Pedal to the Metal
Thomas J. Cocchiola, PE, CSP, Mechanical Engineer
Case Synopsis: An experienced crane operator was instructed to hoist and load 36-foot long steel rails onto the back of a flatbed truck. He had previously operated the crane to load rails many times without incident. The operator was using a hydraulically powered crane mounted to the back of the flat bed truck. The truck-mounted crane had an elevated operator compartment with control levers to extend/retract the boom and foot pedal controls for rotating the crane.
The accident occurred while the operator was hoisting and loading the very first rail of the day. He maneuvered the boom over the rail, hoisted it off the ground and rotated the crane to position the rail above the truck bed. The operator removed his foot from the pedal, which should have immediately stopped the crane rotation. Instead, the crane unexpectedly continued rotating and the rail collided with the operator compartment. The force of impact caused the operator to fall out of the crane and sustain injuries.
Expert Analysis: An investigation revealed the crane continued to rotate because the foot control was stuck. The crane had been repaired because an operator reported the pedal previously stuck and caused unintended movement of a suspended load. Despite the repair, the pedal continued to stick intermittently, which exposed workers to hazards while the crane was operated. An applicable safety standard (ASME B30.22) required periodic inspections and maintenance to ensure the crane was in safe operating condition. The crane manufacturer also required periodic inspections and maintenance. The analysis demonstrated that the failure to properly inspect and maintain the crane, as required, caused the accident.
Result: The case was resolved before trial.