The LVTP-5: The Giant Amphibious Tractor of Vietnam

It was nearly 30 feet long, almost 12 feet wide and weighed close to 40 tons when loaded for combat. Its enormous steel hull could carry more than 30 Marines, transport cargo across open water and climb from the surf directly onto a hostile beach.

The LVTP-5 was one of the largest armored personnel carriers ever placed in regular American military service.

Marines called vehicles like it “amtracs,” short for amphibian tractors. Designed during the 1950s for a massive amphibious assault, the LVTP-5 instead found its defining battlefield in Vietnam—a war of rice paddies, rivers, jungle roads and hidden land mines.

It gave Marines protection, mobility and firepower in places ordinary vehicles could not travel. It also carried a dangerous weakness beneath the feet of everyone inside it.

Born From the Island Campaigns

The Marine Corps entered World War II without a vehicle specifically designed to carry troops from ships across coral reefs and onto defended beaches.

The solution came from an unlikely source.

Florida inventor Donald Roebling had developed a tracked amphibious vehicle called the Alligator to rescue people following hurricanes and floods in the Everglades. The Marine Corps recognized its military potential and helped transform the design into the Landing Vehicle Tracked, commonly known as the LVT.

Early LVTs were originally intended to carry supplies ashore. Combat experience in the Pacific quickly demonstrated that they could also transport Marines over coral reefs that stopped conventional landing craft.

At Tarawa, Saipan, Peleliu, Iwo Jima and other Pacific battlefields, amphibian tractors became essential to Marine landings. Later models received armor, machine guns and cannons, allowing them to support assault troops as they crossed the beach.

After World War II and Korea, the Corps wanted a completely enclosed amphibious vehicle that could carry more Marines, operate in rough seas and provide better protection than the wartime LVTs.

That requirement produced the LVTP-5.

A Landing Craft on Tracks

The designation stood for Landing Vehicle, Tracked, Personnel, Model 5.

The LVTP-5 entered Marine Corps service in 1956. It was designed to carry Marines from amphibious ships to shore without transferring them into smaller landing craft.

Unlike a normal armored personnel carrier, it had to function as both a boat and a tracked vehicle.

The hull was large and box-shaped to provide enough buoyancy to remain afloat while carrying Marines and equipment. Its tracks included specially shaped cleats that pushed against the water and propelled the vehicle forward.

In the water, the LVTP-5 moved at approximately seven miles per hour. On land, it could reach about 30 miles per hour under favorable conditions.

The vehicle carried a crew of three and normally transported as many as 34 combat-equipped Marines. Under less comfortable conditions, even more personnel could be squeezed inside.

A large ramp in the bow allowed troops and cargo to exit from the front. The vehicle could carry ammunition, supplies, smaller vehicles and weapons that would have required several earlier amphibian tractors.

With a length of almost 30 feet and a tall, broad hull, the LVTP-5 looked less like a normal armored vehicle than a small landing ship mounted on tracks.

Powered by a Tank Engine

Moving such a massive vehicle required an equally impressive engine.

The LVTP-5 used a Continental V-12 gasoline engine related to the powerplants installed in American tanks. It produced more than 700 horsepower.

The engine and transmission were located toward the rear of the hull. This allowed the large troop and cargo compartment to occupy most of the vehicle’s interior.

The gasoline engine gave the amtrac the power needed to move its tremendous weight, but it consumed fuel rapidly. The vehicle carried hundreds of gallons of gasoline in fuel cells located low inside the hull.

That arrangement would become one of the LVTP-5’s greatest dangers in Vietnam.

An Entire Family of Amtracs

The basic personnel carrier was only one member of the LVTP-5 family.

The Marine Corps developed several specialized versions using the same enormous tracked hull.

The LVTC-5 was a command vehicle equipped with additional radios and workspace for commanders and their staffs.

The LVTR-1 was a recovery vehicle. It carried equipment for towing or repairing disabled amtracs and other heavy vehicles.

The LVTE-1 was an engineer vehicle designed to clear mines and beach obstacles. Its large toothed blade gave it a particularly unusual appearance. It could also carry rocket-propelled explosive line charges used to blast paths through minefields.

The LVTH-6 was the most heavily armed version. It mounted a 105mm howitzer in a turret, giving Marine units mobile artillery support that could travel from ship to shore with the assault force.

The “H-6,” as it was sometimes known, could provide both direct and indirect fire. Its howitzer could attack enemy bunkers, defensive positions and troop concentrations.

An experimental antiaircraft version was also developed using a turret similar to the one mounted on the Army’s M42 Duster, but it never entered regular service.

Altogether, more than 1,000 LVTP-5-series vehicles were produced.

Going to Vietnam

The LVTP-5 had been designed primarily for large amphibious landings, but the Vietnam War required it to perform a very different mission.

Marines were not repeatedly storming heavily defended beaches as they had during World War II. Instead, Marine forces operated from bases and temporary positions across South Vietnam’s northern provinces.

The terrain included rice paddies, sandy coastal areas, rivers, flooded lowlands and primitive roads. During the monsoon season, heavy rain turned large areas into deep mud that could stop ordinary trucks and wheeled armored vehicles.

The LVTP-5’s wide tracks allowed it to travel across terrain that other heavy vehicles could not negotiate. Its amphibious capability made it valuable around rivers, lagoons and coastal areas.

The 1st and 3rd Amphibian Tractor Battalions operated LVTP-5 variants in Vietnam. The 3rd Amphibian Tractor Battalion deployed there in March 1966 and remained until January 1970, operating around locations that included Chu Lai, Da Nang, An Hoa and Hoi An.

The amtracs transported infantry, ammunition, food, water and other supplies. They evacuated casualties, supported sweeps through contested areas and provided security along roads and waterways.

Marine infantry units s