Send your typical over-the-road truck to the gym to build up some strength and you'll end up with a more capable vocational truck. Go to the next level, let's call it the truck-spec'ing equivalent of steroids, and you'll be looking at a "severe service" chassis. While many construction fleets make the step up from a base-level on-highway truck to the mainstream vocational models, very few fleets will make that next step up to a severe service model.
One key exception, where severe service trucks are more of a rule than an oddity, is in oilfield hauling.
While the structures assembled in oilfield construction are generally less permanent than the bridges, stadiums and office towers built by the typical contractor, the operating environment and demands on the truck in mainstream contracting can be just as severe as those found in the oilfield.
Just as with routine site work, some oilfield hauling involves moving equipment from one site to another with a truck-tractor and lowbed trailer combination. However, unlike urban job sites where the equipment might be off-loaded within a few feet of the pavement, the entire haul in an oilfield move may be performed off-highway.
Not only does this require the truck to have great off-road capabilities, but the absence of weight restrictions off-highway means that a normally divisible load (e.g. blade, slope board and rippers hauled separately) may frequently be moved intact, requiring a truck chassis capable of a much higher GCW rating.
For a rental operation rarely moving anything heavier than a backhoe, choosing a severe service chassis is likely to be overkill. But for the contractor looking to build versatility into a construction hauling fleet, the lesson from the oilfield is to have trucks that will take on anything you can throw at them, with capability to spare.
One extreme example from the oilfield is a "winch truck" or "bed truck" configuration designed to self load/unload equipment that is neither wheeled, tracked or even powered. These severe service trucks are generally equipped with all-wheel drive, twin-steer front ends and tri-drive rear axles, along with a monster winch and a steel cargo deck built to be beaten.
The use of huge capacity winches on these trucks is what enables them to fulfill several roles on a work site. Rollers can be built into various points on the cargo deck to allow the winch to aid in tasks other than loading/unloading, and detachable gin poles can transform the truck into a rudimentary crane for picking and setting equipment or materials.
While on-highway height restrictions may limit some of the potential applications of this exact configuration in mainstream contracting, the ability of these trucks to capably serve the "nomadic" nature of oilfield operations can provide many ideas and lessons about reducing the time and costs of project mobilization. Modular packaging of equipment, skid loading and go-anywhere haul trucks are just a few areas that will easily translate from the oilfield to the job site.
West of the Mississippi, one of the most popular severe service trucks is the venerable Kenworth C500. Born in the logging country of the Pacific Northwest, today's C500 is equally at home moving an excavator across town, hauling overburden out of a quarry or moving drill rig hardware from one mountain to the next.
The backbone of the C500 is a straight-through high-strength frame with single, double or triple rails. Carrying the frame up front are single or tandem steer axles in drive and non-drive configurations, rated to 40,000 pounds and above. At the rear, tandem or tridem drive axles can carry as much as 150,000 pounds.
On top of this solid foundation, the cab is more than just a utilitarian version of its over-the-road siblings. Kenworth combines aluminum, fiberglass and extra steel reinforcement, into an assembly designed for the rigors of off-road operation.
Huckbolts are used to strengthen cab joints for tighter construction, providing a more rattle-free environment for the driver. Thick bulkhead-type doors are hung on stainless steel piano hinges and fit tightly to reinforce the remaining cab structure. The mirrors are mounted on the cowl, not on the door, to protect the mirrors and the doors, especially important with extended mirrors for wide loads.
Built to accommodate engines up to 600 horsepower, the C500 is available with a wide range of main transmissions, auxiliary transmissions, transfer cases, and PTO options to get the power where it needs to go.
Because these trucks need to operate well on both extreme grades and on open highway, spec'ing a multi-speed transfer case or auxiliary transmission is a must to ensure the truck's versatility. Today's transfer case and planetary hub options allow the truck to be operated on-highway without the risk to the drivetrain or the undue tire wear associated with purely off-road haul trucks.
Out front, the typical civilian-style fiberglass hood and fenders can be replaced with steel versions, along with heavy-duty brush guards and skid plates.
Apart from its pure brawn, the C500 also incorporates some brainpower to help it survive in severe service environments. A few examples include fuel tanks supported by a cradle below the tank, as opposed to typical back-mounted or top hung tanks, steel braided hoses for air lines instead of plastic tubing, and available radius arm links on the front suspension(s) to keep axle alignment intact in spite of the punishment of off-road operation.
As if the rigors of off-highway operation weren't enough to throw at a truck, running off-highway at altitudes above 4,000 feet can bring additional demands. Along with performance penalties of as much as 30 percent due to the thinner air, and extremes of weather that can change in minutes instead of hours, the grade percentages of the hills that must be climbed are as often in double digits as not.
With that in mind, it's no surprise that two of Colorado's most successful heavy-haul contractors are big fans of the Kenworth C500.
Since 1981, Speedy Heavy Hauling's core business has been the dismantling, mobilization and reassembly of drilling equipment throughout the Rocky Mountains. The company, based in Grand Junction, Colorado, is also engaged in crane services and heavy hauling. Speedy Heavy Hauling operates 150 Kenworth C500 and T800 power units throughout seven states, as well as 19 Liebherr all-terrain cranes.
Speedy recently took delivery of a new Kenworth C500 eight-wheel-drive twin steer, aptly named "Brutus." The custom truck, a four-axle giant, was engineered to the customer's specifications to take on the high elevation and arduous, rough off-highway terrain in Colorado.
Mark Duncombe, Speedy's executive vice president, said the C500 truck was engineered specifically to handle rig moving. The application includes delivering loads to and from oil fields at high elevations, up to 12,000 feet. The truck has closed-circuit cameras so the operator can see everything around the truck at all times, and 8×8 all-wheel drive to navigate the steep and difficult terrain.
Speedy Heavy Hauling employees built the truck bed and hydraulic systems for the three winches themselves. Upon the C500's delivery from Kenworth, the final work was done in Clifton, Colorado. The installation of the truck bed and hydraulic winches took only five weeks. "It is the only one I have seen with a winch on the front," Duncombe said. "We ordered the twin steer axles to handle the Colorado terrain."
Duncombe said the new Kenworth C500 truck will give Speedy Heavy Hauling an advantage to better serve customers at higher elevations. The truck went into service on its first job for Enacana Oil and Gas. "We're thrilled it went into operation the day after we received the keys," Duncombe said. "We took it up to 11,000 feet, and moved equipment down to an elevation that made it accessible to smaller trucks."
For Girardi Towing and Heavy Haul of Grand Junction, Colorado, running durable and reliable trucks offers a distinct advantage over its competition. "We're one of the few companies for hundreds of miles around that has the kind of equipment that allows us to tow or haul heavy equipment over steep grades and remote areas of the Rocky Mountains," said company co-owner Vic Girardi Jr.
The 32-year-old family-owned business operates in a five-state region along the Continental Divide. The business is divided into three divisions: heavy towing and recovery, heavy haul transportation, and crane and rigging operations. Girardi operates a fleet with 19 Kenworth trucks, including two C500 units equipped for towing and recovery.
One example of the C500's extreme capabilities came when Girardi responded to an accident in a remote area several miles south of Cortez, Colorado. A liquid nitrogen tanker ran off the road and rolled over on to its side into the bottom of a ravine.
Girardi's C500, equipped with tridem rear axles, all-wheel drive, and a 600-horsepower Caterpillar engine, winched the 40-ton tractor and trailer unit up and back onto the road intact. "If we hadn't been able to stand it back up intact, the tanker company would have had to hire an outside firm to drill into the tank and pump the liquid nitrogen out before it could be moved," Girardi said.
Girardi's C500's were also the only trucks in the region capable of retrieving a 30-ton crane from Black Canyon, where the crane had landed after a brake failure in mid-pick.
Moving out of the mountains and down to the plains, the problems shift from altitude and grades, to axle-deep mud. Founded in 1932, Hodges Trucking Company of Oklahoma City is one of the region's leaders in oilfield and heavy transportation.
"In moving the oil rigs, we usually roll off a county road and onto what's called a location road," said Jimmy Hodges, VP of Hodges Trucking. "These roads are usually dirt or gravel and can run from a few hundred feet to several miles. It's pretty tough terrain. When the weather turns bad and these roads are muddy, driving on them gets even harder. Tires will sink in so you can only see the top quarter of them."
"We have twin steer on our Kenworth C500s because we have so much weight on the front end with winches and gin poles (extensions used for hoisting) that we want to spread the weight over both axles," Hodges said. "The twin steer helps provide stability on soft ground."
The company's C500 models are fitted with tandem front axles rated at 20,000 pounds each, tandem rear axles rated at 70,000 pounds, engines rated at 475 horsepower, 18-speed transmissions, and solid-mount suspensions, all bolted to triple-channel frame rails that can span more than 400 inches.
The trucks are equipped with highly specialized rigging made by hand in Hodges' main terminal in Oklahoma City. "We might spend $200,000 or more for a twin steer truck and then we add special equipment worth another $125,000 to the vehicle," said company president Jack Hodges. "We expect them to last 15 to 20 years and they do."
While severe service trucks like the Kenworth C500 aren't terribly practical for strictly on-highway applications where every last pound of tare weight is critical, they're the perfect solution for site work, mobilization and off-road workhorses. Equipped with a winch and an oilfield-style cargo deck, these all-wheel-drive behemoths can easily move equipment and materials to and through the worst of job sites.
Fitted with other specialized options, the severe service trucks combine off-road prowess with a street-legal configuration that will bridge the sizable gap between yellow iron and the lighter rated on/off-highway vocational trucks.
Adding to the C500's extreme credentials, another popular application for this model is in the heavy specialized carrier business where loads can be hundreds of tons, if not several hundred tons, and be so large that they'll barely fit on most roads. This type of load makes moving your average D10 dozer seem more like a Sunday drive.
Sure, an on/off-highway vocational truck will get that D10 to the edge of the pavement to unload, but what if the dozer breaks down somewhere three miles into a job site? All of the sudden, having an off-road capable truck equipped with a heavy duty winch doesn't seem that much like overkill.
Although the initial investment for a severe service truck is quite substantial, the heavier construction more than makes up for the price in terms of longevity. It's not uncommon for the truck to outlast multiple bodies (winch beds, water tanks, etc.). Also, to help put the truck's price tag into perspective, apart from the most basic tractor applications, it's not uncommon for the bodies/equipment mounted on a severe service chassis to be more expensive than the truck.