Alert 99 – 36 Traveling Block/Power Swivel Collision with Stand of Pipe
WHAT HAPPENED:
A fully retracted travelling block and power swivel, during its descent, collided with the top of a stand of pipe being held by the derrick pipe handling machine (PHM) at well center. This event resulted in three retaining bolts shearing on the Power Swivel bell guide and a spacer plate weighing 3 lbs. (1.35 kg.) falling to the drill floor from a height of 93 feet (27.9 m).