Incident summary: An experienced supervisor neglected to adequately inspect a piece of equipment before operating it. As a result, a critical component failed, and the man tumbled 85 feet to his death.
The damage: When it was time to move heavy granite blocks from the bottom of a quarry, a supervisor climbed into the cab of a 90-ton crane positioned about 10 feet from the edge of the quarry’s highwall. The supervisor had been operating cranes for more than 25 years and he was the only person on the crew who’d been trained to run cranes.,/p>
After a 15-ton piece of granite was attached to the crane, the supervisor used the controls to raise the heavy load from the bottom of the quarry.
As soon as the load cleared the edge of the highwall, the boom on the crane began to drop. As the boom descended, the crane tipped over.
The supervisor was unable to exit the cab fast enough and the crane tumbled 85 feet to the bottom of the quarry. As the crane was falling, the supervisor was thrown from the cab.
A worker trained in first aid raced over to the motionless body of his supervisor. He checked for a pulse, but there was none. Emergency responders arrived a short time later, but the supervisor never regained consciousness, and he was declared dead a short time later.
Findings: The supervisor failed to adequately inspect the setup of the crane before using it. A proper inspection might have shown that the boom pawl designed to lock the boom in place wasn’t properly secured. It was the failure of the boom pawl that caused the incident, according to investigators.
(From the Dec. 9, 2019 issue of Safety Alert for Supervisors)