Abstract: On June 5, 2003, Employee #1 and a coworker were cleaning the exterior steel of a building. This is accomplished through the use of a site-unique suspended scaffold, designed and engineered by Skymaster Corporation. Employee #1 and a coworker were in the process of moving the scaffold. The scaffold is suspended by an arm that rides on a tracked trolley. The trolley rides on a pair of rails that are 10 in. in diameter. The track goes around the periphery of the roof which is high on the north and south faces, and lower on the east and west faces. The trolley was being traversed from the southeast face around a corner where a 14 degree slope began decent to the middle of the east face, then back uphill to the northeast face. Employee #1 was riding in the scaffold and the coworker was operating the electric motor controls from the roof, along side the scaffold. As it began to descend the trolley began to slide on the rails, it gained speed until it reached the bottom of the slope then continued to slide uphill 35 ft, where the scaffold began to swing to the side. At this time Employee #1 was ejected from the scaffold, but was held to the scaffold by his fall protection harness. As he and the scaffold swung sideways the scaffold contacted some of the steel walls whose edges were sharp. This sliding along the walls cut the fall protection lanyard, causing the Employee #1 to fall approximately 2 ft to a structural glass ceiling. He received minor bruises and a small cut on his forehead. He was not hospitalized.