The decision, made available on the NSW Caselaw website yesterday, highlighted the dangers of flyrock and the need for mines to continually assess emerging risks especially with hydraulically powered roof supports (chocks).

The accident occurred on April 23, 2010, the last year of the Beltana mine before it transitioned into the Blakefield South longwall operations.

Miner Steven McNab was crushed between an advancing chock and the side of an armoured face conveyor while he lay either dazed or unconscious on the ground.

He is believed to have been knocked to the ground by a flyrock projectile, a 70cm by 39cm by 10cm piece of roof stone that was found on his thigh, although he had “no recollection as to how he came to be lying in the path of the advancing support”

Glencore’s defence team argued that the accident was not reasonably foreseeable, challenged the merits of the possible preventable measures raised by the prosecution, including the inadequacy of potential tilt switch solutions, and also drew attention to the lack of consideration of the possible risk that an operator could be suddenly incapacitated at the face by the wider industry.

However, the judge paid attention to an incident that occurred at the mine five weeks before the accident, with shearer operator Glen Watters struck on the head and shoulder by a large piece of coal which was flung off the drum about 7-9m away.

The mine’s block management plan had also identified an increased risk of flyrock from a thin strata of rock in the area McNab had been working in.

The judge also used the evidence of Beltana crew member Michael Brock, who said all workers were trained to stop all face hydraulics if they saw anyone fall down or get injured at the longwall face.

Ultimately the mine was found to have failed to address a foreseeable risk by not employing an additional man at the face, a support advance controller, to observe the shearer and chock movements.

Glencore had started using a SAC at the face after the accident occurred – which was also commented on by the district court judge.

A sentence will be determined at a later date.

"Glencore is disappointed by the Court’s findings and is currently considering whether to lodge an appeal," a spokeswoman told ICN.