Abstract: Employee #1, a regular employee of a ship builder, was positioning a Skyjack scissor lift, model 3015, in a compartment aboard a ship. Although the lift was to be utilized only on a level surface, the deck of the ship was sloped 3.3 degrees. Employee #1 elevated the scissor lift 15 ft and was running wire through a "wire way" when he moved the scissor lift without lowering it. In doing so, he ran over a 4 in. deck cover plate that was wedged against a 4 in. piece of channel iron being used as a skid rail and that was connected to a portable equipment container. When the right front wheel of the scissor lift ran up onto the channel iron, the combination of the sloped deck and the tire being raised another 4 in. caused the elevated lift to tip over onto its left side. Employee #1 was ejected and fell approximately 15 ft to the deck. He suffered fractures to his hip, left wrist, and spine at the T-12 level. Causal factors in this accident included: (1) The scissor lift was not operating correctly; the speed control had been disabled, allowing extra power to go the unit when it was fully elevated; (2) The area where the equipment was being used was not clear of surface hazards; (3) Employee #1 failed to inspect the unit prior to use, as required; and (4) The employer allowed the unit to be operated on a sloped surface.