Worker Crushed by
Hydraulic Excavator

A 26-year-old construction worker was killed while working in an 8-foot deep trench, trying to remove a concrete sewer casing. He was part of a crew
constructing new sanitary sewer lines along a residential street. The man was standing inside an iron trench box while a hydraulic excavator was being used
to remove the concrete casing around a sewer pipe which was in the trench box. The trench box was 20' long, 8' tall, and 8' wide. The worker was giving hand signals to a co-worker operating the excavator above him because it was impossible for the operator to see the bottom of the trench where the casing was located. There was water in the trench and the victim could not see the encasement very well either. While pulling off the encasement, the bucket teeth slipped off the edge of the concrete and the excavator arm and bucket swung from rebound pressure toward the victim, crushing him against the metal side of the trench box. The victim was standing in a dangerous position, between the bucket and the trench box wall, in line with the force being applied by the bucket. The man soon became unresponsive and was pronounced dead at a local hospital from internal chest injuries. After this incident, the encasement was eventually removed using an air-powered jack hammer. According to photographs of the scene, there was significant room in the trench box for the victim to stand clear of the bucket, out of the swing line for the procedure they were attempting.

 

RECOMMENDATIONS

1. Machine operators must keep machine attachments at a safe distance from co-workers at all times.

—Excavators may cause jerky movements from rebound pressure if the bucket slips.

—Significant play in the mechanical linkages may add to this rebound movement.

—Operators must know the location of all workers around their machines.

2. Employers should train workers regarding safety when working close to heavy machinery.

—This worker placed himself in a dangerous position between the bucket and the trench box.

—These men were accustomed to this work arrangement, unaware of the hazard.

3. Using an air-powered jack hammer is a much safer method to remove concrete casings.