Landing Ship Tank
A Landing Ship Tank (LST) is the largest seagoing amphibious warfare vessel that actually beaches itself to unload; obsolete in the most advanced navies, but is still widely used worldwide. Informally called a "large slow target", its traditional flat bottom and bow doors prevented it from reaching the same cruising speed of other ships in an Amphibious Ready Group.
Tanks and related large vehicles now are landed from Landing craft, mechanized (LCM), Landing Craft Utility (LCU) and Landing Craft Air Cushion (LCAC), launched from the well decks of ships such as a Landing Platform Dock.
While they traditionally had a pair of bow doors, the final U.S. Newport-class, faster than other LSTs, has the droppable ramp characteristic of other landing craft. This class had a destroyer-like bow that was not possible with bow doors. Still, newer types such as the Landing Platform Docks of the San Antonio-class are far more flexible, being able to operate over the horizon with aircraft, and then launching tank-capable landing craft. A 522-foot Newport had a fully loaded displacement of 8792 tons.
World War II LSTs were smaller, with a typical displacement of 2400 tons in a 327 foot hull. Their hull form limited them to 11 knots, in comparison with the 20 knots of a Newport.