From July 1 to October 31 there were 122 reported mine incidents with the largest number falling under the mechanical category. Longwall incidents numbered the highest in the explosion and mechanical categories.

Under the explosion category several incidents were reported involving gas monitoring equipment. In the first case a real-time gas monitoring system at an underground coal mine was not in position and in working order for 10 days. The mine manager was only made aware of the incident two weeks later.

In the second incident the trip setting of 5% was found on the general body methane sensor of a continuous miner. The setting was detected during a routine calibration.

The third high potential incident was found when a non-certified relay was installed into an intrinsically safe circuit of a gas monitoring system.

In incidents involving flameproof equipment, a flameproof light on a shuttle car was damaged and not discovered until routine checks were carried out; a flameproof junction box was found to be operating in an ERZ1 area without a flameproof gland fitted; and flame proofing on a continuous miner was compromised by poor cable termination in the gland entry of the cutter motors.

In three other potential explosion incidents, there was an arc flash when a short circuit developed in a longwall shearer maingate cutter motor junction box which was found to have 70mm of water in the bottom of it; a shuttle car cable failed to unreel when the shuttle car drove off from the boot-end and the cable pulled apart exposing the conductors and causing an open arc; and a worker was hooking up a ring of underground production blast holes when explosives in two holes suddenly started burning. The last incident caused the mine to be evacuated.

Under the mechanical category, the incidents in longwall mines occurred involving a shuttle car, continuous miner and drill rig.

In the shuttle car incident, when the car moved off it started to slide towards a worker standing adjacent to the coal rib. The driver stopped the car before contact was made.

In an incident where a worker did get pinned, the victim was trapped between a drill rig platform and the coal rib, when the platform was moved.

Also in a pinning accident, a drill rig operator leaned across to reset the rig after the power tripped to the continuous miner and accidentally hit the control levers. As he did so the power was restored. The drill pot retracted and pinned the operator.

Still in mechanical but involving a conveyor belt change-out, a belt splicing team took up some slack near the head pulley. This resulted in the belt inadvertently moving 3m at the tail end where a separate crew was working on a different task. The members of this crew had to pull themselves up on support bracing to avoid the belt.

Also under mechanical, a rota-coupling on inter-chock hoses between longwall shields ruptured causing the hose coupling to whip and spray high-pressure emulsion.

In the related Mechanical – Vehicle Loss of Control category, a driftrunner was going down a ramp when the methane cut-out system activated cutting the engine. The emergency brake did not immediately activate so the vehicle travelled a further 20m before the operator brought the machine to a stop at the side of the ramp.

Under the Gravity – Rockfall category an incident occurred where a continuous miner advanced 4m when it was pulled back to trim the corner. As the miner began to trim the corner a block of coal, measuring 3m by 1.5m by 0.8m, slipped and sat against the cutter head. As this was being cleaned up a second block of similar size fell.

Under the same category an incident occurred when after blasting a longwall belt chamber a 7m by 3.5m by 2m section of the adjacent supported roof collapsed.

In electrical incidents a non-electrical person was instructed to access a control cubicle using a tool provided by an electrician and reach through live terminals to reset an overload; and an electrician opened a shuttle car cable reel junction box without isolating the machine at the DCB.

In the Other category, an underground coal mine was evacuated due to an increase in carbon monoxide levels in the goaf exceeding the TARP level; and at another underground coal mine high levels of carbon monoxide were detected from a new seal mixture product being used to construct a 140kPa seal.