Truck Management: A never-ending battle
| October 04, 2007 |
It seems like everything comes harder in Alaska. The freezing winters, rough terrain and isolated living and working conditions can make what passes for routine maintenance chores in the lower 48 states shut an entire construction business down for hours or even days.
Seventeen years ago, Jim Huffman was a single-truck owner-operator running over-the-road freight. Like any good owner-operator, he paid close attention to tread wear, tire pressure and the ill effects of high speed. Today, Huffman is vice president of Black Gold Express, a mine haul operation serving the Fort Knox mining complex near Fairbanks, Alaska. His job may have changed, but Huffman is still paying attention to tire wear – although doing so can be downright depressing. “Between the rocks, mud and ice, the Fort Knox mine can be an absolute tire killer,” Huffman explains. “It’s a place where tire life is measured in months, not miles.”
The gold deposits at Fort Knox are considered low-grade, with the ore peppered throughout with hunks of granite and veins of quartz that can slice through tire rubber like butter. Miners scrape away nearly 115,000 tons of material every day, seven days a week, 365 days a year. Half is waste rock that is hauled to storage dumps, while the other half is stockpiled and fed into a crusher to begin the gold-extraction process.
Huffman’s company specializes in off-highway hauling work. Eight Black Gold rigs carry dirt and rock to the Fort Knox site from a satellite mine nine miles away. As a combination, the tractors with twin 45-foot side-dump trailers gross out at 200,000 pounds and work almost constantly in two 11-hour rotating shifts. Complicating matters is the area’s climate. From October to March, the average temperature is 3 degrees Fahrenheit and the mercury usually doesn’t rise above the freezing mark until May. When it starts to thaw, the ground has the consistency of hog slop.
“Fort Knox is the toughest environment I’ve ever dealt with,” says Huffman. “It’s all off-highway work, and the load and dump sites are littered with rocks. We can’t move every single rock out of the way, but at the same time, grossing all that weight, scraping or rolling over a sharp hunk of granite is very hard on tires.”
In the winter, Huffman expects to get four months from a set of drive tires, and about half that in the summer. “That’s outstanding performance,” he notes. “During spring and fall, we have freeze-thaw conditions that create unstable ground. When we’re forced to chain up, the tires suffer,” Huffman explains. “In the summer, it’s unbelievably muddy. We have to blade off the mud on the road between the satellite mines and Fort Knox and spread a layer of gravel to firm up the road surface. Cold weather is a blessing. The ground freezes and the give us better the traction and the longer the tire life. We don’t have to use tire chains as readily, and we’re not spinning the wheels and chewing up rubber. We’re paid by the ton, so we can’t afford to stop moving because one of our trucks is stuck in the slush or has a flat,” Huffman adds. “We need durability and good grip.”
Steering strength in snow and slush
Until recently, tires were the number one operating expense on Black Gold’s books. Today it’s fuel, although the company still spends approximately $300,000 a year to keep tires on their trucks. And although cold weather is easier on tires – a flat on a rig grossing 200,000 pounds in 40 below temperatures can leave on the side of the road for days. To combat tire costs and failure potential, Huffman manages his fleet with an onsite service department, a consistent tire spec to simplify interchangeability and parts ordering. A proactive retread program extends tire life even further.
Tires are such a high operating cost for Black Gold Express that Huffman has, in his own estimation, tried every make and model on the market looking for the right combination of tread life and durability his trucks need in such harsh operating conditions. “We have to run heavy-duty tires even outside our core application,” he notes. “Most roads in Alaska are still unpaved. So we test tires extensively trying to find a good match for our operating conditions.”
Not surprisingly, Huffman says his test keys in on durability. “There are many factors that go into a well-performing tire, but I mainly watch a tire’s resistance to rock drills,” he notes. “That’s the main cause of tire failure for our trucks. Our top running speed is 35 mph, so heat is not a factor. We’ve got to have a combination of deep lugs for traction and good rubber compound for puncture resistance.”
Huffman now runs 11R 24.5s all around and has equipped his tractors with Goodyear G177 severe-service drive tires and G286s and G287 MSA at the steer positions. “The G177 has a chunky, aggressive tread and soft compound in the tread cap that’s designed to prevent chipping and hold firm on ice and snow,” he notes. “We’ve been using the G286 as a steer tire for a long time, but we’re now cycling in some new all-position mixed-service radials to see how they do.”
During pre- and post-trip inspections, Black Gold Express drivers monitor tire pressure but aren’t meticulous about it. Their top speed is 35 miles an hour, so heat isn’t a concern. Tread depth? It’s not even an issue.
“Our guys are looking for chips and punctures, especially in the sidewall,” Huffman says. “Plain and simple.”
Because Black Gold has only an hour at the end of each shift to service a tractor, the company has a shop and technician on site to make tire changes and minor repairs. Wingfoot Commercial Tire & Service in Fairbanks handles most of Black Gold’s flat repairs as well as retreads; when they’re showing signs of wear, the G177s are capped with a waste-hauler type of tread and installed on the company’s side-dump trailers. “We do everything we can to preserve the casings and tire life,” Huffman explains. “We don’t even sipe the tires because we don’t want to do anything that might invite drilling or chipping. It’s amazing, but we might lose only 5 percent of our casings, if that.”
Wingfoot has also been working with Huffman to introduce the new steer tire to the company’s fleet. “With the winter conditions, the corners at Fort Knox are slick. I figured Jim’s drivers would find that the new G287 had a good bite to it,” says Ron Hoffman, manager of Wingfoot Commercial Tire & Service. “It has an aggressive tread and a wide tread arc that puts more rubber on the ground. When you turn the wheel, the truck turns.”
For his part, Huffman’s willing to give the new tires a try. “We don’t have to run elaborate field trials to see whether a tire works or not. Just give me a few weeks and I’ll tell you.”