CALGARY, Alta. – A trucker will find him or herself in few environments that are as busy and hazardous as a construction site. Dump drivers, however, typically spend a significant portion of their workday manoeuvering around all kinds of obstacles at these job sites – not the least of which are high-voltage power lines.
Each year, dozens of Canadian truck drivers are injured or killed by live power lines. However, Tom Bestwick, senior safety specialist with Enmax Occupational Health and Safety, has a three-pronged approach (no pun intended) to preventing these types of workplace accidents.
For starters, Bestwick says, any dump truck company operating around power lines should visit the site beforehand to identify potential dangers.
“First, you should contact the power authority and request that someone come out and identify the voltage, so they can provide the drivers with the ‘limit of approach,'” explains Bestwick.
The “limit of approach” refers to the closest a dump truck driver can get to the power lines. The limit varies depending on the voltage of the lines and the jurisdiction.
“If you don’t know the voltage, (Alberta) legislation dictates you shall remain seven metres or more away from that power line,” Bestwick says. “That’s the limit of approach for 500,000 volts – the highest voltage in Alberta.”
Operators in other provinces should check with their local power authorities to determine the limit of approach for their regions, as it varies from province to province.
If the limit of approach can’t be respected, the power authority must be contacted. They can de-energize and ground the line or insulate it to prevent contact. However, the authority may need some advance notice to take these measures, Bestwick says
Dump truck operators working near high-voltage wires should meet before each shift so they are always aware of the dangers, he says.
“Each morning when you get to the worksite – even if it’s the same worksite – we recommend holding a tailgate conference where you discuss the work of that particular day and the role of each worker,” says Bestwick. “This refreshes the workers on the hazards and how they’re going to manage them.”
Bestwick also suggests appointing a safety “watcher” whose primary responsibility is to watch the dump trucks and ensure they don’t breach the limit of approach.
Plan for emergencies
All dump truck operators should be ready with an emergency response plan, in case contact is made with active high-voltage lines, says Bestwick.
“Part of that plan is to have a communications means to emergency personnel and the power company,” he says. “If the power company is not notified, they cannot help.”
If a driver’s truck comes into contact with power lines, he should remain in the vehicle. If it’s safe to do so, he can pull away from the lines but he should ensure the lines don’t get tangled in the dump box. It’s only safe to leave the truck once it’s been confirmed that the vehicle is no longer in contact with the lines.
“He’s going to have to have someone outside telling him that it’s safe because in some cases he’s not able to see,” says Bestwick. “If in doubt, always assume the worst.”
In a worst-case scenario where the truck cannot be separated from the lines, yet it has caught fire, Bestwick says “The driver has some serious choices to make.”
The driver must remain calm and ensure he never touches the ground and the vehicle at the same time. Instead, he should jump as far from the truck as possible, landing on both feet. Then, he should shuffle away from the truck using both feet.
“There’s a condition called ground gradient that’s created, which is similar to when you throw a rock into a calm pool,” says Bestwick. “The electricity ripples away from the truck and the voltage drops progressively as you move away. You could receive a serious electric shock (if you step from one zone to another) but if you’re shuffling, you are keeping yourself in one zone so you’re not going to bridge those zones in a step.”
Train your drivers
Dump truck drivers should receive training on the dangers of working near power lines, Bestwick says. Power companies such as Enmax provide such training free of charge. Enmax reps visit industry groups or companies to explain the hazards of operating equipment near power lines. Training ranges from one to three hours. Bestwick says there’s no reason for drivers to continue being electrocuted on the job.
“It happens more than it needs to happen and it’s something that can always be controlled,” he says.