The workers were carrying out routine maintenance, attaching cables to the roof of a New South Wales underground coal mine.
The work platform was attached to the front of a 913 LHD via a quick detach system and was being driven by the LHD operator.
While the LHD was reversing one wheel traversed a 300mm step in the floor, causing the work platform to suddenly pivot upwards and hit the mine roof.
The workers on the platform were jammed between the roof and the platform, resulting in arm injuries including a fracture.
In the NSW Department of Primary Industries investigation it was found poor roadway conditions made it difficult for the LHD operator to control the speed of movement of the work platform.
It was also found that the work platform and LHD arrangement did not comply with the requirements of OHS Regulation 2001, which stipulates working on an elevated work platform.
The DPI has issued a number of recommendations, advising all mines to review their systems of work which require people or materials to be lifted, to ensure they comply with clause 142 of OHS Regulation 2001.
The department added that EWPs should be used with consideration to AS 2550.10 and should comply with AS 1418.10.
It also advised mines to carry out a gap analysis to AS 1418.10 and AS 2550.10 and implement appropriate risk controls for work platforms attached to LHDs.
The DPI said particular consideration should be given to rated capacity of the work platform and LHD arrangement; instability and environmental conditions of the work platform; structural or mechanical failure of the quick detach system, link arms and hydraulic cylinders and hoses on the LHD; and platform control and emergency stop for people on the work platform.
It said attention should be paid to the LHD operator moving the work platform unintentionally; communication between the LHD driver and the people on the work platform; and collision of the work platform.
The department said safe access should be given to and from the work platform with an emergency descent, and guardrails and protective structures should be put in place when working from a height.
