The solution to the problem won the Rio Tinto-owned Kestrel mine the safety innovation award at the 17th Queensland Mining Industry Health and Safety Conference in Townsville last week.
The problem was the difficulty of changing out v-return rollers on two conveyors in the plant up to twice a week. Several risks associated with the change-out were identified by Craig Firth, a contract maintenance employee.
During change-out, two operators were required to work at height, and with the positioning of the conveyors it was hard to design a rescue plan if someone fell.
The task also required the manual handling of approximately 68kg of equipment (two spreader bars and two chain blocks). The equipment was unloaded from a vehicle and carried along a conveyor walkway (approx 50m up stairs at a nine degree incline), with the operator required to maintain three points of contact at all times.
Operators also worked under a suspended load with two chain blocks and two spreader bars supporting the weight of the belt. A chain block was anchored to the belt above by pinching the top conveyor belting. This was not a certified anchor point and was seen to pose a risk.
Firth suggested an improved method of changing out the v-return rollers that involved a “jig”, designed with input from both operations and maintenance personnel. Operator feedback resulted in modifications being made to the design that included: installing stop points to hold the jig in place and prevent it from sliding; adjustment to the sizing of the jig to ensure height was adequate for correct alignment with the roller frame; and modifications to the roller shafts with a bevelled edge to help eliminate variance of height in the rollers for correct placement.
Since installation the jig has removed the hazards identified in the risk assessments, as well as improving the efficiency of the change-out task.
“This is an effective engineering solution that allows for controlled removal and installation of v-return rollers from conveyors,” the mine said in its submission to the Innovation Award panel.
