Alert 10 – 24 Air Valve Malfunction Results in High-Potential Near Miss
WHAT HAPPENED:
The driller was in the process of back reaming when the air supply to the drum clutch of the draw works suddenly bled off. This allowed the drum clutch to release and the top drive system, with a 5-inch drill string attached, to move down approximately 4-meters (13 feet). The drill pipe elevators came in contact with the rotary table resulting in damage to the bails and the link tilt hydraulic cylinders.