Inspection Detail

Inspection: 107539587 - Icf Kaiser Engineers Of Massachusetts

Inspection Information - Office: Boston South Area Office

Investigation Summary

Employees were constructing a precast concrete collar beam to support a manhole lid at the surface entrance of a tunnel shaft. The collar beam consisted of two 12 ft diameter precast concrete rings with a butyl rubber gasket between them. The day before the accident, the top segment was set on top of the base segment without the required gasket. The next day, a Link Belt LS-718 crawler crane was borrowed from the contractor at the adjacent site, and used to hoist the top segment 4 ft above the base segment. Three employees and an independent truck driver began applying the gasket material to the lip of the base segment with the top segment suspended directly above them. After warning the foreman of the hazard of working under the load, the crane operator activated a safety switch designed to engage the spring-applied brakes and locking pawls on all drums. The load came through the brake and pawl and pinned Employee #1's head and arms between the two segments. Later that afternoon, Employee #1 died of multiple head injuries caused by blunt trauma.

Keywords: HEAD, SUSPENDED LOAD, STRUCK BY, CONCRETE BEAM, PINNED, CONSTRUCTION, CRUSHED, ARM, FALLING OBJECT