On September 2 1967, a US Army 8th Transport Group convoy of 39 vehicles was ambushed a few miles west of An Khe by a company of Viet Cong (VC) soldiers. With only weak convoy protection of two Jeeps armed with guns, the results were predictable. Seventeen American soldiers were killed, 13 wounded, and 34 of the vehicles were damaged or totally destroyed.
In another ambush in late 1967, a U.S. Marine convoy of 10 trucks, escorted by tanks, heading for Camp Carrol from Ca Lu on Route 9 was stopped by mines, and then came under attack from small arms and machine gun fire, and rocket propelled grenades. Trapped in a kill zone for five hours until artillery and helicopter gun ships drove off the attackers, the marines suffered 19 dead and many wounded, with only 10 enemy killed.
Truck convoys had always been tempting targets for the VC, but until these events, the insurgent’s long-range sniper and mortar fire, pinprick ambushes, and harassing attacks had been regarded more as a nuisance than a serious threat. With convoys of up to 200 vehicles stretching for many miles, and running seven days a week over poor roads, hilly terrain, and through rain, mud, heat and dust, Route 19, known as ‘Ambush Alley’ in the An Khe and Man Glang passes was a ‘hard road’ for the supplies and material to get through. These deadly attacks would change convoy protocols, and just as interestingly for military vehicle enthusiasts, American ingenuity would lead to the ad hoc creation of a special vehicle that would use elements of armoured personnel carriers, helicopter gunships, with a little nose art from US Air Force bombers thrown in for good measure. The era of the Gun Truck had begun and these vehicles would soon attain celebrity status. Gun trucks clearly provided the inspiration for the armoured cars in the 1979 and 1981 Road Warrior movies and numerous films since.
Armoured Gun Trucks
What, then, could the 8th, 48th, and 500th Transportation Groups do to minimise truck and personnel losses and defend their convoys? A customised vehicle, soon named the ‘Gun Truck’, was bom. Instead of subjecting the modifications to rigorous testing by the army and manufacturer, the gun trucks were simply jury rigged with armour and weapons, making them one of the most unique military vehicles in history, giving the gun trucks their maverick status. Group Commander Colonel Joe Bellino was the first officer to implement the “hardened” truck idea, and he moved fast on it.
Within weeks, armour was installed to ‘harden’ the trucks. Ranging from 0.25-0.5 inches thick, steel plates were affixed to the cab doors, over fuel tanks, and on the sides of the engine.
In the cargo beds, ‘gun boxes’ were constructed of two layers of 10-inch or 12-inch wooden planks, sometimes with the inner wall made of pierced steel planking or solid M8A1 lightweight landing mats, bolted to a timber framework. The space in between the layers was filled with sandbags, but their weight proved prohibitive to the trucks especially when the bags were wet, straining the engines. Gun box protection eventually morphed into two parallel layers of 36” x 48” steel plates, up to 0.75-inches thick, which even proved effective against RPGs.
The 8th Transport group also created a hybrid ‘APC truck’ with a stripped-down aluminium Ml 13A1 Armoured Personnel Carrier hull mounted on the truck bed, while ammunition cans were laid across the floor, and sandbags were placed around the vehicle on cab floors, beds floors, running boards, fenders, etc., to absorb mine shock. The gun crews were relieved to find that the ammo cans did not ‘cook off’ if a truck hit mines or came under fire. Later, cab windows were fitted with 2-inch thick bulletproof glass and drivers and crew wore body armour and steel helmets.
The weaponry installed on gun trucks was truly outrageous. These bad boys were fitted with anything from two to six machine guns with three or four being most common, providing a 360-degree coverage! Initially, the guns were M60s, but from 1969 onwards, M2 Browning .50-calibre machine guns proved the most effective at ‘jungle-clearing’ with a 2,000-metre range. The ‘fifty’ could penetrate double layers of sandbags, trees 16-inches in diameter, or 3ft of loose earth, and could chew through bamboo and brush like an ill-tempered crocodile, all with a 450-600 rounds per minute (rpm) rate of fire.
A few gun trucks were kitted up with 7.62mm Ml34 Miniguns, salvaged or pirated from helicopter gunships. These electrically operated six-barrel rotary Gatling-type guns could spit out 2,000 or 4,000 rpm, with red tracers and a chainsaw-like shriek that must have made them rather unpleasant to face.
Gun crews affectionately remember the weapons test-firing sessions where all the trucks would line up, and one-by-one, open up on a hillside. Each subsequent crew would try to wreak more havoc than the previous one, and local civilians would watch these displays of unbridled ‘rock ‘n’ roll’ firepower with incredulity.
When a convoy was attacked, the gun trucks that were spread out along the convoy, would converge on the hot spot, spread out in the kill zone, and lay down devastating retaliatory fire.
It’s no wonder that the VC placed money bounties on gun trucks and their crews. All hands were armed with 7.62mm M14 rifles, and truck squad leaders had 40mm M79 grenade launchers and .45 calibre M1911A1 pistols. Other weapons in the gun truck arsenals included .45 calibre M3A1 ‘grease guns’, M16A1 rifles, and 12-gauge pump-action shotguns, mainly for clearing the enemy from roadside ditches.
Other gun trucks were mounted with M55 Quad Fifty Machine guns, designed for anti-aircraft work.
Gun Truck Crews
Most of these modifications were done by the gun crews who quickly formed a strong esprit de corps, establishing reputations as aggressive, motivated, self-starting individualists, a kind of rag-tag elite ‘Special Force’ for truckers. Gun truck crews were selected from experienced drivers, many of them bored infantrymen who wanted a piece of the action, rather than lying around a firebase all day being sniped at. Hardly ones to follow regulations, the flamboyant and individualistic crews often had pets aboard their trucks ranging from dogs and cats to birds, lizards, squirrels, and even snakes and monkeys!
The Gun Trucks
The original gun trucks were 2 1/2 tonners from the REO Motor Car Company G-742 series. Of these, the M35A1 and M35A2 were the most widely used. They had a range of 400 miles with an empty weight of 13,4431b. Classified as a 6×6, the ‘Deuce’ had three axles with six wheels, with the rear two axles mounting dual tyres for a total of ten tyres. The rear axles were powered continually, and power could also be applied to the front axle for better traction on mud, sand, gravel, and rough ground and wet roads. The deuce had a 12.5-inch ground clearance, a 36ft turning radius, and could drive through water 30 inches deep.
With pedal to the floor, the in-line, six-cylinder 135 horsepower deuce could just reach 55-60 mph but, with the added weight of sandbags, armour, increased gun crews and the array of weaponry, the deuce proved to be grossly underpowered, often slowing the convoys down.
Enter the ‘five tonner’ G-744 series -a scaled up model of the “Deuce”, some 11% larger than its smaller brother, but with a lot more grunt.
First developed in 1951, and produced in 1953 by GMC and Kaiser, the M54, M54A1, and M54A2 5-ton cargo trucks soon proved to be formidable weapons platforms.
With the same 6×6 configuration, power transfer through the rear, and when needed, front axles, the 5-ton had a 10.5-inch ground clearance, 39ft 3in turning radius, and wading depth of 30-inches. With an empty weight of 19,4801bs, the 5-ton boasted a 7ft 4in x 4ft cargo bed, some 21-inches longer than the deuce, and, with its more powerful 205 horsepower engine, the 5-ton could carry heavier armour, weapons, and ammunition, and still reach 60 mph, with a range of 500 miles.
The macho image of the gun truckers, and the pop culture of the Vietnam War era was reflected in the names sign written on the sides of the gun trucks: Assassin, Black Widow, Dealer of Death, Eve of Destruction, The Grim reaper, King Cobra, Pallbearers, The Rebel, and Wild Bunch, to name a few.
Other uses were quickly found for gun trucks: installation perimeter defence at base camps and fire bases, ground troop support, guarding work sites for engineer details, and covering mine sweeping details.
On December 4 1967, only three months after the attack that cost so many U.S. lives and vehicles, the VC ambushed an 8th Group convoy. The enemy was surprised to see six armoured gun trucks race to the scene and lay down suppressive fire, forcing them to retreat within 30 minutes. Thirteen enemy were killed and one captured, versus one American killed and six wounded.
In the twelve month period from September 1967, there were 36 major ambushes, 65 sniping incidents, 65 mine attacks, and 18 bridges blown on Route 19, costing the Americans 30 killed, 203 wounded, and 287 vehicles damaged or destroyed.
Despite all these attacks, Route 19 remained open and by the end the 8th Transportation Group had driven a total of over 7,331,924 miles and delivered more than 596,572 tons of cargo, and 4,000,000 gallons of fuel in the face of fierce enemy action.
Between 350 and 400 gun trucks were eventually created during the Vietnam War, and today the only remaining original example, ‘Eve of Destruction’, is found in the Army Transport Museum in Fort Eustis, Virginia, restored to mint condition.