Inspector Hamilton v ACN 061 447 621 Pty Limited

4The risk to the safety of Mr Gilchrist and other persons in the vicinity of the tunnel roof when it collapsed are dealt with in Hamilton v PSM. With regard to the risk to Mr Gilchrist's safety the Court found (at [15] to [18]: [15] Mr Gilchrist attended the area of the intersection on two occasions on 1 November 2005. On the first occasion, he mapped the exposed rocks and took a number of photographs. He noted that a "clock-it" hole had not been drilled for the installation of a monitoring device. He returned to the area at about 10am for a second inspection and to install the monitoring device. While there he discussed with Mr Lloyd a number of matters which included the ground conditions, the shape of the tunnel, that is, the fact that the down drive of the MCAA was being "widened out", the rock bolting at the intersection, the condition of the dyke, the spacing of joints and the existence of faults. [16] According to Greg Kotze, a consulting engineering geologist and an expert in engineering geology, rock mechanics, rock mass support and stabilisation, and geological modelling, during the period in which Mr Gilchrist attended the area of the intersection, there was a risk to the health and safety of persons working there because of the risk of roof failure or collapse. In his report dated 12 June 2007, Mr Kotze said that he first attended an inspection of the collapsed site at 6am on 3 November 2005 and conducted investigations. He subsequently attended the site on numerous occasions and carried out geotechnical site inspections, made direct factual observations, compiled photographic records and undertook geotechnical services. This material formed the subject matter of his Report and the basis for his opinions and conclusions. In relation to the risk to employees working in the area during the period of the charge he explained: Inherent in every underground excavation in rock are the combined effects of subsurface disturbance and gravity, which can cause rock masses to fall from the roof of a tunnel and sections of tunnel roof to collapse, thereby presenting a risk (or potential danger to health and safety) to persons working in the tunnel. Between 01 August 2005 and 02 November 2005, the excavation of the ventilation tunnel (MC5B) advanced from approximately chainage 68m to chainage 198m and into the intersection with the Pacific Highway exit ramp tunnel (MCAA). This involved an excavation length of around 160 metres, over a three-month period, which is delineated on the attached Figure 1. Project documents (Geological Mapping Sheets, Ground Classification & Ground Support Determinations - References 1 to 64) indicate that the geological and roof stability conditions encountered in MC5B during this excavation period, were generally worse than had been encountered in other tunnels on the project, and also tended to progressively deteriorate towards and into the MC5B/MCAA intersection (as described below). Deteriorating rock mass and stability conditions in the roof of a tunnel excavation corresponds with an increase in risk (or increased potential danger) to persons working in the tunnel. [17] Mr Kotze identified four primary factors which he said combined to cause the roof collapse at the intersection on 2 November 2005. These were: i) The geological conditions at the site . See References 1 to 21 and Plates 5 to 16. The roof of the MC5B/MCAA intersection is characterised by: Low to very low strength shale bedrock A weathered, low strength igneous dyke crossing diagonally through the intersection Closely spaced rock mass fractures including bedding plane partings, intersecting joint sets, and localised faults. See Figure 2. ii) The large span width of the MC5B/MCAA intersection . The spans or widths of the MC5B and MCAA tunnels are approximately 9 metres (Figures 5, 6 and 7). The diagonal width of the underground opening comprising the intersection of both tunnels however, is up to 22 metres. See Figure 3. The line of maximum span aligns closely with the low strength igneous dyke that crosses through the intersection. iii) Proximity of the tunnel excavations to the ground surface . The crown of the MC5B/MCAA intersection is 13.3m below the level of Longueville Road and around 17m below the existing Pacific Highway off-ramp and ground level at the western end of the Kerslake Apartments. See Figure 4. The intersection is also overlain on its southern side by the Longueville Road retaining wall which comprises anchored concrete piles. The tie-back anchors below horizontal, extending towere up to 18m long and angled down at 50 depths in the order of 2m above the crown of the MC5B/MCAA intersection. Each anchor had been installed into a 125mm diameter hole that had been over-drilled by 05m, continuously flushed during drilling, reflushed and water tested, before being grouted. Some twenty eight (28) anchors are believed to have been installed into the low strength shale rock mass above the MC5B/MCAA intersection. (Reference 67). It is considered likely that the anchor drilling and installation processes would have locally disturbed and weakened the already low strength and fractured shale strata on the northern side of the retaining wall. The MC5B/MCAA intersection was subsequently excavated immediately beneath the wall anchors. iv) The inadequacy of the tunnel roof support installations . The installed roof support which comprised CT rock bolts and shotcrete, was not capable of supporting the rock mass conditions encountered in and above the roof of the intersection, over the excavated span. The adopted roof support system relied on the composite effects of a 200mm thickness of shotcrete from floor to floor, and arrays of CT rock bolts. At the time of the roof collapse in the MC5B/MCAA intersection, the application of shotcrete had not achieved full thickness and did not extend from floor to floor. (References 1, 2, 4 and 5). See Plates 12, 14, 15, 17, 18 and 19. Furthermore, and as described in detail herein, evidence from rock bolts recovered from the failure site is considered to indicate that a significant percentage of the CT rock bolts installed, had not achieved end anchorage or a grouted bond in the roof strata. With a deficiency of roof support, in adverse geological conditions, the intersection collapsed when a critical span width was reached. [18] It follows from the matters set out by Mr Kotze in his Report that Mr Gilchrist, an employee of PSM, was at risk to his safety by reason of his presence in the area of the intersection (where the roof collapsed) at least on two occasions on 1 November 2005. 5The risk to the safety of persons employed by TJH and PB are dealt with in Hamilton v PSM at [19] to [21]: [19] The matters identified in Mr Kotze's Report (set out above) demonstrate a risk of roof or tunnel collapse in the intersection of the two tunnels during the period of the charge, that is, between 27 October 2005 and 2 November 2005. Members of the TJH tunnelling crew reported observations shortly before the roof collapse consistent with deteriorating roof conditions such as persistent rock falls and poor ground conditions. [20] Mr Baker, employed by TJH as a tunneller and truck driver, said that the ground, particularly the lower corner of the MCCA, "had been getting pretty bad", and that there were, "pretty big fallouts of rock". He also said the crew had trouble with the bolts "taking up" and with grouting the bolts because of the cracks in the rock which caused the grout to drip out. Mr Grace, a road tunneller employed by TJH, said that because of the pressure of the dyke in the intersection, they were, "getting a lot of slabby falling rock, and it was very hard to support". He said there was a lot of concern about rock fall and that about four weeks prior to the roof collapse on 2 November 2005, the conditions in the area of the intersection, "started getting really bad". Mr Labruyere's account of the roof collapse on 2 November 2005 has been earlier set out in this judgment. At the time of the roof collapse he was employed by TJH as a leading hand. Mr Shaw, employed by TJH as a road header operator, said he did not feel safe working in the area of the intersection because of his concerns that the rock bolts could not support the soft ground there. Mr Swan, employed by TJH as a shift boss, described the ground in the area as "bad". He said that a week before the roof collapse the crew was using a lot of water to drill holes for inserting 5m rock bolts and the water was coming out "all around us, which shows what the ground is like above". Mr Tyler, a shotcreter employed by TJH, described the ground conditions in the area of the intersection just prior to the roof collapse as, "pretty dodgy", with a few rock falls at the face. He described problems associated with shotcrete adhering to the dyke, saying that after it was sprayed onto the dyke, it "kept on trying to fall off". [21] These accounts, together with Mr Kotze's observations and opinions, demonstrate that a number of workers employed by TJH in the area of the intersection during the period of the charge were exposed to a risk to their safety by reason of a risk of being struck by falling rock and/or tunnel collapse. 6The risks to safety were realised on 2 November 2005 when a large section of tunnel roof collapsed. A detailed account of the incident has been set out in a Statement of Facts, the relevant parts of which are extracted below (from Hamilton v PSM at [11]): [11] ... 16. On Wednesday, 2 November 2005 TJH employees were carrying out excavation works at the junction of two tunnels, the Marden Street ventilation tunnel and the Pacific Highway exit ramp. At approximately 1:40am a large section of the tunnel roof collapsed in the area underneath the Longueville Road off-ramp to the Pacific Highway at Lane Cove. The employees working within the tunnel evacuated the tunnel as the section of tunnel roof collapsed narrowly escaping injury. 17. The collapse led to a significant ground subsidence that affected the stability of a block of home units situated at 11-13 Longueville Road, Lane Cove. There were also concerns relating to a retaining wall that supported the Pacific Highway off-ramp. The incident caused the off-ramp and Longueville Road to be closed and residents of the home units to be evacuated. 18. The incident occurred at the junction of two tunnels: the Marden Street ventilation tunnel (referred to as MC5B) and the Pacific Highway exit ramp excavation (referred to as MCAA). Over the previous weeks MC5B had been advancing towards the line of MCAA and reached the intersection point with MCAA around 17 October 2005. Once this point was reached MCAA was excavated first to the east (referred to as the "up" or "upper" drive), and then to the west (referred to as the "back", "lower" or "down" drive). Work was continuing on this western excavation at the time of the collapse. 19. On the evening prior to the incident, 1 November 2005, the night tunnelling crew ("crew B") commenced their shift at 1900 hrs. The crew was comprised of four workers: John Labruyere, the leading hand, Noel Makene, the road header operator, Bryan Greenfield, the loader operator and Mark Watson, the driver of the dump truck. The crew were all employed by TJH. 20. The crew on the preceding day shift ("crew A"), according to shift reports, had installed and grouted five rock bolts on the MCAA down left, installed but not grouted five rock bolts on the MCAA down left, installed and grouted 2 rock bolts on the MCAA down right, and had installed some shotcrete. The shift report for this shift does not indicate what chainage the excavation of the lower drive of MCAA was at the conclusion of the day shift. Ground Support Classification and Ground support determination reports indicate that the down drive of the MCAA was at chainage 467 when inspected near the start of the day shift. Crew A consisted of Craig Lightfoot, Steve Swain, Glynn Barker and Lawrence Grace. 21. Crew B on the night shift on 1 November 2005/2 November 2005 had cut approximately one metre into the left side of MCAA down drive and had commenced loading out and "mucking out" spillage from the front of the road header when, at about 1:40 am, the rock collapse commenced. Mr Labruyere, described what happened: I was standing on top of the road header next to the operators cab talking to the operator ... We were just doing a bit of mucking out waiting for the shotcreters, ...and I noticed the whole roof, from the centre to right side of MCAA coming down as a whole mass and back towards us, and we were out of there. I can't remember from that point, when we turned around there was stuff falling on our lid and from that point I have a gap in my memory until I reached the truck. One comment from the truck driver was he heard a banging and crashing and got out of his cab, and saw the road header cab was almost completely covered (tab S5 Labruyere, Q36). 22. Once the fall commenced, it increased rapidly when it reached an area where a dolerite dyke was situated. The crew, under instructions from the leading hand, retreated from the area, back to the entrance of MC5B, which was then secured (taped off). 23. The acting shift boss, Craig Bennett, who was operating with another crew in tunnel MC1A East, was then notified of the incident and travelled to the scene of the collapse with the leading hand of crew B. After observing that the area was still unstable, the evacuation alarm was activated and all tunnels in the Marden Street area were evacuated. 24. At approximately 2:00am, a hole was observed off the exit ramp in front of the "Kerslake" apartment block (11-13 Longueville Road). It also appeared that the subsidence had fractured a water pipe, causing a substantial inrush of water into the collapse. 25. Once the tunnels were evacuated and all workers accounted for, management representatives, geologists and engineers were progressively contacted and requested to attend the site. Subsequently, inspections were carried out both underground at the scene of the collapse and on the surface. At approximately 2.30am the hole was observed to be about 4 or 5m diameter on the surface and had undermined approximately 1-2m under the road. 26. Staff considered that the collapsed debris required strengthening before any surface activity could occur. It was proposed to place large diameter hammered rock to form a bridging layer to lessen any pressure on the pile of collapsed debris. However, they needed to remove an electrical sub-station and a dust scrubber from the area before the rock could be placed up against the debris pile delayed this action. This strategy was discarded as observation of the hole at approximately 5:30am revealed the hole had expanded in size. At about 6:00am loud noises were heard to be coming from the hole and it was observed that a substantial secondary collapse had occurred under the existing Longueville Rd exit ramp and a number of piles with the collapsed area of the tunnel were observed to have been undermined by the collapse. The hole at that stage was observed to be around 8-9m diameter. 27. It was at this stage that the decision was made by TJH to commence filling the hole with concrete to mitigate any further collapse. Concrete pumping commenced with one pump at approximately 8am. Two further concrete pumps arrived shortly after and also commenced pouring, the initial pour ceasing at around 3:00pm, having reached a height of 2 metres above the top of the pile. This amount of concrete had been determined as the maximum that could be placed initially without putting pressure on the exit ramp retaining wall. Longueville Road had been closed to traffic at approximately 6:45am. 28. After waiting for the first lot of concrete to cure a second pour was commenced at approximately 9:30pm on 2 November 2005 and completed at around 12:30am the following morning. The third and final concrete pour, which was to reach the level of the top of the retaining wall, was commenced at 6:30am on 3 November 2005 and completed mid-morning. Over the next couple of days, grout was pumped into identified void areas around the collapse to complete the stabilisation works. In total, approximately 2750 cubic metres of concrete and grout was pumped into the collapsed area. 7The evidence led by the prosecution in Hamilton v PSM demonstrates that the risks were reasonably foreseeable. One basis for this conclusion concerned the geological conditions prevailing at the site. These conditions are detailed in the Statement of Facts: 29. The bedrock at the site consisted of Ashfield Shale. In the area of the MC5B/MCAA intersection, the bedrock in the crown of the tunnel had been documented by the Project Geologist as Ground Class LCTG7 and LCTG8, that is, shale of low to very low strength. Previous investigations and assessments in the area had also indicated that the strength of the shale further decreased closer to the ground surface, in turn passing up to residual soil and/or some overlying fill. This material thus comprised a low strength sequence, from the crown of the tunnel up to the surface infrastructure. The Presence of the Dyke 30. The MC5B/MCAA intersection was transected in a southeast to northwest direction by an igneous (doleritic) dyke. The dyke comprised a subvertical, through-going intrusion, generally ranging in true thickness from between 600 and 700mm. Dyke intersections had been encountered previously in MC5B as well as in the main line tunnels and the occurrence of the dyke in or near the MC5B/MCAA intersection was anticipated by site personnel. 31. In previous encounters the dyke was predominantly orange in colour, highly to extremely weathered and of low to very low strength. These conditions are understood to have prevailed through the MC5B/MCAA intersection. The dyke comprises a persistent low strength feature, both laterally and vertically, and its side boundaries constitute low strength defect planes. Rock Mass Joints and Faults 32. Mapping documentation completed by the Project Geologist confirmed that the rock mass into which the MC5B/MCAA intersection had been excavated was relatively highly fractured. The shale in this area was characterised by structures comprising bedding plane partings, joint plane defects and localised faults. 33. Bedding plane partings are subhorizontal to locally dipping defects of variable vertical spacing. They are intersected by inclined to subvertical joint plane fractures. Mapping confirmed the presence of three (3) intersecting joint plane sets, one of which was parallel to the dyke, whilst the other two were both normal and more acutely angled to it. These subvertical fracture sets are locally continuous upwards and spaced as closely as 200 mm apart. They effectively divide the rock mass into a series of vertical columns, which can in turn be subdivided into blocks by intersecting with sub horizontal bedding planes. 34. The rock mass in the MC5B/MCAA intersection was further fractured by localised inclined fault structures that were mapped by the Project Geologist. In combination with the bedding plan partings and joint plane fractures described above, the localised faults further fragmented the rock mass into variously shaped and sized blocks and wedges. Large Span Width of Tunnel Intersection 35. Both the ventilation tunnel (MC5B) and the Pacific Highway Exit Ramp (MCAA) were "Two Lane" tunnels within the Lane Cove Tunnel Project, with spans or widths of approximately 9 metres. At the intersection of the two tunnels however, the width of the underground opening was locally greater. The diagonal width of the MC5B/MCAA intersection was up to 22m. This is a relatively large effective span width to support, particularly when the roof strata were comprised of low strength and fractured shale. Furthermore, the above described weathered and low strength dyke passed through the intersection as a zone of weakness, aligned closely with the line of maximum span. 8The foreseeability of the risks to safety is also demonstrated by the "as found" observable conditions in combination with the method of extraction undertaken at the intersection. The facts reveal that PSM was aware that the design intent for the intersection was not followed: see Hamilton v PSM at [43] to [47]. The consequences of non-compliance with the design intent are set out in Hamilton v PSM in the following paragraphs extracted below (at [38]-[42]): [38] The evidence establishes that TJH failed to follow the revised design for the construction sequence at the intersection of MC5B and MCAA. In summary, the shotcrete, which provided structural support to the roof, was not applied floor to floor. Nor was it applied to the specified thickness (initial application 100 mm to crown and walls with final application 100mm to crown and walls). This meant that not only was there an absence of roof support but, because the shotcrete was not self-supporting, it added an extra load to the roof. In addition, many of the rock bolts, which were meant to anchor, or secure, the shotcrete to the roof, failed. Mr Kotze explained the consequences of this in his Report in the portion extracted above, headed "iv) The inadequacy of the tunnel roof installations". [39] The shotcrete was not applied floor to floor as a result of a procedure adopted by the tunnelling crew referred to as "benching". Benching, and its influence on the ground support system at the intersection, was explained by Mr Kotze in his Report as follows: Benching is the process whereby the full height of an underground excavation is achieved in 2 or more passes, with an interim "bench" (or benches) remaining for subsequent excavation to achieve the full height. The design height of the MC5B/MCAA intersection was approximately 8.5m and benching was employed. As described above, the ground support system adopted in the intersection included an initial 100mm thick application of shotcrete, with a subsequent second application also 100mm thick, to achieve a final 200mm thick shotcrete lining to effectively act as a supporting arch from floor to floor. An impact of benching however, is to preclude the achievement of the full shotcrete lining, until the bench excavations have been completed. Throughout the duration of the time period between initial excavation and final bench excavation, the shotcrete component of the roof support system remains incomplete, as does the corresponding level of roof support. Furthermore, an initial layer of shotcrete lining to the floor of the initial bench, is undercut by the excavation of a subsequent lower bench. This effectively removes the basal support of the initial shotcrete, with a corresponding loss of support to the roof. The overall effect of this process is to enable the roof to be less than fully supported, for various periods of time up to the final establishment of the double shotcrete thickness from floor to floor at final level. During periods of less than full support, the potential exists for roof strata to delaminate and for roof instability to develop. [40] Another critical factor in which the design intent was compromised involved advancing the right-hand drive of the MCAA which increased the span at the intersection at the time of the roof collapse to 22 metres. The effect of this disparity on the stability of the roof at the intersection was described by Mr Kotze in his Report: At the time of the incident, the northern or right-hand side of the MCAA down drive from the intersection, had been advanced by more than the prescribed 1.5m. (Figure 1 and Reference 4). It is understood that the MCAA down drive had been partially installed on its right-hand side only with a number of 4m long rock bolts and with a single application of shotcrete of unknown thickness. (Figure 8). The partial excavation of the down drive on its' right-hand side only, prevented the establishment of a shotcrete arch across the full drive width. See Plates 12 and 15. The excavation and ground support sequence had not been completed. The excavation roof was therefore less than fully supported. The limited support in place at the time could not accommodate the geological conditions encountered in the roof and roof collapse occurred. [41] A further factor involved the difficulties faced by the tunnelling crew with tensioning and grouting the rock bolts at the intersection. These difficulties are well-documented in statements taken from the tunnelling crew who were working in the intersection during the period of the charges. Mr Baker said the bolts "hadn't taken up" and that they had trouble grouting them. Mr Shaw said some bolts would not tension and he had concerns because the ground being rock-bolted was so soft. Mr Swan recalled, "a lot of trouble tensioning" whenever the crew was close to the dyke. He estimated that about 90 per cent of bolts would not tension properly. Mr Watson said he was aware of tensioning problems with the rock bolts. He estimated that about three to four out of ten rock bolts did not tension properly. [42] Mr Kotze, in his Report, considered that the rock bolts installed at the intersection were not properly installed with the result that they would have had a minimal effect in providing roof support. He considered the malfunction of the rock bolts a "very serious issue" and a primary factor in causing the roof collapse on 2 November 2005. He added, by way of further clarification, the following observations: ... the support of the intersection and its transition zones was to be achieved by the composite effects of a 200mm thick shotcrete lining from floor to floor, and arrays of CT rock bolts. Prior to the completion of shotcreting/benching/shotcreting as necessary to achieve the full shotcrete lining (arch) from floor to floor, the support of the roof was reliant on the efficacy of the CT rock bolts. The failure of bolts to tension/end anchor and/or to achieve full grouted bond strength, would effectively leave those locations with very little if any roof support. This is considered to be a very serious issue in terms of both safety to personnel beneath such roof areas, and the potential for delamination and larger scale instability mechanisms to develop in the roof. 9Although no one was injured as a result of the tunnel collapse, the conclusion is inescapable that the risks to safety could have resulted in very serious consequences to those persons working at the intersection at the time of the collapse as well as to the residents of the unit block. 10The measures which PSM failed to take, as particularised in each of the charges, were the subject of findings beyond reasonable doubt in Hamilton v PSM at [48] to [87]. There were available to PSM a number of steps which could have been taken to ensure the safety of the tunnelling work and thereby avoided or reduced the risks. Those steps were summarised by the prosecution by reference to particular paragraphs from Hamilton v PSM. The prosecution's written submissions on this matter, extracted below, are adopted in these sentencing reasons: (a)PSM should have notified TJH of the significance of its non-compliance with the design intent and adequately notified TJH of the effect of what was happening and adequately notified TJH that it should obtain a new design and construction sequence in the area of the intersection (J[50]). (b)PSM should have made Mr Gilchrist's daily observations and recommendations of the area of the intersection subject of further communication to TJH and the same applies to their significance (J[54]). (c)PSM, through its Senior Rock Mechanics Engineer, Mr Clark, should have met one of PSM's contractual obligations under the PSM Rock Mechanics Engineer Consultancy Agreement, namely, to liaise with TJH regarding the design requirements by notifying TJH of the risk of rock collapse arising from its non-compliance with the design intent in the area of the intersection. Instead, Mr Clark abrogated responsibility to PB's Mr Lloyd (J[55] - [57], [62]). (d)PSM, through its Senior Rock Mechanics Engineer, Mr Clark, should have conducted a daily review and analysis of Mr Gilchrist's GC & GSD documents for the works in MC5B and MCAA during the period 27 October 2005 to 2 November 2005 (J[59] - [61], [65] - [67]). (e)PSM should have advised TJH of the subsidence which occurred on 24 October 2005 and recommended that TJH increase the frequency of monitoring measurements when excavations entered the intersection (J[63] - [64]). (f)PSM should have notified PB of certain of the matters referred to above (J[68] - [73]) and as the Court has already concluded in the two of the paragraphs just cited:72. The responsibility to notify PB of the constructor's non-compliance and of the consequential risk of rock collapse rested squarely with PSM. Its failure to do so resulted in the risk to the safety of the workers and residents of the unit block arising from the risk of the tunnel collapse. 73. Given that PSM failed to notify PB of the non-compliance with the design intent by TJH, it follows that PSM did not adequately notify PB that it should provide to TJH a new design and construction sequence for the construction taking place in the area of the intersection (in circumstances where the design and construction sequence provided was not followed). This failure, for reasons earlier stated, and in reliance on the evidence of Mr Kotze in particular, resulted in the risk of tunnel collapse thereby causing a risk to the safety of both workers in the area (both charges) and the residents of the unit block (s 8(2) charge). (g)PSM should have raised the fact (with TJH or with PB) that benching was not included in the design documentation for the intersection (J[75] - [76]). (h)PSM should have adequately notified the PB designers that the construction sequence being employed in the intersection and the MCAA down drive included benching(J[77]). (i)PSM, through its Senior Rock Mechanics Engineer, Mr Clark, should have, and could have, made itself and himself aware of non-compliance with the design due to TJH not applying shotcrete in the area of the intersection to its complete thickness (that is, not according to the design) and not extending it floor to floor. If the designers had been informed no doubt appropriate measures would have been taken to ensure that the shotcrete was appropriately applied (J[78] -[80]). (j)PSM should have adequately liaised with the project designers to facilitate changes to the design, with regard to the performance of the rock bolts at the intersection (J[81] - [86]). (k)PSM should have prevented its employees working in the area of the intersection and advised other workers in the area of the intersection that they should be prevented from performing work there (J[87]). 11General deterrence is a further factor which must be taken into account. It is incumbent on employers to ensure that appropriate systems are in place so that workers and other personnel are not exposed to risks of serious injuries from being struck by falling rocks and/or tunnel collapse. There is a need to impose penalties at a level that will draw the attention of those operating in the tunnelling, excavating, mining, building and construction industries to the necessity of engaging in practices that conform to the requirements of the Act. 12The Court was advised that PSM has no prior convictions. It therefore faces a maximum penalty of $550,000 for each offence.

13The Court was invited by the prosecution to consider subjective factors that might operate in mitigation of penalty. These consist of the following (extracted from the prosecution's written submissions): One subjective factor might be that before and during the charge period genuine attempts had been made by PSM to develop comprehensive systems and procedures designed for the safety of its employees; in particular there existed before the charge period the PSM Rock Mechanics Engineer Consultancy Agreement and what is set out in correspondence between PSM and PB. Secondly, PSM co-operated with WorkCover to the extent that the corporation answered statutory notices to provide documents and its employees were interviewed. Thirdly, the Court might consider whether, in the context of the dangerous industries in which the defendant had operated for some years, the defendant has overall a good record. 14The Court accepts the existence of these three factors brought to its attention by the prosecution and intends to take them into account in mitigation of penalty. 15In addition, the Court will take into account that PSM has no prior convictions which entitles it to leniency.

PSM's role 16In Hamilton v PSM, I found (at [49]): [49] In oral submissions, the prosecution sought to emphasise that it was not enough to simply inform TJH of its non-compliance and the necessity to obtain a new design. The evidence on this aspect demonstrates that TJH knew it was not complying with the design or with the construction sequence. According to the prosecution, the sub-particulars deal with the failure to notify TJH of the significance of its non-compliance. I agree that this should be the approach adopted for consideration of the particulars. PSM were seconded to the LCT project with the requisite expertise and experience of geological conditions in the Sydney basin. They were engaged to assist both in the design stage and the construction stage of the project. It was part of PSM's responsibilities and the expectation of both TJH and PB that PSM personnel would discharge those responsibilities. PSM was expected to alert TJH and PB to the significance of the geotechnical data obtained and the prevailing ground conditions in the area of the intersection and compare those matters with the design as formulated, so that the tunnel support could be revised. 17TJH was the principal contractor on the LCT project. PB and PSM, as specialist contractors, were required to work within the systems designed by TJH. The prosecution submitted that it was incumbent upon TJH to ensure that its specialist contractors complied with its systems, and, that in all the circumstances Thiess and JH were either more culpable or equally as culpable as the specialist contractors. 18In Inspector Hamilton v Parsons Brinckerhoff Australia Pty Ltd (ACN 078 004 798) [2012] NSWIRComm 28, the Court found itself unable to properly assess PB's role by reference to the role of TJH in the circumstances of the Lane Cove Tunnel collapse. The relevant passages from the judgment are extracted below: [46] According to the prosecution, TJH was the principal contractor on the Project with all the attendant duties and responsibilities associated with that role (see Reg. 210 of the Occupational Health and Safety Regulation 2001 (now repealed)). PB, on the other hand, as a specialist contractor, was required to work within TJH's system. In these circumstances, the prosecution asserts, without any further details, that TJH was either more culpable or equally as culpable as PB in the circumstances of the offence. [47] The Court finds it impossible to make any appropriate assessment of PB's role by reference to the role of TJH given the complete absence of detail provided by the prosecution and without the development of any further argument on the issue. Thiess and John Holland have been separately prosecuted and sentenced for offences based on evidence and on particulars that bear very little similarity to the offence to which PB pleaded guilty: Inspector Hamilton v Thiess Pty Ltd [ACN 010 221 486] [2012] NSWIRComm 26. Moreover, both Thiess and John Holland had prior convictions and faced a different maximum penalty of $825,000. 19Here, the Court finds itself confronted with a not dissimilar situation. PSM was convicted of two offences following an ex parte hearing. In contrast, Thiess, JH and PB each pleaded guilty to one amended charge under s 8(1) of the Act. PSM faces a maximum penalty of $550,000. Thiess and John Holland on the other hand both faced a maximum penalty of $825,000. Although the prosecution contended that PSM was either equally culpable or less culpable than that of Thiess and JH, it has not sought to develop the contention by reference to any evidence or other material which might have assisted the Court in giving due consideration to the issue. For these reasons, the Court finds itself unable to consider PSM's role in the circumstances of the offences by reference to those entities also charged in relation to the incident. The Court has already concluded in these sentencing reasons that PSM's role in the circumstances of the incident, by reference to the two offences with which it was charged and convicted, was objectively serious.

Totality 20The principle of totality is also relevant. Although the factual background underpinning each offence reveals substantial overlap, and both offences arise from the same incident, there are distinguishing features. The most notable of these concerns the additional risk, identified in the s 8(2) charge, to which the unit block residents were exposed. This matter was dealt with in Hamilton v PSM at [22] to [25] (in the passages earlier extracted). 21In applying the principle, the Court proposes to follow the approach of Boland J, President, in Inspector Dall v Ullrich Aluminium Pty Ltd [2011] NSWIRComm 156 at [78] and [79], where his Honour said: [78] In considering totality, the court must look to the totality of the criminal behaviour and ask itself what is the appropriate sentence for all the offences: Mill v The Queen [1988] HCA 70; (1988) 166 CLR 59 at 63. The effect of the totality principle is to require a sentencer who has passed a series of sentences, each properly calculated in relation to the offence for which it is imposed and each properly made consecutive in accordance with the principles governing consecutive sentences, to review the aggregate sentence and consider whether the aggregate is "just and appropriate": Mill at 63 citing DA Thomas, Principles of Sentencing (2nd ed, 1979) 56-57; cited with approval in Johnson v The Queen [2004] HCA 15; (2004) 205 ALR 346 at [18]. [79] It would clearly not be appropriate to fix a penalty in respect of the offence involving Mr Murrell and simply double it. That would be to impose a "crushing sentence" on the defendant, inconsistent with its prospects for rehabilitation. However, it would also not be appropriate to fix a penalty for the offence involving Mr Murrell and regard that as a "just and appropriate measure of the total criminality involved": Postiglione v The Queen [1997] HCA 26; (1997) 189 CLR 295 at 307-308 per McHugh J. To do so would pay no regard to the fact that the defendant had failed to ensure two persons, an employee and an employee of a labour hire firm, were not exposed to risk. The defendant had an obligation to ensure both persons were not exposed to risk and the penalty must reflect the seriousness of the defendant's failure in that respect. 22Having regard to the circumstances of each offence, the Court concludes that the s 8(1) offence should attract a penalty of $120,000 and the s 8(2) offence a penalty of $135,000. Taking into account the principle of totality, a penalty of $140,000 should be imposed as an appropriate reflection of PSM's total criminality. This penalty will be divided between the two charges by imposing a penalty of $60,000 for the s 8(1) offence, and $80,000 for the s 8(2) offence.

Other matters 23In oral submissions, the prosecution brought to the Court's attention certain correspondence which reveals that PSM changed its name on 18 December 2008 (from "Pells Sullivan Meynink Pty Limited" to "ACN 061 447 621 Pty Limited"). The prosecution's contention was that it was open to the Court by way of variance or amendment under either ss 16, 20 or 21 of the Criminal Procedure Act 1986 (the CPA) to amend both charges in order to reflect the change of name. 24The Court proposes to make the changes to both charges in the form proposed by the prosecution. An ASIC extract, applicable as at 28 March 2012, tendered by the prosecution during the sentence proceedings, confirms that PSM, as at 18 December 2008, was placed under external administration and at the same time underwent the name change. In these circumstances, the Court grants leave to amend the charges under s 20(1)(a) of the CPA.

Orders 25The Court makes the following orders: In matter No IRC 1991 of 2007: (1) the defendant is convicted of the offence and fined an amount of $60,000 with a moiety to the prosecutor; (2) the defendant shall pay the costs of the prosecutor as agreed or assessed. In matter No IRC 1992 of 2007: (1) the defendant is convicted of the offence and fined an amount of $80,000 with a moiety to the prosecutor; (2) the defendant shall pay the costs of the prosecutor as agreed or assessed. DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 05 October 2012