Inspection Detail

Inspection: 120194600 - Argonaut Constructors

Inspection Information - Office: Sacramento Mining & Tunneling District Office

Investigation Summary

The tunnel pipe jacking bore pit excavation crew of the project's general contractor had completed setting the bottom steel plate at the west end of the trench shield. They were placing a second 12 ft by 8 ft by 1 in. thick steel plate weighing 3,900 lb on top of the bottom plate. In the process, Employee #1, a laborer, attached one end of a half ton rated capacity come-along to a cross member of the trench shield by hooking the cable back onto itself, then attached the other end to a chain secured in a hole in the top plate. Employee #1 tensioned the come-along while standing on the top section of a 16 ft long portable aluminum ladder that rested at the top against the come-along cable. While he was doing this, the cable broke, causing the ladder and Employee #1 to fall approximately 10 ft to the pit bottom. Employee #1 suffered open fractures of both bones of the left forearm, trauma to the left knee, and contusions on the right shoulder. He was hospitalized for two days. It was determined that the primary cause of this accident was placing the ladder against the come-along cable. Hooking the cable back onto itself was a direct factor of the initial failure.

Keywords: KNEE, FRACTURE, SHOULDER, WORK RULES, FOREARM, CONSTRUCTION, METAL LADDER, FALL, CONTUSION, UNSTABLE POSITION