Gerald Gambs, Jr., PE, MME ::::
Case Synopsis: A large, rubber-tiered straddle crane, 50 feet tall and 75 feet wheelbase, was being operated in a rail yard, loading and unloading 40 foot containers. At the end of the graveyard shift, the operator executed a "swing" turn across a triple track, in order that the only operational cab would be on the optimum side for the next shift. During the swing turn, one of the wheels buckled under the frame and the crane collapsed. During the collapse, the turntable bearing at the wheel yoke-to-frame interface ruptured.