Protection of Army truck requires tradeoffs.

• Author: Erwin, Sandra I.

Military truck makers are grappling with how to best satisfy seemingly incompatible goals: building relatively uncomplicated vehicles that can both sustain the rigors of combat and, when needed, effortlessly be plated with thousands of pounds of armor.

Designers and engineers in the United States are learning the hard way that vehicles that originally were not made for crews to survive bomb and grenade attacks cannot simply be shielded with armor, without severely compromising performance and creating new kinds of hazards.

Hanging 1,500-pound armor kits on 7,000 U.S. military trucks operating in Iraq, for example, has led to numerous engine Failures and other malfunctions attributed to the excess weight on vehicles that were not necessarily engineered for those heavy loads, particularly the lighter Humvees. Some truck manufacturers also are concerned that drilling holes in the cab to hang the armor may weaken the chassis.

Fully up-armored Humvees have 3,000 pounds of armor, but come with bigger engines and transmissions. The basic Humvees that are now getting bolt-on armor plates never were intended to carry that much weight over extended periods. The additional weight, further, means that soldiers cannot carry any cargo or extra passengers.

Making trucks "survivable" has to be balanced against practical considerations, such as mobility and operators' needs, said Gem Paul Kern, head of the Army Materiel Command.

"When we do these survivability designs, it's not just a question of encapsulating somebody," Kern said in a recent interview. Vehicle protection must be viewed in the context of the specific environment where troops are fighting, he noted. When Army engineers designed an armor door kit for the Humvee, for example, they had to take into account that soldiers needed to stick their rifles out the window.

For the duration of the Iraqi conflict, soldiers and Marines will make do with current armor technologies, but as new vehicle programs get underway in the years ahead, the Army expects to develop more advanced options. It is a safe assumption that survivability will become a primary consideration in future vehicle designs, said Jeff Carie, program manager at the Army Tank-Automotive Research, Development and Engineering Center. As TARDEC prepares to oversee the new future tactical truck system (FTTS) for the Army, there is a growing consensus that vehicles will need to be designed with the proper axle-loading weight and cab designs...