Army testing diesel-electric truck: "ThThe Army is now testing a new Heavy Expanded Mobility Tactical Truck, or HEMTT A3 -– a 35,000-pound, diesel-electric-powered truck able to improve fuel economy by 20 percent and transport up to 100 kilowatts of exportable power.
The HEMTT A3 is now going through 20,000 miles of durability and performance testing at Aberdeen Proving Ground, Md. The testing is designed to assess capabilities such as max speed, grade climbing and fording, officials said.
The truck was also displayed in the Pentagon courtyard Oct. 15 by Oshkosh Defense as part of an Energy Awareness Month display.
"The Army operational and tactical need to reduce dependence on consumable fuels is a continuing science and technology challenge across the Soldier, Ground, and Air domains,” said Dr. Marilyn M. Freeman, deputy assistant secretary of the Army for research & technology.
The diesel-electric HEMTT A3 uses a diesel engine to power a generator – which in turn sends electrical power through cables to small motors on each of the axles. An ultracapacitor is used to store energy.
“We have an A/C induction generator that takes the place of an automatic transmission on a conventional truck. We have power cables that run from the generator to inverters or drives that control the electric motors,” said Stephen Nimmer, director, engineering and programs, defense technology development, Oshkosh Defense.
The testing at Aberdeen will also examine the truck’s extreme-weather starting ability, checking to see if the truck functions as intended at below zero temperatures and extreme heat conditions such as 125 degrees Fahrenheit.
“At cold and hot temperatures we made sure the truck could export A/C power. At 125 degrees Fahrenheit, we evaluated the air-conditioning system to cool the cab to a certain level over a certain period of time,” Nimmer said.
The durability and performance testing are aimed at preparing the HEMTT A3 for formal production.
“We have gone into Aberdeen TRL (technology readiness level) 7. When we finish the testing we will have satisfied ourselves that the technology has matured to a TRL-8 level and we will be ready for full rate production and operational evaluation,” said Nimmer.
The HEMTT A3 has also been configured to power up a Phalanx weapons system to provide area protection. On Sept. 28, the Army’s Counter Rocket Artillery Mortar program, known as CRAM, facilitated a successful live-fire demo at Yuma Proving Ground, Ariz.
“The truck was exposed to rocket-propelled mortars and it had a perfect record of mortars tracked versus mortars intercepted. In the case of the Phalanx, we have hard-wired our generator to the Phalanx weapon electronic control system,” Nimmer said.
The truck was at the Pentagon as part of Energy Awareness Month efforts that officials said were aimed at highlighting scientific progress in areas related to energy efficiency and energy security.
“Our goal is to be strategically positioned with our partners in the research, academic and industrial communities to capture and evaluate new energy technologies whenever and wherever they occur,” said Freeman.
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