The LVT (Landing Vehicle Tracked), better known as the Alligator. It was a modification of the original Alligator, a swamp rescue vehicle developed in 1935. The Alligator was an amphibious tank and the star of many U. S. Marine Corps landings in the Pacific. It was propelled by scores of small paddles on it tractor treads. Alligators performed a variety of chores. Some carried infantry, some carried supplies, some acted as light tanks, and others as self-propelled guns. Some were armored, some were equipped with turrets and the 37 mm gun of the M 3 light tank (Stuart tank to the British) , and others carried a 75 mm howitzer. All of them, in spite of the guns and armor, were light enough to float and seaworthy enough to make a sometimes lengthy trip from an anchored troop ship to the beach of a Pacific atoll.
There were two types of amphibious vehicles developed by the Americans in WWII to cross the shoals and beaches in the Pacific theater. One was the personnel carrier, or LVT (landing vehicle, tracked), generally equipped with a ramp in the rear which allowed troops to debark quickly under some cover; and the LVT(A), or armored amphibian, which was actually an amphibious tank. Although their names are similar, the LVT(A)4 was an entirely different machine from the LVT-4 vehicle. The LVT(A)4 was derived from the earlier LVT-2 Amtracs. Production for the new “Amtank” vehicles began in 1944, the LVT(A)4 being born from the US Marines’ urgent request for increased turret firepower from the earlier (A)1’s high velocity 37mm weapon (mounted in a M3 type turret). The result was the substitution of a 75mm howitzer (mounted in a M8 type turret) which considerably improved the potential for enemy bunker busting. But, in order to mount the M8 style turret on the roof of the (A)1, it was necessary to make some modification to the upper hull. These included increasing the size of the turret ring and lengthening the hull rear to provide space for the cramped engine compartment.
The LVT-4 was a natural continuation of the unique US Amtrac series of vehicles that were initially developed down in the Okeechobee marsh area of Florida back in the 1930s by a gentleman by the name of Donald Roebling. Originally built from light-weight aluminum, Mr. Roebling’s Alligator/ Crocodile tracked vehicles could travel equally well on land and water, and therefore caught the attention of the US Navy/Marine Corps as a potential rescue vehicle for downed pilots. After the start of WWII, a contract was awarded to Roebling to build 200 of his vehicles, but this time they were made from steel instead of aluminum. Originally designed to carry cargo, the Army vehicles gradually evolved into an armored fighting vehicle with some of the various types covered over and fitted with gun turrets. Generally called “Amtrac” (armored tractor)- or on occasion “Water Buffalo”- the LVT series of vehicles became very important assault and transport carriers during the island hopping campaigns of the Pacific theater in WWII, and to a lesser extent in Europe. Identifying the vehicles in the LVT series is sometimes difficult, as there were a couple of manufacturers and models of each type. It was the LVT-4 that was the first of the series to have an open cargo bay and a rear ramp for loading/unloading.
The LVT-4 differed from the LVT-2 in having a loading ramp at the rear, which enabled it to carry large loads such as Jeeps and some light weapons. It carried machine-guns on pintles at the front and sides.
These vehicles were very much a compromise design to obtain the best possible performances overland and on water. The two are disparate requirements, but the LVTs achieved a good working compromise and were thus able to carry amphibious warfare from the Rhine to the islands of the Pacific.
LVT-2 and LVT-4
Developed from a civil design intended for use in the Florida swamps, the LVT-1 was not really suited for combat, being intended solely as a supply vehicle. The Pacific war was to prove the need for a more capable amphibious assault vehicle. This emerged as the LVT-2, which used a better all-round shape to improve water performance, though it was still a high and bulky vehicle. Another improvement was a new suspension and the track grousers were made better by the use of aluminium W-shaped shoes that were bolted onto the track and could thus be easily changed when worn or damaged. A definite logistic improvement was introduced by use of the engine, final drive and transmission from the M3 light tank. At the time the LVT-2 was being developed these components were readily available and made spare-part supply that much easier.
The steering system of the LVT-2 gave considerable trouble at first, for the brake drums operated in oil and prolonged use of the steering bars could result in the brakes seizing up on one side. Training and experience solved that problem.
On the LVT-2 the engine was mounted at the rear, which restricted the size of the cargo compartment. This was relatively easily designed out of the overall layout by moving the engine forward and mounting a ramp at the rear to ease loading and unloading. Thus the LVT-2 became the LVT-4, which was otherwise generally similar. Of all the LVT series the LVT-4 was produced in the largest numbers: 8,348 produced on five production lines; in contrast 2,963 LVT-2s were produced on six lines. There were some design differences between the LVT-2 and LVT-4: for instance, the driver’s controls were rearranged on the LVT-4, but the main improvement was that all manner of loads could be carried on the LVT-4, ranging from a Jeep to a 105-mm (4.13-in) field howitzer.
Most LVT-2s and LVT-4s were armed with 12.7- or 7.62-mm (0.5- or 0.3-in) machine-guns on rails or pintles, but there were two versions of the LVT-2 that had heavier weapons. The LVT(A) 1 was an LVT with an M3 light tank turret mounting a 37-mm gun; this was intended to supply fire support during the early phases of an amphibious landing during the interval immediately after reaching the beaches. The gun proved to be too light for this role, so it was later supplanted by the short 75-mm (2.95-in) howitzer mounted in the turret of the M8 Howitzer Motor Carriage to produce the LVT(A) 4. On both of these gun vehicles the turrets were mounted towards the rear of the cargo area, which was covered in by armoured plate.
The ordinary LVT-2s and LVT-4s became the main load carriers of the early Pacific operations. The first LVTs were used in action at Guadalcanal, and thereafter every island-hopping operation involved them. Some were used in Europe during the Scheldt and Rhine operations of 1944-5 and there were numerous odd ‘one-off attempts to mount various types of weapon in them, ranging from rocket batteries to light cannon. Flamethrowers were fitted in some numbers, but all these types of armament should not disguise the fact that the LVT-2 and LVT-4 were most often used to carry ashore the first waves of US Marines.
The Tarawa landings on November 20, 1943, used landing vehicles, tracked (LVTs) for the first time in amphibious warfare. These were true armored amphibians, which could be deployed from landing ships into the water, then driven directly up to the beach and driven well inland, so that troops did not have to wade or walk ashore. Unfortunately, a shortage of LVTs meant that second- wave assault troops had to be carried in conventionally on landing craft. Worse because of faulty calculation of tides, many of the landing craft ran up on coral reefs, obliging the marines to wade long distances ashore. This exposed them to enemy fire and created heavy casualties that greatly imperiled the landings on the first day. Nevertheless, under Maj. Gen. Julian Smith, the 2nd Marine Division managed to occupy positions on the southern shore of the island as well as on the western end, thereby forcing the Japanese garrison to divide. This ultimately proved fatal to the defenders, and although the enemy counterattacked with suicidal banzai charges, the marines held their positions and, by November 23, had overrun the small island.
Powerplant: one Continental W970-9A petrol engine developing186.4KW (250hp)
Weights: unloaded 11000 kg (24,250 lb); loaded 13721 kg (30,250 lb)
Dimensions: length 7.975m(21 ft 6 in); width 3.25m(10ft8in); height 2.5m(8 ft 2.5 in)
Performance: maximum land speed 32km/h(20mph); maximum water speed 12 km/h (7.5 mph); road radius 241 km (150miles); maximum water radius 161km(100miles)
Armament: one 12.7-mm (0.5-in) and one 7.62-mm (0.3-in) machine-guns