Alert 07 – 17 Near Miss – Lost Control of Drawworks
WHAT HAPPENED:
A stand of drill pipe had been drilled down using the top drive. The Assistant Driller (AD) was at the drawworks controls but allowed the pipe to be drilled low enough to “trip” the low level setting of the Crown/Floor Protection Device (CFPD). The AD then activated the manual bypass to continue drilling down one more foot. Once he drilled down the extra foot, the AD attempted to pick up the drill string with one hand on the clutch and the other on the Crown/Floor Protection Device bypass control. The AD was unable to accelerate the motors enough to get the drawworks to start hoisting and the drawworks spooled off the drilling line rather than picking up the drill string. The elevators set down on the rotary table and the elevator links impacted the bottom of the topdrive, bending the elevator links.