An incident report from the WA Department of Mines and Petroleum has warned EWP and telehandler operators about the danger of impact to hydraulic valve check blocks on outriggers and hydraulic rams.
A worker was badly injured after his telehandler with EWP attachment tipped over during work in an open pit.
The worker was 12 metres off the ground, trying to manually remove a rock from the pit face, however the rock fell and struck the hydraulic valve check blocks on the front right stabiliser of the telehandler.
The sudden loss of stability caused the telehandler to tip over and trap the worker against the pit wall, pinning his legs six metres up from the pit floor.
After the rescue the worker was found to have a fractured lower right leg and crush injuries to his left foot.
The rock caused the valve check block to shear off from the hydraulic system, causing loss of fluid and pressure and retraction of the outrigger.
It was ascertained by investigators that the worker had not considered the potential for equipment to be struck by falling rocks.
Other findings about contributing causes included the valve covers were not adequate for protection from falling objects, and that the design of the basket did not prevent body parts from protruding past the edge protection of the basket in the event of uncontrolled movement.
The DMP recommended companies conduct a review of equipment fitted with check valves to determine if a risk of impact exists for the check valve and block.
For tasks involving work at height, workers should identify scenarios where objects could fall and strike critical equipment and people below.
For elevated work baskets, workers and management should determine the adequacy of the basket’s design to prevent body parts extending past edge protection in the event of uncontrolled movement.