Alert 05 – 07 Unsafe Hoisting & Rigging Practice
WHAT HAPPENED:
The monkey board assembly was being removed from the derrick during the rig out stage of the operation; the derrick was in the horizontal position. Two gin pole trucks were positioned on either side of the derrick with slings secured to the bottom skid of the monkey board assembly. Three workers had positioned themselves inside the monkey board assembly to remove the pins, which secured the monkey board assembly to the derrick. When the last pin was removed, the monkey board assembly flipped 180 degrees and contacted the ground. The three workers were thrown from their positions inside the monkey board assembly, to the ground.