Weyerhaeuser’s Grande Prairie, Alberta timberlands operationVariable Tire Pressure Control 101: What are its benefits?

By Tony Kryzanowski

Variable tire pressure control is the ability to change a vehicle’s tire pressure for changing road conditions. Tire Pressure Control (TPC) systems installed on vehicles like log haul trucks provide a way to change tire pressures on the move, according to road conditions and the load being carried.

Tire pressure control systems—available commercially for about the past 25 years—have been refined and deliver multiple benefits to drivers, log haul contractors, forestry companies, and municipalities.

For log haul contractors, the use of TPC can extend the log haul season, in some cases almost to year-round operation, making it easier to keep good drivers. This also creates the potential of needing fewer drivers and trucks to haul the same volume.

Shane Thorlakson owns and drives a truck for Timber Service, a log haul company with 10 haul trucks in Quesnel, B.C. All are equipped with Tireboss TPC systems, marketed by Edmonton, Alberta-based TPC International. The system is also installed on one of the company’s low-bed trucks. They deliver logs to Tolko’s operations in Quesnel. Their trucks are tri-drive quads and their trailers are Super-B tandems.

Their first TPC system was installed 20 years ago in 1995, so Thorlakson has extensive experience with the technology. He says use of their TPC systems has allowed them to obtain permits from the Ministry of Highways to extend their log haul season—and to start earlier when road bans are in place. They have extended their haul season to almost the entire year, compared to when they hauled logs using trucks without TPC systems.

Operating TPC-equipped log haul trucks—particularly on block roads at lower tire pressure—delivers better 
traction, less road damage, and trucks can often climb slick and steep grades without assistance. Thorlakson has witnessed TPC’s traction capabilities himself: the first time he tried to climb a steep grade with a TPC equipped truck, he was the only truck delivering logs that day since he was the only one able to climb the hill.

The Forest Engineering Research Institute of Canada (which is now part of FPInnovations) and USDA Forest Service have reported that traction increases by up to 42 percent for TPC-equipped logging trucks, depending on road surfaces. On roads with steep grade and switchbacks, contractors have reported there is no longer a need for dozers and other equipment to help trucks up steep slopes.

“TPC-equipped trucks have better traction, a smoother ride, and there are benefits to the truck with less vibration,” says Thorlakson.

Timber Service is authorized by TPC International to install their own Tireboss systems and they have re-used systems on multiple trucks over the years. They carry out regular maintenance on their systems and have gotten good longevity from them, said Thorlakson.

For forest companies, an extended log haul season results in more consistent log delivery to mill sites. In terms of road maintenance, test results have found a 25 to 33 percent reduction in surface material depth—to support the same type and weight of heavy haul vehicles—using high tire pressure. Road grading could be reduced in some cases by 75 to 80 per cent. In some field demonstrations, moderately rutted roads caused by operating vehicles at high tire pressure were actually “healed” through using lower tire pressures—and forest companies have confirmed this to be the case in commercial application.

For drivers, when tire pressure is reduced and trucks are operated empty, there is a smoother ride, particularly on resource roads with potholes and washboards. Drivers have reported less fatigue, which translates into safer operation. Drivers have also reported decreased stopping distances during emergency braking of loaded vehicles and less chance of jack-knifing with empty vehicles. There is also better steering control in snow and ice conditions when using the optimum recommended tire pressure for load and speed.

For municipalities, they have fewer maintenance costs on municipally maintained roads when log trucks operate with reduced tire pressure. Variable tire pressure technology also reduces wear on road surfaces, decreasing the rate of surface material breakdown, resulting in a decreased need for dust control. Given greater driver control and alertness when operating at lower tire pressure, log trucks are also operated more safely on municipal roads.

Logging and Sawmilling Journal
May/June 2016

On the Cover:
On the B.C. Coast, it’s about getting the wood to the water, but before it hits the water, it needs to be harvested in the woods. And this September will see the full range of harvesting equipment working at the DEMO 2016 show being held in Maple Ridge, B.C. Please see the preview story on DEMO, beginning on page 28 of this issue. (Photo of B.C. dryland sort by Paul MacDonald).

Beetle attack: but this time it’s the spruce beetle
As if the B.C. Interior has not been hit hard enough by the mountain pine beetle, there have been recent increases in the spruce beetle population in the Central Interior of B.C. Details on what is being done to fight/contain the latest scourge in the forests.

Sawmill muscle
EACOM Timber partnered with equipment supplier Autolog to optimize the company’s Val D’Or and Timmins sawmills, achieving value uplift at both operations, strengthening them and giving them more market resilience.

Logging partners in profit
An award-winning logging partnership between the Quatsino First Nation and Western Forest Products on the B.C. Coast is delivering efficiencies—and profits—to the two partners.

A (sawmill) offer you can’t refuse
Weyerhaeuser Canada made Alberta sawmill owner Guido Unger a (good) offer he couldn’t refuse: the purchase of a used USNR line that will allow his sawmill to ramp up production considerably.

Coming in September: DEMO 2016
Full details on the upcoming largest logging equipment show in Canada this year: DEMO 2016, being held in Maple Ridge, B.C. from Sept. 22-24, with all of the major logging equipment manufacturers represented.

Hands-on harvesting approach
Nova Scotia logger John Dorey has been recognized by the Canadian Woodlands Forum for his hands-on approach to meeting the needs of woodlands clients, and excelling at partial harvesting.

Getting more control over log hauling
Weyerhaeuser’s Grande Prairie, Alberta timberlands operation is phasing in more tire pressure-controlled equipped log haul trucks, allowing them to increase their access on steep logging roads, even in bad weather.

Variable Tire Pressure Control 101: What are its benefits?

More chips to go...
New Brunswick’s Billy and Ronnie Gillespie are innovators when it comes to their chipping operation

Urban logging in Alberta
Alberta’s Shawn Moore has moved beyond the oil patch, and his tree removal business has now morphed into doing urban logging—and they’re diverting trees from the landfill.

The Edge
Included in this edition of The Edge, Canada’s leading publication on research in the forest industry, are stories from the Canadian Wood Fibre Centre and Alberta Innovates - Bio Solutions.

The Last Word
Winters aren’t what they used to be, and that simple fact is impacting the forest industry, says Jim Stirling.


Tech Update: Forwarders

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