Alinta was entitled to ask Clarke to re-perform the Net Power Output test, it never did.
Alinta’s expert, Mr Maynard, is not an engineer, but has extensive trade qualifications and industry experience. This includes gas turbines, although with Siemens turbines rather than Jenbacher turbines. His observations on trips and alarms encountered during the commissioning process are of less assistance than Mr Cole, where Mr Cole was an unchallenged expert in Jenbacher generators. Mr Maynard's opinions were also largely based on Mr List’s assessment of the extent and import of the trips and alarms encountered, which was an unsteady foundation for his opinions.
Mr Maynard said that it was clear from the chronology (which he acknowledged was largely drawn from Mr List's observations) and supporting documentation that the generator units were “experiencing alarms and trips that were not a result of a failure of components … but rather because the facility was not yet in a completed condition, where the control system and cooling system could adequately allow the units to operate over the required ambient temperature range whilst maintaining the critical parameters within Jenbacher specified limits". Where a unit was experiencing a trip for which there was no component fault that could be rectified, this indicated to him that the system was inadequately designed or not yet fully commissioned and required further modification or tuning (parameter changes) before it could operate commercially as intended.
Mr Maynard's opinion was that the level and nature of the alarms experienced until 24 November 2022 was unsatisfactory as it demonstrated that the units could not be operated in the specified ambient conditions whilst maintaining key monitored variables within the normal operating ranges. For the facility to be fit for its intended purpose, it should have been in a condition where these variables were effectively controlled such that there was no runaway to exceed critical limits and result in unit trips.
But Mr Maynard's opinion is, I think, based on a false premise. It is clear from Mr Cole's unchallenged evidence that each trip had a clear explanation revealed by the trip code and the Jenbacher Operations Manual. This would have allayed Mr Maynard's concerns, I think, if he had fully understood the significance of each trip or alarm. Clause 7 of Sch 3A provided that “Successful completion of the Guarantee Test shall be conditional upon only a satisfactory level of alarms, standing alarms and warnings occurring during the tests.” Much of Mr List’s concerns about the level of alarms related to tests conducted on dates other than the Guarantee Tests, including the demonstration on 10 November 2022 at 38°C. That is not the required contractual focus either.
Essentially for the reasons advanced by Clarke, I am satisfied that Practical Completion was achieved on 10 November 2022. Clarke passed the second Guarantee Test. Clarke and Alinta agreed to use the temperature data from NPS1 for the purpose of the second Guarantee Test and, thus, that the test was conducted at an ambient temperature of 34°C. I accept Mr Haddon’s expert opinion that Clarke accounted for this when conducting the test by running all auxiliary fans at full throttle. Adjusting for this, Mr Haddon calculated that the Performance Guarantees were met.
I accept the evidence of Mr Cole and Mr Nielsen that, during the test, five warnings were encountered of which one caused two generators to ‘de-rate’ temporarily but did not cause those engines to shut down. The generators affected by the ‘de-rate’ maintained stable output before and after the warning. Having regard to level of alarms, standing alarms and warnings occurring during this test, Jenbacher’s specifications and instructions in respect of those alarms, as explained by Mr Cole, I consider that the level of alarms, standing alarms and warnings occurring during the test was satisfactory. Clause 2(d) of Sch 8 obliged Clarke to provide the results of the tests to Alinta before Practical Completion was achieved. These results were provided on 10 November 2022. Practical Completion was achieved on that date.

On 1 December 2022, the Superintendent issued an assessment of EOT 12, allowing nil days. It is convenient to address Clarke's claim in respect of EOT 12. Clarke contended that, in performing its obligations under the contract, Alinta was obliged to make available an electricity network which was capable of providing backfeed and receiving the electricity that NPS2 was capable of generating: cl 17.1(a). Alinta failed to do so, this being a breach and a Compensation Event, entitling Clarke to an extension of time. Clarke provided the necessary notices and EOT claim and now sought an extension of time of eight days and delay costs of $162,517.64.
Alinta contended that Clarke was obliged to manage and coordinate with Alinta but failed to coordinate network availability: cl 17.1(b). But for that failure, there would have been no issue with Alinta making the network available in accordance with cl 17.1(a). Further, there was no delay, having regard to Clarke’s August 2022 program. Alternatively, any activities that were delayed were not on the critical path. Further, any delay arose from Clarke’s breach of cl 17.1(b). Further still, there were concurrent delays for which Clarke was responsible and liable, related to 14 items on the Punch List.
Alinta submitted that the three days of delay opined by Mr Griffith on 13 to 15 October 2022 were to identify and rectify a defect. Clarke was not entitled to an extension of time on that account: cl 12.11(a). Defective work does not fall within the definition of Extension Event. In any event, Clarke was not delayed by Alinta on those dates, when regard was had to a wider array of contemporaneous records. Mr Harvey was said to have accepted that his opinion did not reflect what in fact occurred. The delay experts otherwise agreed that the delay was five days.
Alinta further submitted that Clarke had not proven delay on any other occasions, where no lay witness was called who participated in the test and Mr Harvey relied on assumptions in his letter of instruction, which were largely derived from EOT 5 itself. Alinta submitted that Mr Harvey was led into error in respect of what happened on 7 October 2022. Mr Harvey reasoned backwards from the fact that emissions and vibration testing was done on Generator 12 on 7 October 2022 to conclude that Clarke selected that generator because it was the “worst performing” of the 14. In fact, Generator 12 suffered from a fault that took it out of operation. From at least 1 October 2022, Generator 12 was “unavailable due to TechJet issues”. On 5 October 2022, Mr Vickery sent an email to Mr Columbus stating that the failure on Generator 12 had “delayed full station testing and unit testing for noise/vibration and emissions”. Mr Harvey was not able to give a clear answer to how long (if at all) Clarke’s work was delayed on 7 October if the tests on Generator 12 were left out of the analysis. The Court could have no confidence in Mr Harvey’s opinions because they were not built on assumptions that fully reflected the facts. He was said to be briefed with incomplete and inaccurate information.
In reply, Clarke submitted that its claim to being delayed between 13 and 15 October 2022 arose from its need to run the generator engines to full load, or near full load, from 13 October 2022 to perform testing to rectify defects AE 169 and AE 170. On its true construction, cl 17.1(a) can include the rectification of defects. The clause was drawn in wide terms. It should not be construed as excluding the provision of electricity to fix defects. There was no basis to imply such a term, not the least because it would not be reasonable nor go without saying.
Clarke relied on Mr Harvey’s evidence that oscillations were potentially caused from the network managed by Alinta, such as resonance between NPS1 and NPS2, harmonic interactions amplifying at a particular frequency or network constraints, and other matters outside of Clarke’s scope or control. As the Network Service Provider, Alinta was obliged to manage the electricity network such that, in its satisfactory operating state, electricity could be transferred continuously: cl 1.8.2(c), Technical Rules. As events arising out of Alinta’s failure to ensure the stability of the network, these were acts or omissions of Alinta, where Alinta was required by cl 17.1 to provide an electricity network. This could not be concurrent delay. Alternatively, these were network events which occurred in commissioning NPS1, to enable the generators to operate in the network. This was not delay for which Clarke was responsible.

I have earlier set out the contractual provisions in respect of EOT claims: see [396], [478]. Mr Harvey was of the opinion that Alinta failed to make available an electricity network capable of providing backfeed and receiving electricity from NPS2 on multiple occasions between 20 September 2022 and 15 October 2022. This failure resulted in significant delays to commissioning testing. The delays were primarily caused by late network access, restricted load availability and network unavailability during testing periods. Clarke’s scheduled testing was significantly impacted on 10 separate days over this period, where tests required specific loads or full facility capacity and were unable to proceed due to inadequate network access. The overall impact of the commissioning schedule was substantial. Proper planning and coordination could have mitigated many of these issues, as the commissioning schedule was available well in advance. He considered that Alinta did not fulfill its contractual obligations under cl 17.1(a) on multiple occasions, resulting in significant delays and disruption to the commissioning process.
In his report, Mr Harvey relied on the details of network availability as set out in Clarke’s letter of 11 November 2022 submitting the claim for EOT 12. But that data was copied verbatim from the Commissioning Test Schedule and Two Week Lookahead circulated by Clarke on 14 and 18 October 2022. There are numerous emails from Clarke’s Mr Granger to Clarke and Alinta personnel involved in the commissioning process, providing updated versions of these documents as testing and commissioning progressed. Mr Vickery agreed that these documents described what Clarke planned to do and, insofar as the lines in the schedule were “greyed out”, described what had happened in the past. He assumed that the schedules were prepared accurately by Clarke’s Mr Granger. Each of the entries relating to testing which formed part of EOT 12 are “greyed out”. These schedules are business records: s 69, Evidence Act. I reject Alinta’s submission that the premise of Mr Harvey’s opinion is without foundation absent Clarke calling its personnel who were involved in each test to give evidence.
I do not think the fact that Mr Harvey was not provided with emails in his instructions, showing that Generator 12 was non-operational for a period of time, supports the submission that his report was premised on insufficient information. Mr Harvey assumed that, because testing was carried out on Generator 12, this was the worst performing generator. Mr Harvey relied on an extract from contemporaneous business records of the testing events. The correspondence Mr Harvey was taken to in cross-examination did not undermine the accuracy of those records.
Alinta called no expert evidence in response to Mr Harvey. Nor was there any explanation as to why the network was unavailable. According to Mr Walker’s affidavit (tendered by Clarke), Clarke’s Mr Granger regularly sent a commissioning test schedule and two week lookahead Excel worksheet, called the “Commissioning Test Schedule” to Alinta. There were weekly commissioning meetings, planning for the week ahead. There were daily 7 am pre-start meetings, which would describe the intended testing, any simultaneous activities to be considered and clarify any communication requirements between Clarke and Alinta Operations. There was also a 4 pm commissioning de-brief meeting, which covered what was and was not achieved that day and what was planned for the following day. That is, Alinta had plenty of notice as to when Clarke needed access to the electricity network.
I am satisfied that Clarke is entitled to an extension of time for EOT 12. Practical Completion was delayed by Alinta’s failure to make the network available for commissioning, as required by cl 17.1.

The delay experts broadly agreed on the delay caused by EOT 12. Mr Griffith assessed eight days while Ms Halloran assessed five days. The difference between them was whether the testing carried out on 13 to 15 October 2022 was a normal part of the commissioning process required to achieve Practical Completion, or rectification of defects for which Alinta was not required to provide network access. If Alinta was responsible for providing network access on these days, then Ms Halloran’s assessment of the delay was the same as Mr Griffith.
The disputed three days of delay turn on whether Alinta’s obligations under cl 17.1 obliged it to make the electricity network available in order to attend to items on the Punch List. Clause 17 is silent in this regard. The clause simply obliges Alinta to make the electricity network available “which is capable of providing backfeed and receiving electricity that the Facility is capable of generating in accordance with this agreement”: cl 17.1(a). Clarke is obliged to manage and coordinate to ensure the Connection with the Facility and to comply with the Technical Rules and to indemnify Alinta for any breach of the Technical Rules: cll 17.1(b), 17.2, 17.3. The definition of Connection sheds no further light on the matter. Clause 17 is agnostic as to whether the Contractor wishes to use the electricity network to address an item on the Punch List or otherwise. That is, the fact that network availability was needed to rectify defects does not disentitle Clarke to the three disputed days of delay.
But Alinta’s argument, I think, turned on cl 12.11(a) (concurrent delay), that is, “disregarding the effects of th[e] Extension Event, Practical Completion was or would have been delayed during the same period by a cause of delay which is not an Extension Event”. This turns on whether the Punch List items investigated on these three days were “minor omissions and minor Defects” within the meaning of cl 2(a) of Sch 8, “which do not prevent the Facility from being used for the Intended Purpose; and … the rectification of which will not adversely affect the convenient use of the Facility for the Intended Purpose.”
On the days in question, both items had just been added to the Punch List. Alinta had given both items a Category 5. It appears to have been too soon to say whether Clarke agreed with that categorisation. Clarke sought network availability to investigate both Punch List items.
As to Punch List Item AE 169, there is no evidence as to whether it was a minor Defect or not on these three days. Mr Harvey was the only witness to comment on this Punch List item and he noted that, for the period which he was asked to examine, it was a Category 6 item and a minor Defect. But the period examined by Mr Harvey began on 24 October 2022. There is no evidence as to whether it was a minor Defect or a major Defect before then, beyond Alinta’s categorisation of the item as Category 5. That fact alone is not enough, I think, to establish that Punch List Item AE 169 was preventing the Facility from being used for its Intended Purpose.
There is more information available in respect of Punch List Item AE 170. Mr Harvey tracked through various iterations of the Punch List and noted the following additional entries beyond those earlier extracted:

Mr Harvey noted that AE 170 was originally issued as a Category 5 item but Clarke claimed that the defect was resolved and demonstrated on 14 October 2022. Alinta re-opened the defect when a power oscillation reappeared on 7 November 2022, albeit at a lower magnitude than when the item was initially reported on 4 to 6 October 2022. On 15 November 2022, Clarke requested that the defect be assigned as Category 6. Alinta accepted this request on 23 November 2022. Based on this information, in his opinion, AE 170 was a minor Defect with effect from 14 October 2022.
Is implicit in Mr Harvey’s observation that he agreed that AE 170 was not a minor defect before 14 October 2022. Nor did Mr Harvey accept that the problem underlying AE 170 was necessarily due to a problem with NPS2. While resolving the oscillations was Clarke’s responsibility, Mr Harvey noted that oscillations may be a result of network constraints outside Clarke’s scope. There may be a harmonic disturbance, or oscillations of reactive power, caused by the network which Clarke was not able to control and, in fact, may not even be able to identify whether those conditions were there.
Whether the oscillations were caused by NPS1 or NPS2 or the network or a combination of this, I am satisfied that Punch List Item AE 170 was not a minor omission or minor Defect: Sch 8, cl 2(a). The occurrence of oscillations inhibited the Facility’s capacity to be connected to the electricity network: Sch 8, cl 2(b). These three days involved something of a ‘chicken and egg’ problem; the Facility could not be rid of this Defect absent investigation and testing but Clarke could not undertake investigation and testing without network availability.
Clause 12.11(a) records the contracting parties’ agreement as to how such a situation should be resolved: “The Contractor is not entitled to an extension of time for a delay … caused by an Extension Event to the extent that, disregarding the effects of that Extension Event, Practical Completion … would have been delayed” in any event. The Extension Event is Alinta’s failure to provide network availability, as opined by Mr Harvey.
The contemporaneous records indicate that Clarke struggled to investigate the problem on 13 October 2022 due to intermittent network availability at lesser loads than needed. Similar problems occurred on 14 and 15 October 2022, but Clarke could see no oscillations on 14 October 2022 and cautiously reported on 15 October 2022 that the problem appeared to be resolved, albeit further testing was preferred. If Alinta had provided network availability on 13 October 2022, would Clarke have been able to resolve this Punch List Item sooner? Where Clarke was liaising with Jenbacher in Austria, and Jenbacher’s engineers were observing the test remotely and providing input and feedback, I consider it likely that Clarke would have been able to resolve Punch List Item AE 170 sooner than it did and, likely, by the morning of 14 October 2022. As Clarke needed to resolve this Punch List item before achieving Practical Completion in any event, I will exclude 1.5 of these days as concurrent delay. Clarke is entitled to an extension of time of 6.5 days

Clarke’s delay costs sought for EOT 12 comprised labour costs, flights, accommodation, equipment hire and contracted services, bank guarantee costs, materials and subcontractor margin and subcontractor overhead recovery. The quantity surveyors calculated delay costs on either five days or eight days. I have allowed 6.5 days.
For eight days delay, Mr Cox arrived at a figure of $162,517.64 while Ms Halloran calculated $142,675.31. Using Ms Halloran’s labour rates, Mr Cox calculated $125,709.31 while Ms Halloran arrived at a figure of $93,146.94.
For five days delay, Ms Halloran assessed delay costs at $63,277.90. Using Ms Halloran’s labour rates, Mr Cox arrived at a figure of $84,971.94. Using Clarke’s schedule of labour rates, Mr Cox arrived at a figure of $114,007.52 while Ms Halloran arrived at the slightly lower figure of $102,514.19.
Again, Ms Halloran excluded Clarke labour costs for personnel assessed as performing non-time-related or direct work-related roles. Flight and accommodation costs were pro-rated over the delay period and for time-related roles only. Site equipment hire and contracted services costs were pro-rated as well and non-time-dependent costs were excluded. The costs of extending the bank guarantee were allowed but materials and subcontractor margin and overhead recovery were excluded.
For reasons earlier given, I consider that Mr Cox’s use of Clarke’s schedule of hourly rates for its personnel accords more closely to the language of the contract, as does his approach generally. If I take the delay costs calculated by Mr Cox for eight days delay, and divide that figure by eight, the result is $20,314.71 per day. If I do the same exercise with Mr Cox’s delay costs for five days, and divide that total by five, then the result is $22,801.50 per day. Where I have arrived at 6.5 days’ delay, and where the amounts in issue are not large, I have taken the mid-point between these ‘daily rates’ ($21,558) to calculate delay costs for 6.5 days, being $140,128. The figure is not exact but close enough. If the parties want to give me the exact figure, I will amend the orders accordingly.

Clarke contended that Alinta waived its right to insist upon satisfaction of the conditions precedent in cl 12.1(b)(2) or (3) because it did not comply with cl 12 either. The Superintendent did not respond to EOT 1 within the required period and Alinta failed to cause the Superintendent to do so. Nor did Brett Anderson assert that cl 12.1(b)(3) was not satisfied because service was not effected on the then Superintendent.
Clarke submitted that cl 43.3 did not preclude waiver: Civil Mining & Construction Pty Ltd v Wiggins Island Coal Export Terminal Pty Ltd [2017] QSC 85 at [799] (Flanagan J). Alinta waived its right to require compliance with the conditions precedent by election: Agricultural and Rural Finance v Gardiner at [57]-[58] (Gummow, Hayne and Kiefel JJ); Corbett Court Pty Ltd v Quasar Constructions (NSW) Pty Ltd [2008] NSWSC 1163 at [110] (Hammerschlag J); SHA Premier Constructions Pty Ltd v Lanskey Constructions [2019] QSC 81 at [42]-[44] (Boddice J); Srinivas Pty Ltd v Vansan Construction Pty Ltd [2025] VSC 381 at [79]-[92], [161] (Matthews J); Civil Mining & Construction at [797].
Clarke submitted that cl 12 constituted a code for dealing with EOTs. The parties were entitled to insist upon strict performance: Walton v Illawarra at [40]-[42] (McDougall J); Parkview Constructions Pty Ltd v Futuroscop Enterprises Pty Ltd [2023] NSWSC 178 at [222] (Rees J). Alinta was not entitled to ‘cherry pick’ the provisions that suited it, insisting on the conditions precedent but “causing” the Superintendent not to comply with his obligations under cl 12.9: Agricultural and Rural Finance v Gardiner at [57]. Mr Ravi was not aware that he had to make his determination within a particular timeframe. Alinta’s correspondence was said to have encouraged the prolongation of the Superintendent’s delay. It would be unconscionable for Alinta to insist upon its rights whilst denying Clarke the benefit of a determination made in accordance with cl 12.9.
As pleaded, Alinta contended that it, at no time, waived compliance with cl 12.8(a) in any respect. The subject was not addressed in Alinta’s written submissions. Orally, Alinta conceded that none of Clarke, Alinta or the superintendents adhered to the timeframes specified by the contract. But while the superintendents dealt with EOT 1 even though it was ‘barred’, Alinta never said that it did not require compliance with the conditions precedent. Alinta’s actions were said not to be in the territory described in Civil Mining & Construction at [792]. EOT 1 was the first claim for an extension of time and there was no existing course of conduct. (That was certainly the case when EOT 1 was made, but was no longer the case by the time that EOT 1 was determined.)
Waiver “involves an abandonment of a right by acting in a manner inconsistent with the continued existence of the right”: Grundt v The Great Boulder Pty Gold Mines Ltd (1937) 59 CLR 641 at 658 (Latham CJ); [1937] HCA 58. Waiver is an imprecise term, capable of describing different legal concepts, notably election and estoppel: Commonwealth v Verwayen (1990) 170 CLR 394 at 406 (Mason CJ); [1990] HCA 39. As Mason CJ there explained, an existing legal right is not destroyed by mere waiver; unless consideration is present, something in the nature of an election or an estoppel is required. Waiver amounting to an election occurs where a party is entitled to alternative inconsistent rights and acts in a manner which is consistent only with having chosen to rely on one of these rights: at 406-7 (Mason CJ), 452-3 (Dawson J). Waiver may also arise where a person agrees not to raise a defence or conducts themselves as to be estopped from raising it: at 407.
Clause 43.3 does not stand in the way of the suggested waiver. As Flanagan J explained in Civil Mining & Construction at [799]:

Likewise in SHA Premier, the principal waived compliance with contractual provisions in respect of variations by adopting a practice of issuing work orders, thereby waiving its entitlement to subsequently insist on strict performance of the contractual terms in respect of variations: at [44].
I consider that Alinta waived its right to insist upon satisfaction of the condition precedent in cl 12.1(b)(2) and (3) for three reasons. First, the contractual regime for EOT claims to be determined promptly, by a fair and reasonable arbiter, had entirely broken down. None of the timeframes for the Superintendent’s determination of EOTs were observed. Alinta may not have helped in this regard, inserting itself into Clarke’s applications for EOTs, providing extensive submissions and unsolicited responses to Clarke’s submissions to the Superintendent, often on the day when the Superintendent would otherwise have been due to provide a determination. None of this was conducive to the Superintendent determining Clarke’s claim for an EOT within 15 Business Days. Mr Ravi was “overwhelmed” and, ultimately, neglected to determine EOT 1 at all. The same pattern of non-conformity followed during the reign of Mr Marshall.
The Superintendent’s role was then undermined by Mr Marshall’s private communications with Alinta. The Superintendent’s role was effectively destroyed when Alinta replaced him on becoming aware that his indicated ‘fair and reasonable’ determination of whether Practical Completion had been achieved was not to something with which Alinta agreed. Where the process mandated by the contract for the Superintendent to determine EOTs had been observed in the breach, Alinta waived its right to have Clarke held to strict compliance with the procedural requirements of that regime.
Second, by asking Mr Anderson to belatedly determine EOT 1, Alinta thereby chose between inconsistent rights and waived reliance on the failure to comply with the conditions precedent. The starting point is that, throughout this protracted process, Alinta was clear in its correspondence that Clarke had failed to comply with the conditions precedent in cll 12.6 and 12.8 such that EOT 1 should simply be refused. That said, Alinta then proceeded to respond, at length, as to why Clarke was not entitled to EOT 1 in any event or without prejudice only entitled to a portion of the claim.
By October 2022, now 19 months since Clarke made EOT 1, Practical Completion was imminent. Alinta did not need to have EOT 1 determined in order to calculate liquidated damages once Practical Completion had been achieved. The contract provided a mechanism for Alinta to repay liquidated damages if the Date for Practical Completion was later extended: cl 19.1(b). (Consistently with this, Alinta levied liquidated damages before EOT 12 was determined.) Also looming was a compelling claim by Clarke for breach of cl 38.2(a) of the contract, which obliged the Principal to ensure that the Superintendent performed its functions “within the time expressly required [or] within a reasonable time.”
Against that backdrop, Alinta now asked the third Superintendent to determine EOT 1 at his earliest convenience. When commissioning Brett Anderson with this task, Ms Phillips provided him with a link to the relevant correspondence. I do not know what correspondence was included in the link. Presumably, it was the same correspondence I have read. Presumably, Mr Anderson thereby became aware that Alinta had maintained throughout that EOT 1 failed for want of compliance with the conditions precedent. He would also have become aware that Clarke accepted that it had omitted to provide the Superintendent with EOT 1 in time.
Having been given this task, Mr Anderson sought a wide range of material from Alinta. The material sought indicated that he was proposing to review EOT 1 on a substantive basis, having regard to the native file for the initial program and subsequent monthly reports, rather than on the simple point that the Superintendent was not initially copied on the notices of delay or EOT 1. Alinta provided the material sought without demur.
There is a real disjunct here between the contractual requirements, Alinta maintaining its contractual position in correspondence, and conduct. As Matthews J observed in Srinivas, “Waiver is determined objectively by reference to whether the conduct is inconsistent with the maintenance or assertion of a particular right” and does not depend on whether a party intended to waive that right: at [161].
Viewing these events overall, I consider that Alinta’s conduct in instructing the third Superintendent to determine EOT 1 was inconsistent with the assertion that EOT 1 should simply be rejected for failure to copy the notice of delay and EOT 1 to the Superintendent in the first place. Alinta had already made that point in correspondence. Alinta was not asking Mr Anderson to determine EOT 1 to be nice to Clarke. Alinta was acting in its own interests to protect itself from a claim for breach of contract under cl 38.2(a). Alinta elected to have Clarke’s claim for EOT 1 determined on a substantive basis by the Superintendent to improve its position in respect of any claim under cl 38.2(a).
Third, the Superintendent was a “Principal Associate”: cl 1.1. Alinta was responsible for the acts or omissions of a Principal Associate, this being a Compensation Event: pars 2 and 3, definition of Compensation Event; cl 1.1. The Superintendent was the Principal’s agent.
I do not have the complete picture as to how Mr Anderson was briefed with this task, where Mr Thomas did not give evidence. On the available contemporaneous material, I think it is significant that, on being given this task, Mr Anderson privately communicated to Mr Thomas, seeking a wide range of material, “To ensure our review is without reproach”. Mr Anderson appears to have been alive to Alinta’s concern to mitigate the risk of a claim for breach of cl 38.2(a) and (b). As in Civil Mining & Construction, the Principal’s representative accepted and decided EOT 1 without reference to the notification requirements: at [796]. Mr Anderson was presumably aware of the notice requirements, having been provided with the relevant correspondence which canvassed that point. He did not require strict compliance with the condition precedent or decide EOT 1 by reference to that provision: at [797]. The contractual requirements were waived by the conduct of the Principal’s own agent.

Clarke contended that it was delayed in commencing the works as a result of Alinta’s failure to complete the relocation of underground services. Clarke issued notices of delay accordingly. After Clarke prepared a variation proposal to relocate the services, at Alinta’s request, Alinta proceeded to engage a third party to undertake these works. On 24 December 2020, Alinta gave Clarke another notice under cl 15.1(a), granting non-exclusive access to the site. The incomplete works were detailed in the Project Status Report provided on 13 January 2021 and, ultimately, Alinta requested Clarke to provide a variation proposal to complete these works. By 27 February 2021, Clarke had completed the relocation works, including satisfactorily backfilling and compacting the land disturbed by the removal of the services. Clarke was not able to commence the civil and structural works until 28 February 2021.
What was the Extension Event that first delayed the Work? Clarke put forward, essentially, three contenders.
First, Clarke contended that Alinta’s breach of cl 2.3 of the contract – issuing a notice to proceed before it was in a position to provide non-exclusive access to the site – gave rise to a Compensation Event, which in turn constituted an Extension Event under the contract, and provided a basis for EOT 1. I have concluded that this was not “a breach of this agreement by the Principal”.
Second, Clarke contended that Alinta’s failure to ensure that underground services were moved from the Facility Land, and to adhere to its representation that it would relocate such services by either 3 September 2020 or 16 October 2020, prevented Clarke from commencing civil and structural Work as planned. Further, Alinta failed to properly backfill the soil disturbed by the relocation works by either 3 September 2020 or 16 October 2020. Both failures were said to constitute a negligent act or omission by Alinta, or an act or omission, being a Compensation Event and thus an Extension Event.
Alinta accepted that, after execution of the contract, it stated that it would remove and / or relocate certain services, being the sewerage line, Telstra line and service water line. But these services were removed by 24 December 2020, or alternatively, 6 January 2021 or, alternatively, 12 January 2021. Alinta denied having made the alleged representations.
I have found that the representations were made by Mr Wozniuk before the contract was signed. As earlier set out, Alinta repeated this representation at a series of project meetings. I have also concluded that the removal of existing underground services did not form part of Clarke’s scope of works under the contract. Alinta was obliged, under cl 15.1, to give Clarke access to the site sufficient for Clarke “to perform the Work” which, according to the initial program, was bulk earthworks. Further, to the extent that Alinta removed existing underground services after the date of the contract, then Alinta was obliged to return the site to the condition that it was in before the services were removed, including backfilling and compacting the land disturbed by its works to a level consistent to the land before those works were performed: cl 16. Alinta’s failures in this regard were a Compensation Event. It was a breach of the agreement by the Principal and an act or omission not caused or contributed to by the Contractor’s failure to comply with cl 9.1: pars 1 and 3, definition of Compensation Event. I do not think it was a negligent act or omission under par 2 of that definition. That does not matter.
Third, Clarke contended that Alinta should have issued a notice of delay on 15 October 2020, where it was guilty of delay as it had not removed the underground services and this was likely to delay the works. The same could be said as at 20 October 2020, between 24 November 2020 and 4 December 2020 and as at 4 January 2021.
Alinta contended that whether it gave notice of delay was neither here nor there. I agree that, where Clarke did not suggest that this was an Extension Event, it is not necessary to consider this breach of contract further.
Fourth, Clarke contended that the Superintendent failed to assess the EOT 1 claim within the required time, and Alinta failed to ensure that the Superintendent did so. But this was not said to give rise to an Extension Event either and can be put to one side too.
It follows that there was a Compensation Event, being Alinta’s failure to remove the existing underground services, compacting and backfilling where necessary to return the site to the state it was in on the date of contract, before Clarke was due to arrive on site to commence bulk earthworks.

Alinta denied that its relocation of existing services prevented Clarke from performing the Works. Clarke had warranted that it had inspected and investigated the site and acknowledged that it was not entitled to make any Claim arising out of Site Conditions: cl 16.1. It was Clarke’s design for bulk earthworks that intruded onto BHP water lines (outside the Contractor Site). Clarke failed to provide a compaction value for backfilling and trenching. Clarke failed to progress the Work and / or there was concurrent delay for which Clarke was responsible and Clarke failed to take all reasonable steps to mitigate delay: cll 12.11, 12.12.
Alinta admitted that not all site services had been relocated as at 4 January 2021 but contended that Clarke was not thereby delayed in progressing the Works. The problem was that Ahrens’ tender pricing was on the basis of complete and unrestricted access to the site rather the non-exclusive access provided by the contract. Ahrens was not prepared to commence work absent a signed contract, and this did not occur until 11 February 2021. Clarke did not have a contract with Ahrens, a construction methodology (until 24 February 2021), safe work method statements (until 27 February 2021) or materials to commence the Work in any event.
Clarke contended that it had not sought to obtain tender pricing on the basis that Ahrens would be given complete and unrestricted access to the site. Ahrens was in a position to commence work in October 2020 under a purchase order issued on 1 October 2020. Ahrens accepted the purchase order by correspondence and by its conduct in mobilising to site. Purchase orders were a commonly accepted way of completing the works. The reason why Ahrens was not prepared to commence work, and why it required a subcontract, was that Alinta had not completed the relocation of underground services.
Alinta’s delay was said to have caused other delays and difficulties between Clarke and Ahrens. Ahrens had mobilised to site and was prepared to commence the bulk earthworks in mid-October 2020. Ahrens then refused to come on site because it did not have control of the site. Clarke submitted that Ahrens was ready and able to commence the bulk earthworks when initially scheduled but, by February 2021, the situation had changed. Ahrens’ insistence that it enter into a formal contract arose because it felt it had been disadvantaged by the delay commencing the earthworks and a potential change in the scope of works. This was a consequence of Alinta’s failure to comply with its promise to remove the services. There were practical limits on what Clarke could do to compel Ahrens to undertake the work.
Clarke submitted that this was not a case where it sat by without attempting to comply with its duty to mitigate. For much of that period, Alinta could think of few activities that Clarke could perform. Nor did Ahrens contemplate performing works while the underground services were being removed. Nor would the parties have contemplated that, when Alinta removed existing underground services, it would leave the site in a condition that would create more work for Clarke, where it was a fixed price contract. Clarke contended that it was unsafe and impractical to complete bulk earthworks prior to this being done. Clarke otherwise sought to take practical steps to mitigate delay.
The parties’ contentions and evidence on these issues involved, essentially, a first tranche of lay witnesses and contemporaneous documents as set out at the beginning of this judgment and a second tranche of expert evidence concerning bulk earthworks. Whilst both tranches are relevant to determination of these issues, it is convenient to deal with the parties’ arguments concerning the first tranche before considering the expert evidence.
Clarke did not call for tenders on the basis of complete and unrestricted access to the site; this was not mentioned in Mr Stevens’ RFQ. But that was the basis on which Ahrens submitted a quote, being “Site access to all areas shall be 100%”. Clarke had no reason to think that would not be the case, where Alinta had said that it would remove existing underground services before Clarke arrived on site. The contract and the attached program were consistent with this arrangement.
I reject the submission that Clarke was unable to begin bulk earthworks according to the program in any event, absent executing a contract with its subcontractor. Ahrens was quite prepared to mobilise to site on the basis of a purchase order and did so (twice). Notwithstanding the absence of a signed contract, Ahrens proceeded to submit variations and EOTs. Alinta did business with FRC in the same way, albeit I accept that FRC’s scope of work was much less.
Problems emerged when Ahrens could not get on with the job as planned, and for a protracted period. Clarke and Ahrens’ bickering about variations and EOTs already submitted did not help. Tempers frayed as time went on. But fundamentally, Clarke and Ahrens were faced with a change in circumstances brought about by Alinta’s inability to effect the removal of existing underground services in time for bulk earthworks to commence according to the program. That was largely because Alinta had underestimated the types, and extent, of existing underground services on the site, notwithstanding that Alinta had information in its possession which enabled Mr Schofer, at least, to prepare a more detailed and accurate picture of what lay beneath the ground. But absent Alinta’s delay in removing existing underground services, the strains between Clarke and Ahrens would not have had an opportunity to develop. None of these problems would have arisen.
Clarke examined every which way to commence bulk earthworks sooner. Clarke endeavoured to persuade Ahrens to begin on site whilst FRC continued to work, including by starting on part of the site whilst FRC finished work on another. Not even Mr Shuker thought that was a good idea. He was not sure why someone would mobilise to the site to do bulk earthworks, “because it was always known that clearing needed to be done”. The contemporaneous records document Clarke’s sustained efforts to try to get Ahrens to go to site. Ultimately, Ahrens simply refused to do it. Clarke then hired FRC to go to site and do what work it could, while everyone waited for Ahrens.
The reasons for Ahrens’ refusal are hard to argue with, including that no time or cost would likely be saved. Further, and just as important, Ahrens was understandably reluctant to embark upon bulk earthworks without any assurance as to the quality of the backfilling and compaction undertaken by FRC when earlier removing underground services for Alinta. This had obvious cost implications, should the backfilling and compaction works prove inadequate and require further work. This had obvious risk implications, exposing Ahrens to a claim on its warranty should inadequate backfilling and compaction works diminish the quality of Ahrens’ work.
As to the suggestion that Clarke did not have a construction methodology and safe work method statements until shortly before Ahrens began work, Mr Stevens said, “it’s quite usual to do this just before you get onto site, because you need the people that are carrying out the works to do the paperwork”. His evidence on this was not challenged. The suggestion that Clarke did not have materials to commence the Work is a reference to fill from the quarry. The problem was not getting fill to site but getting a subcontractor to use the fill. That was Ahrens. For the reasons already outlined, Ahrens was not coming to site until the end of February 2021. Getting fill to the site any earlier would have been pointless.
For these reasons, so far as the first tranche of material is concerned, I am not satisfied that there was a concurrent delay by reason of inter alia Clarke’s delay in executing a formal contract with Ahrens; nor did Clarke fail to mitigate this delay in its efforts to get Ahrens to site.

It remains to consider expert evidence as to whether Clarke could have, or should have, commenced bulk earthworks before underground services were completely removed, in order to minimise delay. Mechanical engineer Mr Griffith was the expert for Clarke and civil engineer Nagamuttu Narendra Nathan was the expert for Alinta in respect of earthworks.
Mr Griffith examined the site plan showing underground services, circulated by Mr Whelan on 16 October 2020. Noting that the site footprint for civil works was some 100 m x 80 m, Mr Griffith regarded the construction site as “particularly compact”. Based on his construction experience, Mr Griffith regarded the site as offering limited ability to carry out multiple construction activities simultaneously safely and efficiently. On a small site, the interaction between different trades competing for work space, together with access restrictions and additional safety procedures, inevitably affected the ability of each trade to carry out their works in the most efficient manner. He had observed the practical effects of such interactions on many projects, and this resulted in productivity being lower than it would otherwise have been. The existing services shown in Mr Whelan’s drawing traversed from one side of the site approximately halfway across the site and prevented works from being accessed from all but one side of the site. Coupled with the small size of the site, Mr Griffith considered that it was impractical to commence earthworks until all of the underground services had been relocated. Not only was it inefficient to carry out earthworks at this time, but it presented a high risk that existing services could be damaged and reduce the efficiency and extend the time it would take to complete removal.
Mr Griffith considered that Clarke’s Weekly Project Status Report of 12 January 2021 indicated that there was unconfirmed scope and responsibility for the removal of underground services and unknown timing for completion. These conditions continued to make it unsafe and inefficient to carry out bulk earthworks at that time. Further, commencing bulk earthworks without being able to complete those works would provide little, if any, benefit in minimising the impact of the delay as undertaking bulk earthworks in two or more sections decreased efficiency, including additional work and re-work at the interface of each section and delay and disruption due to having to remobilise the construction crew. Given the small size of the site, the successor activities could not safely be commenced until all bulk earthworks were completed.
Where it was neither safe nor effective, and hence unreasonable, to commence bulk earthworks until existing services had been relocated, Mr Griffith considered that Clarke’s actions in assisting in the relocation of underground services by carrying out potholing to locate the type and location of existing services, completing a variation proposal and mobilising its subcontractor immediately after existing services had been relocated led to the conclusion that Clarke had taken all reasonably available steps to avoid or mitigate the delay. Where bulk earthworks was the first construction activity to be carried out after mobilisation, and was a necessary predecessor to its successor activities, the delay could not be mitigated or avoided by resequencing the works as the successor civil works activities could not physically start until bulk earthworks had been completed.
Mr Griffith considered that it was reasonable for Clarke not to have commenced bulk earthworks or other construction activities until 28 February 2021. The small area of available work and restricted access made it unreasonably inefficient to carry out any earthworks and presented a high risk that fire services or sewer lines could be damaged, with adverse impact on fire protection and health and safety implications should the sewer line (or other services) be damaged. Before 19 November 2020 (when Ahrens had completed its potholing works to identify the location of existing underground services), the nature and location of existing services was not known. This increased the risk of damage to the services and danger to the workers carrying out civil works before this date and was contrary to industry safe practice.
Mr Griffith considered that additional delay and disruption may have been caused if Clarke had mobilised its workforce and plant and equipment to commence bulk earthworks, without knowing when the full area of works would be made available such that the work could be completed once commenced. Proceeding in this manner may have caused additional cost due to the lack of continuity, requiring personnel and plant and equipment to be stood down and potentially demobilised from the site (again) until the remainder of the work site became available. In Mr Griffith’s experience, breaks in construction continuity always caused delay due to the time required to re-establish the construction crew at the workface and for the crew to re-familiarise themselves with the work. Further, it was unsafe for Clarke to commence bulk earthworks with other contractors on site and open unbarricaded excavations. Given the small size of the site and the successor activity to bulk earthworks, conduits and underground services could not safely be commenced until all bulk earthworks were completed.
Mr Nathan said the site was “like a 15 lot housing project”. He considered it “commonsensical” to conduct bulk earthworks on the site whilst remaining underground services were removed, including by the use of “spotters” or traffic managers. Only one spotter would be needed. Mr Nathan considered that there was no reason why earthworks could not have been commenced in half of the southern construction area which had no underground services at any time. This area was at least 1,800 m2 and was more than big enough to allow earthworks to proceed on a staged basis. Fill could have been brought to site by B-double trucks, spread and compacted.
In the other half of the southern construction area, where most of the underground services were located, Mr Nathan considered that Clarke could have carried out the earthworks progressively once services were relocated, to avoid delays to earthworks. He would expect a contractor to undertake a risk assessment and put in place appropriate safety measures and working arrangements to enable this to occur. Where Clarke only had to liaise with FRC, safety concerns could have been managed by designating site access, site turning and dumping areas and delineating the earthworks area with traffic cones, tapes and regular toolbox meetings. A staged approach to earthworks could have been taken with Ahrens, with any additional costs sought to be recovered from Alinta rather than delaying the whole of the works.
Mr Nathan was also of the view that Clarke was able to re-excavate and compact trenches in the southern construction area in five days, with appropriate plant and personnel. Having looked at photographs of FRC undertaking this work with manually operated plate compactors, he considered that an excavator mounted plate compactor should have been used for a quicker and safer result. It would have been a simple thing to hire an 8-tonne excavator with a vibrating plate in Newman and compact the existing trenches, rather than dig out the trenches and “make a big mess”. It would take a maximum of two days to finish re-compaction. Bulk earthworks could have commenced whilst trench backfilling and compaction works were underway, given the size of the site.
Mr Griffith disagreed that simply compacting the top couple of 100 mm of material and leaving the underlying material uncompacted would suffice, as it would potentially be subject to later subsidence. Nor did Mr Griffith agree that re-trenching and compaction could be done in five days, having regard to the tasks undertaken according to site diaries. There was nothing to indicate that the works carried out by FRC were not carried out expeditiously or efficiently given the constraints of a small site.
Mr Griffith noted that Mr Nathan was only asked to consider the impact of the sewerage line, the Telstra line and the service water line, but not all underground services that were on site. Relocating all services would have a cumulative impact on the time taken to do so, together with compaction, testing and the number of excavations and restrictions to access, each adding to the impracticality of commencing bulk earthworks prior to service relocation. The half of the southern construction area considered available for bulk earthworks by Mr Nathan was 65 m wide by 28 m wide, but the service water line ran along the edge. Once allowance was made for the works required to remove the service water line, with the necessary batter and safety gap, the available work area was more like 12 m wide, rather than 28 m. Little benefit would be gained by undertaking work on this area separately from bulk earthworks for the whole site.
Mr Griffith did not necessarily agree that a competent contractor, having been told that the site would be available, would immediately direct their subcontractor to mobilise to site. The contractor would want to make sure that the subcontractor would get continuity of work, to keep the subcontractor employed continuously. It would be pointless and, indeed, counterproductive to bring a subcontractor to site if they could not actually physically perform the work.
Clarke submitted that even if the method of work proposed by Mr Nathan was open, it would not have saved time because Ahrens took the view that what he was proposing was unreasonable and dangerous. Mr Nathan was unaware of the full scope of the work that was undertaken in the region of the bowl, because he was asked to assume that only certain services had to be removed, was not provided with FRC’s site diaries and had no understanding of the dimensions of the work otherwise being performed on the southern construction area. Using tapes, traffic cones and bunting to mark the safety zone was inconsistent with Clarke’s minimum safe systems of works. His analysis did not accommodate the “hindrance” which Ahrens in fact experienced as late as 22 February 2021.
Alinta submitted that by 6 January 2021, any remaining existing services were on the boundary of the Contractor Site or outside that site. Alinta submitted that the Court would accept the evidence of Mr Nathan that backfilling and compaction works could have been completed in five working days. To the extent that FRC took far longer than this to complete that work, this was said to be explained by the fact that FRC was undertaking various works during the period including vacuuming redundant potholes opened by Clarke, undertaking the relocation of the fire ring main, stockpiling soil and the like. Further the Site was not fully resourced, that is, more teams could have been brought on to do work. Clarke had safety systems in place to enable multiple trades to work on the site at once, including excavation. This involved spotters, barricades and procedures around existing services. Mr Griffith gave evidence by reference to legislation that was not in force at the time and without reference to Clarke’s systems of work. Nor did he have regard to the geotechnical report, which enabled a 90o angle of trench walls and repose for batters. Mr Griffith prepared his first report without reference to the time lapse photographs of the work on the site, which was said to demonstrate how the risk of excavation was managed.
Mr Nathan was an enthusiastic and delightful expert, who was more knowledgeable about earthworks. But Mr Griffith was more knowledgeable about the implications of undertaking the works in a particular fashion on a program.
I do not doubt that, with enough notice and planning, bulk earthworks could have been undertaken in conjunction with the removal of existing underground services. But proceeding in the manner described by Mr Nathan was not the basis on which Clarke had prepared to undertake the work. Nor was it the basis on which Ahrens had tendered to do the work. Both Clarke and Alinta had agreed to do their respective works for a fixed price. Following Mr Nathan’s suggestion of a staged approach to earthworks – and seeking to recover any additional costs from Alinta rather than delay the whole of the works – posed a palpable commercial risk. Alinta had not been receptive to Clarke’s claims for additional costs to that point, in particular, Alinta had flatly refused Clarke’s variation proposal for these works.
Further, Clarke was endeavouring to sort out this problem without the assistance of Mr Nathan or Mr Griffith. Clarke’s views reached at the time, by Mr Vickery, Mr Stevens and Mr Columbus, were based on their combined experience, site photographs, reports from Clarke’s personnel on site and Ahrens’ views on the subject. They concluded that it was not practical to proceed as Mr Nathan opined that they could have. Clarke’s views reached at the time were, I think, reasonable based on the material then at hand, including Clarke’s work health and safety obligations. I also have regard to the fact that Ahrens ultimately did offer to commence bulk earthworks whilst FRC remained on site, mobilised to site but was unable to start work. Ahrens “parked up” on discovering that “our site is other contractors working space”.
Having regard to the expert evidence, I am not satisfied that Clarke failed to mitigate delay by commencing bulk earthworks before underground services were completely removed.

In the second tranche of expert evidence, Mr Griffith was the delay expert for Clarke and Ms Halloran was the delay expert for Alinta. Again, it is sufficient to to set out how Mr Griffith approached the task, and to note where Ms Halloran disagreed with that approach.
The baseline program was that circulated by Clarke on 9 October 2020, attached to the September 2020 monthly report. The Extension Event began affecting the works on 20 October 2020, being the day that bulk earthworks were scheduled to commence in the baseline program. To assess the impact of the Extension Event, Mr Griffith added a delay activity to the baseline program for the relocation of existing services and linked that activity to “Site Mobilisation & Preparation” as the predecessor activity and to “Bulk Earthwork” as the successor activity. The forecast date of Practical Completion in the impacted program was 13 May 2022, being 64 calendar days. As the baseline program forecast the Date of Practical Completion as the same as the date provided by the contract, there was no Total Float in the program.
Mr Griffith considered that the cause of the delay was the failure by Alinta to relocate the existing services by the date required for bulk earthworks to commence as planned. Based on the assumption that relocation of the existing services did not form part of the Work, this failure by the principal constituted a Compensation Event and hence an Extension Event. The critical path in the baseline program ran through the “HV switch room – 11kV switchboard – subcontract; manufacturing switchboard” and “delivery of switchboard to switch room” procurement activities. Bulk earthworks became critical on 11 December 2020 after the 7.4 weeks float was reduced to zero by the delay. Critical delay commenced on 11 December 2020 and ended on 27 February 2021. Clarke was entitled to an extension of time of 64 days for EOT 1.
Mr Griffith was of the view that there was no concurrent delay as the baseline program showed no other construction works were scheduled to be carried out until after completion of the bulk earthworks. Nor were there any construction works scheduled to be carried out concurrently with bulk earthworks.
Mr Griffith considered that Clarke took all reasonably available steps to avoid or mitigate the delay. Ahrens was ready to commence bulk earthworks as originally planned and did commence bulk earthworks the day that the construction area was handed over. No part of the delay was caused by Clarke or its civil subcontractor. Mr Griffith did not attach any particular significance to the date when Ahrens signed its contract with Clarke, as his analysis was based on actual dates when Ahrens attended site to perform work, including long before the contract was executed.
The experts differed at this point in three respects.
First, Mr Griffith was instructed to assume that any extension to the Date for Practical Completion was to include any amount of float in any Work activity delayed. Mr Griffith noted that the affected activity, Bulk Earthworks, had a Total Float value of 7.4 weeks, which was reduced to zero by the delay. That is, 52 days of Total Float was consumed as a result of the Extension Event. Based on the assumption he was asked to make in respect of loss of activity float, Clarke was entitled to an EOT of 52 days for loss of float as well.
Ms Halloran agreed that there was 52 days loss of activity float but disagreed with the premise that it should be added. For reasons earlier given, I consider that Ms Halloran’s approach in respect of loss of activity float is consistent with the contractual language. No additional EOT should be given on account of the loss of activity float.
Second, Mr Griffith carried out a further analysis based on the program attached to the October 2020 monthly report circulated on 11 November 2020: see [166]. It will be recalled that Mr Viliani had amended the logic in that program between “Cladding of the Powerhouse and Insulation” and powerhouse electrical installation, from ‘Start to Start’ to ‘Finish to Start’. When Mr Viliani did so, Clarke was discussing the sequence of work with Ahrens and Alinta, apparently with a view to minimising the risk of incident or injury. I inferred that it was thought that it would be safer not to start powerhouse electrical installation until the cladding was complete.
Mr Griffith said he thought that it would be helpful to see what effect the change in logic had. This was relevant to delay analysis, even though that change occurred in the program circulated after the baseline program, as it indicated that the logic in the baseline program – that electrical installation occurred at the same time as cladding insulation – was neither reasonable, realistic or achievable. On this analysis, Clarke was entitled to an EOT of 92 days plus a further 24 days for loss of float. In this scenario, the critical delay commenced on 13 November 2020 and ended on 27 February 2021.
The change in logic remained in place until April 2021, when additional detail was added to this part of the program. The logic for Powerhouse 1 was changed somewhat, so that the electrical works began while roof cladding was partially complete. That logic differed from what Mr Viliani had proceeded upon when making the change in November 2020. But the change in logic remained the same for Powerhouse 2 until September 2021. The program logic for Powerhouse 1 remained essentially the same to September 2021, with electrical installation commencing once the roof cladding was 57% to 80% complete.
Ms Halloran agreed with Mr Griffith’s calculations on his further analysis but disagreed with the premise. Ms Halloran considered that powerhouse cladding and electrical works were not planned to commence until some six to eight months in the future. The hard logic in the program change was not supported by actual events in the As-built programs, which indicated that there neither powerhouse was constructed in this manner.
Clarke submitted that when considering the appropriate program, the parties had to look prospectively to events which were scheduled to occur many months in the future. The fact that the works came to be done, ultimately, differently does not mean that their prospective analysis was unreasonable or inappropriate. It could have been altered for a myriad of reasons which were entirely appropriate at the time of construction.
Alinta submitted that the Court would not infer in Clarke’s favour that the change made to the September 2020 program (as contained in the October 2020 program) was a change in network logic that was “reasonable” or otherwise “appropriate” within the meaning of cl 12.10(g). This was particularly so when the As-built works proceeded in parallel. Insofar as Mr Griffith considered the program change may be preferable to avoid safety issues, Alinta submitted that the As-built records showed that this was not a matter that troubled Clarke, with multiple disciplines co-ordinating works on the powerhouses while the cladding was being installed. Clarke had effective safety systems in place to manage risks involved.
Mr Griffith’s consideration of a change in logic in the subsequent program aligns with the principles of determining delay set out in cl 12.10, which provided:

Mr Griffith has followed these steps, identifying the program current at the time the Extension Event first delayed the Work (September 2020), and then considering whether that program was “reasonable, achievable [and] appropriate”. Where a substantive change to the logic was made in the next program, and that change in logic remained in place for six to twelve months, Mr Griffith’s opinion that this indicated that the September 2020 program was not “reasonable, achievable [and] appropriate” seems reasonable. It is a matter on which Mr Griffith was qualified to form a view.
Mr Griffith took this step in his analysis without a specific instruction to do so, that is, he considered that it was an appropriate analysis in discharging his task as a delay expert. I note also that the change in logic in the October 2020 program by Mr Viliani was after three “Incident / Injury Free” workshops conducted with Ahrens and Alinta, apparently with a view to minimising the risk of injury or incident. It was not a change in logic made after a delay event to exaggerate the effect of that delay event on the program. The change in logic was made after consultation with Alinta and for apparently good reason.
How the works were ultimately undertaken is not the focus of time impacted analysis. The focus is on the effect of the delay event on the program. According to the protocol of the Society of Construction Law Delay and Disruption Protocol as extracted in Alstom, “time impact analysis is based on the effect of Delay Events on the Contractor's intentions for the future conduct of the work in the light of progress actually achieved at the time of the Delay Event … the amount of EOT may not precisely reflect the actual delay suffered by the Contractor … it generates results showing entitlement:” at [1271].
As such, the fact that the change in logic was not how the works were ultimately undertaken does not undermine the reasonableness of Mr Griffith’s opinion. That does not matter for the purpose of a time impacted analysis. And it is the fact that the works were ultimately conducted differently that was the basis of Ms Halloran’s rejection of the October 2020 program. Where the contract requires the effects of the Extension Event to be assessed using a time impacted analysis, I consider that Mr Griffth’s approach is more closely aligned with the contract: cl 12.10(a).
Further, how these works were ultimately undertaken was likely impacted by the events in respect of EOT 4, where the works were re-planned and conducted out of sequence in order to accommodate the inability of Ahrens’ crews to get to site, the use of local casual labour and consequent efforts “to try to pull this back on track”. In the result, I accept Mr Griffith’s opinion on the change in logic.
The third point of disagreement between the experts was the assumptions that Ms Halloran was asked to make based on the expert opinion of Mr Nathan. Where some of the scenarios explored by Mr Nathan were abandoned by Alinta in its closing submissions, it is sufficient to focus on Scenario 3, being that bulk earthworks could have commenced on 6 January 2021. This was considered on two bases.
First, Ms Halloran assumed that re-trenching and compaction was not Alinta’s responsibility, or a competent contractor would have co-ordinated the works so that any re-trenching and compaction was undertaken in parallel with earthworks. On this basis, Ms Halloran calculated that delay was only 13 days. Mr Griffith agreed with Ms Halloran’s calculations but disagreed that commencing bulk earthworks by 6 January 2021 was safe or would provide any benefit in reducing the impact of delay.
Second, Ms Halloran assumed that Alinta was responsible for re-trenching and compaction and Clarke could not have co-ordinated those works with earthworks, Ms Halloran calculated a delay of 18 days. Ms Halloran added that there was nothing to stop Clarke making a claim for losses that arose due to carrying out works in a modified manner. Mr Griffith disagreed with Ms Halloran’s calculations, calculating a delay of 20 days (which Ms Halloran accepted) but remained of the view that it was unsafe and provided little benefit to proceed in this manner.
In the result, Mr Griffith and Ms Halloran agreed that, if Clarke could have commenced earthworks on 4 January 2021, then there were 13 days of critical delay plus 52 days loss of activity float and, on the alternative analysis (assuming that the Court considered that appropriate) there was 41 days critical delay plus 24 days loss of activity float. If the day to commence earthworks was 13 January 2021, then the experts agreed, with the same qualifications, that there was 20 days critical delay plus 52 days of activity float or, on the alternative analysis, 48 days plus 24 days loss of activity float. If the relevant date was 28 February 2021, there were 64 days of critical delay plus 52 days of activity float or, alternatively, 92 days plus 24 days loss of activity float.
The third point of difference between the delay experts can be put to one side. I was not satisfied that Clarke could, or should, have commenced bulk earthworks in conjunction with removing remaining underground services and backfilling and compacting the site to Ahrens’ satisfaction. In the result, Clarke is entitled to an EOT of 92 days.

The third tranche of expert evidence was in respect of delay costs. The quantum expert for Clarke was Mr Cox and, for Alinta, Ms Halloran. For reasons earlier given, I prefer Mr Cox’s approach to labour costs, the allowance of a margin on flights and accommodation, and his approach generally. I agree with Ms Halloran’s approach that delay costs should not include an amount for the loss of activity float. With that in mind, costs sought by Clarke in respect of EOT 1 included subcontractor costs (Ahrens’ variation for re-mobilisation of $74,580), site equipment hire, flights and accommodation, finance costs, labour and off-site storage.
Clarke’s quantity surveyor, Mr Cox, assessed the delay costs from 20 October 2020 to 27 February 2021, excluding the Christmas non-work period in the program and excluding activity float. In the joint report, he assessed delay costs from 10 December 2020 to 27 February 2021 at $541,247.59 and was of the opinion that these costs and expenses related to Work activities delayed, prolonged or disrupted and did not include the cost or expense of personnel and other resources redeployed.
If Alinta’s quantity surveyor, Ms Halloran, assumed that Clarke could not start bulk earthworks until 28 February 2021, then Ms Halloran assessed delay costs at $276,663.94, or using Clarke’s schedule of rates, $506,597.31. The latter figure is relevant given my earlier conclusions. The main point of difference, other than points of difference which I have already dealt with on other EOTs, was storage costs.
As for storage costs, Mr Vickery said that, as project manager, he needed to order specialised items for a project well in advance of when the item was needed on site, as these items are not available ‘off the shelf’ and often involved long manufacturing times. Ordering these items well in advance allowed for any unforeseen production or delivery delay and mitigated the impact of such delays on the project schedule. Specialist items, once ready for delivery to site, were usually stored by the supplier to keep the item in good condition. Given the delay encapsulated within EOT 1, the suppliers charged storage costs in respect of air radiators, HV electrical cables, generator ventilation assemblies, gas engine exhaust silencers and exhaust pipes and a station main transformer.
Having regard to Mr Vickery's further affidavit, Mr Cox allowed this in full. He considered that it was not appropriate to limit the cost of the delay period only as off-site storage charges may exceed the period by way of minimum charge or a minimum period. Mr Vickery had provided details of items that were required to be ordered in advance, the impact of delay and the need for additional storage beyond the delay period. Mr Cox considered that the storage requirements and timings had been validated.
As for off-site storage costs, Ms Halloran only included charges for the portion of storage costs that overlapped with the delay period. Where storage dates were not stated and overlap with the delay period could not be verified, the storage costs were excluded. Non-time-related charges such as one-off transportation expenses or single-load freight were not considered to be time related and were also excluded. Ms Halloran considered that there was no evidence that these costs were caused by the EOT claim. In some instances, the storage costs were for periods that were longer than the delay period and she had reduced the storage costs to align with the extent of critical delay.
As to off-site storage costs, Alinta submitted that Ms Halloran correctly excluded costs related to transport and insurance, as those amounts would have been incurred regardless of the delay. Ms Halloran has also correctly limited the recoverable costs to substantiated amounts referable to the delay period. While Mr Cox suggested that “off site storage costs may exceed the period by way of minimum charge or a minimum period”, but there was no evidence that was the case here.
Clarke submitted that Ms Halloran’s views in respect of storage costs would fall away if Clarke owns the float. Clarke submitted that cl 12.4 did not limit recovery to the costs and expenses incurred for periods where there had been no critical delay, nor qualify Clarke’s right to damages to costs incurred in the period of the delay. All that was required was an extension to the Date for Practical Completion and a causal link between that delay and the costs and expenses: GEC Marconi Systems at [1167]-[1170] (Finn J). The consequences of delay may pre-date or post-date the period of critical delay, including because other work is delayed. Storage costs were a prime example. A reasonable person in the position of Alinta should be taken to have known that many projects require specialised, made to order items which need to be ordered in advance and stored to ensure their ongoing availability.
As earlier noted, cl 12.4(a) provides that “the Principal must pay to the Contractor the reasonable additional costs and expenses directly incurred by the Contractor as a result of that delay”. Direct loss and expense has been equated with loss and expense which flows naturally from the breach: GEC Marconi at [1170]. The question is whether Clarke had to store these items as a consequence of the delay. It did. There does not need to be a neat correspondence between the period of delay and the period of storage for the storage costs to be recoverable. I consider that Mr Cox’s approach is reasonable.
Ms Halloran was also asked to assess delay costs on the assumption derived from Mr Nathan's opinion, that Clarke could have started bulk earthworks much earlier. As earlier mentioned, Mr Nathan provided three scenarios but, given Alinta's acceptance in closing submissions that Clarke could not have started bulk earthworks until January 2021, it is only necessary to consider Scenario 3. This was on two bases. First, if re-trenching and compaction was not Alinta’s responsibility, or a competent contractor would have coordinated the works, so that any re-trenching and compaction was undertaken in parallel with bulk earthworks such that there was no delay, then Ms Halloran assessed delay costs at $111,587.62 (being 13 days of critical delay). Second, if Alinta was responsible for re-trenching and compaction and Clark could not have coordinated those works with bulk earthworks and would have been delayed by five days, then Ms Halloran assessed delay costs at $124,217.87 (being 18 days of critical delay). Mr Cox calculated delay costs for Scenario 3 as $282,212.17 for the first basis. For the second basis, he calculated delay costs of an additional $29,166.72.
For reasons earlier given, I do not think it is necessary to consider delay costs on the basis of the scenarios provided by Mr Nathan where I have concluded that it was not reasonable or practicable for Ahrens to begin bulk earthworks before it ultimately did. In the result, I consider that Clarke is entitled to delay costs for EOT 1 of $541,247.59. I am uncertain whether this figure captures the delay costs in the event that EOT 1 was 92 days. The parties invited the Court to ask the delay experts for calculations on the basis of an extension of time other than the figures given by the quantum experts in their joint reports. If there is a difference for the 92 days, I would be pleased to know it.

If I am wrong about waiver, then Clarke contended that the Commencement Date should not be treated as 19 August 2020, as Alinta was in breach of cl 2.3 by issuing the notice to proceed when it did. Alinta was also said to be in breach of an implied duty of cooperation and, where Alinta cannot take advantage of its own breach of contract, was not entitled to invoke cll 12.1(b), 12.6 and 12.8 to bar the EOT 1 claim where, had Alinta not acted in breach of contract itself, those provisions would not have been enforced.
Clarke submitted that the ‘prevention principle’ prevented Alinta from doing anything to put an end to the parties’ agreement that the services be removed from the site before Clarke commenced work: Stirling v Maitland (1864) 122 ER 1043 at 1047 (Cockburn CJ), cited in D Lewison & K Hughes, The Interpretation of Contracts in Australia (2ed, 2025, Lawbook Co) at p 347 [6.13]; Probuild Constructions at [116], [118], [139] (McColl JA, Beazley ACJ and Macfarlan JA agreeing); Spiers Earthworks at [47], [62] (McLure P, Newnes JA agreeing); cf Growthbuilt Pty Ltd v Modern Touch Marble & Granite Pty Ltd [2021] NSWSC 290 at [26], [68]-[75] (Henry J).
Clarke submitted that Alinta should be taken to have contracted on the basis that it wished the contract to be performed and, accordingly, must be taken to have agreed that it would not actively prevent performance: The Interpretation of Contracts in Australia at p 347 [6.13]; Peters (WA) Ltd v Petersville Ltd (2001) 205 CLR 126; [2001] HCA 45 at 142 (Gleeson CJ, Gummow, Kirby and Hayne JJ). The contract envisaged that Clarke would have 567 days to complete the Works after the Commencement Date. In these circumstances, the proper construction of the contract was that Alinta could not give a notice under cl 2.3 which prevented Clarke from achieving Practical Completion within that timeframe, by issuing a notice to proceed where the underground services would not be removed in time for Clarke to start the Works.
Clarke contended that the ‘prevention principle’ was not displaced by cl 12. The superintendent had no discretion to grant an EOT where Clarke did not give a valid claim for an EOT. But Alinta was obliged to exercise its discretion under cl 12.2 reasonably, honestly and fairly, having regard to the ‘prevention principle’ and pursuant to an implied term that it exercised its discretion in good faith. When refusing to exercise its discretion under cl 12.2, as advised by its communication of 13 October 2021, Alinta did so without acknowledging that it had failed to give Clarke access to the Facility Land on and from 3 September 2020, and acted in breach of cll 2.3 and 15.1 and / or the implied duty of cooperation. Clarke contended that Alinta should have exercised its discretion to approve the EOT 1 claim and not relied upon any failure by Clarke to satisfy the condition precedent in cl 12.1(b).
Clarke submitted that the expression “absolute discretion” was not sufficient to exclude recourse to the prevention principle but may simply indicate that the decision was vested in, and only in, Alinta: Topfelt v State Bank of New South Wales at 13,216. Such words may exclude any constraint on a power that it be exercised in good faith or reasonably: Vodafone Pacific Ltd v Mobile Innovations Ltd [2004] NSWCA 15 at [195]-[198] (Giles JA, Sheller and Ipp JJA agreeing). However, this was said to be an unlikely construction where the contract related to the construction of a major power station and there was delay caused by an event beyond Clarke’s control: Macquarie International Health Clinic Pty Ltd v Sydney Local Health District (2020) 103 NSWLR 443; [2020] NSWCA 161 at [271] (Bathurst CJ, Bell P and McCallum JA agreeing). Even absolute discretion may be the subject of an estoppel: Pamplin v Irwin [2024] NSWCA 213 at [103]-[107] (Leeming JA, Bell CJ and Griffiths AJA agreeing).
Alinta accepted that there was a duty to cooperate: *Les & Zelda Investments Pty Ltd (*atf Les & Zelda Family Trust) v Whitehaven Coal Ltd (No 4) [2026] NSWSC 107 at [1130] (McGrath J); Mackay v Dick (1881) 6 App Cas 251 at 263 (Blackburn LJ); Stirling v Maitland at 1047; Butt v M’Donald (1896) 7 QLJ 68 at 70-1 (Griffiths CJ). But that was subject to the terms of the contract: Beerens v Bluescope Distribution at [54] (Nettle JA, Redlich JA agreeing); Campbell v Backoffice Investments at [168] (Gummow, Hayne, Heydon and Kiefel JJ). The prevention principle is a “reflection” of the duty to cooperate: Bensons Property Group at [114]. A failure to cooperate will only occur where there has been a breach of the contract: Bensons Property Group at [112].
Alinta accepted in its closing submissions that Clarke did not have non-exclusive access to the site until 24 December 2020 and, with the Christmas period, could not be expected to start work until 6 January 2021. Alinta agreed that there were existing services on the site as at 19 August 2020 but denied that Alinta could not give non-exclusive access to the Facility Land. Giving the notice to proceed under cl 2.3 did not preclude, prevent or excuse Clarke from being aware that the Works were delayed, or were no longer continuing to delay Practical Completion and / or complying with the conditions precedent in cl 12.1(b)(2) and (3). Nor, on a proper interpretation of the contract, did it abrogate or modify Clarke’s obligations to comply with the conditions precedent.
Alinta submitted that the contract expressly dealt with the consequences of a failure to cooperate by the definition of a Compensation Event including “a breach of the agreement by the Principal” and “any act or omission of the Principal or a Principal’s Associate”. The Contractor was entitled an EOT in this event, under cl 12. In these circumstances, Clarke could not point to an alleged act of prevention to contend that this agreed machinery could not be invoked by Alinta. To the extent that Alinta issued a notice to proceed and Clarke was prevented from performing the Work, Clarke could seek an EOT.
The first act of prevention relied upon by Clarke was Alinta issuing a notice to proceed when it was in no position to give Clarke the necessary access to the site to perform the Work. Where issuing the notice meant than time began ticking on the Date for Practical Completion, then it was said to behove Alinta to give an ex gratia extension of time under cl 12.2(a) even if Clarke failed to submit EOT 1 to the Superintendent on time. Clarke essentially submitted that Alinta should have exercised its discretion to extend time under cl 12.2(a), and the ‘prevention principle’ may lead the Court to conclude that Alinta was bound to do so. I have concluded that Alinta was not in breach of cl 2.3.
The second act of prevention relied upon by Clarke was that Alinta should have issued a notice of delay on various dates from 15 October 2020 to 4 January 2021 under cl 12.5(c). I have concluded that Alinta did breach the contract in this respect. Less clear was how these ‘acts of prevention’ should have led Alinta to exercise its discretion to extend time under cl 12.2(a) such that the Court should grant an extension now. Clarke’s submissions were silent on this point and I am tempted to treat this as not pressed.
Clause 12.5(c) and (d) provided:

The prevention principle is enlivened where conduct hinders or impedes performance; it is not necessary to demonstrate that it made performance impossible: Bensons Property Group at [122]-[127] (Niall, Emerton and Sifris JJA).
The purpose of cl 12.5(c) and (d) was, presumably, for the Principal to provide the Contractor with detailed information to enable the Contractor to make arrangements so that the Work was disrupted as little as possible and additional expense caused by the delay was minimised. Alinta provided at least some of this information during the course of its correspondence and meetings with Clarke. Likely, the fact that Alinta did not provide that information in the format required by the contract did not make it any easier for Clarke to deal with the delay caused by Alinta, but I do not consider that failure to give notices of delay hindered or impeded Clarke’s performance and amounted to an ‘act of prevention’, such that Alinta was obliged to, and the Court should now, give an EOT.
If I am wrong about this, the learned authors of Hudson’s Building and Engineering Contracts note that “In the absence of an applicable extension of time clause, acts of prevention by the [principal], whether authorised by or breaches of the contract, will set time at large and invalidate any liquidated damages clause. … Where the act of prevention … goes to part of the delay but not to the whole, the entire liquidated damages clause will still be invalidated, unless an applicable extension of time clause exists which enables a new completion date to be set”: at [6-033].
The question is whether the contract is effective to exclude the application of the prevention principle and the consequential loss of the right to liquidated damages. Everything turns on the proper construction of the contract. In Spiers, McLure P concluded that the purpose of the EOT provisions (the relevant clause there, cl 35.5, is set out at [119]) was not to exclude the prevention principle but to bring it into line with the implied duty to cooperate: at [61]. Her Honour added at [62]:

If I am wrong about this, then in the alternative to its contractual claim, Clarke contended that Alinta represented that it would relocate existing underground services including, but not limited to, a Telstra fibre line, mechanical services (such as fire water services) and water services. This representation was made at the site meeting on 26 July 2019 and the conversation between Mr Wozniuk and Mr Jose shortly before the contract was signed. Alinta’s progress in removing underground services was reported at the project meetings which followed on 11 and 25 June 2020, 16 July 2020, 17 September 2020 and 20 October 2020, followed by Alinta requesting a variation proposal from Clarke and then engaging a contractor itself.
By this conduct, Alinta was said to have represented that it would complete the relocation of underground services and in a way that would not delay Clarke’s work. This conduct gave rise to representations as to a future matter within the meaning of s 4 of the Australian Consumer Law. Clarke relied on these representations and did not take any steps to complete the relocation of underground services until 8 February 2021. But the representations were false, where Alinta did not have reasonable grounds to make the representations. The representations were misleading or deceptive, or likely to mislead or deceive Clarke to believe that Alinta would complete the relocation works and that Clarke would not be held responsible for any resulting delay to the Date for Practical Completion. The loss or damage suffered was the same, being denial of an entitlement to an EOT and delay costs. Alinta denied these allegations.
Applying the four steps identified in Self Care IP Holdings Pty Ltd v Allergan Australia Pty Ltd (2023) 277 CLR 186; [2023] HCA 8 at [80] (the Court), Clarke submitted that Alinta’s representations conveyed the meaning that the underground services would be removed in a way that did not delay the work. Clarke submitted that when considering what was said, one must objectively assess what was conveyed, having regard to all of the contextual circumstances: C Lockhart, The Law of Misleading or Deceptive Conduct (6ed, 2023, LexisNexis) at p 127 [3.40]. The circumstances indicate that Mr Wozniuk intended Clarke to rely upon his representations, where the purpose of the site visit was to allow prospective tenderers to formulate the scope of works.
Clarke submitted that the representations were in relation to a future matter. Alinta had not adduced evidence that Mr Wozniuk had reasonable grounds for making the representations, where it was his knowledge which is relevant for the purposes of s 4 of the ACL: Quinlan v ERM Power Ltd (2021) 7 QR 377; [2021] QSC 35 at [32]-[33] (Bowskill J); Girchow Enterprises Pty Ltd v Ultimate Franchising Group Pty Ltd (Final Hearing) [2023] FCA 420 at [16] (Thawley J); Australian Competition and Consumer Commission v Woolworths Ltd [2019] FCA 1039 at [129] (Mortimer J). The Court should preclude Alinta from affording the consequence of its conduct, in particular, relying upon the conditions precedent in cl 12.1 which sought to oust the consequences of its misleading conduct: Viterra Malt Pty Ltd v Cargill Australia Ltd (2023) 74 VR 1; [2023] VSCA 157 at [438]-[440] (Sifris, Walker and Whelan JJA); Brighton Aust**ralia Pty Ltd v Multiplex Constructions Pty Ltd (2018) 56 VR 557; [2018] VSC 246; DIF III - Global Co-Investment Fund LP v Babcock & Brown International Pty Ltd [2019] NSWSC 527 at [273] (Ball J).
Alinta submitted that it could not have made the representations alleged as there was no suggestion that Mr Wozniuk said anything about BHP water lines, backfilling and compaction. The potential clash with BHP water lines only arose from the fact that Clarke’s design extended beyond the Contractor Site and this was not known in May 2020. To the extent that Alinta represented in August and September 2020 that it would relocate the water, sewer and Telstra lines, those were representations as to future matters and Alinta had reasonable grounds to do so. Nor could Clarke be found to have relied on Mr Wozniuk’s representations given the entire agreement clause and that Mr Jose appreciated that Clarke should record such a thing in the contract.
I have already found that Mr Wozniuk represented at the site visit and shortly before the contract was signed that Alinta would remove existing underground services before Clarke arrived on site. This representation was repeated by Alinta personnel at the project meetings from June 2020 on. Alinta’s repeated statements on this subject were clear.
The next step is to consider whether the representation made was false, misleading or deceptive or likely to mislead or deceive, this being a “quintessential question of fact”: Australian Competition and Consumer Commission v Telstra Corporation Ltd [2007] FCA 1904 at [14]-[15] (Gordon J). When determining whether conduct is misleading or deceptive, the Court needs to ask itself whether the impugned conduct, viewed as a whole, had a sufficient tendency to lead a person exposed to the conduct into error: Campomar Sociedad Limitada v Nike International Ltd (2000) 202 CLR 45; [2000] HCA 12 at [98] (Gleeson CJ, Gaudron, McHugh, Gummow, Kirby, Hayne and Callinan JJ); Australian Competition and Consumer Commission v TPG Internet Pty Ltd (2013) 250 CLR 640; [2013] HCA 54 at [39] (French CJ, Crennan, Bell and Keane JJ); Campbell v Backoffice Investments at [25] (French CJ). Conduct is only likely to mislead or deceive if there is a real or not remote chance or possibility of it doing so: Global Sportsman Pty Ltd v Mirror Newspapers Pty Ltd (1984) 2 FCR 82 at 87 (Bowen CJ, Lockhart and Fitzgerald JJ).
When determining whether conduct is misleading or deceptive, it is necessary to consider that conduct from the perspective of a reasonable person in the position of the person complaining of it: Ireland v WG Riverview Pty Ltd (2019) 101 NSWLR 658; [2019] NSWCA 307 at [65] (Macfarlan JA, Bell ACJ and Barrett AJA agreeing), citing Butcher v Lachlan Elder Realty at [37]. In attending to this task, “It is necessary to view the conduct as a whole and in its proper context”: Australian Competition and Consumer Commission v Coles Supermarkets Australia Pty Ltd [2014] FCA 634 at [41] (Allsop CJ). It invites error to look at isolated parts of a corporation’s conduct: Butcher v Lachlan Elder Realty at [109]; Ireland v WG Riverview at [66].
Whilst Clarke had looked at the site itself, for the purpose of deciding whether to submit a tender and, later, for the purpose of preparing drawings, Alinta was likely to know more about the site than Clarke, including as to what the existing underground services were and how difficult it would be to remove those services in any given timeframe. It was reasonable for Clarke to think that Alinta knew what it was talking about.
Where Alinta was making a representation as to a future matter, that is, its ability to remove the existing underground services before Clarke got to site, the question is whether Alinta had a reasonable basis for making the representation. And I think the answer to this question may change depending on which representation is being considered.
At the time of the site visit, what Alinta did know is that the interface schedule included ‘As built’ plans and drawings from 1995 and 1996 on. From this schedule, which he appears to have helped compile, Mr Wozniuk would have appreciated that NPS1 had been constructed some 25 years earlier. Alinta’s engagement of a surveyor, McMullen Nolan Group, to locate underground services indicates that Alinta was not entirely sure what services had been installed, and where, in the intervening decades. That was the situation when the site visit was held. Mr Wozniuk did not know exactly what was under the ground and how difficult or time consuming it would be to remove it. But where tenders had yet to be submitted, a tenderer selected and a contract negotiated, it was reasonable to think that there was ample time to remove whatever services were there before the chosen tenderer came to site. The representation made at the site visit was not misleading or deceptive at the time it was made.
By the time of the meeting shortly before the contract was executed, Mr Wozniuk had the survey to hand, which warned that there may well be more underground services given the “very ineffective” radar scanning of the area. What Alinta also had, but apparently did not examine closely, was the Reliance Information. (When later reviewed by Mr Schofer, he produced a drawing which indicated that there were more underground services, and those services were more extensive across the site, than suggested by the survey alone.) Nor had Alinta prepared a scope of works for a contractor to remove the existing services, or begun to look for a contractor to do the work: see [119].
But there remained some time after the contract was executed before Alinta could expect the arrival of Clark. The program attached to the contract indicated that Clark was not expected to arrive on site until 16 October 2020. That was five months away. I am not satisfied that Mr Wozniuk’s representation made at that time was misleading or deceptive either.
I accept that Clark relied on these representations when executing the contract, but that was what the contract said anyway. As time went on, it became apparent that Alinta was unable to do what it said that it would. But it does not follow that Alinta’s pre-contractual representations were misleading or deceptive. Nor was there any representation that Clarke would not be held responsible for any resulting delay to the Date for Practical Completion. For these reasons, I would not have granted relief under the Australian Consumer Law.

If I am wrong about this, then in the further alternative, Clarke contended that Alinta was estopped from relying on cl 16.1 (Site Conditions), disputing Clarke’s entitlement to EOT 1 or otherwise contending that Alinta was not responsible for completing the relocation works. Clarke was to perform civil and structural works under the contract but, in order to do so, the relocation of underground services had to be completed. But Alinta was responsible for those relocation works, as acknowledged in various project meetings. By reason of Mr Wozniuk’s representations and what was said by Alinta at project meetings, Alinta represented that it would complete the relocation works and in a way that would not delay the Work to be undertaken by Clarke. By not accepting Clarke’s variation proposal and engaging FRC to complete the works, Alinta was said to have further represented, including in project meetings in November and December 2020, that it would complete the relocation works. Clarke justifiably believed in the truth of these representations and did not undertake the remaining relocation works until 8 February 2021.
Alinta was said to be attempting to resile from those representations by not undertaking the relocation works such that Clarke could commence its works at any time before 28 February 2021. Alinta also relied on cl 16.1 of the contract and disputed Clarke’s entitlement to EOT 1, contending that Alinta was not responsible for completing the relocation of underground services. Clarke would suffer prejudice if Alinta was permitted to do so, being denial of an entitlement to an EOT and delay costs. Alinta denied these allegations.
Clarke submitted that pre-contractual statements can found an estoppel despite the existence of an entire agreement clause: Saleh v Romanous (2010) 79 NSWLR 453; [2010] NSWCA 274 at [52] (Handley AJA, Giles JA and Sackville AJA agreeing); Crossman v Sheahan [2016] NSWCA 200 at [242] (Ward JA, Payne JA agreeing); Golden Mile Property Investments Pty Ltd (in liq) v Cudgegong Australia Pty Ltd [2016] NSWCA 224 at [70] (Ward JA, Basten and Meagher JJA agreeing).
Clarke further submitted that the meaning of representations is to be determined objectively according to the impact that whatever is said may be expected to have on a reasonable representee in the position and with the known characteristics of the actual representee: see PA Keane, Estoppel by Conduct and Election (3ed, 2023, Sweet & Maxwell) at [4-001]; Q (a pseudonym) v E Co (a pseudonym) [2020] NSWCA 220 at [15] (Meagher JA, Leeming and Payne JJA agreeing); Workplace Safety Australia v Simple OHS Solutions Pty Ltd (2015) 89 NSWLR 594; [2015] NSWCA 84 at [140] (Bathurst CJ, Basten JA agreeing), [195] (Emmett JA). The meaning of the representation may be informed by conduct over a period of time: Evans v Evans [2011] NSWCA 92 at [107] (Campbell JA, Giles JA and Sackville AJA agreeing). An estoppel by representation confers upon the representee a right to have his / her legal relations with the representor determined on the facts represented. It is generally a case of all or nothing: Estoppel by Conduct and Election at p 15 [1-023].
Clarke submitted that, where promissory estoppel arises, a court of equity may restrain the exercise or enforcement of the promisor's rights: Saleh v Romanous at [62], [73]-[74]; CPB Contractors Pty Ltd v Rizzani De Eccher Australia Pty Ltd [2017] NSWSC 1798 at [343] (Ward CJ in Eq); Kramer v Stone (2024) 281 CLR 484; [2024] HCA 48 at [37]-[40] (Gageler CJ, Gordon, Edelman and Beech-Jones JJ). A representation can be established even if the expectation that was induced had elements of uncertainty: Evans v Evans at [121], [124]; Trentelman v The Owners – Strata Plan No 76700 (2021) 106 NSWLR 277; [2021] NSWCA 242 at [120] (Bathurst CJ). Alinta should be required to fulfil the assumption on which Clarke relied: Kramer v Stone at [41]. Clarke was not required to start work before the services were removed because Alinta represented that this was so. Otherwise it would be unconscionable for Alinta to seek to avoid the consequences of its conduct by invoking procedural bars in cl 12: Saleh v Romanous at [62].
Alinta submitted that the estoppel case fell at the first hurdle as the representations were not made. (I disagree.) Further, there was nothing in the representations that concerned the enforceability of cl 12. The estoppel, if made out, merely provided a basis for preventing Alinta from contending that an Extension Event had not occurred, so that Clarke could then claim an extension of time under cl 12 subject to complying with the conditions precedent in cl 12.1.
The elements of promissory estoppel are set out above: see [289]. Alinta represented that it would remove existing underground services before Clarke arrived on site. That was what the contract said too. Alinta was in breach of contract by failing to provide Clarke with access to the site “to perform the Work” when bulk earthworks were due to start. That was a continuing breach which had the result, as Alinta accepted in its closing submissions, that Clarke could not be expected to start work until (at least) 6 January 2021. Alinta was in further breach of contract by failing to backfill and compact the land disturbed by its removal of underground services, to a level consistent with the state of the land before those works were performed, that is, to the Site Conditions referred to in the contract. Alinta maintained that it was not obliged to do this at the time. But did Alinta not represent that, if it failed to remove underground services in time, properly, or at all, then it would grant an EOT or suspend the contractual regime in respect of EOTs. Clarke did not plead nor prove that Alinta had induced an assumption that it would not insist on compliance with the contract in respect of EOTs.
Clarke contended that, if Alinta was permitted to resile from its representation, then it would suffer prejudice in the form of being denied an EOT and delay costs. But such detriment does not flow from Clarke’s conduct in refraining from removing the underground services in reliance on Alinta’s representation that it would. That detriment flows from Alinta denying Clarke’s EOT claim on the basis that the contractual requirements for EOTs were not met. The detriment is not connected with the representations pleaded and proved. For these reasons, I would not have granted equitable relief and, indeed, there is limited scope for estoppel in comprehensive contractual regimes.

Clarke sought to recover the same heads of loss from Alinta by reason of its failure to ensure that the superintendents performed their function under the contract. I have already determined whether Clarke is entitled to each head of loss. It was not suggested that, if Clarke failed to recover any particular head of loss that it could recover such loss from Alinta via the alleged breach of cl 38 of the contract. As such, no particular purpose is served in examining this additional cause of action. I do not propose to do so. This judgment is long enough.
Finally, Clarke sued each of the superintendents in tort. The damages sought against each superintendent were, effectively, the same remedies sought against Alinta in respect of the extension of time, variation, or Certification of Practical Completion as was within that particular superintendent’s remit. That is, no additional loss was sought from the superintendents than that sought, and now determined, vis a vis Alinta.
The first question is whether a duty of care was owed by the superintendents to Clarke. As McHugh J explained in Hill v Van Erp (1997) 188 CLR 159; [1997] HCA 9, “Anglo-Australian law has never accepted the proposition that a person owes a duty of care to another person merely because the first person knows that his or her careless acts may cause economic loss to the latter person”: at 211. As the majority of the High Court put it in Woolcock Street Investments Pty Ltd v CDG Investments Pty Ltd (2004) 216 CLR 515; [2004] HCA 16, damages for pure economic loss “are not recoverable if all that is shown is that the defendant’s negligence was a cause of the loss and the loss was reasonably foreseeable”: at [21] (Gleeson CJ, Gummow, Hayne and Heydon JJ).
The circumstances in which a duty of care will arise in a claim for pure economic loss are set out in Woolcock Street Investments v CDG, recently followed by the High Court in Mallonland Pty Ltd v Advanta Seeds Pty Ltd (2024) 283 CLR 507; [2024] HCA 25 at [39] (Gageler CJ, Gordon, Steward, Gleeson, Jagot and Beech-Jones JJ). In Woolcock Street Investments v CDG, the majority explained at [23]:

In Woolcock Street Investments v CDG, McHugh J elaborated, “In this context, vulnerability to risk means not that the plaintiff was exposed to risk but that by reason of ignorance or social, political or economic constraints, the plaintiff was not able to protect him or herself from the risk of injury”: at [80]. Further, the capacity of a person to protect themselves from damage by means of contractual obligation is often a decisive reason for rejecting the existence of a duty of care in tort in cases of pure economic loss: at [94].
For example, in Aquatec-Maxcon Pty Ltd v Barwon Region Water Authority (No 2) [2006] VSC 117, Byrne J found a want of vulnerability between the parties involved in a complex building project with well-documented contractual relationships. His Honour noted, “It cannot be over-emphasised that this is a major commercial project undertaken by a public authority supported by a firm of consulting engineers”: at [268]. Further, the contractual arrangements were of a very formal kind with specifications, a tender process and extensive discussions and negotiations between the public authority and builder. Further, “the parties in question are all professionals in varying aspects of the building industry who have come together to produce a complex and substantial engineering plant. They have bound themselves in a particular contractual hierarchy … by formal and sophisticated contracts … entered into at arm’s length after negotiation”: at [273]. His Honour noted that “the parties providing the services … assumed the risk of liability in the event of deficiency in those services and this was doubtless reflected in the price agreed to be paid for them”: at [274]. There was no duty to avoid economic loss for want of vulnerability between the parties in the contractual hierarchy.
Clarke contended that it was vulnerable to suffering loss if the superintendent failed to exercise reasonable care and skill in carrying out their responsibilities under the contract. It was at least reasonably foreseeable that Clarke could suffer loss and damage if the superintendent did not carry out their functions with reasonable care and skill, including if they failed to act independently and impartially. In the premises, the superintendent owed a duty of care to Clarke to exercise reasonable care and skill to avoid economic loss to Clarke and, by accepting their appointment, each superintendent assumed a legal responsibility to Clarke. Each superintendent was said to have breached this duty in determining, or failing to determine, the matters which arose during the course of their appointment. Alinta was said to be vicariously responsible for the conduct of Mr Ravi and Mr Marshall. (Alinta accepted that it was vicariously liable for their conduct.) The superintendents denied these allegations.
I consider that Clarke lacked the necessary “vulnerability” such that no duty of care was owed by the superintendents. There was a comprehensive and lengthy agreement between Clarke and Alinta setting out their respective rights and obligations. Both contracting parties were well-resourced and had legal assistance in drafting the contract. Clarke had the opportunity to include provisions in the contract that gave it recourse if the Superintendent did not do their job, and the contract included such provisions.
The contract provided that Alinta was to ensure that the Superintendent acted “honestly, fairly and reasonably and arrives at reasonable determinations”: cl 38.2. Clarke is able to pursue Alinta for breach of this obligation, as it has in these proceedings.
The contract provided that Alinta would pay “the reasonable additional costs and expenses directly incurred by [Clarke] as a result of” delays caused by a Compensation Event, where Compensation Event includes “a negligent act or omission of … a Principal Associate” and, in turn, “Principal Associate” included the Superintendent: cll 12.4, 1.1, see also cl 12.14. Further, the contracting parties agreed that they could dispute a Superintendent’s determination if they were dissatisfied. cll 35.3(a), 1.1.
A duty will not be imposed between sophisticated, well-advised parties who have negotiated a detailed contract: Woolcock Street Investments v CDG at [96]. Nor can it be said that “by reason of ignorance or social, political or economic constraints” Clarke was not able to protect itself from the risk of injury: Woolcock Street Investments v CDG at [80]. There was no ignorance. Nor were there any “social, political or economic constraints”. Clarke was an experienced commercial operator. There was no duty. It is not necessary to consider the remaining issues in the tort claim.

I consider that Clarke has largely succeeded in these proceedings. I have set out the costs orders which I consider ought follow. But I will hear from the parties if they seek a different order, including any special costs orders. For these reasons, I make the following orders:
Declare that the plaintiff is entitled to an extension of time of a period of 142 days to the Date for Practical Completion, as that term is defined in the Engineer Procure Construction Contract dated 15 May 2020 between the plaintiff and the first defendant (the Contract).
Declare that the Date of Practical Completion is 10 November 2022, as that term is defined in the Contract.
Judgment for $7,192,414 in favour of the plaintiff.
Direct the parties to confer on the matters at [749], [852] and [907] of the judgment and, within 14 days, provide any further calculations, noting the extent of any remaining disagreement, so that Order 4 may be varied accordingly.
Direct the parties to confer on interest pursuant to cl 22.11 of the Contract and, within 28 days, provide interest calculations to the Court, noting the extent of any remaining disagreement, so that the judgment sum in Order 4 may be varied accordingly.
Direct the parties to notify any errors or omissions within 28 days.
First defendant to pay the plaintiff’s costs of the proceedings.
Make no order as to the second and third defendants’ costs of the proceedings, with the intent that those costs be borne by the first defendant.
Order the plaintiff to pay the fourth defendant’s costs of the proceedings.
Grant liberty to any party to seek to vary the costs orders by providing submissions (limited to three pages) and affidavits in support of the costs order sought within 35 days, with any submissions in response (limited to three pages) and affidavits in response to be filed within 42 days of this judgment, such application to be determined on the papers.
Otherwise dismiss the Amended Summons and Amended Cross-Summons.

Clarke Energy (Australia) Pty Ltd v Alinta Energy Transmission (Roy Hill) Pty Ltd

At a glance

Court

Decision date

Before

Catchwords

Source

Catchwords

Judgment

Parties

Legislation Cited (8)

Cases Cited (105)

JUDGMENT

The task

The witnesses

The site

The tender

The representations

The contract

Removing underground services

Notice to proceed

Relocating site amenities

Asking Clarke to remove underground services instead

The program

Who ‘owns’ the float?

Civil works subcontractor mobilises to site

Alinta tries to do it for less

Finishing the job

Bulk earthworks begin

Alinta’s breach of contract

VO 05 – site amenities

Contractual provisions

Estoppel

Quantum

A slip with EOT 1

COVID-19 lockdowns

Superintendent “overwhelmed”

The relay panel

A ‘walk-down’

EOT 4 – COVID-19

Contractual provisions

Entitlement to extension

Duration of delay

“this panel is ‘live’”

EOT 11 – relay panel

Contractual provisions

Entitlement to extension

Duration of delay

Delay costs

Commissioning

Requirements for practical completion

Design Criteria

First Guarantee Test

The last superintendent

Second Guarantee Test

Practical completion

Date of Practical Completion

EOT 12 – network availability

Entitlement to extension

Duration of delay

Delay costs

EOT 1 – bulk earthworks

Contractual provisions

Waiver

Entitlement to extension

Concurrent delays / mitigation

Bulk earthworks

Duration of delay

Delay costs

Prevention principle

Australian Consumer Law

Estoppel

Liquidated damages

Early generation agreement

Other amounts

Superintendents

Orders