Responding to soldiers' fears of roadside bombs and sniper bullets in Iraq (search), the Pentagon has issued new guidelines on how military trucks and Humvees (search) can be customized with homemade armor.

The guidelines come after several deploying Army Reserve or National Guard units took it upon themselves to get extra armor for their vehicles, only to learn that they would have to go through official channels and testing before they could use it.

While not encouraging Army units to buy their own armor, the military is acknowledging it's an option, Maj. Gary Tallman, a Pentagon spokesman for Army weapons and technology issues, said Thursday.

An Army field manual published in 1997 contains basic guidance for "vehicle hardening," describing how to use sand bags for protection and explaining some of the mechanical problems that can result from being weighed down by extra armor.

New guidance was e-mailed during the past week to Army commanders, detailing what types of materials units should buy, where they can get the supplies and how they can get their specific armor designs tested for use, Tallman said.

The Army's updated procedures were prompted partly by the Jefferson City-based 428th Transportation Company (search), which in December turned to a local steel fabricator to make steel plating for its five-ton trucks and Humvees.

Like many transportation companies, the unit's vehicles have thin metal floorboards and, in some cases, canvas doors that aren't designed for combat.

Tallman said at least two units already in Iraq also have made their own armor for vehicles.

The Army is trying to produce more than 4,000 heavily armored Humvees for duty in Iraq, but that may take until 2005. The Army also has ordered 8,400 add-on kits that will provide armor protection to ordinary Humvees and can be installed in the field. Officials expect to have all the kits delivered before year's end.