A longline vessel was participating in a fishery for rockfish and halibut. The crew were in the process of retrieving a string
of gear when it became hung up on the ocean floor. The crewmember at the hydraulic winch controls attempted to
remove the gear from the ocean floor by applying full power to the hydraulics. The strain on the rigging caused the jib
boom, located directly overhead of the crewmember at the controls, to fall, fatally injuring the crewmember.
The vessel was rigged with an outboard block at the end of a jib boom secured from and perpendicular to the main boom.
The jib boom was held in place by fore and aft wire rope stays. It was held horizontal by galvanized chain extending from
the outboard end of the jib boom up to the
main mast. The jib boom fell when a weld in a
link in the chain failed. The chain used in the
rigging was a 3/8-inch Schedule 30 (Grade 3)
galvanized chain (commonly referred to as
"Proof Coil" or "Proof Chain"). This chain is
a high-carbon, non-alloy chain, which was
not designed and is not recommended by
chain manufacturers for overhead lifting.
Safe work practices:
- Ensure that all chain rigged for overhead
lifting is approved and rated for that
function, such as a Grade 8 or
Schedule 80 alloy chain.
- Be aware of the intended use and rated
capacities of ropes, chains, cables,
fittings, and attachments when
installing overhead rigging, including the
compounding effect of triangulation.
- Ensure that workstation locations limit
workers' exposure to injury should any
part of the rigging fail.
- Whenever possible, replace overhead
booms used to guide lines with outboard
davits that would fall overboard should a
failure occur.
