The GCV might finally break open the last frontier to hybrid drives
If ' vice president of weapon systems, Mark Signorelli, is thinking big with BAE's entry in the competition for the U.S. Army's new Ground Combat Vehicle (GCV), he is starting off well. “Locomotives have been running on electric drives and hybrid-electric systems since the 1950s. Submarines have been diesel-electric or hybrid-electric since the 1920s.”
This could be the right mindset if your company is using its $450 million U.S. technology development contract to design a 70-ton tracked combat vehicle with a hybrid-electric drive train. In trying to get to the battlefield in combat vehicles, however, hybrid-electric drives have had to pull a lot of freight.
In the summer of 2006 the price of gasoline rose steadily toward a record at the time, and after many brutal months in Iraq it seemed like the trend would only continue. As the world's largest single oil consumer with an annual fuel bill of about $10 billion, the Pentagon had gas prices on its mind.
At that time both BAE andLand Systems (GDLS) had advanced hybrid-electric designs in the running for defense contracts—BAE, with its wheeled and tracked manned ground vehicle variants under the Future Combat Systems (FCS) program, and GDLS with a 20-metric-ton 8 X 8 wheeled Advanced Hybrid-Electric Drive platform with in-hub permanent magnet motors under the U.K.'s Future Rapid Effects System (FRES). BAE's Hagglunds subsidiary in Sweden was also fielding a hybrid-electric, the SEP T2 16-metric-ton armored personnel carrier in tracked and wheeled variants. There were even a handful of hybrid-electric Humvees.
Six years later? All three programs are more or less mothballed. The Swedish army passed on the SEP, FRES remains embattled, and FCS was abandoned. But not all was lost.
“The hybrid technologies under development for SEP live on in civil heavy-duty vehicles—like in mining, terminal logistics and airports,” says Hagglunds spokesman Hakan Karlsson. He says hybrids have 20-30% lower fuel consumption, lower maintenance costs and increased sustainability of operations.
BAE is also seeing some of its work reincarnated. After the collapse of FCS, the Pentagon launched a new effort to replace the Bradley Fighting Vehicle. The new ground bruiser—part tank, part armored personnel vehicle—is under technological development through the end of 2013, with BAE and GD the two main competitors. BAE's early prototype mobility tests for its GCV bid used engines and generators left over from FCS.
“It will evolve from where that was, but it's the same basic technology, sized and scaled to meet the new requirements,” Signorelli says.
BAE is pushing forward in its GCV bid with a series drive train, betting on increased fuel efficiency, mobile power supply and the design flexibility afforded by getting away from a traditional mechanical model.
Its drive concept for the 70-ton giant centers on two in-line six-cylinder diesel engines from Germany/U.K.-owned Tognum, a traction drive system fromand a Saft lithium-ion battery pack which is a variant of those flying on the . In a series design the diesels are not connected to the transmission but act as generators for the battery, which runs two electric motors producing about 700 hp each. The electric motors drive the tracks, providing instant torque at zero rpm.
The series design is part of BAE's aim to deliver a modular platform, which is one of the four priorities for the GCV, the others being force protection—accounting for the bulk of the vehicle—capacity for a nine-man squad and a seven-year window for the first production unit. “The hybrid-electric is lighter and smaller, so we can reduce the volume under armor; or conversely are able to add more armor or force protection with no penalty in terms of the drive train,” Signorelli says. “The engines are more manageable in terms of packaging. We don't have to place them near the transmission, because the only connection between the two is the power bus.” Power from the batteries is an added bonus—the design means each vehicle can deliver up to a megawatt of electricity, enough to power 1,000 homes.
Still, Signorelli expects a tough competition over the next 18 months. Details on GD's bid have yet to fully emerge, while U.S. budgets are under pressure and there is an ongoing debate on Capitol Hill about the utility of heavy vehicles in asymmetric warfare. But indications are that whatever the outcome on the GCV, hybrid-electric designs will continue their slow but steady march into the production line.