COAL OPERATIONS AUSTRALIA LTD v INDUSTRIAL RELATIONS COMMISSION OF NSW & Rodney Dale MORRISON
[2005] NSWCA 346
At a glance
Source factsCourt
Court of Appeal (NSW)
Decision date
2005-07-20
Before
Spigelman CJ, Mason P, Handley JA, Wright J, Boland J
Source
Original judgment source is linked above.
Judgment (17 paragraphs)
Background Facts 6 The charges of which the Claimant was convicted by the Full Bench arose from the collapse of a roof in an underground coalmine. This occurred on 6 July 1998 killing one employee of the Claimant and injuring another. 7 At the time of the accident, the Claimant was engaged in mining coal from a seam of coal known as the Great Northern Seam. The seam is marked by a horizontal layer of conglomerate above and a geological feature known as the "Abwa Tuff Member" below. The layer of conglomerate formed the roof of the mine. 8 The accident occurred during the creation of a horizontal tunnel, known as a "heading". Tunnels of this character are excavated with the assistance of a machine known as a "continuous miner". These machines extended the heading by removing coal from the end of the tunnel (the "face"). 9 As a heading was extended, from time to time it became necessary, for reasons of safety, to support the roof of the newly formed tunnel. Two means of support were employed at the mine: temporary support in the form of timber props and permanent support by means of inserting bolts into the conglomerate roof. Roof bolting was effected by the drilling of a 1.4m hole in the roof, followed by the insertion of a bolt of the same length, together with a chemical adhesive to fix the bolt in place. It was common ground that this was an appropriate method of supporting the roof. 10 The trial judge, Peterson J, outlined the system in place for both the provision of roof support, and the assessment of roof stability, during the process of excavating a heading: "[26] … After the continuous miner has mined a particular area, the area is a 'no-go' zone for staff engaged in the mine until the roof has been tested and/or supported. That support will consist of either temporary support in the form of timber props or permanent support by way of roof bolting. [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. [28] The condition of the conglomerate roof at Wallarah roof [sic] is variable. The standard means of testing the roof is to strike it with a length of drill steel in a process called 'sounding the roof'. A solid ring will be accepted as indicating a sound roof whereas a hollow or flat sound induced by the steel will indicate a 'drumminess' of roof, perhaps inducing an increase in the number of bolts applied to the roof." 11 The minimum support rules, to which his Honour referred, are mandatory provisions made pursuant to the OH&S Act and the Coal Mines Regulation Act 1982, the effect of which I consider more fully below. 12 The holes in which the bolts were inserted were bored with the assistance of a particular machine known as a "Falcon Roof Bolter". His Honour described the manner in which these machines were operated: "[30] 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." 13 In addition to the procedure of sounding a roof, information relevant to the assessment of roof stability could also be obtained from the drilling procedure. His Honour said: "[31] Abnormalities in the conglomerate layer are also detectable in the drilling process, from the condition of the product of the drill hole, and the presence of any water. Holes may be drilled as test holes and, in theory, left unfilled if they reveal no problem in the roof. The evidence was that the practice of the miners at Wallarah, however, was to utilise a roof bolt in all test holes regardless. 14 At about 11.00pm on 5 July 1998, a team of miners lead by Mr Ken Tytherleigh as deputy, comprising Messrs Anthony Carroll, Tony Dickson, Noel Pezely and Russell Anslow, commenced their shift. Their task was to undertake mining by extending a particular heading (B Heading in Number 3 Unit in the South West Panel of the mine) using a continuous miner. Mining commenced at the T-junction of B Heading with a perpendicular tunnel known as "Cut-Through 2". When the team reached the intersection it encountered water in a quantity that required removal prior to the commencement of mining. The source of the water was a geological fault in the coal seam that had been encountered in another heading. Approximately 90 minutes was spent pumping the water away before mining began. 15 Mining commenced at about 1.15am on 6 July 1998. As the heading was extended into the coal, approximately 16 shuttle cars of coal were cut from the face of the heading. At this point, the heading hit a geological fault in the coal seam. The fault ran at an acute angle alongside the heading on the right hand side. With the extension of the heading, the fault and the heading had converged. 16 When the fault was encountered, it was reported to the relevant Under Manager, Mr Ronald Wallace. Mr Wallace attended the work site, arriving at approximately 2.00am. The trial judge described the nature of the inspection carried out by him: "[36] He attended at the mining point upon becoming aware of the fault having been struck. He 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'." 17 However, all mining did not cease. After taking measurements to determine their precise position, the Under Manager and Team Leader realised that the heading had been extended to the point at which it was intended to intersect with a proposed cut-through. As a consequence of this finding, it was determined to "square up" the end of the heading prior to finishing. 18 There was some dispute relating to the precise instructions given by Mr Wallace in relation to the erection of the additional support. However, no issue was made of this before the Full Bench, which proceeded on the following basis: "[23] … 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." 19 The direction to place bolts 1.5 m apart had the effect of increasing the density of roof bolts from the previous distance of 3m apart. 20 Messrs Carroll and Dickson then took a break. During their absence, the continuous miner was removed and the process of bolting commenced. Mr Wallace remained at the site for a total of about one hour. Just before he left the site, the first fall occurred in the area of the face. Mr Wallace left the site and the drilling and bolting process continued. 21 During the drilling process there were a number of signs indicative of roof instability: water flowed from the newly-drilled holes, and the drill steel in the bolter was given to jamming. When Messrs Dickson and Carroll returned from their break, Mr Anslow informed Mr Dickson that he had noticed evidence of a soft layer in the conglomerate (a "parting") while drilling the last hole. 22 Messrs Carroll and Dickson relieved Messrs Anslow and Pezely from the task of supporting the roof. However, they immediately perceived a problem with the air supply to the Falcon Roof Bolter, and spent some time inspecting the air hosing. 23 The second fall occurred whilst the air supply was being checked. This fall consisted of approximately 6 metres of stone, with the roof falling back from the face to a point about 1.5 m from where the last bolts had been installed. 24 The roof was sounded, and found again to be "competent". The trial judge described what happened next: "[45] … 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."