An interesting site which is dedicated to the Transport Coy Units that fought in Vietnam. Kind of a parallel between the "ambush alley" of the past and the IED highways of today. Some of the names of these vehicles are incredible as with the pictures of them.
"Another change was the modification of the armor on some guntrucks into "box" structures in the beds. Within this box were kept weapons, tools, extra wheels and tires, water and oil, and a fire extinguisher. Thus, the guntrucks served not only as security vehicles but also as maintenance trucks, capable of protecting and restarting disabled vehicles on potentially dangerous sections of highway.
As a protection against enemy rockets, double walls of steel plate were attached to some gun-trucks. The theory was that incoming rockets would be detonated on contact with the outer wall. Shrapnel would then bounce harmlessly off the inner wall, never reaching the crew.
Many of the guntrucks replaced the M60 machine gun with .50-caliber machine guns, either alone or in multiple mounts. One innovation was the "quad-fifty." This weapon consisted of four electronically synchronized .50-caliber machine guns mounted in the bed of a 2 1/2-ton truck. At one time, 8th Group was employing seven of these weapons.
A few escort vehicles were equipped with the 7.62-millimeter "minicannon," a modern version of the Gatling gun. This "smoker" was capable of delivering 6,000 rounds per minute. The guntrucks became such fortresses that after a day of convoy duty many were put to work during the night, patrolling transportation unit compound perimeters. Civilian contract convoys, some traveling the same routes as 8th Group, often "borrowed" gun-trucks for escort duty, in which the armored vehicles continued to prove their ability to make the enemy pay dearly for his attacks" Guntrucks of Ambush Alley Reproduced from the Army Logistician, July-August 1986
http://academic.uofs.edu/faculty/gramborw/atav/gunstory.htm
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