THE huge bin which dumped 10 tonnes of coal refuse onto the cabin of truck driver David Oldknow and killed him had malfunctioned at least once previously, an inquest heard yesterday.
Glebe Coroners Court heard how the ‘‘reject bin’’, which was programmed to pour the chitter in 10-tonne increments into trucks and trailers, had on at least one occasion released two loads within seconds of each other and before a truck driver could manoeuvre his rig into place.
Mr Oldknow, 59, was crushed to death when the chitter crashed onto the fibreglass cabin of his Kenworth truck in the early hours of February 18, 2009.
The experienced Singleton truck driver was subcontracting to Daracon, which had the contract to remove the chitter from the Xstrata-owned Ravensworth underground coalmine.
The inquest has heard that there was a range of safety procedures which needed to be ticked before truck drivers could use a remote control to open the hydraulic gates of the chute and allow the chitter to be unloaded.
It included passing stop and go traffic lights and three motion sensors which needed to be tripped before the load would be released.
The inquest, in front of Deputy State Coroner Scott Mitchell, has heard of several scenarios which could have caused the load to pour on top of Mr Oldknow, including malfunctions.
It also included the possibility that Mr Oldknow had driven slightly around the refuse chute to avoid highly corrosive liquid pouring from the bin before reversing his rig back into position.
Several truck drivers who worked on Mr Oldknow’s night shift, as well as the day shift supervisor, have told the inquest that dodging around the dropping liquid was a well-used practice to save their trucks and extra work.
Another truck driver, Greig Delaney, told the inquest yesterday how he had once parked his truck and dog trailer under the 500-tonne bin and tried to use a remote control to unload 10 tonnes of chitter when the electronics of the bin began but the hydraulics to open the chute failed.
Mr Delaney said when he tried again, the doors opened, tossing the 10 tonnes into his truck before almost immediately dumping another 10 tonnes before he could place his dog trailer in position.
The inquest continues.