Inspector Nash v Bulga Underground Operations Pty Ltd
[2014] NSWDC 186
At a glance
Source factsCourt
District Court of NSW
Decision date
2014-11-05
Before
Curtis J
Source
Original judgment source is linked above.
Judgment (25 paragraphs)
Introduction 1The defendant, Bulga Underground Operations Pty Ltd (Bulga), is charged with failing to ensure the health, safety and welfare of its employee Steven McNab in contravention of section 8(1) of the Occupational Health and Safety Act 2000. 2At approximately 9:30 PM on the evening of 23 April 2010 Mr McNab, a long wall miner at Bulga's Beltana Coal Mine in the Hunter Valley, suffered severe injuries when, after falling to the ground, his body was crushed between the toe of an automatically advancing roof support and the side of the continuous armoured face conveyor. 3Mr McNab was dazed or unconscious immediately before the injury and has no recollection as to how he came to be lying in the path of the advancing support. 4He was found semiconscious and pinned between the two pieces of machinery with his helmet fallen off, and a fresh graze on his left temple in a position that would have been protected by the helmet if it had remained in place on his head. 5A piece of roof stone approximately 70cm x 30cm x 10cm was lying across his thigh.
The System of Work 6At Beltana an underground seam of coal approximately 3m in depth, 250m wide and 3km in length was mined by a retreating long wall system. 7This system proceeded by driving two horizontal access drives into the wall at the bottom of a previously open cut mine, one on each side of the seam and joining those drives with a lateral drive at the far end of the seam. 8The long wall mining machinery was then assembled in the lateral drive, stretching the full width of the seam. The machinery extracts coal by sweeping cutters to and fro along the whole length of the wall heading in the direction of the mine entrance. The overburden collapses into the void formed behind the retreating machinery. 9This machinery consists of two distinct assemblages. 10The first is the roof support system. At Beltana this consisted of a continuously abutting line of 173 hydraulically operated roof supports each approximately 1.7m in width, resembling a flattened C shaped in section, the open face directed towards the body of coal to be extracted. The top of each roof support, which bore against the roof, is called the canopy. The bottom of each roof support includes two flattened metal plates called pontoons. These pontoons form the walkway traversed by the miners who operate the system. 11The roof support system was manufactured by Joy Machinery, purchased by the defendant in 1994 and previously used in the South Bulga mine. After that mine closed the supports were renovated and installed at Beltana when it opened in 2003. 12The second assemblage is the cutting apparatus constituted by a pan line conveyor and Shearer. The Shearer at Beltana was manufactured by DBT and purchased by Beltana in 2003 specifically for use in this mine. 13The pan line consists of a continuous line of articulated metal box sections, which support both the track along which the Shearer runs and the armoured face conveyor (AFC) that carries the cut coal away. Each unit of the pan line is connected to the opposite roof support by a relay bar, which passes between the two pontoons of the roof support. 14The Shearer comprises a chassis that contains electrical engines and electronic controls connected to a track of the pan line by a ratchet drive. At each end of the chassis pivots a ranging arm, holding a rotating cutting drum approximately 2m in diameter and 1m in width. The drums are fitted with auger shaped cutting vanes that funnel the cut coal onto the AFC. 15As the Shearer sweeps across the coal face, the leading cutting drum cuts the top half a web of coal approximately 1m deep into the face. The ranging arm of this drum is elevated or lowered to conform to the desired plane of the roof line, called the horizon. The trailing drum cut the bottom half of the web to the same width, and is also elevated or lowered to conform to the desired plane or horizon of the floor. 16Changes to the horizon are necessary to follow undulations in the coal seam. 17An unsupported roof void of 1m, the width of the cut, is created behind the Shearer as it advanced across the face. The roof supports, hydraulically driven, are automatically and sequentially advanced into this void, to protect that section of the roof. This movement closes the 1m gap between the toe of each unadvanced pontoon and the face of the pan line. (Mr McNab was crushed in this space). 18After the advance of the roof supports the relay bars gradually and sequentially extend to push the pan line forward into the void, now protected by the advanced roof canopy, that was created by the path of the Shearer. This action brings the track of the Shearer on the pan line close to the face in preparation for the next sweep of the Shearer on its return run. 19The length of the unsupported roof, between the Shearer and the last advanced roof support is called the headway. The length of the headway is controlled by changing the distance behind the Shearer at which the next roof support in sequence advances. 20As the Shearer moves further away from the last advanced support an electronic device on the Shearer signals the next roof supports in sequence to advance so as to maintain a constant headway. 21It is important to note that the Shearer can move faster than the rate at which the roof supports advance, and that the roof support system is driven by an independent power source. After the Shearer is stopped for any reason, the roof supports will continue to advance until the preset safe headway is achieved. 22Before the signal to advance is sent, the device on the Shearer sends a preliminary signal to the roof support by which it is "primed" to advance. The prime signal triggers a buzzer and a light on the roof support to warn workers of its impending advance. Those warnings continue as the support advances slowly, taking about 10 seconds to close the 1meter gap. 23The Shearer is controlled by two miners who walk along the walkway constituted by the pontoons. Each miner operates a handheld remote control. One controls the lead drum and the other the trailing drum. These controls permitted the miners to control the speed of the Shearer and the height of each drum to follow the contours of the seam. The controls may be placed in automatic mode in which the speed of the Shearer and the height of the drums operated within preset parameters generated by the preceding cut. 24It is necessary that each of these operators remain in sight of the cutting drums in order to observe and control the horizon being cut by the drum under their control. Failure to control and coordinate the upper and lower horizons may result in the Shearer failing to follow the seam and become "ironbound" or wedged fast between the roof and the floor. 25This proximity to the coming drums exposes the drum operators to the hazard of being struck by "fly rock" being pieces of coal or fallen roof stone flung by the rotating cutter drums over the sides of the armoured face conveyor into the walkway. 26The distance to which the fly rock was projected depended on its size. Large pieces, called "surfboards", which they resembled, did not move a great distance and slid from a top of the AFC into the walk way. Smaller pieces, between the size of golf balls and soccer balls could travel greater distances and strike the miners with some force. 27Beltana recognised the risk of fly rock causing some injury, and sought to control the risk by creating no-go areas or "caution zones" in the immediate vicinity of the cutters, and instructing the miners to move further away from the Shearer when the size and volume of fly rock became hazardous.