Gun Truck - Vietnam War

Vietnam War

During the Vietnam War, it was the mission of the US Army Transportation Corps to ferry supplies from the coastal ports of Qui Nhon and Cam Ranh Bay to inland bases located at Bong Son, An Khe, Pleiku, Da Lat, and Buon Ma Thuot. The logistical requirements of the MACV were huge, and 200-truck convoys were not uncommon. These formations were tempting targets for Viet Cong guerrilla groups, who often sprung ambushes in remote areas.

One unit that often fell victim to such attacks was the 8th Transportation Group, based in Qui Nhon. The stretch of Route 19 between An Khe and the Mang Giang Pass became known to them as "Ambush Alley" as incidents occurred there on an almost daily basis.

Providing security for convoys proved virtually impossible, as the Military Police units whose task it was did not have the manpower or equipment to control the whole highway. Other military units only controlled the stretch of road within their designated area of operations, and for much of the way, it fell onto the transport units to ensure their own security. At first they did this with armed jeeps, but these rapidly proved inadequate, in the face of improved Viet Cong weaponry and tactics.

On September 2, 1967, a particularly devastating attack killed seven drivers, wounded 17 and destroyed or damaged 30 trucks. To remedy the obvious vulnerability of the supply convoys, a "hardened convoy" concept was implemented, protected by a new type of security vehicle. This gun truck, as it became known, was based on the two-and-a-half-ton cargo truck, protected by a barrier of sandbags, and armed with two M60 machine guns. Hardened convoys were smaller than previously, being composed of only 100 trucks, and their security detail was increased until there was one gun truck for every 10 transport trucks.

In the event of an ambush, their role was to drive into the kill zone during the first few minutes of the attack, and saturate the attackers with their firepower. Early designs proved flawed, as the sandbag protections quickly became waterlogged in the frequent rains, weighing down the whole vehicle. They were later replaced with ad hoc steel armor plating, salvaged from scrap yards. The crew consisted of a driver, two gunners, a non-commissioned officer, and sometimes a grenadier armed with an M79 grenade launcher.

On November 24, 1967, during an engagement in "Ambush Alley", a group of gun trucks managed to thwart an ambush. The convoy lost six transport trucks and four gun trucks damaged or destroyed, and several drivers were killed and wounded, but the Viet Cong lost 41 KIA and were forced to withdraw.

Despite the increased security, transportation units still came under attack, forcing the gun truck units to improve the design of their vehicles. The two-and-a-half-ton trucks were underpowered, and the addition of armor and weapons slowed them down, leading to their replacement by five-ton cargo trucks that formed the basis for larger gun trucks. The improvised nature of these vehicles meant they varied considerably in appearance. They were given colourful nicknames such as "Duce is Wild," "Cold Sweat"," "Iron Butterfly" or "Pandemonium" that were often painted on the sides in large letters.

Their armament consisted of various combinations of weapons including M60s, .50-calibre machine guns, and XM 134 miniguns. Anti-aircraft weapons such as the Bofors 40 mm gun, or quadmount .50 cal. machine guns were also used. Most of these were obtained by cannibalising damaged infantry weapons that the transport units often carried on their return trip.

Armor plating had to be scavenged form various sources, including from the South Vietnamese army. Sometimes a double thickness of armour was fitted, with a space between each layer, to provide protection against anti-tank rockets. In other cases, the entire hull of an M113 armoured personnel carrier was mounted on the bed of a five-ton truck, thus providing all-round protection for the crew. Despite their aggressive names, gun trucks were strictly defensive weapons, being used only for convoy escort and perimeter defence duties.

Gun trucks suffered from several drawbacks. The added weight of armour, weapons and ammunition increased fuel consumption, as well as creating maintenance problems and reducing the durability of the truck frames. Also, the personnel assigned as crew to the security vehicles were no longer available for transport duties, thus reducing the lift capacity of each unit. Despite this, they were generally regarded as a success.

In all, an estimated 300 to 400 trucks were transformed in this way. They were intended as a temporary solution, but the Transportation Corps never received enough of their proposed replacement, the V-100 armoured car, so the gun trucks continued to serve until the end of the American involvement in Vietnam, in 1973. With the end of the Vietnam War, the need for such vehicles disappeared and most were either scrapped or returned to cargo carrying. One truck, an M54 named by its crew "Eve of Destruction," has been restored and is on display at the Army Transportation Museum at Fort Eustis, Virginia.