BAE Makes Big Bet on Hybrid-Electric Drive

BAE Systems’ prospects for winning the Army’s coveted ground combat vehicle contract will hinge on a hybrid-electric drive propulsion system that has never been used on a large military vehicle.
The company is betting that the Army will see the technology the way it does. A hybrid-electric GCV will be its only entry to the high-stakes competition.
“It certainly has got a lot of attention, both good and bad,” Mark Signorelli, vice president and general manager of vehicle systems at BAE, said of the company’s proposal.
Early skepticism centered on the maturity of hybrid electric drives for combat vehicles, he said. The general public, and some in the Army, only think of the technology as something on the Prius, or city buses, he said during an Oct. 22 briefing on the sidelines of the Association of the United States Army annual convention in Washington, D.C.
Hybrid-electric engines combine a traditional engine with an electric engine that uses regenerative braking that converts kinetic energy into additional power.
“A lot of folks believe it is a radically new approach to propulsion systems in combat vehicles,” he admitted. In fact, they are widely used in industrial settings. Almost all heavy mining equipment is diesel electric. Caterpillar Inc. has used the engines in bulldozers. Submarines have employed them since the 1920s, he told reporters.
“We believe it is a technology that has been mature, and we have done  a lot of work over the last three years to further advance that technology and make it ready for this class of combat vehicle,” he said.
The Army awarded General Dynamics Land Systems and BAE technology demonstration phase contracts in August 2011 to develop their programs. General Dynamics' proposal was for a vehicle with a diesel only engine.
Electric power and storage, allows integration of new technologies “and allows us to fundamentally architect a new combat vehicle,” he said. The number one benefit is packaging flexibility, or the ability to configure the vehicle in different ways than one can with a conventional mechanical drive system, he said. Those make engineers a slave to the relationship between the engine and the transmission, he said.
Conventional engines take up most of the front of a vehicle,  and creates the need for under-armor. They force designers put the crew further back in the vehicle.
The dual-engine in BAE’s proposed hybrid-electric system can move soldiers further up in the compartment, compress the area they are in, and put the needed protection in a smaller space. That takes away an armor weight burden, he said.
The hybrid engine provides high torque, so it can turn on a dime, giving drivers added agility, Signorelli added.
The ability to store energy can add silent mobility and silent watch capabilities, he said. The extra power it produces will allow the Army to integrate new lethality systems such as directed energy weapons. “It opens up a whole new area of lethality applications for the Army when before frankly there was no way for them” to do that, Signorelli said.
Overall, there is 3 tons of weight savings in the 70-ton vehicle, he asserted. The electric drives are inherently lighter and there is also less need for armor. The Army could reduce the weight of the GCV or provide more protection for the same weight.
One of the two engines can be lost and it will still move and continue to operate. “I think we’re talking about a little bit more than a limp home,” he said. It can move 35 kilometers per hour on one engine “which is pretty significant in a vehicle in the 70-ton weight class.”
Most important for soldiers in the field, the engines are more reliable than their conventional counterparts, he said. Yes, they can reduce the amount of fuel consumed, but that is not driving the Army’s requirements, he said.
Of course, the Army is not taking the company’s word for it. The 27-month technology demonstration phase continues.
BAE has set up a “hotbuck,” or a mock, static truck with the engine configuration and pressure points that simulate real road courses in a variety of road conditions in a Santa Clara, Calif., facility. It hopes to have put the engine through 1,000 miles of testing by May and 2,000 miles by September prior to the Army selecting winners for an anticipated engineering and manufacturing development contract, he said.
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Topics: Combat Vehicles