Abstract: A six-person power line crew was installing 1000 MCM, single conductor aluminum cable from one bus tie to another. A 4.6-meter-long hallway separated the two bus ties. The employees were using a truck winch to pull the aluminum cable through a duct. They passed a 19-millimeter-diameter pulling rope with a floating block through the duct. While the employees were using the winch on the pulling rope, the conductor in the duct became snagged. As the supervisor shouted to stop the winch, the rope snapped. The sudden release of tension on the floating block caused it to swing back and strike one of the employees, who had been working about 1.5 meters away. He was hospitalized with a fractured left lower arm. The pulling rope was rated to sustain a load of up to 8160 kilograms.