MONTREAL, Que. — Some truck components have been around for so long that they rarely receive a second thought, and dual fuel tanks are a perfect example.

Introduced to extend the range of trucks between refills, the tanks are usually mounted on opposite sides of the frame rails. But this also introduces hazards that emerge with two separate filling points.

Any employer or owner a truck with dual tanks should have a safe work practice for fill ups, based on manufacturer specifications and those for the pump itself, says Mark Elias, a spokesman for Ontario’s Infrastructure Health and Safety Association.

Major truck stops and commercial fueling stations often have double fuel pumps – including the “satellite” pump used to fill the tank on the passenger’s side of the vehicle. And that’s where the fueling should begin.

“Once complete, the driver returns to the main side and fills, then returns the nozzle to the pump and proceeds to collect his receipt at the card reader,” says Patrick Ritchie, general manager of wholesale sales and site operations at Petro-Canada. “We recommend drivers take the time to check that both hoses are disengaged and returned to the dispenser before printing their receipt and exiting the fueling island.” When filling, engines should be shut off and pump nozzles should be attended at all times, to prevent any spills if a pump malfunctions.

It’s an open secret that some drivers tamper with the nozzle so that both pumps fill both tanks simultaneously. The problem is that an unattended nozzle could fall out of the tank while filling, leading to spills, slip and fall risks, or even fires.

The average flow rate of a commercial diesel pump is around 100 litres per minute and can go as high as 140. At a flow rate of 100 liters per minute, more than 1.5 litres per second will pour through the spout. That’s a lot of fuel, and the spills can lead to fines in addition to the hazards.

Not every operator with dual tanks fuel up at locations with dual pumps. In these cases, drivers should first fill the tank closest to the pump, and then turn the truck around to fill the second tank.

That’s exactly what drivers are instructed to do at Transport Econo-Nord, in St-Jérôme, Que.

“Sometimes we don’t have access to a secondary pump while on the road, and that’s where it can get tricky. For example, in northern Ontario, where we don’t always get the same facilities than on the 401 headed for Toronto,” says fleet president Patrice Ouimet.

It can be tempting to extend the hose under the straight truck or behind a tractor, but that’s definitely a “no-no” for Francois Daly, national director, pipeline commercial network at Parkland Fuel Corporation (Ultramar). “Never drag the nozzle under the truck or between the tractor and trailer.”

Petro-Canada’s Ritchie agrees that should be avoided. “Throwing or sliding the hose and nozzle often leads to damage, which could, over time, lead to failure of the equipment,” he notes, referring to the risk of tearing the hose or damaging the couplings. Besides, leaving a pressurized hose of flammable liquid next to hot exhaust pipes can’t be a great idea.

There’s one simple way to dodge the problem, according to Ouimet. Simply fill up one of the tanks if it will hold enough to reach a destination. “The level will equalize between the two tanks by gravity once on the road.” Freightliner’s EquiFlo system offers an example of equipment that will do that.

Besides that, the company discourages any unnecessary fueling on the road because it buys fuel in bulk.

Denis Houle, an instructor at Centre de formation du transport routier (CFTR) in Mirabel, Quebec, advises against dragging hoses around the front of trucks as well – and not just in the name of safety. “It could damage the hood or other components located in the front. Sometimes, these hoses can also be dirty or greasy and contaminate the windshield,” he says.

Houle, a former driver, understands the temptation of trying not to turn a truck around. Some pumps automatically shut down after being inactive, requiring a new transaction. But procedures are developed for a reason.

Still, couldn’t trucks use systems like those found on aircraft, which include pumps and hoses to transfer fuel from one wing to another without requiring each to be filled individually?

Thorsten Franz, general manager of Magna Steyr Fuel Systems — which supplies fuel tanks and systems to various OEMs – thinks it’s possible.

“Right now we don’t deliver a pump system like this but it wouldn’t be a problem if it was requested,” he says. “We do have two options. One is a pump system within the fuel tank, and the other one is a pump system outside the fuel tanks, which would be the best solution because it would be easier to service.”

There are no legal barriers, either.

“There are no Canadian federal regulatory requirements for the specific components used in liquid fuel systems on vehicles that weigh more than 4,536 kilograms,” Transport Canada said, responding to a question from Today’s Trucking.

“It would be easier to fuel and it could also be a time-saver,” says Steffen Zannek, engineering manager, commercial vehicles at Magna Steyr Fuel Systems. Although, challenges like mounting, and temperatures during the pumping process, would need to be overcome.

Jim Nachtman, a product marketing director – displays at Navistar International, is skeptical that issues like the added cost, weight, and potential pump failures would be overcome.

“Those are some of the reasons why we stick with a simple, low-cost, and efficient design. We have offered dual fuel tanks for many, many years on a lot of our products, and that design has proven to be the design that the marketplace purchases and what the voice of the customer tells us that the market wants,” he says.