Warren Power & Machinery, Inc.

A two-person team was removing hydraulic cylinders from a bulldozer. The tooth of the ripper was removed and the frame was resting on wooden cribbing. The lower portion of the ripper frame remained connected to the unsupported H-frame by an articulating pin. The injured employee was using his left hand to hold the striking point of a side sledge hammer against the retaining pin of the cylinder being disconnected while a coworker used the hammer. Upon freeing the pin, the H-frame immediately settled toward the ground, causing the ripper frame to rotate around the articulating pin connecting it to the H-frame. The employee's left arm was caught between the frame and hammer, resulting in a forearm fracture.