The Landing Vehicle Tracked (LVT) was a class of amphibious warfare vehicle, a small amphibious landing craft, introduced by the United States Navy, Marine Corps and Army during World War II. Originally intended solely as cargo carriers for ship to shore operations, they rapidly evolved into assault troop and fire support vehicles as well. The types were all widely known as amphtrack, amtrak, amtrac etc., all being portmanteaus of amphibious tractor, as well as alligator or gator.
Amphibious tractors or amtracs were used extensively in the Pacific theater during World War II as part of the island hopping campaign. Mike Sullivan first boarded one by descending from a troopship via netting at Tarawa. The light craft proceeded slowly like a barge but used its tracks to claw over a reef and then onto the beach. The frontal armored door/ramp protected from machine gun fire but the troops (including Sullivan) were exposed as soon as it dropped to let them hit the beach.