Date of incident: June 2013
Notice of incident number: 2013137290129
Employer: Company installing and repairing transmission lines

Incident summary
Two power-line workers were seriously injured when the self-propelled boom-supported elevating work platform (the lift) they were working from tipped over. The workers were elevated about 50 feet off the ground, and operating the lift in an unstable configuration on uneven and soft ground. The workers were poorly trained, the lift had not been properly inspected, and the safety devices on the lift, which would have warned the workers of the unsafe operating conditions, had been disabled.

Investigation conclusions
Causes

• Use of the lift in rough terrain resulted in tip-over: The lift was operated on very rough, sloped terrain, contrary to the manufacturer's instruction. As a result, it tipped over, and the two workers were seriously injured.
• Incorrect choice of lift for the work: An adequate risk assessment was not undertaken to choose a lift for the work. The employer could have selected more appropriate equipment or work methods, based on a consideration of the rough terrain at the worksite.

Underlying factors

• Lack of worker training: Workers were not trained in the lift's operational limitations, especially the requirement for using the lift only on a level, stable surface. They were not trained to understand the operation, function, and testing of the safety devices. The workers were not trained how to inspect the lift before operating it to ensure that the controls worked properly.
• Lack of equipment inspection: A complete inspection of the lift would have determined that the safety devices intended to warn workers of an unsafe operating configuration did not function.
• Lack of supervision: Supervisors did not ensure that the lift was used safely, and did not ensure that workers were adequately trained to inspect and operate the lift.
• Deliberate circumvention of safeguards: An unknown individual or individuals deliberately circumvented safeguards, which permitted the lift to be used in a manner that did not warn operators of unsafe operating conditions, in particular lift instability, resulting in injuries to workers. Active safety devices would have warned the workers of instability and would have prevented the equipment from being operated in an unsafe manner.

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