Amphibious Landing Ships, Tank

Winston S. Churchill [possibly the most ubiquitous figure of the early 20th Century] developed the concept of a "tank-landing lighter" that could put tanks directly ashore in World War I. However, it was not until World War II that he recalled the need for an ocean going ship to move tanks to beaches. The U.S. Navy took the lead in designing the LST. Its unique characteristics included a reduced forward draft of less than four feet for successful beaching. It also had bow doors and ramp, nine-knot speed, and a flat bottom. After seven months the keel for the first LST was laid. The first LST was commissioned 27 October 1942. Nicknamed "Large Slow Targets," LSTs saw action in every theater of World War II and performed multiple missions.

Tanks and other heavy equipment were normally carried in a landing ship, tank (LST) [said to mean Large Slow Target]. At the time of the Korean War, the US Navy LST was a 328-foot long ship with a bow ramp that was capable of running up onto a beach (beaching) to discharge tanks, vehicles, personnel, or other cargo and then pulling back off the beach (retracting). Smaller landing ships were 203-foot long landing ships, medium (LSMs) and 120-foot landing ships, utility (LSU), which had been known as landing craft, tank (LCT) during World War II and were redesignated landing craft, utility (LCU) after the Korean War.

No LSTs became available in time for the initial landings in North Africa under Operation Torch, but three "Maracaibos," modified shallow draft tankers that were forerunners of the LST's, were used. The Landing Ship Tank (LST) proved to be the backbone for assault and supply efforts during Overlord. With Operation Overlord, only by beaching LSTs near high tide and unloading straight across the dried out beaches at low tide were the Allies able to continue the build up. Hard packed, light gradient beaches at Quiberon Bay could support the direct unloading of Landing ship, Tank (LSTs) at low tide, a capability fall storms threatened to end on the Normandy beaches. One response to the failure to acquire deepwater ports was the allocation by the US of additional LSTs, previously earmarked for the Pacific.

The post-War LST-1179 Newport-class Tank Landing Ships are larger and faster than earlier wartime LSTs, and represent a complete departure from the previous concept of Amphibious Tank Landing Ships. The traditional bow doors, which had characterized LST construction since the first vessels of this type were built during World War II, were replaced by a 40-ton bow ramp supported by two distinctive derrick arms. The hull form necessary for the attainment of the 20-knot speeds of contemporary amphibious squadrons would not permit bow doors. The conventional flat bottom hull was redesigned to include a destroyer-type bow enabling the ships to attain speeds in excess of 20 knots. This feature enables her to operate with modern high-speed amphibious forces. A stern gate also makes possible off-loading amphibious vehicles directly into the water, though unlike LSDs and LPDs, there is no floodable dock deck.