On a drilling rig offshore in the Gulf of Mexico, an operator for a cementing contractor was trouble shooting an electronic instrument failure. He suspected a discharged battery in a battery box was the problem. He plugged a wheeled battery charger (like those in all service stations) into a three-prong extension cord carrying household 115V current, and was killed by electrocution. A BSEE Panel investigated the incident and determined that the extension cord was shorted in its female end with the ground wire burned off. This allowed a hot wire from the extension cord to connect with the ground wire of the battery charger. The ground wire of the battery charger then energized the metal case and when the operator knelt on a wet deck and touched the battery charger case, current passed through his hand to his knee, stopping his heart. The root causes of this fatality lie with:
