Keep Safe Distances from Power Lines

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Take a look at this video which goes through an accident in Canada where an operator was killed when his scissor lift came into contact with power lines.

Preliminary half-year data from IPAF’s accident reporting project show three fatalities due to electrocution while using aerial work platforms (AWPs). All three fatalities occurred in the United States. Previous data reveal that electrocutions were the single largest cause of fatalities among AWP operators in the US in 2012, and in 2013, seven out of 53 AWP fatalities worldwide – 13% – were the result of electrocution.

Electrocutions occur when the operator or the boom inadvertently come too close to or touch overhead cables. The operator victims are usually not trained electricians, but happen to be working close to power lines, performing tasks such as maintenance, construction, and trimming vegetation.

Current evidence suggests that the most probable reasons such incidents occur are:

  • Apparent lack of awareness of the proximity of the overhead power lines
  • Apparent complacency or lack of awareness of the voltage running through the cables
  • Moving the boom in the wrong direction when close to overhead cables
  • Operating the boom erratically and not stopping when and where expected

Qualified line workers do receive detailed training before working on or near energy installations, so the greater risk is from those who have not had that specific training and just happen to have to work near energized overhead cables.

Users of AWPs must complete a risk assessment to identify all potential hazards associated with AWP use prior to equipment being used on a project. Method statements are created to mitigate or eliminate the potential hazards. The industry has developed a best practice document for AWP risk assessment that can be downloaded at www.awpt.org/publications/risk-assessment.

Where possible, the overhead cables should be de-energized and tagged before work begins. However, this is not often possible as power companies are reluctant to disrupt public supplies. If “de-energizing” is out, consideration should be given to protecting operators and others in the platform, by “shielding” the cables and using specialist insulated aerial devices which are specifically designed to work near electrical hazards. The use of overhead cable proximity indicators should also be considered when the risk of working near overhead cables is identified.

Emphasis is placed on the Minimum Approach Distance (MAD), the safest distance a person without specific training is permitted to come to live overhead cables.

When operating any platform, it is essential to use the controls to apply smooth, slow and calculated movements of the boom, ensuring it moves in the desired direction and stops where intended, and you do exceed the MAD.

Note that you do not need to touch the wires to be in danger, just being close will place you at significant risk. The higher the voltage and the more moist the atmosphere, the further electricity can jump. That is why, when working near overhead cables, the MAD should be clearly marked on the ground, allowing for maximum boom outreach. You should also ensure extra supervision is provided and emergency plans are in place.

Through its training programs, IPAF endeavors to remove confusion and reduce the risk by training operators and managers on the need for extra measures once any of two specific safe distances are breached. These are:

  • 50ft (15m) + fully extended boom from electrical pylon
  • 30ft (9m) + fully extended boom from cables on wooden poles

These recommended safe distances meet or exceed those specific in ANSI standards and OSHA requirements.

Working from an AWP closer than these distances is allowed, but extra measures must be in place; 30 and 50 feet plus the fully extended boom are the “triggers” for extra risk assessments and the need to seek the advice of the electricity supplier or qualified person who can positively identify:

  • Which cables carry electricity
  • The voltage of the energized cables
  • The appropriate MAD
  • Any extra measures required before work continues

Aerial lifts are designed to provide a safe means of working at height – but they are only a safe option if their use is planned and managed appropriately. Electrocution is one of the leading hazards associated with their used in the USA. Make sure you, and those you are responsible for, apply the “30- and 50-foot plus fully extended boom” rule to ensure that you stay safe.

 

See IPAF’s guidance on working near power lines, “Stay Safety at Height”, available at the Publications section of www.ipaf.org and www.awpt.org