“A scoop operator had dismounted his scoop and positioned himself in the swivel portion of the scoop while resetting the circuit breaker,” the agency noted of its inspection of an undisclosed underground mine.
“Upon the scoop operator's resetting of the circuit breaker, the scoop's hydraulic pump motor started, thereby posing a potential crushing injury to [him].”
MSHA also cited a related accident in Alabama in 2001 where a battery-powered scoop operator received a dislocated hip when resetting the circuit breaker and became pinned between the scoop and the roof.
“The scoop operator had leaned across the frame of the scoop to reset the circuit breaker and had inadvertently pressed the bucket's ‘lower’ lever,” the agency noted.
“When he reset the circuit breaker, the hydraulic pump motor started, the bucket lowered, and the frame of the scoop arched at the center section, thereby pinning the operator into the roof.”
The agency previously stated that all designs for battery-powered scoops should include a separate pump motor start switch if seeking MSHA approval. It also said in PIB P04-01, released in January 2004, that scoops already in use have a separate switch installed and maintained, and that operator training be conducted on the amendment.
“Another means to reset the circuit breaker in a battery-powered scoop without placing the scoop operator in a hazardous position is the installation of a mechanical device similar to the gas feed cable on a lawn mower.
“This device can be mounted to the battery-powered scoop with a connector which is attached to the circuit breaker handle and operated by a ‘T’ handle in the operator's compartment, [allowing] the resetting of the circuit breaker without having to leave the operator's compartment,” it said, adding that many battery-powered scoops were now made with that device.
If a mine’s scoop was not equipped, the agency said a parts distributor could provide the mechanical device and the installation, and that modification did not need to be reported to MSHA. In the meantime, thorough inspections of all units were highly recommended.
For any questions or to obtain a printable copy of the alert for posting, visit the agency’s website.
