These trucks will be able to go where almost any other  vehicle can go, and not get left behind.

These trucks will be able to go where almost any other vehicle can go, and not get left behind.


We concentrated our efforts on improving the new trucks' capabilities  in soft soils and mud.

We concentrated our efforts on improving the new trucks' capabilities in soft soils and mud.


Believe it or not, the military's Hummer is already closing in on the 20-year mark, and defense planners are busy looking for a replacement. One of the more innovative approaches is to modify commercial pickups to perform some missions now handled by Hummer.

The Commercially Based Tactical Truck (Combatt), is supported by the National Automotive Center, DaimlerChrysler AG, and Ford Motor Co., and involves AM General, maker of the original Hummer (also known as the Humvee or HMMWV). AM General is now part of General Motors. Spearheading the project is Tacom, the Army's Tank-automotive and Armaments Command.

The Combatt plan is to employ commercially based trucks as replacements for Army Hummers now used to move cargo and troops with. In all, the modified trucks would replace about 70% of the Army's 120,000 Hummers. The new vehicles would transport troops and cargo to the battlefield, but would not be used in the battle area. "They will get close to the battle zone, and be able to go where any other Army vehicle can go, but we won't put them right up on the line," says Hal Almand, project manager for Combatt.

An innovative and cost-saving twist to the plan is that the Army would lease the beefed-up trucks from various auto companies for three to four years, then they would be available for sale to anyone wanting bona fide off-road vehicles able to handle severe operating conditions.

Benefits all around
Combatt brings numerous cost savings. Perhaps most obvious is that it lets the Army take advantage of high-volume commercial production and continuous improvements in automotive technology. It also costs less to beef up a civilian vehicle than to field a custom military design. Contractors rather than troops will maintain the trucks, so inventory devoted to Combatt vehicles can be minimal. Replacement parts can be shipped via overnight service to repair depots, a practice the British are currently using in Bosnia. "We could probably rely on similar contractor support in Western or Eastern Europe because of the international presence of Ford, GM, DaimlerChrysler, Freightliner, and the other auto and truck companies," says Almand. He estimates Combatt could save 60 to 70% of acquisition costs, not to mention the savings in owner-ship and maintenance.

Training and fuel costs would also be lower. Troops wouldn't need much specialized training to learn how to drive the new trucks. And the lighter Combatt has twice the fuel efficiency of the Hummer.

Gearing up for the Army
Combatt vehicles will start off as six-passenger crewcab pickups with full-sized beds capable of carrying 4,100 lb of cargo. They will be powered by a diesel V8. In the Army, they will use JP-8 as fuel, a kerosene-based formulation originally intended for jet engines. (The JP stands for jet propellant.) "Using JP-8 will cut performance by about 8 to 9%," says Almand. "But it will be in keeping with the Army policy of 'one fuel forward,' meaning all vehicles and engines on the battlefront will use the same fuel, thus streamlining logistics."

Then the Army will add several systems aimed at improving off-road performance, including Hydra-Lok differentials and tire inflation systems from Dana Corp.'s Spicer Axle Div., run-flat inserts that let the truck operate despite losing pressure in all four tires, variable damping shock absorbers from Krupp Bilstein of America, and adjustable air-helper shocks from Firestone. A computer and flat-panel display on the dash coordinates and controls the new systems. The computer also provides cues and advice to drivers as to when and how they should use the various systems. The trucks will travel on Goodyear MTR tires with Rubicon tread. The tread, which covers some of the sidewall, makes the truck sure footed over almost any terrain, especially soft soils.

"The Army has used commercial trucks off-road as far back as the early 1970s, and we had some in Desert Storm," notes Almand. "But they wouldn't operate in sand at all, or on the muddy roads of Europe. That's why we concentrated our efforts on improving the new trucks' capabilities in soft soils and mud."

The Hydra-Lok limited-slip differential gives the trucks four-wheel drive and transfers wheel torque as conditions demand. The tire-inflation system lets drivers adjust tire pressure to individual wheels for improved performance and comfort. The air-helper shocks automatically adjust to keep the truck suspensions in the middle of their wheel travel, thus maximizing wheel movement regardless of the load.

Other additions include a night-vision system from Lockheed Martin, a collision avoidance system from Eaton, and a GPS and CD-ROM-based navigation system. Vorad, Eaton's collision avoidance system, will be used on the front and rear right-hand side of the trucks. Up front, it will help drivers maintain proper distances from vehicles during convoys in poor or even zero visibility. And on the right side, it alerts drivers of vehicles and obstacles in their blind spot. The night-vision system, a $9,000 add-on, will probably go only on special vehicles, such as those used by a commander. The nonaimable imaging system will output visuals to the flat-panel dis-play, not a heads-up dis-play as found in night-vision options on Cadillacs and Buicks.

While there are no firm plans to add weapons to Combatt vehicles, at least one company is exploring the idea, according to Almand. "They are adding a weapon that is aimed and controlled by a joystick and flat-panel display, so no gunners will be exposed to fire."

Unlike their Hummer counterparts, Combatt vehicles will not have armor protection for the occupants or underbody mine protection. "That adds weight and cost, and is somewhat of an engineering challenge," says Almand "But they won't be up on the battle front, so the lack of protection shouldn't be a factor. Otherwise, these trucks will be able to go where almost any other vehicle can go, and not get left behind."