Fatality Assessment and Control Evaluation (FACE) Report for Wisconsin: Lineman at Hydroelectric Utility was Asphyxiated When the Safety Rope Attached to His Harness Became Entangled in a Revolving Turbine Shaft.

摘要

A 34-year-old male lineman (the victim) died of asphyxiation when the safety rope attached to his harness became entangled in a revolving turbine shaft. The victim was employed as a lineman for the city's hydroelectric utility, and was inspecting a 75-year-old turbine that was idle following replacement of a dam. He was working with a co-worker in the enclosed flume that channeled river water through the turbine. The victim donned a fall protection harness and entered the flume via a ladder lowered from a floor opening in the platform above the flume. His safety rope was held by a co-worker standing on the platform. Another co-worker held the safety rope of the co-worker who was working in the flume with the victim. Although the major portion of the water flow had been blocked off, a small steady stream of water leaked through the control gates and flowed through the area. The knee-high, flowing water struck the turbine vanes which caused the 4 1/4-inch diameter shaft to rotate about 20 rpm. The turbine was tagged out at the utility station, but there was no lockout device to stop the revolution caused by the leaking water stream. After inspecting the area around the turbine, the victim noted that many of the turbine vanes were 'frozen' in place, rather than swinging on the bolts which held them in place. He and the co-worker in the flume began striking the vanes with a maul, to break the crust that prevented them from moving. After several strikes, the victim apparently slipped in the water and fell toward the spinning shaft. His safety rope got caught on a shaft coupling, and his harness was pulled tight to the shaft. The victim's body stopped the rotation of the turbine shaft. The co-worker cut the rope after he realized what happened, and called for help up to the two co-workers. The co-workers secured the generator wheel so the victim could be cut loose without the wheel restarting. Emergency services responded, and cut the victim free of the shaft. He was transported to the hospital, where he was pronounced dead. The FACE investigator concluded that, to prevent similar occurrences, employers should: (1) install a locking brake which stops the rotation of hydroelectric turbines when maintenance and repair is necessary; (2) develop and implement a written hazardous energy control program that includes specific procedures for all machines that could result in a release of hazardous energy; and (3) provide training in the recognition and avoidance of unsafe conditions to workers who are assigned tasks outside their normal duties.