Rodney Dale Morrison v Coal Operations Australia Limited

Drake Personnel Ltd t/as Drake Industrial v WorkCover Authority of NSW (Inspector Ch'ng) (1999) 90 IR 432 Edwards v National Coal Board [1949] 1 KB 704 Fountain v Alexander (1982) 150 CLR 615 Knowles v Anglican Church Property Trust (No. 2) (1999) 95 IR 380 Law Society of New South Wales v Bruce (1996) 40 NSWLR 77 CASES CITED : McMartin v Broken Hill Proprietary Co Ltd (1988) 100 IR 241 Shannon v Comalco Aluminium Limited (1986) 19 IR 358 Slivak v Lurgi (Australia) Pty Ltd (2001) 205 CLR 304 WorkCover Authority of New South Wales v Fletcher Constructions Australia Limited (2002) 123 IR 121 WorkCover Authority of New South Wales (Inspector Byer) v Cleary Bros (Bombo) Pty Ltd (2001) 110 IR 182 WorkCover Authority of New South Wales (Inspector Legge) v Coffey Engineering Pty Ltd (No. 2) (2001) 110 IR 447

HEARING DATES: 04/27/2004; 04/28/2004; 07/22/2004 DATE OF JUDGMENT: 11/10/2004

APPELLANT: Mr S Crawshaw SC Mr P Ginters of counsel SOLICITORS: Crown Solicitor's Office LEGAL REPRESENTATIVES: RESPONDENT: Mr B Hodgkinson SC Mr M Shume of counsel SOLICITORS: Sparke Helmore

JUDGMENT: - 1 - INDUSTRIAL RELATIONS COMMISSION OF NEW SOUTH WALES IN COURT SESSION

CORAM : Wright J, President Boland J Staunton J DATE: Wednesday, 10 November 2004

RODNEY DALE MORRISON v COAL OPERATIONS AUSTRALIA LIMITED

Application for leave to appeal and appeal from the decision of Peterson J given on 15 August 2003 in Matter Nos IRC 6726 and 6727 of 2001 JUDGMENT OF THE COURT [2004] NSWIRComm 239

1 The application for leave to appeal and appeal before us is made pursuant to the provisions of s197A of the Industrial Relations Act 1996.

2 On 6 July 1998, an accident occurred at the Wallarah Colliery at Crangan Bay in the south eastern corner of Lake Macquarie. The Colliery was being operated by the respondent, Coal Operations Australia Limited. On that day, a section of the roof fell in causing fatal injuries to a coal miner, Mr Anthony Carroll, and seriously injuring another, Mr Tony Dickson. At the time of the roof fall, the miners were engaged in drilling the roof to secure it with roof bolts. 3

As a result of the above accident, the respondent was charged with two offences arising under s15(1) of the Occupational Health and Safety Act 1983. Those offences were characterised in the proceedings before us as the Erection of Roof Support Charge (Matter No IRC 6726 of 2001) and the Assessing Roof Stability Charge (Matter No IRC 6727 of 2001).

4 In his judgment, Peterson J dismissed both charges on two grounds: (i) That the defendant had made out a defence under s33(2) of the Occupational Health and Safety Act 1983 in that the work being performed at the time of the accident was work permitted to be done under the Coal Mines Regulation Act, Regulation and Rules , they being associated occupational health and safety legislation; and, in the alternative, (ii) The prosecution had not established a relevant failure by the defendant in relation to s15(1) of the Occupational Health and Safety Act 1983 .

5 The charges were pleaded as follows: IRC Matter No 6726 of 2001 On 6 July 1998, at the Wallarah Colliery, Crangan Bay, Nords Wharf, in the State of New South Wales, the Defendant, being an employer, failed to ensure the health, safety and welfare at work of all its employees, in particular, Anthony James Carroll and Tony Ian Dickson, in that it failed to provide or maintain systems of work that were safe and without risks to health contrary to section 15(1) of the Occupational Health and Safety Act 1983.

a) There was a potential risk to the health, safety and welfare of the employees working in the vicinity of the area described as Face area sequence 131, Production Panel 3 in Production District 3 on 6 July 1998 in that there was risk of a roof fall while the employees were working there;

b) The Defendant's failure and/or omission was the failure and/or omission to provide or maintain adequate systems of work that were safe and without risks to health in relation to the erection of roof support in the vicinity of the area described as Face area sequence 131, Production Panel 3 in Production District 3 in circumstances where roof bolting was to take place; c) There was a causal connection between the risk to the health, safety and welfare of the employees referred to in (a) above and the Defendant's failure and/or omission as dealt with in (b) above. IRC Matter No 6727 of 2001

On 6 July 1998, at the Wallarah Colliery, Crangan Bay, Nords Wharf, in the State of New South Wales, the Defendant, being an employer, failed to ensure the health, safety and welfare at work of all its employees, in particular, Anthony James Carroll and Tony Ian Dickson, in that it failed to provide or maintain systems of work that were safe and without risks to health contrary to section 15(1) of the Occupational Health and Safety Act 1983.

a) There was a potential risk to the health, safety and welfare of the employees working in the vicinity of the area described as Face area sequence 131, Production Panel 3 in Production District 3 on 6 July 1998 in that there was risk of a roof fall while the employees were working there; b) The Defendant's failure or omission was the failure and/or omission to provide or maintain adequate systems of work that were safe and without risks to health in relation to assessing the stability of the roof structure in the vicinity of the area described as Face area sequence 131, Production Panel 3 in Production District 3; c) There was a causal connection between the risk to the health, safety and welfare of the employees referred to in (a) above and the Defendant's failure and/or omission as dealt with in (b) above.

6 Specific failures were also particularised prior to the commencement of proceedings at first instance. These will be addressed later in this judgment.

7 The appellant appeals against the whole of the decision of Peterson J and the orders made. In so doing, the appellant identified the grounds of appeal as follows: (a) The trial judge erred in finding that the defendant had made out a defence under s33(2) of the Act; (b) The trial judge erred in failing to find that the defendant had failed to provide or maintain systems of work that were safe and without risks to health contrary to s15 of the Act; (c) The trial judge erred in failing to find that there was a potential risk to the health, safety and welfare of the employees working in the vicinity of the area described as Face area sequence 131, Production Panel 3 in Production District 3 on 6 July 1998 in that there was risk of a roof fall while the employees were working there;

(d) The trial judge erred in characterising (at paragraph 29) the charges and the proceedings that were before the Court as being a 'case [that] revolves around the techniques employed in achieving the bolting process rather than the ultimate efficiency of the process itself' ;

(e) The trial judge erred in failing to give consideration to, or adequate consideration to, the particulars and the submissions in relation thereto relied upon by the prosecutor in support of the charge in IRC 6726 of 2001;

(f) The trial judge erred in failing to give consideration to, or adequate consideration to, the prosecutor's submission that to the extent that the defendant's support rules dealt with the assessment of the stability of roof structures they are not rules for or with respect to the support of the roof that were enabled by the Coal Mines Regulation Act 1982 (NSW); (g) The trial judge erred (at paragraph 91) in finding that the prosecutor alleged 'that the failure to utilise rig-mounted bolting machines of the type which were used in other parts of the mine is the relevant failure.' ;

(h) The trial judge erred (at paragraph 93) in placing reliance on and concluding that because the experts' reports did not suggest that the accident in question could be anticipated the experts' reports went 'directly to the foreseeability of the accident and the question of whether there was any relevant, and identifiable, failure by the defendant/s.' ;

(i) The trial judge erred (at paragraph 94) in relying on the finding that 'none of the very experienced miners present at the time, and observing these features, recognised them as notifying the actual danger which was present' as providing a basis for the conclusion that the defendant had not failed to provide or maintain systems of work that were safe and without risks to health contrary to s15 of the Act;

(j) The trial judge erred (at paragraph 94) in placing reliance on the fact that it could not be concluded that an assessment of the roof at the relevant time would have produced the view that Mr Carroll was at 'serious risk' in undertaking the task he did as providing a basis for the conclusion that the defendant had not failed to provide or maintain systems of work that were safe and without risks to health contrary to s15 of the Act;

(k) The trial judge erred (at paragraph 96) in finding that an alternative method of roof support of having the 'roof supported with timber props in advance of the area in which Messrs Dickson and Carroll were bolting' would have resulted in employees working 'to an unavoidable extent' under unsupported roof;

(l) The trial judge erred (at paragraph 98) in placing reliance on 'the necessity of the relevant parties to respond to their assessment of roof condition' as providing a basis for the conclusion that the defendant had not failed to provide or maintain systems of work that were safe and without risks to health contrary to s15 of the Act;

(m) The trial judge erred in that his Honour found that the charge in IRC 6726 of 2001 had not been made out without giving consideration to, or adequate consideration to, the question of whether the defendant had made out a defence pursuant to s53 of the Act.

8 The factual background giving rise to the charges is largely uncontroversial.

9 The respondent operated and part-owned the Wallarah Colliery. As at 5-6 July 1998, coal was being mined at the Colliery from the Great Northern Seam. This seam is found between what is known as the Teralba Conglomerate (above it) and what is known as the Awaba Tuff Member (below it). Faults are known to occur in this seam and had occurred at the Wallarah Mine prior to the accident on 6 July 1998.

10 On 6 July 1998, the Wallarah Colliery was operating under support rules for first workings in the Great Northern Seam. Those support rules had been made pursuant to the provisions of s102(1) of the Coal Mines Regulation Act 1982 (CMRA) and approved as required pursuant to the provisions of s105 of that Act. When taken together, those sections state: 102 Support rules (1) The manager of an underground mine shall make rules (to be known as support rules ), not inconsistent with this Act, with respect to the support of the roof and sides of working places and roadways in the mine. and 105 Copies of rules and schemes to be sent to the district inspector (1) The manager of a mine shall send to the district inspector within 7 days of: (a) making any rules, or any alteration thereto, under this Division, or (b) preparing a scheme, or any alteration thereto, under this Division, a copy of the rules, scheme or alteration. (2) A district inspector shall, within 28 days of the receipt of rules, a scheme or an alteration sent to the district inspector by the manager of a mine under subsection (1): (a) serve on the manager a notice confirming the rules, scheme or alteration, or (b) take action under section 106 in respect of the rules, scheme or alteration.

11 The support rules so made and approved for the Wallarah Colliery provided: Great Northern Seam Minimum Support Rules Required for Remote Control Miner [1] During face advancement, a test hole is to be drilled at 3m centres at any place across the roadway, with a minimum depth of 0.9m. As appropriate, temporary support may be placed (at maximum 3m intervals) until such times a test hole is drilled. [2] The maximum distance of exposed roof beyond the last test hole or temporary roof support, to the face shall be 10m. [3] Workmen are not to proceed beyond the last test hole or temporary support unless the roof has been tested by sounding with a metal bar or suitable metal object & found secure. [5] Four way intersections are to have a minimum of 5 bolts, a minimum of 1.0m in length, located in similar positions as shown in the diagram. ie; One bolt in each quadrant & one in the approximate centre. This shall be completed immediately after the formation of the intersection. [6] A mining official may direct that additional support above the described minimum rules be installed when roof conditions deteriorate. [7] Roof Supports are to be installed to resin installation standards as displayed by the manufacturer.

12 In addition to the above written rules, the minimum support rules also contained, as required, diagrammatical illustrations of the positioning of test holes, roof bolts and temporary roof support (brattice props).

13 While the minimum support rules are identified to be the rules required for a Remote Control Miner, it is not in dispute they were the relevant rules applying at the time of the accident notwithstanding that a Remote Control Miner was not being used to insert the roof bolts.

14 As well as the minimum support rules, further general provisions with respect to support rules are contained in the Coal Mines Regulation (Support - Underground Mines) Regulation 1984. That Regulation relevantly provides: Support for travelling roadways and working places ... [6] The person for the time being in charge of a part of a mine shall ensure that the roof and sides of every travelling roadway and working place in that part of the mine are secure in accordance with the support rules for that mine. ... Voluntary setting of additional supports [12] Nothing in this Regulation shall be construed as preventing a person from setting supports in the person's working place in a mine at more frequent intervals than those specified in the support rules for the mine.

15 At about 11:00pm on 5 July 1998, a crew comprising Mr Ken Tytherleigh as Deputy and mine workers Anthony Carroll, Tony Dickson, Noel Pezely and Russell Anslow commenced night shift at the Wallarah Colliery.

16 The area in which the Work Team was working was in close proximity to and running at a shallow angle more or less parallel with a fault zone.

17 When the Work Team first reached the work area there was a large amount of water in what is known as the 2 CT intersection. This water was coming out of the fault which had been hit in another heading. The Work Team spent about 90 minutes pumping this water out. 18 The Work Team commenced cutting coal at approximately 1:15am on 6 July 1998. Mr Pezely was operating the continuous miner, Mr Dickson was acting as cable hand, Mr Carroll was driving the shuttle car and Mr Anslow was acting as a rouseabout.

19 The Work Team had cut and filled approximately 16 cars of coal during the shift when they hit the fault at the heading. As the mining had progressed, the miner had come closer to the fault, which was running at a shallow angle in towards B heading on the right hand side of the miner.

20 When the fault was hit, it was reported to Mr Ronald Wallace, the night shift Undermanager. Mr Wallace arrived at the worksite at B heading at about 2:00am.

21 At this point it is important, we believe, to refer to his Honour's judgment in outlining the factual circumstances following Mr Wallace's arrival at the work site. That is as follows: [36] ... ... He (Mr Wallace) inspected the area with Mr Tytherleigh. They made certain observations of coaltops (residues of coal attached to the roof) and water coming out of the roof towards the left hand side of the heading. A sounding of the roof indicated that it sounded good. [37] Mr Wallace deposed that upon sounding the roof it had a 'good ringing sound. It sounded very competent'. He said that he instructed Mr Tytherleigh that they would cease mining and that he wanted 'extra support put up, plus a row of props along the edge of the Fault, and then I wanted the area taped off'. [38] They then discussed where 3 cut-through would 'hole through'. It was measured and discovered that they were at that very point. They decided to square up the end of the heading before finishing. [39] Mr Wallace testified that he told Mr Tytherleigh that the extra support would be a double row of bolts with props along the edge of the Fault. [40] Mr Tytherleigh had no recollection of that instruction having been given by Mr Wallace although he said it was possible. The other members of the crew did not give any evidence of Mr Tytherleigh instructing them to undertake that work. [41] I note that Mr Wallace claimed he had told Mr Tytherleigh not to work under unsupported roof and that he had told Mr Dickson the same thing. However, he agreed that it was not possible to carry out such orders with the equipment available without working under unsupported roof. [42] Messrs Carroll and Dickson then had crib break. The continuous miner was flitted (removed) from the face and bolting in B Heading then proceeded. Up to this time the normal pattern of bolting with single bolts 3 metres apart had been undertaken. Mr Wallace testified that he ordered the bolting to occur thereafter at 1.5 metre spacing.

22 Whilst it is clear that there was some dispute as to the precise instructions Mr Wallace may or may not have given to Mr Tytherleigh, no issue was made of it in the hearing before us. What is clear is that after Mr Wallace gave his instructions, the mining activity continued with double bolting 1.5 metres apart. As we understand the evidence, no steps were taken to put up props along the edge of the fault.

23 Mr Wallace was at the work area for about one hour. Just before he left, there was a roof fall consisting of some ply that had fallen out of the face plus coal tops had fallen.

24 During the roof bolting process that continued after Mr Wallace left, water was coming out of the roof from the bolt holes. As well, the drill steel of the roof bolter was jamming, indicative, as his Honour found, 'of a poor roof.'

25 Later in the shift, Mr Carroll and Mr Dickson returned from their crib break and took over the roof bolting process from Mr Anslow and Mr Pezely. In handing over to them, Mr Anslow reported, in the process of drilling a hole, he had noticed a parting in the hole that was evidence of a soft layer in the conglomerate. 26 While Mr Carroll and Mr Dickson were bolting, they experienced problems with the air pressure in the Falcon roof bolter. While the air hoses were being checked, another fall occurred. This consisted of approximately six metres of stone. The roof had fallen back from the face to a point about 1.5 metres from where the last roof bolts had been installed.

27 Again, it is appropriate to refer to his Honour's judgment as to the events that followed: [45] After the fall the roof was sounded and still sounded competent. While Messrs Carroll and Dickson were drilling the last hole, Mr Dickson noticed a parting in this hole and the drill steel became jammed. Mr Carroll then attempted to free it either by striking it with another steel or pulling at it which was a normal way of freeing drills that were jammed at the mine. [46] At this point, Messrs Carroll and Dickson were working approximately 1.2 metres away from the last roof bolt they had inserted, which was the nearest support of the roof. [47] I am not able to accept the suggestion in the evidence of the Mine Surveyor, Mr Lord, that there was timber support in this vicinity. The suggestion is contrary to the evidence of those members of the mining crew who were present at the time. [48] It was while Mr Carroll was attempting to free the jammed drill steel that the roof fell, burying Mr Carroll and causing him fatal injuries and pinning Mr Dickson by the legs, which sustained multiple fractures.

28 In the proceedings before Peterson J, the respondent relied heavily on the provisions of s33(2) of the Occupational Health and Safety Act as providing a complete defence to the charges before the Court. Indeed, in the proceedings before us, the respondent submitted that the appellant had challenged his Honour's finding that s33(2) of the Occupational Health and Safety Act did provide the defence as had been contended by the respondents at first instance. That is so.

29 On that point, the respondents repeated the submissions made before Peterson J which, in part, stated: [1] The Prosecutor relies in relation to both charges (on) the proposition that the offence is committed when any of the relevant employees but in particular Mr Dickson and/or Mr Carroll worked under unsupported roof on the 5/6 July 1998. It is at a time when they are working under unsupported roof that they are said to be exposed to a risk. The Prosecutors case is answered by the application of section 33 of the Occupational Health and Safety Act 1983 (the 1983 Act) and in conjunction with the relevant provisions of the Coal Mines Regulation Act 1982 (CMRA) which deal with requirements for, and making of support rules and the regulations that deal with the same topic made under the CMRA. [2] Section 33(2) of the 1983 Act renders a person not guilty of an offence under Part III of that Act, which Part includes section 15, where the offence alleged is in respect of any act which is (either) expressly permitted (or omitted) to be done by or under the associated occupational health and safety legislation.

30 We would put to one side for the moment what we consider to be a misconception on the part of the respondent as to the proposition the prosecutor is said to rely upon in relation to both charges. We turn instead to the issue of leave to appeal relevant as it is to the reliance placed by the respondent on the ambit and construction of s33(2) of the Occupational Health and Safety Act as a defence to the charges before the Court. 31 The appellant submitted that leave to appeal should be granted because his Honour's decision contains significant errors. Those significant errors went, in part, to the proper construction and ambit of s33(2) of the Occupational Health and Safety Act. The proper construction and ambit of s33(2) of the Act has not been the subject of consideration at an appellate level. The provisions of s33(2) have been re-enacted as s132(3) of the Occupational Health and Safety Act 2000. The proper ambit and construction of those provisions raise substantial issues of importance and public interest that will have widespread application: see Knowles v Anglican Church Property Trust (No. 2) (1999) 95 IR 380.

32 In opposing leave, the respondents submitted that the principles enunciated in Knowles relevant to leave to appeal had not been satisfied, they being:

· leave will not lightly or automatically be granted;

· leave will be restricted to appropriate cases meeting the public interest test required by s188(2) of the Industrial Relations Act 1996;

· a factor for consideration is whether, in substance, a new or materially different case is brought on appeal;

· consideration is to be given as to whether an appeal raises substantial and important questions.

33 We accept the correctness of the principles enunciated in Knowles on the question of leave. They assist us in reaching our conclusion that leave should be granted. The matters raised in the appeal relevant to the proper ambit and construction of s33(2) of the Occupational Health and Safety Act (and its statutory successor) raises an important issue of considerable public interest. It is an issue with application beyond the proceedings presently before us and goes directly to prosecutions brought pursuant to the combined operation of the provisions of the Occupational Health and Safety Act and the Coal Mines Regulation Act together with the regulations and rules made pursuant to that Act. As well, for reasons we later develop, his Honour's judgment was in error.

34 Central to the argument raised by the respondent at first instance, and again before us, was the practical application of the minimum support rules, in particular, minimum support rule 3 which, by way of restating says: Workmen are not to proceed beyond the last test hole or temporary support unless the roof has been tested by sounding with a metal bar or suitable metal object and found secure.

35 At the time of the accident, the two workmen, Mr Carroll and Mr Dickson, were working under unsupported roof. They were doing so in order to continue with the roof bolting process. As a necessary prerequisite to that and in accordance with minimum support rule 3, the workmen would and did 'sound' the roof with a length of drill steel to assess its competency. In other words, a solid ring would be accepted as indicating a sound roof whereas a hollow or flat sound induced by the steel would indicate a 'drumminess' of the roof.

36 When the roof was sounded as good or competent, the workmen would then move forward under the unsupported roof to continue the roof bolting. That is the procedure that was being followed when the roof fell, killing Mr Carroll and seriously injuring Mr Dickson. In short, notwithstanding the tragic outcome, the respondent asserted that what Mr Carroll and Mr Dickson were doing in working under unsupported roof at the time of the rock fall was a system of work that was expressly permitted by the minimum support rules, rule 3 in particular; Those minimum support rules had been properly drawn up and approved as required by the Coal Mines Regulation Act and the Coal Mines Regulation (Support - Underground Mines) Regulation 1984. Accordingly, it was a system of work 'expressly permitted' and as such could not be an offence because of the operation of s33(2) of the Occupational Health and Safety Act which states: A person is not guilty of an offence under Part 3 in respect of any act or omission which is expressly required or permitted to be done or omitted by or under the associated occupational health and safety legislation.

37 Before dealing with the application and construction of s33(2) relevant to the matter before us, we turn to address what we consider is a fundamental misconception on the part of the respondent as to the proposition the appellant is said to rely upon in relation to both charges. It is a misconception that, in our view, has carried over into his Honour's judgment and led his Honour into error in that he failed to give proper consideration both as to the nature of the offences alleged as well as the failures particularised within each of the offences before the Court.

38 The respondent has consistently submitted, both at first instance and before us, that the appellant relied, in relation to both charges, on the proposition that the offence is committed when any of the relevant employees, but in particular Mr Dickson and/or Mr Carroll, worked under unsupported roof on 5/6 July 1998. That is, it is at a time when they are working under unsupported roof that they are said by the appellant to be exposed to a risk.

39 In our view, on a consideration of the offences charged and the alleged failures as particularised, the respondent's contentions as to the underlying premise of the appellant's proposition are not correct. Reference to the alleged failings identified by the appellant in the charges contains one reference only to the absence of any roof support within each of the charges.

40 In our view, what the prosecution is alleging within the offences charged are failures relating to the respondent's system of work going to assessing the stability of the roof and the erection of the roof support in the circumstances prevailing at the respondent's place of work on 6 July 1998 at Face area sequence 131, Production Panel 3 in Production District 3. In alleging the system of work offences, the prosecution subsequently, but prior to the hearing at first instance, particularised the failures it relied upon going directly to the overall system of work relevant to the offences pleaded. It is those failures that the prosecution is required to establish and for the judge at first instance to consider. There is some general reference to aspects of those specific failures contained within his Honour's judgment (for example, reference to the rig mounted bolting machines in paras [91] and [97] of his judgment). But there is no part of his Honour's judgment that we can point to that would demonstrate with certainty his Honour considered the failures relied upon relevant to the overall system of work in place at the time of the accident.

41 We turn to a consideration of the ambit and construction of s33(2) of the Occupational Health and Safety Act. This involves, firstly, an acknowledgement of s39 of the Act. Section 39 provides: The provisions of the Mines Inspection Act 1901 , the Mines Rescue Act 1994 and the Coal Mines Regulation Act 1982 and the regulations and rules made thereunder shall, for the purposes of this Act, be associated occupational health and safety legislation.

42 As well, s32 and s33 provide: (32) Subject to this Division, the provisions of the associated occupational health and safety legislation shall be observed in addition to the provisions of this Act and the regulations. (33) This Act to prevail (1) Except as provided by subsection (2), where any provision of the associated occupational health and safety legislation is inconsistent with a provision of this Act or the regulations, the provision of this Act or the regulations shall prevail. (2) A person is not guilty of an offence under Part 3 in respect of any act or omission which is expressly required or permitted to be done or omitted by or under the associated occupational health and safety legislation.

43 It is clear, in our view, the intention of Parliament was to render the provisions of the Occupational Health and Safety Act paramount when dealing with an employer's obligation to ensure the health, safety and welfare at work of employees (or non-employees as the case may be). As s33(1) makes clear, the Occupational Health and Safety Act shall prevail to the extent of any inconsistency as between its provisions and those in the associated health and safety legislation.

44 There is the exception provided in s33(2) to which s33(1) refers. That exception offers a defence in narrowly defined circumstances. That is, where an act is expressly required or permitted to be done, or an omission is expressly required or permitted to be omitted. Section 33(2) must be considered within the context of the legislation in which it appears, that is, in a statute that imposes an absolute obligation on employers to ensure the health, safety and welfare of workers at work.

45 The Coal Mines Regulation Act and the regulations and rules made thereunder are part of the legislative structure designed to ensure that employers meet their obligations consistent with the objects of the Occupational Health and Safety Act. This associated health and safety legislation is replete with an emphasis on safety. It was designed by the legislature to be such. As was said by the Minister for Industrial Relations and Minister for Technology in his Second Reading speech to introduce the Bill: The coal mining industry is undoubtedly a dangerous industry in which to work ... The principal bill and the regulations to be made under it will provide a comprehensive safety and health code. They will provide all the elements necessary to achieve a safe working environment.

Legislation, no matter how comprehensive or penal, will not improve safety within the industry unless management and workmen adopt a conscious attitude towards safe working practices. This means that management must plan and execute the working of the mine conscious of the need to preserve the safety and health of the workmen. It means, also, that the workers must perform their work conscious of their own safety and that of their work mates. Above all, it means that management and workmen alike should avoid the temptation to cut corners or to take unnecessary risks in order to maintain production or to execute a task.

46 Against that background of clear legislative intent of the Occupational Health and Safety Act and associated health and safety legislation, the approach to be taken to how s 33(2) is applied is a strict one given that, in the circumstances of this case, it allows support rules to be made in relation to a mine the effect of which is, contrary to the obligation on the employer under s 15(1) of the Act, to expressly require or permit an act or omission that may expose persons to risks to their health and safety.

47 We consider the Legislature's intention in providing for the exception in s 33(2) was that in allowing for support rules to be made that may expose persons to risks to safety, it envisaged everything practicable to be done to avoid that risk had been done. With all practicable measures in place an act or omission expressly required or permitted may then be done or omitted. Nothing outside of the precise requirement or permission is allowed to be done or omitted.

48 In other words, although the obligation under s 15(1) is to ensure that persons are not exposed to risks to health and safety, s 33(2) provides a limited exception. Thus, provided all possible precautions are taken, certain acts and omissions expressly required or permitted, but which may not be consistent with the duty to ensure safety, will not render a defendant guilty of an offence.

49 The support rules applicable at the time of the alleged offences purported to put in place, it seems to us, all practicable measures to avoid risks to safety. The rules have to be read together and no one rule can be viewed in isolation. So that the scheme of the rules involved the drilling of test holes, the placement of test holes, the placement of roof bolts, the placement of temporary support as appropriate and a reliance on the discretion of a mining official to direct additional support above the minimum rules when roof conditions deteriorate.

50 In this context and in addition, minimum support rule 3 provides that "Workmen are not to proceed beyond the last test hole or temporary support unless the roof has been tested by sounding with a metal bar or suitable metal object & found secure". In our opinion, the rule permits workmen to proceed beyond the last test hole or temporary support. That is, to be located under unsupported roof, provided the roof has been sounded and found to be secure. The word "secure", as it is used in the support rules, does not mean that there is no risk of a roof fall. The roof is only secure to the extent that it gives a solid ring and sounds "competent" when struck by the metal bar or does not sound hollow or flat (see [28] of Peterson J's judgment). Striking the roof may not indicate a fault or anomaly such as that described in the expert evidence before Peterson J and, therefore, may not reveal a serious risk to the safety of any worker located under unsupported roof. That workmen may be subjected to such a risk without it giving rise to an offence is, to say the least, of concern, but that is the effect of applying the exception in s 33(2).

51 Given our view that minimum support rule 3 permitted workmen to be located under unsupported roof it follows that there was no failure on the part of the respondent in so far as Messrs Carroll and Dickson were under unsupported roof using the Falcon Roof Bolter to bolt the roof. It does not follow, however, that the respondent is exculpated.

52 We will come to the specifics shortly, but it is inconceivable in our view, with all of the indicia of real, let alone potential, risks to safety existing with the unstable roof conditions, that s33(2) could afford a defence to an overall system of work that was, on any objective consideration, inherently unsafe given the conditions prevailing.

53 There is no doubt, on the evidence to which our attention was drawn, in the part of mine being worked by Mr Carroll and Mr Dickson on 6 July 1998, roof conditions had deteriorated to the point of instability. Those indicia of roof instability were: (i) Ground water emanating from the roof and other parts of the area being worked; (ii) Jamming of drill steels during bolt hole drilling and roof parting; (iii) Prior roof falls; (iv) Mining parallel to a known fault; and (v) Guttering of ribs and roof condition deteriorating.

54 Rule 6 of the minimum support rules provide that additional support greater than the minimum support may be installed when roof conditions deteriorate. That is what Mr Wallace directed when he first inspected the worksite when he became aware the fault had been struck. Sounding of the roof established that it was competent. Notwithstanding that, Mr Wallace ordered mining to cease. As well, he wanted extra support put up, plus a row of props along the edge of the fault and he wanted the area taped off.

55 The decision was also taken at that point to 'square up the end of the heading before ceasing'. In effect, mining work continued for a time, the only difference being that the roof bolting was increased to 1.5 metre spacing instead of the usual three metres.

56 By all accounts, the working conditions continued to deteriorate as far as roof stability was concerned. That is, water was coming out of the roof from the bolt holes and the drill steel was jamming. As well, the second roof fall occurred, consisting of six metres of stone that fell back from the face to a point 1.5 metres from where the last of the roof bolts had been installed. On any view, all of these events represented ongoing indicia of unstable roof conditions.

57 While all the above indicia were occurring, the roof bolting under unsupported roof continued apace on the problematic basis that the roof continued to sound competent.

58 Notwithstanding these overall circumstances obtaining on 6 July 1998, what the respondent contended was that the employees, Mr Carroll and Mr Dickson were, at the time of the accident, working in accordance with the approved minimum support rules. Those minimum support rules permitted employees to work under unsupported roof once 'the roof has been tested by sounding with a metal bar or suitable metal object and found secure'. That had been done. What they were doing, it was submitted, was an act expressly permitted to be done and, accordingly, no offence could arise because of the provisions of s33(2).

59 The flaw in that submission is the respondent was not charged with an offence that had as its sole contravention that it had failed to provide or maintain systems of work that were safe and without risk to health in that it permitted employees to work under unsupported roof after sounding the roof with a metal object in accordance with the minimum support rules for the mine. The respondent was charged with two offences that went to the respondent's system of work pertinent to the erection of roof support and assessing the roof support. Within each of those 'system of work' charges there were multiple failures alleged by the prosecution. In order to determine whether an offence was committed it is necessary to consider each of those alleged failures. Any alleged failure that is inconsistent with minimum support rule 3, which permits work under unsupported roof, cannot constitute an offence by virtue of s 33(2) of the Act. Any other alleged failure may constitute an offence if it can be made out on the evidence and if a causal connection can be found between the act or omission giving rise to the failure and the risk to safety. It is, therefore, necessary to consider each of the charges and the alleged failures as particularised in order to determine whether the charges have been made out.

60 This takes us to the second part of Peterson J's judgment where his Honour considered, if he were wrong in respect of s 33(2), whether the prosecution had established a relevant failure or failures under s 15(1) of the Act. His Honour considered the respective offences in a rolled-up manner. Likewise, the specific failures particularised by the prosecution. While such an approach may be appropriate, in the present case we consider it led Peterson J into error. We have considered the offences independently. As well, within each of the discrete offences alleged, we have determined the approach of considering the specific failures particularised within the two offences.

61 As earlier stated, the two charges were characterised in submissions before us as the Erection of Roof Support Charge and the Assessing Roof Support Charge. The risk pleaded in relation to both offences is the same. That is, the risk of a roof fall while the employees were working at Face area sequence 131, Production Panel 3 in Production District 3 on the 6 July 1998. The employer's alleged failures were the failure and/or omission to provide or maintain adequate systems or work that were safe and without risks to health in relation to the erection of roof support and in assessing the stability of the roof structure respectively.

62 It is relevant at this point to set out the specific failures alleged by the prosecution in relation to each of the charges. Whilst no direct reference was made to them in his Honour's judgment, there is no issue between the parties that, prior to the commencement of the proceedings at first instance and in his opening address, the prosecutor identified specific alleged failures with respect to the two charges. They are important in the proper consideration of the issues before us.

63 Before we turn to consider the substance of the alleged offences, it is necessary, we believe, to make some comment as to the nature of the charges as framed and pleaded by the prosecutor.

64 As already indicated, one of the charges goes to the system of work in relation to the erection of roof support and the second goes to the system of work in relation to assessing the stability of the roof structure.

65 The logical sequence inherent in the overall system of work in underground mining activity and roof stability, in particular, is that it would be necessary, in the first instance, to assess the overall stability of the roof. It would be a natural first step, in our view, given the importance of securing a stable roof. That assessment would include the relevant mining official such as a deputy or undermanager taking account of geological or other indicia that, when taken together, would lead to a considered view as to the condition of the roof, whether it was safe to continue mining and, if so, what roof support should be in place.

66 In short, there is a two-step decision-making process within the system of work - the assessment of the roof and the erection of roof support consequent upon that assessment. It is the appellant's contention, reflected in the charges pleaded, that the respondent failed on both counts of the process. That is, it failed to adequately assess the stability of the roof and then failed to erect adequate roof support.

67 In IRC Matter No 6726/2001 (the Roof Support Charge) the failings alleged were: (a) The system of work in relation to the erection of roof support required the use of hand held drilling and bolting equipment which placed employees underneath or immediately adjacent to the part of the roof being drilled or bolted. (b) The system of work in relation to the erection of roof support did not require the provision of temporary support immediately adjacent to the part of the roof being drilled or bolted. (c) The system of work in relation to the erection of roof support was not sufficiently prescriptive in relation to unstable roof conditions. (d) The system of work in relation to the erection of roof support was uncertain in its operation.

68 In relation to the drilling machine being used, the evidence before his Honour was that, at the time of the accident, the drilling machine was a rotary percussive drill known as a Falcon Roof Bolter. As his Honour described at [30] of his judgment: While the drill is sometimes referred to as a 'hand held' drill, the drill sits on top of a telescopic leg which extends by hydraulic action to push the drill machine up to the roof. The drill, the drill steel having been loaded into the top of the machine, is then operated by a control lock or lever.

69 Reference to the hand held nature of the Falcon Roof Bolter would appear to be related to the need for the miners to manually manoeuvre the drill into position immediately under the roof to be bolted. That meant, generally speaking, when being used, the miners were working under unsupported roof. Again from his Honour's judgment there is evidence that, when the roof was 'bad', temporary support in the form of timber props were installed prior to the installation of the permanent support (bolts, primarily) using a roof bolting machine. Mr Mark Levey, the Mine Manager for Wallarah at the time of the accident gave evidence to that effect.

70 The use of a hand held drill such as the Falcon Roof Bolter is to be distinguished from rig mounted bolting machinery that allows the operator to be under supported roof at any time. His Honour made reference to the use of both machines in his judgment as follows: [61] In comparing the use of rig-mounted roof bolters and Falcon bolters Mr Levey was asked in chief: Q. Which was the safer method? A. Both systems are safe.

Q. How is the hand held Falcon method safe? A. In good roof conditions they are both the same. In poor roof conditions, one, you carry out the temporary support manually, the other is done hydraulically. They are both safe. Q. If you carry out the temporary support with a hand held method is that the case? A. Yes.

Q. You are talking about timber props there? A. Yes.

Q. Putting timber props in as temporary supports do you have to go under unsupported roof? A. No.

Q. How is that to be avoided? A. Well, as you advance into poor roof you install a prop in advance as you move forwards but no more than 600 to 700mm, such you are always working in the influence of the previous support, you always have another support beside you. … A. If you have got two metres of bad roof you will put up a row of timber across so high, put up the timber unsupported by the timber you previously set until you get where you want to support it permanently, bringing in the Falcon bolter to put up all the required permanent supports in between the timber, the bolts go up between the timber then you remove that temporary support. [62] He also gave the following answer in response to a question in chief: Q. What instruction, if any, did you provide to undermanagers or deputies in relation to assessing the requirement for extra support in conditions other than normal? A. That it be supported adequately for the level of deterioration of the roof. [63] Mr Levey described in cross-examination why rig-mounted bolting equipment was not being used in the area of the accident as being the result of the conditions met. He said: A. ... the height of our workings was such that it was impractical to use the rigs. … A. ... the overall seam thickness decreased in that area of the mine. Now, you have got to leave coal on the floor to give us a cover above an extremely weak clay stone floor that is below that, so you need half a metre of coal above the clay to ensure that you can continue to move forward, otherwise you bog your equipment. When you take that into account, there was no height left to practically use the rigs. … Q. What happened when the rigs were damaged because of the heights at which they were working? A. They were damaged in many ways, but a general one would be they have bumped the drill mast and that has leaned forward or lent backwards, and because of the clearances they would bump up against it with the roof. This machine is 60 tonnes, it doesn't worry too much about that sort of thing, so, if it wants to drive forward it will damage the drill mast. It is a metal rod that sits up beside the part of the drill rig and it gets bent. Now, you can't use it then because the drillhead that slides up and down the drill mast doesn't function any more, it is on a bent piece of metal, so you have to take it off.

71 There was evidence that rig mounted bolting machines had been used at the Wallarah Colliery prior to the accident and were available to be used on 6 July 1998. Nevertheless, for reasons that we understand had to do with the clearance height of the mine in that area on 6 July 1998, a decision had been taken to proceed with the roof bolting using the Falcon Roof Bolter. The result of that decision was that at the time of the accident the miners operating the Falcon Roof Bolter were working under unsupported roof.

72 The appellant pointed to evidence that was before his Honour indicating that in the use of the hand held Falcon Roof Bolter it was possible to use it in conjunction with the use of timber props as temporary support while the bolting process was taking place. In other words, in utilising such an approach the operators of the hand held bolter would not be working under unsupported roof.

73 On this issue his Honour said as follows: [90] One issue at the heart of the prosecution is whether the bolting process, undertaken with a Falcon roof bolter which itself provided no roof support, involved a failure by the defendant/s of a kind relevant to create the offence/s raised in the charges. [91] The prosecution alleges that the failure to utilise rig-mounted bolting machines of the type which were used in other parts of the mine is the relevant failure. The defendants argue that the rig-mounted equipment was unsuitable for use in this area because of the limited space between the floor and the roof and that after the cessation of mining, following the accident, special equipment had to be designed and constructed to enable the continuation of mining in this area.

[92] It is evident that the opinions of the three experts in relation to this accident are responsive to the circumstances which developed, rather than critical of the process which was being undertaken prior to the accident. The opinions necessarily look at probabilities and, as Dr Moelle observed "bolting operations under erosional Teralba conglomerate are evidently best conducted with bolting machinery that allows the operator to be under supported roof at any time" (my emphasis). This observation shows the response to the circumstances of the accident rather than an anticipation of what would have, or should have, happened in terms of work practices prior to the accident.

[93] These aspects of the experts report go directly to the foreseeability of the accident and the question of whether there was any relevant, and identifiable, failure by the defendant/s.

74 Reference to the opinion of Dr Moelle in the above passage that the 'best' way to conduct the bolting process was to use bolting machinery that allows the operator to be under supported roof can, quite properly in our view, be read as being the safest way to conduct such operations. That much is evident given the context in which Dr Moelle expresses that opinion. As well, Dr Moelle's written report also stated: The setting of temporary timber props serving as indicators for roof adjustment movements should be considered under Teralba Conglomerate roof, as well as the use of remotely controlled bolting devices.

75 As well, reference by his Honour to 'the foreseeability of the accident' arising from the experts report is, in our view, erroneous. On this issue we agree with counsel for the appellant that his Honour relied upon the expert evidence to introduce the notion of foreseeability of an accident in relation to the question of whether there were relevant failures by the respondent. That point was squarely addressed by the decision of the Full Bench in Drake Personnel Ltd t/as Drake Industrial v WorkCover Authority of NSW (Inspector Ch'ng) (1999) 90 IR 432 at 452 as follows: The concept of 'reasonable foreseeability' is not, in our view, apt to be applied in relation to the duties owed under the OH&S Act. The duties imposed by the Act are not merely duties to act as a reasonable or prudent person would in the same circumstances: see Carrington Slipways Pty Limited v Callaghan (1985) 11 IR 467 at 469. Under s15(1) the obligation of the employer is 'to ensure' the health, safety and welfare of employees at work. There is no warrant for limiting the detriments to safety contemplated by that provision, to those which are reasonably foreseeable. Whilst employers are not liable for risks to safety which are merely speculative or unduly remote (see Kirkby v A & M I Hanson Pty Ltd (1994) 55 IR 40 at 50), the terms of s15(1) specify that the obligation under that section is a strict or absolute liability to ensure that employees are not exposed to risks to health or safety. It is inappropriate to seek to substitute a different test for that specified in s15(1).

Secondly, the arguments advanced on behalf of the appellant in this respect erroneously concentrate upon the foreseeability of the particular circumstances of the accident in question. The general duties created by the OH&S Act are directed at obviating 'risks' to the health, safety and welfare of persons in the workplace: see Haynes v C I & D Manufacturing Pty Ltd (1995) 60 IR 149 at 158-159. The occurrence of an accident and the sustaining of injuries by an employee will certainly represent relevant evidence of the existence of a risk to the health and safety of employees and the seriousness of that risk. However, it is not the accident itself which constitutes the offence, but rather the failure of the employer to ensure that its employees are not exposed to risks while at work.

76 Adopting the approach as enunciated in the above passage, it is important in assessing an employer's liability under the Occupational Health and Safety Act not to focus on the accident itself as establishing that liability but to examine the system of work prevailing at the workplace for evidence of a failure by the employer to ensure that its employees are, or were, not exposed to risks while at work.

77 There does not appear to be any dispute that the system of work being undertaken in erecting roof support at the time of the accident required the miners to use the Falcon Roof Bolter - otherwise referred to as the hand held drilling and bolting equipment. Further, in using that equipment at that time, the miners were standing underneath or immediately adjacent to the part of the roof being bolted and that roof was unsupported.

78 Whilst the employees were undeniably exposed to risks in using the roof bolter under unsupported roof, in our opinion the combination of s 33(2) of the Act and the minimum support rules permitted the two workmen to be performing the work described in particular (a) under unsupported roof. Accordingly, there could be no guilty finding based solely on particular (a).

79 The system of work failure particularised as failure (b) in the Roof Support Charge states that the roof support system of work 'did not require the provision of temporary support immediately adjacent to the part of the roof being drilled or bolted'. As we understand the evidence, reference to 'temporary support' refers to timber props. His Honour's conclusions in relation this failure, as best as we can ascertain, is to be found at [96] of his judgment as follows: In any event, had the roof been supported with timber props in advance of the area in which Messrs Dickson and Carroll were bolting, then necessarily, any worker who might have installed the timber props, a process involving measurement, cutting of the prop to approximate size and then hammering wedges beneath it so as to create a tight fit, would then have been working, to an unavoidable extent, under unsupported roof.

80 The evidence of Mr Levey, highlighted earlier in this judgment, contradicts his Honour's conclusion in the above extract. In other words, the evidence of Mr Levey would indicate that it was possible to erect temporary support in the form of timber props while at the same time working under supported roof. The evidence of Mr Levey on this issue would also seem to suggest that while that could be done, it was not without its practical problems. That is, Mr Levey gave evidence of utilising temporary timber supports earlier in 1998 at Wallarah and, he said, '...we had trouble getting the hand held Falcon Bolter in to bolt the roof because there was so many props'. In other words, it would appear that the use of timber props as temporary support alongside the use of the Falcon Roof Bolter created a number of practical difficulties that may well have dissuaded the respondent from utilising them conjointly at the workplace.

81 More importantly, rule 6 of the minimum support rules vested significant discretion in the relevant mining official to direct 'additional support ... be installed when roof conditions deteriorate'. It may safely be assumed, in our view, that additional support in the context of rule 6 would embrace not only additional roof supports in the form of bolting but also the temporary support provided by timber props as described by Mr Levey.

82 Reference to the phrase 'did not require' in relation to the provision of temporary support pleaded in this particular failure would indicate, in our view, that the system of work at the time of the accident should have made such provision a mandatory requirement as part of the overall system of work. That being so, the employer failed to provide for that mandatory support. Given the circumstances prevailing at the workplace at the time of the accident pointing to roof instability, including two prior roof falls at the workplace, the conclusion that such a requirement should have been in place seems inescapable.

83 We are satisfied that the prosecution has established failure (b) as particularised in the Erection of the Roof Support Charge. That is, that the system of work in place failed in that it did not require the provision of temporary support immediately adjacent to the roof being drilled or bolted. We are also satisfied, given the indicia of unstable roof existing at the time, the failure to provide for temporary support is directly related to the risk identified, that being the risk of a roof fall. The failure to provide temporary support immediately adjacent to the roof being drilled or bolted is not overcome by the fact that Messrs Carroll and Dickson were permitted to be under unsupported roof; one is not inconsistent with the other.

84 Failure (c) as particularised within the Roof Support Charge pleads that the system of work in relation to the erection of roof support was not sufficiently prescriptive in relation to unstable roof conditions. (our emphasis)

85 We read the phrase emphasised above as meaning, where unstable roof conditions existed, the steps to be undertaken as part of the system of work in order to ensure the work was performed free of risks to safety, were not sufficiently prescriptive to ensure that outcome. The phrase 'not sufficiently prescriptive' is understood by us to mean that in relation to the unstable roof conditions, there was an inadequacy or failure to give definite or precise directions or instructions to do or not to do a particular thing. Further, we construe the phrase 'in relation to' widely, satisfied by the connection between the unstable roof conditions and the alleged insufficiency in the system of work prescribed to deal with the problem. As was said by Giles J in Law Society of New South Wales v Bruce (1996) 40 NSWLR 77 at 84: The phrase 'in relation to' is wide, satisfied by a connection or association between the two things in question: R v Murphy (1985) 158 CLR 596 at 611. It should not be read down unless there be compelling reason to do so: Fountain v Alexander (1982) 150 CLR 615 at 629.

86 The phrase 'in relation to' was commented upon by his Honour at [86] of his judgment as being a phrase 'while wide is not unrestricted ...' Having regard to the view expressed by Mason J in Fountain v Alexander (1982) 150 CLR 615 that such a phrase should not be read down unless there was a compelling reason to do so, we discern no such compelling reason to do so in the matter before us. 87 We take the view that, in the context of the underground coal mining industry, the need to ensure the stability of the roof of the mine would be an essential factor in safely undertaking underground mining activity. As his Honour said at [84] of his judgment: In the context of underground mining, it is difficult to perceive any necessary function more important to the safety of workers in the mine than the support of the roof.

88 It is obvious that if the mine roof is not stable, there is a very real possibility of a roof fall with all of the attendant dangers and problems that such an occurrence would cause. The steps taken as part of mining activity to secure the roof by way of bolting and/or temporary supports evidence the importance of such an issue. As well, the legislative provisions already referred to reinforce the importance of having approved minimum support rules and the acknowledgment of the need to go beyond them when roof conditions deteriorate at any time. Overarching those specific legislative provisions in relation to that particular activity is the obligation on the mine operator to take whatever action may be necessary in the interest of safety (clause 9, Managers and Officials Regulation) as part of ensuring the health, safety and welfare of employees (or non-employees) at work, as required by s15 of the Occupational Health and Safety Act 1983 (or s8 of the Occupational Health and Safety Act 2000).

89 That his Honour recognised the importance of a secure roof and the need to take account of deteriorating conditions pointing to roof instability is referred to in his judgment, as well as the role his Honour perceived the minimum support rules played in securing a risk free work environment. His Honour would appear to recognise the limitations of the minimum support rules when considered in conjunction with clause 6 of the Support - Underground Mines Regulation. As he said at [78] of his judgment: ... it is difficult to see how the rules would conform with regulation 6 as being support rules which require the relevant person to ensure the roof is secure in accordance with them. That is, the uncertainty resulting from an absence of precise direction would seem to minimise their efficacy.

90 There is no doubt, in our view, that the minimum support rules are not prescriptive as to what constitutes unstable roof conditions or what to do precisely in the event of unstable roof conditions except to say that a mining official may direct that additional support above the prescribed minimum rules be installed when roof conditions deteriorate.

91 Beyond the minimum support rules, it would seem, as best as we can determine from his Honour's judgment, much was left to the ultimate discretion of the relevant mining official as to what should be done in the event of unstable roof conditions existing. For example, as his Honour stated in relation to decisions made as to the number of bolts to be inserted in securing the roof: [27] The number of bolts to be inserted in the roof must conform, as a minimum, with the minimum support rules. It is a matter for the discretion of the miners as to whether a greater number of bolts are utilised. That determination will be made by the miners including the deputy according to the conditions of the roof as experienced and relying on the knowledge and experience of the deputy and the miners involved.

92 As well, on that same issue, his Honour made reference to what could be characterised as the extensive discretionary decision-making authority beyond the minimum support rules by reference to the evidence of Mr Levey, the Mine Manager at Wallarah. As his Honour stated at [57]: ... Mr Levey had signed off on the minimum support rules applicable at Wallarah in relation to extraction mining. He testified that no other written instructions were provided to mining crew members in relation to support and there was no reassessment undertaken of roof structures. No general oral instructions were given with respect to the erection of roof support or the assessment of roof stability. 93 His Honour went on to describe the practice that Mr Levey had indicated existed in the industry for a number of years. That being, amongst other things, that, when the roof was 'bad', temporary support in the form of timber props were to be installed prior to the installation of permanent support in the form of bolts.

94 That may or may not be so. But what is clear to us is that the circumstances confronting the miners at the respondent's workplace on 6 July 1998, required a decision to be made that encompassed not just the minimum support rules and any practice that may have existed up to that time in relation to the erection of roof support, but decisions to be made to enable work to continue or otherwise whilst ensuring, subject to s 33(2), that the employees concerned were not exposed to risks to their health and safety.

95 There is no doubt that the minimum support rules were not sufficiently prescriptive as to what constituted unstable roof conditions and equally so, as to what was to be done, in any precise way, when such conditions did exist. But the failure pleaded goes beyond the minimum support rules to the actual system of work designed to deal with unstable roof conditions. The evidence before his Honour to which our attention has been drawn would indicate that beyond the minimum support rules and the discretion inherent in them to provide additional support 'when roof conditions deteriorate', there was nothing in any prescribed form that could be relied upon. There is the 'practice' that Mr Levey described and to which we have earlier referred. Relying on a somewhat loosely articulated practice within the industry as constituting a system of work above and beyond the minimum support rules is, on any view, inadequate when considered against the obligation to ensure a system of work that was absent a risk to the health and safety of the employees concerned subject, in this case, to s33(2).

96 Is the failure of the respondent to sufficiently prescribe the system of work to be followed in order to identify and then deal with unstable roof conditions causally related to the risk identified, that is, the risk of a roof fall? We are satisfied that is the case. Whilst we accept that it may not be possible to exhaustively prescribe every potential indicia of an unstable roof, we are satisfied that, given the geological and other considerations that existed at the Wallarah Colliery, it was possible to indicate with some precision what was meant by 'when roof conditions deteriorate'. For example, in the circumstances existing in the relevant part of Wallarah Colliery where mining activity was being conducted on 6 July 1998, the evidence before the Court was of known indicia of roof instability. Amongst others, his Honour made reference to the expert opinion of Mr Darryl Stevenson, a geologist with Geological and Mining Services Australia. His report, in part, stated: Several people leading up to and following the major roof fall that killed the miner made a number of observations that have enabled this Author to postulate on the causes of the roof failure: Northeast to southwest trending faults were observed and mapped within several roadways and were expected to be intersected within B Heading. The easternmost fault was intersected during the early hours of 6 July 1998, mining within B Heading ceased, and roof support operations were commenced. The special care required when mining in a direction sub-parallel to fault strike was acknowledged by Mr R Wallace, an experienced miner.

Within the unsupported and newly supported section of B Heading a number of other geological features were present and observations noted. The overall impression was that of an area of the mine that was not considered to be 'normal.' Water was observed dripping from the roof, and guttering, rib spalling and weighting on brattice props was also observed. A noticeable roof separation/parting had formed and was detected by the miners involved in roof bolting and there was also a 'sedimentary structure' which appeared to delineate the deteriorated area. (our emphasis)

Prior to the fatal fall, roof deterioration and falls were observed to commence at the face, near the newly intersected fault, and proceed outbye. The last major fall prior to the fatal fall terminated about 2 m inbye the last line of installed roof bolts and resulted in what is described as an approximately 2 m wide lip of unsupported roof. This remaining 2 m wide lip failed during an attempt to remove the drill steel from the final test hole.

The most obvious warning signs of the impending accident were the rapid roof deterioration and failure that commenced soon after the fault was intersected, the outbye progression and morphology of the falls, and the presence of a roof parting in the immediate roof. (our emphasis)

97 It is apparent, in our view, that there were clear geological and other indicia well known in the underground mining industry, that were indicative of an unstable roof. On the basis of Mr Stevenson's expert opinion, which was accepted by his Honour, those indicia were certainly present and deteriorating.

98 Given the known indicia of an unstable roof and the importance of ensuring a safe and secure roof in underground mining activity, it is imperative that employers should identify with as much precision as possible, the known indicia of an unstable roof and the steps that are to be taken when such indicia exist. One of those steps would be to cease mining immediately until the situation had been properly risk assessed. That was, in fact, Mr Wallace's initial decision when he first arrived at the worksite at about 2:00am. For reasons not fully known but predominantly, it would seem, because the roof continued to sound competent, mining activity continued in order to square up the end of the heading before finishing. It was, on any view, an unwise and unsafe decision given the roof conditions then existing. Not only did mining activity continue but it persisted beyond a second and more extensive roof fall some time shortly after. Again, the continuing activity was justified by relying on sounding the roof as the determinant that it was safe to do so notwithstanding all indicia to the contrary. It is difficult to visualise a more unsafe system of work. Further, this unsafe system can be traced directly to the absence of any oral or written prescription designed to protect employees by identifying matters that, taken together, constituted a risk to safety at work and how they were to be addressed to safely and proactively deal with that risk.

99 We are satisfied that failure (c) in the Erection of the Roof Support Charge is established.

100 Failure (d) pleads that the system of work in relation to the erection of roof support was uncertain in its operation. We have to say that we cannot identify with any particularity or certainty what is meant by the appellant in alleging that the system of work was 'uncertain in its operation'. In the absence of any evidence that would assist us, we are of the view that the failure cannot be established and is accordingly not proven.

101 We are satisfied beyond reasonable doubt that the respondent failed to provide or maintain a system of work that was safe and without risk to health, contrary to s15(1) of the Act. Specifically, the respondent's failure in relation to the erection of roof support in the vicinity of the area described as Face area sequence 131, Production Panel 3 in Production District 3 in circumstances where roof bolting was to take place has been established as particularised in failures (a), (b) and (c) as pleaded.

102 We turn now to the Assessing Roof Stability Charge. In relation to this charge, the alleged particularised failures were identified as follows: (a) The system of work in relation to assessing the stability of the roof structure was not sufficiently prescriptive in relation to the indicia of unstable roof conditions. (b) The system of work in relation to assessing the stability of the roof structure was uncertain in its operation. (c) The system of work in relation to assessing the stability of the roof structure did not require that work cease below unsupported roof in the event of the indicia of unstable roof conditions being present.

103 The first thing we emphasise is that the failures particularised are centred on the respondent's system of work, not the minimum support rules. True it is that the minimum support rules do become relevant in that they are part of the respondent's system of work in relation to matters going to assessing the stability of the roof and the subsequent erection of roof support.

104 Failure (a) as particularised within the Roof Assessment Charge pleads that the system of work in relation to the assessment of the roof was not sufficiently prescriptive in relation to unstable roof conditions.

105 To the extent that reliance is placed on the minimum support rules as relevant to the assessment of the stability of the roof, we have no hesitation in concluding that they are bereft of any such prescribed indicia. Certainly, reference is made in support rule 3 that the workmen are not to proceed beyond the last test hole or temporary support unless the roof has been tested by sounding with a metal bar or suitable object and found secure. But that rule does not go to what we perceive to be the nub of the alleged failure as part of the offence pleaded. That is, that the respondent should have identified those indicia that workmen should have regard to when going about the task of assessing the stability of the roof.

106 It is no answer to particular (a) of the assessing roof stability charge to say that minimum support rule 3 permitted employees to proceed beyond the last test hole or temporary support once the roof had been tested by sounding with a metal bar and found to be secure.

107 It is untenable, we consider, to interpret s 33(2) to mean in this case that notwithstanding the respondent failed to provide sufficient guidance to employees as to what constituted unstable roof conditions indicating a risk of a roof fall that this failure is overcome by a minimum support rule that permits workmen to work under an area of unsupported roof once they found the roof was secure by testing it with a metal bar.

108 Testing the stability of the roof using a metal bar has very significant limitations. That the roof might be found to be "secure" after testing with a metal bar does not ensure safety. It could not be said, in our opinion, that sounding with a metal bar provides sufficient guidance to employees as to what constituted unstable roof conditions indicating a risk of a roof fall. And when it is considered there were obvious signs of unstable roof it is difficult to avoid the inference that notwithstanding minimum support rule 3 allowed workers to be located under unsupported roof, there was an over reliance placed on that rule regarding the stability of the roof, which had the effect of dramatically increasing the risk to their health and safety.

109 It is clear to us that the indicia of unstable roof and what they represented were at least recognised in part by Mr Wallace, the Undermanager, when he visited the site at approximately 2:00am when the mining activity hit the fault at B heading. In addition to encountering the fault, there was water coming from a fissure in the mine roof. As well, while Mr Wallace was present, the first of three roof falls occurred. All of these indicia were present notwithstanding that the roof was sounded as competent. We note that Mr Wallace seemingly did not consider that because the roof sounded competent, that he wanted work to continue. Indeed, he initially decided that work would cease only to then permit the additional mining activity to square off the heading subject to increasing the density of the roof bolts.

110 Given the known and deteriorating condition of the stability of the roof from the time Mr Wallace arrived at approximately 2:00am, it is obvious that work should have ceased while a thorough risk assessment of the situation was undertaken. The situation prevailing seemed to be that the only prescriptive guidance available to properly assess the roof stability was the minimum support rules. They were evidently inadequate in being of any assistance in responding to what was clearly a workplace situation fairly quickly moving to one of real risks to safety.

111 What was required was something in the nature of a checklist that was known to and understood by all employees as to those indicia that pointed to an unstable roof. That information was vitally important so that all of the workmen were aware of signs to look out for and act upon where the stability of the roof was an issue. It is an issue of vital importance in all underground mining activity and it certainly was in the circumstances surrounding the offence before us.

112 We are satisfied that failure (a) as particularised has been established and that the causal nexus to the risk as identified is present.

113 Failure (b) pleads that the system of work in relation to assessing the stability of the roof structure was uncertain in its operation.

114 It is unclear, on the evidence to which we were taken, as to what the prosecution relies upon to assert that the assessment of the roof structure was 'uncertain' in its operation. If it means that it was uncertain in not being sufficiently prescriptive as to what to look for in undertaking such an assessment, it is inherently duplicitous having regard to particularised failure (a) as pleaded. If it means that the system of work as to roof assessment was uncertain as to the process to be followed by the relevant mining official in going about that task then we would say that we could not be confident as to the requisite standard. That is, there is evidence that when the fault was first hit, the Undermanager Mr Wallace was notified and he attended the worksite, assessed the roof and made certain decisions that have already been detailed. There would appear to be a laxity in adherence to his directions or perhaps a misunderstanding as to what Mr Wallace ordered to be done. 115 In any event, we are not satisfied that the appellant has established this failure with certainty and the necessary particularity and accordingly, it is not made out.

116 Failure (c) pleads that the system of work in relation to assessing the stability of the roof structure did not require that work cease below unsupported roof in the event of the indicia of unstable roof conditions being present. Although workmen were permitted to work under unsupported roof in the circumstances described by minimum support rule 3, there is nothing inconsistent between a rule that permits work to be performed under unsupported roof and a charge that the system of work did not require work to cease below that roof in the event that it became apparent the roof was unstable.

117 As is evident, there is no mention in the minimum support rules that directs work to cease in the circumstances prevailing at the respondent's worksite on 6 July 1998. That is, indicia of deteriorating roof conditions. Outside of the minimum support rules, there does not appear to be any evidence of a system of work that directed mining activity to cease below unsupported roof in circumstances of an unstable roof. On any view, given the clear risk to safety that such a situation presented to the workmen concerned, there should have been. There was, on the evidence, a decision taken by Mr Wallace when he first visited the worksite for work to cease. For reasons that have already been detailed, mining activity did continue. What we find difficult to comprehend is the decision presumably taken to press on with mining activity following the second, and seemingly more significant, roof fall that followed after Mr Wallace left. By that stage, circumstances demanded that work cease immediately in the face of an increasingly risk-laden situation at the workplace.

118 In our view, the system of work was simply inadequate in that it failed to require that work cease under the unsupported roof in the circumstances where all of the indicia pointed to the presence of unstable roof conditions. The causal nexus between that failure and the risk to safety as identified is self-evident.

119 We are satisfied that failure (c) as pleaded is established.

120 Further, we are satisfied beyond reasonable doubt that the respondent failed to provide or maintain a system of work that was safe and without risk to health, contrary to s15(1) of the Act. Specifically, the respondent's failure to adequately assess the stability of the roof structure at the workplace described as face area sequence 131, Production Panel 3 in Production District 3 has been established with respect to particularised failures (a) and (c) as pleaded.

121 Given the view we have come to in relation to the offences charged, it is necessary to consider the provisions of s53 of the Act. The appellant specifically raises this as one of the grounds of appeal expressed as follows: The trial judge erred in that his Honour found that the charge in IRC 6726 of 2001 had not been made out without giving consideration to, or adequate consideration to, the question of whether the defendant had made out a defence pursuant to s53 of the Act.

122 Peterson J makes no reference to s53 of the Act in his judgment. Given that he dismissed both charges that is not surprising. Indeed, counsel on behalf of the respondent submitted, in the circumstances, there was no need for his Honour to give consideration to s53 and its application.

123 On behalf of the appellant, it was acknowledged that the question of a s53 defence does not arise for consideration unless and until the prosecution establishes to the requisite standard that the offence as charged has been made out: see WorkCover Authority of New South Wales v Fletcher Constructions Australia Limited (2002) 123 IR 121 at 135. Nevertheless, it was contended his Honour erroneously placed reliance on matters that may have been relevant to the question of s53 defences in concluding that the two charges had not been made out.

124 Suffice to say at this point that the offences having been established to the requisite standard, it is certainly necessary for us to consider s53. Section 53 of the Act provides: It shall be a defence to any proceedings against a person for an offence against this Act or the regulations for the person to prove that: (a) it was not reasonably practicable for the person to comply with the provision of this Act or the regulations the breach of which constituted the offence, or (b) the commission of the offence was due to causes over which the person had no control and against the happening of which it was impracticable for the person to make provision.

125 The raising of a defence under s53 of the Act places an onus on the defendant. That onus is a civil onus: see Shannon v Comalco Aluminium Limited (1986) 19 IR 358 at 359; Drake Personnel Limited t/as Drake Industrial v WorkCover Authority of New South Wales (Inspector Ch'ng) (1999) 90 IR 432 at 457.

126 We believe that we should approach our considerations as to s53 by separately considering the two limbs of s53, that is, s53(a) and s53(b) given they are expressed in the alternative.

127 A defence under s53(a) requires the defendant to meet the objective test as to whether it was reasonably practicable for the defendant to have complied with the Act. As was stated by Walton J Vice-President in WorkCover Authority of NSW (Inspector Byer) v Cleary Bros (Bombo) Pty Ltd (2001) 110 IR 182 at 204: An objective determination must be made as to what measures were reasonably practicable in the circumstances of the case. This determination is not restricted to the state of knowledge of the defendant or to the measures, if any, which the defendant had contemplated.

128 In Cleary Bros, Walton J reviewed the relevant authorities as to the proper meaning and application of the words 'reasonably practicable'. Amongst others, he considered the judgment of Asquith LJ in Edwards v National Coal Board [1949] 1 KB 704 (particularly at 712) as well as the decision of the High Court in Slivak v Lurgi (Australia) Pty Ltd (2001) 205 CLR 304. In summation, his Honour said at 206-207: It is evident from these authorities that what is required by s53(a) of the Act is a balancing of the nature, likelihood and gravity of the risk to safety occasioning the offence with the costs, difficulty and trouble necessary to avert the risk. At one end of the scale, it could not be reasonably practicable to take precautions against a danger which could not have been known to be in existence: see Jayne v National Coal Board [1963] 3 All ER 220 at 224 and Shannon v Comalco Aluminium Ltd (at 362). Similarly, if the happening of an event is not reasonably foreseeable then it will not generally be reasonably practicable to make provision against that event: see WorkCover Authority (NSW) (Inspector Mayo-Ramsay) v Maitland City Council (1998) 83 IR 362 at 381; WorkCover Authority (NSW) v Kellogg (Aust) Pty Ltd (at 259) and Austin Rover Ltd v Inspector of Factories (at 627) per Lord Goff and (at 635-636) per Lord Jauncey of Tullichettle.

At the other end of the scale, there will be cases, such as the present, in which known or obvious risks to safety exist. In these circumstances, the defendant will not have established a defence under s53(a) of the Act where it was reasonably practicable to have complied with the Act by ensuring that persons were not exposed to those risks. This may be the case because no measures were reasonably available or because measures which were available were not reasonably practicable. As has been discussed, the assessment of the reasonable practicability of those steps requires a balancing of the quantum of the risk with the sacrifice (in money, time and trouble) in adopting the measures necessary to avert the risk. In my view, where there is a known risk which entails the potential for serious injury to persons in the workplace, the defendant will generally have to demonstrate that the costs, difficulty or trouble occasioned by the measures significantly outweigh the risk. This must be done by reference to the charge as brought by the prosecutor. 129 The principles expressed by Walton J in the above passage were approved and expressed to be compelling by the Full Bench in WorkCover Authority of NSW (Inspector Legge) v Coffey Engineering Pty Ltd (No. 2) (2001) 110 IR 447 at 467.

130 In considering the application of the principles enunciated in relation to s53(a) to the facts and circumstances of the offences before us, we can discern no evidence that would establish that it was not practicable for the respondent to comply with those matters going directly to the breach of the Act as pleaded.

131 However, in relation to particular (a) of the Roof Support charge we have found that the respondent has a defence under s 33(2) of the Act. It is, therefore, unnecessary for us to consider whether a defence also exists under s 53(a) or s 53(b), although we are of the view that it was reasonably practicable for the respondent to utilise methods of bolting the roof other than the hand held roof bolter used in the area of the mine where the roof collapsed on 6 July 1998.

132 In relation to failures (b) and (c) as established in the Roof Support charge, there was no evidence that the respondent could rely upon to support a proposition that it was not reasonably practicable as part of the system of work to require the provision of temporary support immediately adjacent to the part of the roof being drilled or bolted. Indeed, the evidence of Mr Levey to which we have earlier referred, is to the contrary.

133 Likewise, it was clearly reasonably practicable for the respondent to be more definitively prescriptive both as to the indicia of an unstable roof and the process to be followed where unstable roof conditions existed. While a degree of discretion may be required dependant on the extent and nature of roof instability, the risk to safety that such a situation represented demanded more than a reliance on perceived industry practice or a particular person's experience at any given time.

134 Finally, we can discern no basis that would enable the respondent to assert that it was not reasonably practicable to have a system of work in relation to assessing the stability of a roof structure that did not encompass a provision where the indicia of an unstable roof being present, that work under unsupported roof should cease.

135 In our view, the respondent has not discharged the onus required to establish it was not reasonably practicable for them to comply with s15(1) of the Act relevant to the breaches alleged. Accordingly, the defence under s53(a) must fail.

136 In relation to any defence contended for under s53(b), our view can be briefly expressed. That is, there is no evidence that we can discern that would satisfy the onus placed on the respondent in relying on the provisions of the sub-section.

137 In McMartin v Broken Hill Proprietary Co Ltd (1988) 100 IR 241 Grove J determined that in considering a defence under s53(b), the defendant must combine its proof that the facts giving rise to what would be an offence occurred due to causes over which it had no control and demonstrate that it was impracticable for it to make provision against the causative facts contained within the meaning of 'commission of the offence'.

138 Accepting that approach, we consider that the facts giving rise to the offences before us occurred due to causes over which the defendant had complete control and against which it was practicable for it to have made provision against. Accordingly, any defence under s53(b) must fail.

139 For the reasons expressed, we are satisfied that the alleged offences have been made out and his Honour was in error in dismissing them. Accordingly, we make the following orders:

· The decision of Peterson J given on 15 August 2003 in Matter Nos IRC 6726 and 6727 of 2001 acquitting the respondent is set aside;

· The offences charged against the respondent are found proven;

· The proceedings will be listed before the Full Bench, at a date to be fixed, to make directions for the finalisation of the proceedings.

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