It wasn't until the U. S. Army was involved in Vietnam that the necessity of armor for the M151 series became apparent. During WWII there had been half-hearted attempts to produce a 1/4-ton vehicle that included armor protection. But, even using minimum weight materials the chassis still seemed to always be overloaded; leading to poor handling and shortened vehicle life. With the intensity of the Vietnam conflict increasing, the call for an armored vehicle (particularly from the Military Police) put development back on the priority list. The first vehicles to receive up-armoring were the base M151. By Vietnam many of these vehicles were already over six years old (with a projected 12 year life). Out of desperation modifications were made in the field. Just like later in Iraq, scrap armor or just steel plate and ingenuity produced the first rudimentary protection.

The vehicle that would see the most change in protection was the M151A1. Besides the improvised protection there were two armored kits officially developed for the vehicle. The first looked very much like the improvised vehicles, with a simple armor plate in front of the passengers, and a crew compartment enclosed in a box. The second armor kit was better thought out, with opening doors as standard, higher plates around the front and sides, and even more important armor glass 2.5 inches thick fitted so the crew didn't have to expose their heads and shoulders.

Catching the end of the Vietnam War, the M151A2 series seem to have only been equipped with the last official version of the armored kit, that is .25 inch armor plate and the armored glass windows. With the end of US involvement in the conflict, the kits were soon removed from any surviving vehicles except for the few on display in museums.

David Haugh © March 2007