Inspection Detail

Inspection: 311597777 - Maxim Crane Works, Lp.

Inspection Information - Office: Cincinnati Area Office

Investigation Summary

On November 21, 2007, Employee #1, a crane operator, was using a 170-ton Demag AC-140 mobile crane to assemble a tower crane station at a construction site. Coworkers had put together 160 ft of the tower crane jib section. Employee #1 made the 17,000 lb lift above the height of overhead power lines and proceeded to rotate the load to align it with the tower crane. As he turned the load, it created a problem with the boom angle. Employee #1 held his load height as he boomed down. In doing so he was faced with the load radius increasing to 100 percent of the crane's capacity, but he had not achieved the necessary radius to clear the load-to-boom rotation. Once at 100 percent of capacity, the Demag AC-140 shut down controls. Employee #1 restarted the crane in override mode and continued to boom down. As the crane became lighter, he induced load dynamics, trying to boom up to close back the radius. The crane was already near the tipping point, and the load caused the crane to overturn. Employee #1 suffered minor bruising to both legs and to his right forearm. He was checked out by Emergency Services, and was medically released at the site. Employee #1 was wearing his seat belt and he had the cab door closed at the time the crane overturned.

Keywords: ERECTION PROCESS, CRANE BOOM, WORK RULES, MOBILE CRANE, OVERLOADED, CONSTRUCTION, CRANE OPERATOR, CONTUSION, OVERTURN, UNSTABLE POSITION