Inspection Detail

Inspection: 305355984 - Aluma Systems

Inspection Information - Office: Santa Ana District Office

Investigation Summary

On July 6, 2005, Employee #1 was working for a company engaged in renting and erecting scaffolds. Interior and exterior finishing work was in progress and to facilitate ceiling work, a crew consisting of six workers was installing suspended scaffolds. The ceiling of the hall was approximately 80-ft high. Each section of the scaffolding consisted of two 14-ft long by 8-ft wide steel walers, which were hung by four cables protruding through holes in the ceiling. They were anchored to a beam structure extending above the roof. After attaching two cables to each of the two walers at the ground level, they were pulled up in place by two motorized winches installed on the roof. Then two workers would install six cross beams between the two walers followed by sheets of plywood to complete the assembly of a section of suspended scaffolding. The four suspension lines were assembled using wire ropes, threaded rods, washers, hex nuts, eye nuts, and turn buckles. A turn buckle couples the two pieces of wire rope, which are terminated by threaded rods. As the buckle is turned, the threaded rods travel in or out of the buckle to provide needed adjustments to the length of the suspension line. The crew had already installed five sections of the suspended scaffolding. They were in the process of leveling the platform on the fifth section. Employee #1 and coworker #1 were on the suspended platform while coworkers #2 and #3 were on the roof adjusting the lengths of the suspension lines by rotating the turn buckles. Employees #1 and coworker #1, on the suspended scaffolding platform, were in communication with coworkers #2, and #3, on the roof, with a two-way radio system. After checking the level of the platform, Employees #1 and coworker #1 were advising coworkers #2, and #3 to adjust the appropriate suspension lines by rotating the corresponding turn buckles. As coworker #2 was rotating a turn buckle to adjust the suspension line, the entire section of the line below the turn buckle was turning instead of just the threaded end of the suspension line. This inadvertent torsion on the suspension line loosened the hex nut at the lower end of the line, which was holding the waler in place. The nut came completely off the threaded end of the suspension line and the suspended platform collapsed. Employee #1 fell approximately 70 ft and died. Coworker #1 was found hanging by his fall arrest gear and he was rescued successfully without any physical injury.

Keywords: ERECTION PROCESS, COLLAPSE, PPE, LANYARD, FALL, FALL PROTECTION, SCAFFOLD, SCAFFOLDING