Alert 20-07 Uncontrolled Descent of Crane Boom

WHAT HAPPENED:

The operation involved offloading 9 5/8” casing from a supply vessel to the rig’s cantilever deck. The crew was utilizing a main deck crane, operating on a single line (“whip line”). Two bundles with three casing joints each were in the process of being lowered on top of the casing already stacked on the cantilever deck. Suddenly, the crane boom wire parted causing the load and crane boom to drop and then come to rest on top of the casing stack on the cantilever. No personal injuries occurred as a result of the incident…