The Amphibious Vehicle, Tracked (LVT) is an amphibious warfare vehicle and amphibious landing craft, introduced by the United States Navy and United States Marine Corps. (The USN and USMC use "L" to designate Amphibious vessels, also called "L class.") The United States Army, Canadian Army and British Army used several LVT models during World War II, and referred to those vehicles as "Landing Vehicle, Tracked." Originally intended solely as cargo carriers for ship to shore operations, they evolved into assault troop and fire support vehicles. The types were known as amphtrack, "amtrak", "amtrac", etc. (portmanteaus of "amphibious tractor"), and "alligator" or "gator." Development The Alligator The LVT had its origins in a civilian rescue vehicle called the Alligator. Developed by Donald Roebling in 1935, the Alligator was intended to operate in swampy areas, inaccessible to both traditional cars and boats. Two years later, Roebling built a redesigned vehicle with improved water speed. The United States Marine Corps, which had been developing amphibious warfare doctrine based on the ideas of Lieutenant colonel Earl Hancock Ellis and others, became interested in the machine after learning about it through an article in Life magazine and convinced Roebling to design a more seaworthy model for military use. Both the US Navy and Roebling resisted the idea of a military design, the US Navy because it felt conventional landing craft could do the job, and Roebling because he wished his invention to be used only for peaceful purposes. Roebling was persuaded after war broke out in Europe, and completed a militarized prototype by May 1940. The Bureau of Ships requested a second prototype with a more powerful engine, and the USMC tested the design in November 1940. Impressed by the second prototype, the Bureau of Ships placed a contract for production of 100 units of a model using all-steel construction, for a more rugged and easily produced design, and the first LVT-1 was delivered in July 1941. Another 200 units were ordered even before the first production units were delivered. After more improvements to meet requirements of the Navy, made difficult by Roebling's lack of blueprints for the initial designs, the vehicle was adopted as "Landing Vehicle Tracked" or LVT. The LVT-1 design The contract to build the first 200 LVTs was awarded to the Food Machinery Corporation (FMC), a manufacturer of insecticide spray pumps and other farm equipment, which built some parts for the