Superior Rock Work Pty Ltd

Incident description:

A worker was assisting excavator operators working on a boulder wall construction at a civil construction site. The boulder wall ran for approximately 100 m. At the southern end (where the incident occurred) the earth wall was 3.2 m in height. Just prior to the incident a worker threw a portable pump into a wet area of the trench to remove water that was running down and pooling. The pump did not land correctly and was not able to pump the water out. A worker got into the trench to dig a hole for the portable pump when the ground started to subside on the high side of the trench. The trench collapsed and fatally crushed the worker.

Investigation findings:

There were no physical barriers or any other controls in place to prevent a person inadvertently entering into the trench.

There were no controls in place to manage:

• the construction of a 3 m to 4 m deep sub-vertical excavation in fill and weak foundation alluvium
• the maintenance of long sections of the excavation were left open and unsupported for a considerable period of time
• excavators working in close proximity to the excavation face
• stockpiling of boulders immediately behind the excavation

Considerations for prevention:

Systems to exclude workers from the trench or implementation of control measures such as shoring, battering or benching to prevent the collapse of the trench.

Obligation holders should consider the requirements of section 27A of the Workplace Health and Safety Act 1995 which outlines obligations relating to risk management. The company should also consider the requirements of the Workplace Health and Safety Regulation 1997, in particular section 210, subdivision 9, Division 3 'risk from working in trench more than 1.5 m deep'.

Court result:

The company was found guilty and fined $75,000 with no conviction recorded.

• Excavations and trenches
• Risk Management