By Patrick Falzon, ESA powerline safety specialist
Special to Ontario Construction Report
On Sept. 19, 2019, four worker powerline contacts resulted in two fatalities. One involved a construction worker who was operating a truck-mounted drill when the boom arm came into contact with an overhead powerline. Contacts like these are avoidable. Powerline safety protocols and reminding yourself and co-workers to remain mindful of any electrical dangers is imperative.
According to the Ontario Electrical Safety Report, in the past 10 years the Electrical Safety Authority (ESA) has recorded over 1,300 overhead powerline contacts. The construction sector contributes to the highest number of these contacts each year particularly with haulage, excavating and aerial lifting.
The most notable hazards for those who work near overhead powerlines include:
- Direct contact with high-reach equipment such as, but not limited to, boom trucks including vac trucks, cranes, excavating equipment and dump trucks
- Indirect contact with high-reach equipment in close proximity to the overhead powerline
- Bringing down powerlines on the equipment or on the ground
Safety protocols on site
Incorporating signage throughout the job site is one of the best ways to alert workers of any unseen or missed dangers to identify overhead powerlines. Bright flags on utility lines are also an excellent way to spot overhead wires and some utility companies may provide flags on lines near the construction site. Orange cover ups on wires do not provide protection for construction workers.
Construction workers are often in a position where they may not have a complete view of the dangers around them. For example, workers can find their view obstructed by the vehicles they are operating. Having a designated competent signaler to warn operators of nearby electrical dangers can be the difference between a workplace incident and every worker going home safely at the end of the day.
A designated competent signaler will ensure equipment and vehicles stay three metres (10 feet) away from any overhead wires (see Limits of Approach). Three metres (10 feet) is the minimum safe distance up to 150,000 volts as contrary to popular belief, direct contact is not needed for electricity to cross or jump over to high-reach equipment.
Signalers are even more important for contracted services such as dump trucks as this group is likely not aware of on-site dangers and account for 60 per cent of the electrical contact incidents on site. A designated competent signaler with knowledge of all overhead wires on-site can eliminate electrical contacts from raising their box and reminding operators to lower the box before moving. For those who are behind the wheel of a dump truck, remember to load and unload materials away from overhead powerlines.
Protecting yourself: Protection during electrical contact
Despite the best precautions, incidents still may happen. Here is some guidance and recommendation if a powerline falls on your vehicle:
- Always assume the powerline is live
- Do not panic and remain inside the vehicle. This can prevent injury as electricity is travelling through the frame of the vehicle to the ground and not directly through you
- Inform everyone to stay 10 metres (33 feet) away from the vehicle
- Call 911 and the local electrical utility and inform them an overhead powerline contact has been made
- Do not exit the vehicle until the utility worker indicates it is safe to do so
If you need to exit the vehicle for any reason such as a fire, then you may consider the following precautions:
- Jump away from the vehicle
- Be sure to land with both feet together without touching the vehicle and ground at the same time
- Shuffle heel to toe until you are 10 metres (33 feet) away
If you’re a witness to a powerline contact incident, do not immediately rush to assist and stay 10 metres (33 feet) away from the point of contact. When electricity is travelling to the ground, it ripples throughout the surrounding area, known as a ground gradient. The voltage of ripples depends on proximity, meaning the closer you are to the affected vehicle or downed powerline, the higher chance for serious electrical injury or death. The best thing to do is to call 911 and the local electrical utility.
Don’t be complacent
Distractions and complacency at the job site are deadly so always remember to STOP before carrying out any task, LOOK for any dangers, and LIVE.
Look out for your co-workers. Simply understanding the electrical dangers of the site is not enough. Strive to become a safety ambassador and make sure everyone gets home safely at the end of the day.
If your company or organization would like an awareness session on electrical dangers or signage for your job site, please reach out to ESA at Patrick.Falzon@electricalsafety.on.ca or visit esasafe.com/contact.
Patrick Falzon is a Powerline Safety and Code Specialist at the Electrical Safety Authority. He has more than 30 years of experience in the electrical industry, serving local communities and organizations as a design technician and safety educator.