Government of Western Australia | An underground mining contractor has been fined $540,000, and ordered to pay $8,414 in costs, after an October 2022 rock fall in a ventilation shaft at the Hamlet Underground Gold Mine near Kambalda, which killed a driller and injured a probationary offsider.
RUC Mining Contractors Pty Ltd pleaded guilty in the Kalgoorlie Magistrates Court to two counts of the same offence, exposing a worker to a risk of death, injury, or harm to health, contrary to sections 19(1) and 32(1) of the Work Health and Safety Act 2020.
This offence does not indicate that the breach caused the fatal incident. However, it highlights a failure in relation to risk management.
Magistrate William Yoo imposed on RUC Mining Contractors, which Gold Fields Australia Pty Ltd engaged to conduct raise bore-drilling work at the Hamlet Underground Gold Mine, part of its St Ives Gold Mine, a single fine of $540,000 for the two counts.
In October 2022, an RUC Mining Contractors-employed driller and probationary offsider were engaged in disassembling a reamer by unbolting and removing wings attached to the reamer’s centre box at the base of a ventilation shaft, which had been drilled using an underground mining technique known as raise boring.
Reamers must be disassembled and removed from the holes they create. At the time of the fatal incident, the disassembly method that RUC Mining Contractors employed involved pulling the reamer’s head to the side of the raise, rotating the reamer’s head to position its worked-on parts beneath supported ground and behind protective curtains.
As the reamer was not centred in the hole, RUC Mining Contractors staff were experiencing difficulties hanging the curtains, made from rubber conveyor belt material, and draping them over the reamer’s head. To enable the centring of the reamer in the hole, an RUC Mining Contractors employee booked a jumbo operator to install a torque plate on the ventilation shaft’s right-hand wall. However, in the meantime, disassembly work continued.
During that period, the RUC Mining Contractors area manager visited the mine and observed that the protective curtains were not properly installed. Also, the area manager instructed the driller to climb off the reamer as the driller was working too close to the curtains directly beneath the hole and, consequently, beneath unsupported ground.
The fatal incident occurred about an hour after the RUC Mining Contractors area manager left the ventilation shaft. The driller was standing on top of the reamer’s head, undoing bolts on its top. The probationary offsider was standing on the ground close to the reamer’s edge, feeding the driller the air hose for the rattle gun they were using. The driller was standing under unsupported ground. A rock fall happened, striking the driller and causing the probationary offsider to fall to the ground. The driller died instantly. The probationary offsider suffered minor physical injuries and a psychological injury.
