Crane load hits elevated work platform

A synthetic fibre sling has failed during a leg assembly through use of a crane near Lithgow in NSW.

The crane was lifting the leg assembly into position on a skyline conveyor when the sling failed, allowing the assembly to move and come into contact with a boom-type elevated work platform (EWP).

Investigations suggest that the slings had worn on the sharp edges of the flange and the bolts. The remaining sling, when removed, also had some cuts and abrasions through the outer casing and into the core.

Based on the positioning of the EWP with respect to the load, the Mine Safety investigation found it was reasonably foreseeable that if a sling was to fail during the lift, the EWP could have been struck by the load.

The EWP had two workers on board, who anchored their harnesses to the conveyor walkway and exited via that walkway.

The mine operator had identified that several sets of the conveyor’s legs were deformed by both the weight of coal on the legs and the passing of stockpile dozers on the coal. The legs still had sufficient structural integrity for the required load but it was decided to replace them. New legs were designed and a change-out method using cranes was developed.

The lifting plan for the task included both cranes on the one plan, even though they were independent lifts. The pro forma for the lifting plan did not give guidance on sling selection, nor did it provide adequate space to specify all the lifting equipment selections.

Image credit: ©iStockphoto.com/diego cervo