Alert 00 – 21 Near Miss – Crownout
While pulling the bottom hole assembly out of the hole, an assistant driller failed to note the length of the BHA stand and ran into the crown, shattering the wooden sills. Pieces of the wooden sills rested on top of the blocks and did not fall. The Crown Protection Device (CPD) failed to engage the brake in time to avoid contact with the crown sills. The potential for serious injury and damage was very high; fortunately, no injuries or serious equipment damage occurred.