At the top of a 10-foot-high mound of dirt, Gary Schmiedel takes in the silence. The military truck he’s driving barely hums just before it careens down a steep incline into a muddy pool.
Normally the vehicle — a Heavy Expanded Mobility Technical Truck or HEMTT — would be so loud the occupants wouldn’t be able to talk to each other, said Schmiedel, vice president of product engineering for Oshkosh Truck Corp. But this version is about as loud as a standard sedan, with a smooth ride, splashy computer screens and a comfortable interior.
This isn’t your dad’s military truck, a bumpy, loud gas guzzler. This is a hybrid made at the request of the Defense Department.
Oshkosh Truck, the military’s exclusive provider of the Army’s heavy cargo-hauling HEMTT vehicles, is finishing up prototypes of its electric hybrid. It not only increases gas mileage by about 20 percent from the standard 3 to 4 miles per gallon, it generates enough electricity to power a city block or hospital. The company, based in this city about 100 miles north of Milwaukee, just signed a contract to produce a prototype of a similar vehicle for the Marines.
It’s not clear how the hybrid technology will affect prices for the military vehicles, whose diesel version costs from $200,000 to $400,000, said Schmiedel, vice president of advanced product engineering for Oshkosh Truck. Even modest reductions in gas mileage help, he said, pointing out that 70 percent of what military vehicles carry is fuel.
The hybrid technology can be far-reaching, said Schmiedel. Commercial vehicles such as garbage trucks and emergency vehicles all could benefit from using less fuel, he said. The Department of Energy has said it hopes to double the fuel economy of garbage trucks by 2010.
The ability to generate power could be another selling point, Schmiedel said. The technology has a storage system capturing energy that would otherwise be wasted in the braking process. The generator can produce up to 300 kilowatts of power — enough to run 50 homes for an indefinite amount of time, he said. In response to Hurricane Katrina, Oshkosh took a hybrid truck to New Orleans and used it to pump out a hospital basement.
“First and foremost it’s a truck. If it has the flexibility to act as a generator in a pinch, that’s a heck of a disaster recovery attribute,” Schmiedel said.
The military is working with several companies to get power systems into its hybrid vehicles, said Paul Mehney, communications officer with the U.S. Army Tank Automotive Research, Development and Engineering Center, in Warren, Mich. Hybrid generators would eliminate the need to haul in a separate diesel generator, he said.
“It comes in real handy in the field. You can power an operation center out of that. You can power water purification systems off that,” Mehney said.
The push to develop heavy hybrids will be huge in the coming years as companies tweak products for different markets, said Robert McCarthy, an analyst with Robert W. Baird & Co.
While manufacturers such as Honda and Nissan have said they’re considering slowing down production of hybrid vehicles due to sluggish sales, development of the technology for military and commercial use doesn’t seem to be waning, Schmiedel said. FedEx recently announced it would add 75 diesel electric hybrids to its fleet of 18 in use in Sacramento, New York, Tampa and Washington, D.C.; and refuse and recycling hauler Waste Management Inc. has worked with three companies, including Oshkosh Truck, to develop hybrid technology and alternative fuels for its fleet of 22,000 vehicles.
Schmiedel and others at Oshkosh have been working since 1999 on the technology, called ProPulse. The company has made two trucks. It plans to make a few more and turn them over early next year for government testing, a process that could take a year, he said.
Though hybrid technology has been around for several years in passenger vehicles, adapting it for larger vehicles isn’t as easy, Schmiedel said. Military vehicles must often carry thousands of pounds of cargo — 13 tons for the HEMTT — and endure hills, little pavement and angles that few standard vehicles can handle. That all means engines and axles must be configured just so.
In the case of the newest version — called the HEMTT A3 — a diesel engine powers a generator that sends power to electric drive axles. Energy is stored when trucks coast or decelerate. The motor turns into a generator and provides power back into the vehicle, which can be used for the next acceleration or later to power outside sources.
In tweaking the ProPulse technology, Schmiedel said engineers created dozens of other perks, such as shrinking vehicle weight and placing engines in a way that makes maintenance easier. A specialized technician used to spend up to 24 hours swapping an engine but now any mechanic can do it in 20 minutes.
“What we think will drive hybridization is when there is some benefit over and above saving fuel,” Schmiedel said.
Other attributes include a center of gravity that is nearly a foot lower than the older vehicles, meaning tipping is less likely. Because the engine is shifted, the interior cab isn’t broken up by the girth — and noise — of the engine, which means there’s space for a third passenger.
Oshkosh Truck, which saw nearly $3 billion in sales last year, has made nearly 20,000 HEMTTS, with an estimated 2,500 in use in Iraq. One-third of the company’s sales come from the military. The company also makes tow trucks, garbage trucks, concrete mixers and fire trucks.
Though other companies are working on similar technologies, it makes sense for the government to contract with Oshkosh because it already supplies the Army’s heavy military vehicles, said McCarthy, the Robert W. Baird analyst. He warned that progress will be slow even though the industry has come a long way in advancing its hybrid technology.
“The fuel efficiency savings for those applications can be huge. If you have the additional advantage of being able to use some of that power to operate other systems like you would in a garbage truck, even better,” he said.