What key safety measure should be used when equipment such as this excavator is reversed?

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Various kinds of powered mobile equipment are used in many workplaces. Such equipment can pose safety hazards to not only the workers operating the equipment but also other workers in the area, especially when the equipment is being backed up or reversed.

This picture from the Health and Safety Executive in Great Britain shows the aftermath of an incident in which a worker was crushed beneath a tracked excavator. A company director was using the excavator to transfer waste from a main pile to an adjacent manual-sorting area. The injured worker moved behind the excavator to pick up an old door and place it in a skip.  As he did so, the director reversed the excavator, crushing the worker beneath one of the tracks. He sustained serious crush injuries to his right leg, which later required amputation.

An HSE investigation found numerous errors:

  • The company failed to ensure effective communications between the operator of the excavator and people working in the yard
  • The operator would have been affected by a “blind spot” of up to eight metres directly behind the excavator
  • The excavator’s reversing alarm and beacon weren’t working, a mirror was missing from the side of the cab and there was no camera or mirror on the rear of the vehicle.

Similar incidents have occurred in Canada, too. For example, three paving company workers disconnected a trailer from their truck. When a worker got into the vehicle and slowly reversed it towards the work site, it ran over and killed another worker. The Ontario company pleaded guilty to failing to ensure that the vehicle operator was assisted by a signaller and was fined $100,000 [Springside Paving & Construction Ltd., Govt. News Release, Feb. 23, 2011].


Because of the inherent dangers to workers, visitors and other pedestrians from mobile equipment, the OHS laws typically require the use of a “signaller” or a worker who’s assigned to communicate with and be the eyes of the operators of mobile equipment. A signaller is generally required:

  • Whenever certain powered mobile equipment is operated
  • When the equipment operator doesn’t have a clear and unobstructed view
  • When the equipment backs up or travels in a reverse direction
  • When lowering material into an excavation or trench.

Signallers must generally be “competent persons,” who:

  • Are stationed in a safe position in continuous view of the equipment operator;
  • Have an unobstructed view of the area into which the equipment is being moved; and
  • Aren’t otherwise occupied while the equipment is in motion.

Signallers should communicate with equipment operators using standard hand signals or by radio. In addition to signallers, powered mobile equipment should usually have alarms to warn anyone nearby when they’re reversing or even moving at all.