Crane contacts overhead powerlines

Queensland's Electrical Safety Office (ESO) and Workplace Health and Safety Queensland are investigating an incident where a mobile crane contacted overhead powerlines. One worker was electrocuted, another suffered serious injuries, while a third required hospital treatment.

Investigations are continuing.

Preventing a similar incident

Contact with overhead or underground powerlines can be fatal. You don't need to come in direct contact with powerlines to receive an electric shock, electricity can 'flashover' or arc across air gaps. All powerline voltages are lethal, with the risk of flashover increasing as the powerline voltage rises.

A person conducting a business or undertaking (PCBU) must ensure electrical safety.

Before working near overhead or underground electric lines, a PCBU needs to conduct a site-specific risk assessment.

If you must work near powerlines, you should follow these steps:

1. Develop a safe system of work before you start
   • ensure no person, plant or object at the workplace comes within an unsafe distance of an overhead or underground electric line
   • identify overhead and underground powerlines by consulting the electrical entity, maps and talking to the property owner
   • conduct a site-specific risk assessment and develop a safe system of work to identify potential hazards, including energised overhead electric lines, associated electrical equipment and the whereabouts of any underground electric lines – considering too:
     • the type of plant and equipment/tools used
     • site and weather conditions
     • type of work being done
     • set-up and pack-up procedures.
   • put risk controls in place – the most effective way of controlling the risk is to de-energise the line for the duration of work where there is a risk of contact.
2. Keep workers and contractors informed about electrical safety
   • induct and train your workers and contractors in safe work procedures, emergency procedures, and exclusion zones
   • carefully plan the tasks to be completed near powerlines and work away from them whenever possible, not towards or underneath them
   • show your workers the safe distance from a powerline by using clear and resilient markings at ground and driver eye level
   • ensure people are aware that powerlines sag or sway in hot or windy weather.
3. Avoid going into exclusion zones
   • make powerlines and poles visible (ask your electrical entity for permission to paint power poles, mark pole stays and/or have them install markers or flags on the powerlines)
   • operators should use a safety observer when working near powerlines
   • follow the safety advice you obtain from your electrical entity.

Under the WHS Regulation duty holders must work through this hierarchy to choose the control that most effectively eliminates or minimises the risk, so far as is reasonably practicable. This may involve a combination of two or more different controls.

Hierarchy of control measures include:

1. Elimination – this may include planning ahead to:
   • de-energise the electric line for the duration of the work
   • re-routing the electric line away from the work area, or
   • replacing existing overhead electric lines with underground electric cables.
2. Substitution – this may include performing the work another way for example:
   • using alternative plant which is not tall enough to enter an unsafe distance to the power lines.
3. Isolation – for example, erecting a physical barrier to prevent any part of the plant or equipment or a person or anything held by a person, or attached to a person entering an unsafe distance.
4. Engineering controls – examples of which include:
   • limiting movement of plant with mechanical stops to safe distances from power lines
   • fitting plant with programmable zone limiting devices
   • mechanically limiting slew speed of a crane to slow (note: allow for load sway when the brake is applied)
   • use of GPS geo-fencing to prevent entry into an unsafe distance.
5. Administrative controls – examples of making hazards more visible:
   • use of ground-based warning signs to indicate the location of overhead electric lines and defined work areas (for example, use of corflute models of persons pointing to powerlines)
   • arranging electricity entities to install Rota markers to ensure power lines are clearly visible to machinery operators
   • use of electronic proximity alarms on machinery.

Administrative controls and PPE do nothing to change the hazard itself. They rely on people behaving as expected and require a high level of supervision.

The Look up and live powerline safety planning tool is available at lookupandlive.com.au. The tool is an interactive geospatial map that displays Energex and Ergon Energy electricity networks.

Statistics

Since 2010, there have been nine fatalities in Queensland resulting from plant or equipment contact (or near contact) with overhead powerlines. Three resulted from crane contact, two were elevated work platforms, while the others involved a farm spray rig, tree pruning pole, agricultural irrigation pipe and billboard edging.

Prosecutions and compliance

A Queensland billboard company was recently fined $250,000 after a worker received an electric shock from a powerline that the company knew was a hazard and which was closer than the three-metre exclusion zone required under state law. A worker employed by the defendant received an electric shock from a 33kV overhead powerline while changing the skin on an advertising sign in 2016. The Magistrate noted that the degree of harm that might result from electric shock from the power line was death or severe injury and given the nature of the work and the limited training provided to workers, the likelihood or risk from electric shock was high. He also said there were available and suitable ways to eliminate the risk of electric shock, but the company made no effort to contact Ergon Energy to request the powerline be moved or raised. It was also noted the cost of eliminating the risk was relatively minor, especially in proportion to the risk involved.

In 2018, a North Queensland agriculture farm was fined $200,000 in the Cairns Magistrate Court for the electrocution of a worker in 2016. The worker was operating a cherry-picker to trim avocado trees when he died after the pruning tool he was using came too close to the 22,000-volt lines. The Magistrate mentioned that workers had been given verbal reminders about the powerlines prior to the incident, but this was deemed inadequate, and more suitable safety measures should have been in place.

In 2017, an operations manager/head rigger for a construction site subcontractor and the site supervisor for the head contractor each were fined $7,500 for two offences. These offences were for directing workers, despite their objections, to lift and place a concrete tilt-up panel at an unsafe distance from high voltage electric lines on consecutive days. This placed the crane operator and riggers at risk of death or serious injury. The site supervisor for the head contractor was aware of the risks and objections from workers but agreed to the directions of the operations manager/head rigger of the subcontracting crane company.

Penalties

Government inspectors can now issue on the spot fines of up to $600 for an individual and $3,000 to businesses who breach exclusion zones, fail to identify risks and don't implement appropriate control measures.

More Information

• Electrical safety Code of Practice 2010 - Working near overhead and underground electric lines (PDF, 231.59 KB)
• Electrical exclusion zones film
• How to manage work health and safety risks Code of Practice 2011(PDF, 1048.03 KB)
• Look up and live powerline safety planning tool - Ergon and Energex

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