Running on Empty

Diesel fuel prices in the United States have climbed nearly $2 per gallon in the last year, according to figures from the Energy Information Administration (EIA), Washington, a statistical agency of the U.S. Department of Energy. Diesel prices averaged $4.886 per gallon on the West Coast and $4.789 on the East Coast, as reported by the EIA July 7. Diesel prices averaged $4.697 per gallon in the Gulf Coast and $4.672 in the Rocky Mountains as of July 7, according to the EIA, while the Midwest saw an average price of $4.654.

"Over the next few months, these prices are projected to remain near the June 30 price of $4.65 per gallon, as refiner margins begin to weaken slightly, offsetting the projected rise in crude oil costs," the EIA concludes.

While many factors affect an operation’s fuel efficiency, as higher fuel prices become an unavoidable reality, many suppliers to the industry are touting how their equipment can offer fuel savings for mobile document destruction companies.

Because the truck’s engine is most often used to power the onboard shredder, a vehicle’s fuel economy is not fully expressed in terms of miles per gallon. "The industry has to somewhat change its barometer to cost per hour of operation from miles per gallon," says Michael Oden, director of sales and marketing for Axo Shredders Corp., Kitchener, Ontario. "This provides a more detailed measurement of how their trucks operate."

According to Joe Roberto, vice president of sales and marketing for Shred-Tech, Cambridge, Ontario, a shred truck generally uses slightly less fuel when shredding for an hour than it would driving on the highway for the same duration.

With the shredder playing such a prominent role in the vehicle’s overall fuel consumption, it’s an important factor to consider when selecting a shred truck and the area where shred truck manufacturers have the most control.

"Engine power use during shredding has a dramatic effect on fuel economy," says Vinnie Carpentieri, national sales manager, mobile division, for Vecoplan LLC, High Point, N.C. "An easy way to understand this is to simply listen to the truck’s engine while it’s powering the shredder under load. You will hear the engine rev and the turbo kick in frequently," he says. "This is the same as stepping on the gas. The engine is in fact accelerating to meet the demand placed on it by the hydraulically powered shredder."

In its newest shred truck, the VST 42e, Vecoplan has replaced the hydraulic power driven by the truck’s power take-off (PTO) with PTO-driven generator power to electrically operate its onboard shredder, which has the effect of equalizing the load on the PTO and nearly eliminating engine accelerations, Carpentieri says. "And as we all know, if you want to increase fuel efficiency, just lay off the gas," he adds, noting that a fuel savings of 17 percent per hour is possible.

In addition, Vecoplan’s VST 42e’s QuickLink technology allows the shredder to be operated as a plant-based system by shutting down the truck engine and plugging into a building’s electrical system.

Vecoplan also has increased the throughput of the shredder on its VST-42e by between 90 percent to 130 percent, Carpentieri says, which reduces the time it takes to shred a pound of material by between 45 percent to 65 percent.

Shred-Tech also has focused on improving the shredder onboard its newest shred truck, the MDS-15GT. Roberto says in 1995, the company’s MDS-20 consumed nearly 9 gallons of fuel for every ton of paper shredded. However, the MDS-15GT consumes only 2.1 gallons of fuel while shredding that same ton of paper, largely because of advancements in the company’s shredder technology, he says. The MDS-15GT’s shredder is capable of shredding 6,000 to 8,000 pounds per hour, according to Shred-Tech.

To further improve the vehicle’s overall fuel economy, Shred-Tech constructs its shredder bodies of aluminum, which reduces the weight of the MDS-15GT by nearly 1,000 pounds, Roberto says. Shred-Tech has realized a weight savings of nearly 5,000 pounds by using aluminum in the construction of the shredders in its larger shred trucks.

Vecoplan also has sought to lighten the empty weight of its shred trucks by constructing the vehicles’ bodies from Therma-Lite, which Carpentieri describes as "an advanced space-age material that provides superior strength and puncture resistance while minimizing weight."

Brian Drew, sales manager for Shredfast, Airway Heights, Wash., says features like remote idle ramp-up, increased legal payload and a patented auto synchronized feed system help the company’s customers offset their fuel costs.

"The auto synchronized feed system is synchronized with the RPM of the main shafts on the shredder head," he says. "As the main shafts vary in RPM, the auto synchronized feed system will neutralize so it does not overfeed or underfeed the shredder, but gives it the optimum amount of product in a pressurized manner." Drew continues, "As the main shafts slow, it disengages to meter the amount of product that goes through it. The shredder does not auto-reverse, killing throughput, which is the key to profitability."

He adds that while the engine operates at a higher RPM during shredding, lowering fuel economy, the best way to offset this inefficiency is with a shredder that provides higher throughput.

Oden says Axo has been committed to fuel economy since its inception in 2004, when it introduced a remote start/stop function at the operator’s engine panel that allows the operator to shut off the engine without climbing into the cab.

"When given the proper tools, we feel operators will use them," Oden says of features such as remote start/stop, which is catching on among shred truck manufacturers.

"Prior to a remote engine management system on the operator’s panel, they would just leave the engine running," Oden says of many shred truck operators. "A mid-size engine burns a gallon of fuel per hour on idle."

Shred-Tech has introduced a predictive-idle feature to reduce fuel consumption as well as unnecessary wear to the shredder. Roberto says a computer in the shredder detects when the shredder is empty, shifting to low idle after 82 seconds. After 142 seconds, the computer disengages the PTO, which takes power from the engine and transmission and transfers it to the hydraulic system to operate the shredder. After 202 seconds of idling with no material in the shredder, the predictive idle feature turns off the engine. A remote start/stop feature allows the operator to turn on the shredder from outside the cab when he or she is ready to begin shredding again.

Shred trucks manufactured by Shredfast feature idle ramp-up, which Drew says helps to lower fuel burn in shredding mode. "If a remote engine ramp-up or start is available, equipment should remain at low idle or off as product is being collected at the customer’s location and brought to operation idle just prior to processing," he says.

"Diesel fuel is becoming a very serious part of everyone’s P&L (profit and loss) statement every month now," Roberto says. "A lot of our customers are trying to get their customers to agree to fuel surcharges. It’s not always easy to do that. It’s in everyone’s interest to make trucks consume less fuel."

While a driver’s habits can influence fuel economy, many manufactures say mechanical solutions can help to control some of these behaviors.

Drivers’ habits can have a considerable effect on the fuel economy of a shred truck, but they are also the factor over which company owners and managers have the least control. Therefore, training is critical, as is communicating a company’s expectations of its drivers.

"In order to encourage positive changes in drivers’ habits, companies need to first decide exactly what they expect of their drivers, next commit it in writing and finally make sure that this information is communicated fully and clearly to the drivers," Vecoplan’s Carpentieri suggests.

"A driver is interested in getting from Point A to Point B, not the overall process of operating equipment," Drew says. "The bottom line is a driver with no aptitude for operation will probably cost far more in equipment repair than fuel cost anyway."

Roberto also suggests instructing drivers to drive for fuel economy. But he also suggests mechanical solutions, such as speed limiters or governors, which can restrict the vehicle’s speed. "You can take a truck to a local dealer and ask them to adjust the governor," he says. Roberto, who operated his own on-site information destruction company for 10 years before joining Shred-Tech in 2004, says he had the governors adjusted on the 10 shred trucks his company operated in Chicago to have them run a few miles above the highway speed limit at maximum.

Preventive vehicle maintenance also contributes to achieving optimal fuel economy.

Mobile destruction firm Colorado Document Security (CDS), Grand Junction, Colo., keeps a close eye on its fuel economy and performs fuel economy checks monthly. Scott Fasken, founder and vice president of operations of CDS, says he tracks the mileage on his trucks regularly. "That’s one of the ways to make sure the truck is running right," he says. "If you have a change in your mileage, it’s telling you that you have a problem somewhere."

CDS checks tire pressure every morning before the trucks are dispatched. "You can lose 3 to 5 percent in fuel economy with under-inflated tires," Fasken says. The company also performs oil changes more often than recommended by the factory. "The factory talks about miles, but it’s like driving 40 miles for every hour you are shredding," he says.

The company also has the tires on its trucks rotated every 10,000 miles.

Maintenance is such an important factor in maintaining optimal fuel economy that Axo encourages its customers to set up an appointment with their dealers’ service managers to review vehicle maintenance, Oden says.

"It’s always best to perform maintenance on a regularly scheduled basis," Carpentieri says. "Maintenance on the truck that is critical to achieving optimal fuel economy includes changing the oil and lubricants, changing air filters, maintaining proper wheel alignment, maintaining proper tire pressure and following the manufacturer’s maintenance schedule on the engine and transmission."

The use of synthetic oils and lubricants can also improve a vehicle’s overall performance. In the winter, CDS uses lower viscosity oils, as recommended by the truck’s manufacturer. Fasken also uses heaters on the trucks’ engines and hydraulic tanks in the winter to reduce the load on the engines.

Preventive maintenance on the shredding system is also important. "Like the truck itself, all oils and lubricants on the components of the shredding system should be maintained and changed on a regular basis," Carpentieri says. Additionally, the shredder’s wear parts should be examined for wear and replaced when necessary.

"After a new customer takes delivery of our equipment, our corporate trainer makes sure the equipment owner and operator understand how to maintain the chassis and the equipment as well as introducing them to their local repair facilities," Drew says. "Preventive maintenance is the single largest factor in maintaining a low cost of operation."