Army Goes Green with FED Alpha
The Pentagon uses a lot of fuel -- in the Army's case, it's mostly JP-8 -- so it's working on fuel economy like everyone else. Developed by the TARDEC (Tank Automotive Research, Development, and Engineering Center), Ricardo plc and Army Materiel Command, the FED Alpha is one of two light tactical vehicle prototypes built. (The second one, FED Bravo, is a hybridversion of the first vehicle.)
"Light" in tactical vehicles means an 11,650-pound truck with 2900-pound payload, and 15,400-pound GVWR (Army math). It's built around a blast-shielded aluminum monocoque to transport four soldiers with armament in blast-attenuating seats and cooling vests. It's about 17 feet long, 7.5 wide, and nearly 7 feet tall.
Power comes from a four-cylinder, 4.5-liter, common-rail Cummins said to be making 200 hp and 560 lb-ft (no emissions controls). It's coupled to a 30-kW 24-volt starter/generator for power production that draws big loads at low rpm, so the Cummins has a small overdriven supercharger that clutches and ducts in with the engine at low rpm, then out as revs reach turbo operating range. Accessories are electric, so the front of the engine is uncrowded and has plenty of fuel lubricity aids for longevity. The Aisin six-speed auto is much like unit in the Ram Chassis Cab.
Air springs have titanium coils inside; a broken bag merely causes a 1-inch drop in ride height, and Koni FSD shocks control travel. Hutchinson composite run-flat wheels carry low-rolling-resistance Goodyear Unisteel 335/65R22.5 all-terrains. Brakes are outboard-mounted discs.
TARDEC simulations put fuel economy at 7.1 mpg on urban mission, 4.8 cross-country, and 12.6 convoy and tactical idling (remember the big generator) at a half-gallon an hour. Although that may not sound economical to a pickup driver, it's an improvement of roughly 70 percent.