GRANDE PRAIRIE, Alta. – Logging is arguably the most rugged and demanding application you can force upon a Class 8 truck. And spec’ing a proper logging truck is equally challenging.

A logging truck must be good in the bush and economical on the highway. It must be able to climb hills, pull through mud and in some cases also be versatile enough to perform seasonal jobs such as gravel hauling during the off-season.

Specifications for a log truck will vary depending on the region you’re hauling in.

But there are a few key spec’s and aftermarket components that can help improve your efficiency in the bush and on the road.

Triple the fun

An increasing number of loggers are spec’ing tri-drives, which allow for increased weights and better traction in the bush.

“We’re selling lots of tri-drives,” says Mike Colbourne, sales manager with Western Star and Sterling Trucks in Grande Prairie, Alta. “About two-thirds of the logging trucks we sell are tri-drives. They get a little more weight on them and they get around better.”

Brian Burgoyne, sales manager with Nanaimo Mack, adds tri-drives also allow you to haul longer logs. He also notes the increase in popularity with tri-drives – about 60% of log trucks Nanaimo Mack sells are tri-drives. Other common spec’s for log trucks include air ride suspensions, 20,000-lb front axles and double frames. Most customers prefer 500-plus horsepower engines, says Burgoyne.

Watching weight

Reducing weight on log trucks is important to most loggers – as long as it doesn’t come at the expense of durability.

“Weight is critical,” says Burgoyne, noting most customers opt for a single exhaust, a single, small fuel tank, a day cab and aluminum wheels. The Forest Engineering Research Institute of Canada (FERIC) has been stressing the importance of trimming down logging trucks through its Star Truck program which provides spec’ing assistance to log haulers.

The very first ‘Star Truck’ was built for a contractor hauling for Tembec in Nouvelle, Que. in 1999. The typical configuration in this application was a tandem tractor and four-axle semi-log trailer, which combined to weigh about 22,000 kgs. With FERIC’s guidance, the contractor spec’d a Star Truck that included: severe-service aluminum rims; smaller fuel tanks; an aluminum cab protector; a Tire Pressure Control System; an on-board weigh scale; an in-cab auxiliary heater; an on-board computer to collect and store data on productivity; a single tractor frame rail; and a lightweight multi-product semi-log trailer. Collectively, the spec’s added up to a higher purchase price to the tune of $43,300 – however, the TARE weight of the tractor and trailer were shaved by 3,000 kg compared to the fleet average.

The tractor-trailer operated at a TARE weight of 19,400- to 19,800-kg depending on fuel levels.

The lightweight spec’s resulted in a 9.8% increase in payload which equalled 44 more trips over the course of a year at no additional cost to the operator. The Star Truck also hauled 8.6% more product per litre of fuel used and the cost per tonne of wood transported was reduced by 8%. FERIC estimates pegged the fuel savings at $5,070 per year compared to the fleet average.

Given the higher up-front purchase price for the Star Truck, however, the relatively long payback period of 8.5 years may be prohibitive for some contractors. But the experiment found something as simple as spec’ing a lightweight trailer alone can result significant savings and at a premium of about $10,500, it can pay for itself in as little as a year.

On-board scales

Lloyd Gano, a veteran log hauler based in Courtenay, B.C., is pretty good at guesstimating how many logs he can legally haul. But in order to maximize his payload and avoid overweight fines, he has equipped his truck with TruckWeight’s Smart Scale system. It measures the weight of his vehicle every minute (or every 15 seconds while loading) and displays the GVW and individual axle weights on a handheld unit.

“I’ve been at this for more than 40 years, so I have a pretty good idea how much weight I can legally and safely put on my truck,” says Gano, who drives a 1996 Kenworth hauling fir, hemlock and spruce to mills on Vancouver Island. “To make money though, you have to be exact. Gut feel isn’t good enough.”

The Smart Scale system consists of a sensor that measures temperature and pressure changes in the air suspension to determine the vehicle’s weight. The weights are transmitted to a handheld reader that displays the data. The handheld unit can receive data from the sensors from within 150 feet of the truck.

“When my truck is being loaded, I can look at the handheld unit and then radio the loader operator, ‘I need 2,000 lbs on the trailer and 1,000 on the truck, or 1,500 on the front and 2,000 on the back.’ He can adjust accordingly and work quickly,” explains Gano.

TPCS

Tire Pressure Control Systems (TPCS) – commonly known as Central Tire Inflation – are gaining acceptance as a tool to extend the hauling season and go places other trucks wouldn’t dare. TPCS allows the driver to drain air out of the tires from inside the cab. The lower tire pressures create a larger contact patch and spread out the weight of the load.

In 2003, FERIC conducted a study to determine if TPCS could help B-trains better navigate soft forest roads. An eight-axle B-train that lowered its PSI to optimum levels was able to travel through a soft and muddy test section. However, the next two eight-axle B-trains were not so fortunate – both had their TPCS systems turned off and both got stuck in the mud. Once their tire pressures were lowered, they were able to back right out of the mud.

TPCS has been proven to reduce damage on forestry roads and mill yards. In fact, some mills have begun pressuring their trucking contractors to use TPCS and have extended the hauling season for those who use it, since they are less likely to tear up the yard when their tire pressures are lowered.Tire pressure control systems don’t come cheap, however. It can cost $25,000-$30,000 to equip a tandem axle tractor and B-train with the system.

Automatic transmissions

“In the last year, I’ve sold more automatic transmissions (to loggers) than I’ve sold in 15 years,” says Western Star’s Colbourne.

These are fully-automatic Allison transmissions, capable of GVWs as high as 350,000 lbs. Pierre Pouliot, owner of TransDiff Peterbilt of Quebec, says one customer has realized a fuel savings of 500 litres per week by using an Allison automatic on an off-road Pete 367 logger hauling weights of up to 350,000 lbs with planetary drives and an auxiliary transmission. Mind you, he has also spec’d a 500 hp engine rather than the traditional 600 hp to achieve the fuel savings.

The auxiliary transmission reduces engine revs by about 350 RPM, contributing to the fuel savings. Pouliot says the Allison is making believers out of his customers – most of whom traditionally spec’d a manual.

Jean-Francois Aussilou of Allison Transmission has been leading the charge for the company as it makes inroads into the logging sector.

There are about 200 Allison-equipped Canadian logging trucks in operation today, Aussilou estimates, most of them in Eastern Canada.

“Owner/operators are enjoying the increased safety – they don’t have to shift anymore,” says Aussilou. “They enjoy the durability, there are fewer failures and at the end of the day they find it is more productive and they definitely end up making more money.”

Shifting can be a challenge in logging, due to the profile of the roads drivers navigate.

“The action of shifting itself can be a real challenge. Road conditions are extremely challenging and there are situations where you really don’t have the time to do a shift,” said Aussilou. “With the fully-automatic, there is no power interruption during a shift and that is really what makes the major difference.”

Spec’ing an automatic transmission isn’t always enough to realize improved fuel mileage, points out Aussilou. He encourages customers to spec’ smaller engines and be cognizant of their driving habits.

“There are different aspects to look at when you talk about fuel economy and the operation of the transmission is definitely one of them,” Aussilou says. “If you drive aggressively, you’re going to burn more fuel than if you anticipate and drive economically, and that is true with any kind of transmission.”