Lockheed Martin to build hybrid electric propulsion system for army line-haul tractor

11 November 1999

Lockheed Martin Control Systems announced it will design and build a hybrid diesel-electric propulsion system for a US Army line-haul tractor. The vehicle, to be developed under a program managed by Radian Inc. and performed in cooperation with Volvo Trucks North America, will be significantly cleaner and more efficient than current diesel trucks. A prototype Class 8 demonstration truck is to be delivered to the Army’s Tank-automotive and Armaments Command (TACOM) by December 2000. A Volvo VNL64 series tractor will serve as the platform.

The project, awarded under a US Army program that promotes joint military and commercial development of advanced vehicle technology, draws on Lockheed Martin’s commercial experience in producing its HybriDrive™ propulsion systems for transit buses and other large vehicles. According to Lockheed Martin, its hybrid propulsion technology has been proven in more than 80,000 miles of revenue service in urban mass transit and on vehicles ranging from delivery vans to an Army tactical truck.

The hybrid truck will be driven both by an AC motor and diesel engine. The motor will propel the vehicle at low speeds, and at highway speeds the truck will be powered entirely by the diesel engine. The electric motor will be powered by batteries that are continually charged by an on-board generator.

The hybrid configuration will give the 4 x 6 truck shift-free power from standstill to top speed while providing the same towing capacity as the standard diesel configuration. Fuel economy is expected to be significantly better than a conventional truck, and emissions are projected to be 50% lower. Additional advantages:

• Elimination of the mechanical transmission and clutch eliminates maintenance and overhaul.
• The engine will require less maintenance because it does less revving than that in a conventional truck.
• A “regenerative braking” system will reverse the motor’s magnetic field during braking to slow the vehicle, generating additional electricity to charge the batteries and reducing brake wear.

The Army already is evaluating a 5-ton truck equipped with Lockheed Martin’s HybriDrive™ system, part of the Army’s Family of Medium Tactical Vehicles.

The development contract for the hybrid truck was awarded to Radian Inc. under TACOM’s Dual-Use Science and Technology Program, created to develop technologies that improve efficiency and emissions performance for both military and commercial vehicles.

Lockheed Martin Control Systems, based in Johnson City, NY, deigns and manufactures electronics systems for global defense, civil, space, and commercial markets. Products include flight controls, engine controls, mission computers, launch vehicle controls, and controls for the locomotive industry and the emerging hybrid electric vehicle market.

Radian Inc., based in Alexandria, VA, is the Army’s technical services firm for vehicle technology and logistics. Radian will provide program management, integration, and testing support.

Source: Lockheed Martin Control Systems