Amphibious Ships and Landing Craft. Amphibious operations—large‐scale attacks of hostile shores by combined naval and land forces—were a special feature of World War II. The need for special craft to support amphibious assault had been clearly foreseen and U.S. Fleet maneuvers of the 1920s and 1930s tested designs for boats to carry artillery, tanks, and assault troops. In the thirties two commercial designs emerged: the “Eureka,” designed by Andrew C. Higgins for work in the Louisiana swamps; and the “Alligator,” Donald Roebling's track‐laying rescue vehicle for the Florida Everglades. These became the workhorses of the U.S. forces—the Landing Craft Vehicle Personnel and Landing Craft Mechanized (LCVP, LCM) from the Higgins boat and the Landing Vehicle Tracked (LVT, in later development redesignated Assault Amphibian Vehicle, AAV) from the Alligator. The LCVP had a capacity of 36 troops or 8,100 pounds of cargo; the LCM carried 30 tons; and the LVT 24 troops.

The design for larger landing ships was spurred by the need to transport and land large mechanized forces in the European theater. Two general types derived from British designs (1940–41) were conceived: the Landing Ship Tank (LST), which beached, opened its bow doors, and let down a ramp to rapidly offload tanks and other vehicles; and the Dock Landing Ship (LSD), a combination troop transport and floating dry dock capable of transporting the largest landing craft in its well deck and launching them by opening a stern gate.

Other British designs adopted for American use were the Landing Craft Tank (LCT; in later development Landing Craft Utility, LCU) and the Landing Craft Infantry (LCI). The LCT was equipped with a bow ramp and the largest model carried up to three 50‐ton tanks; the largest LCI carried 200 troops, who debarked on deployable gangways. The most important U.S. Army development was the DUKW, a 6×6 cargo truck surrounded by a boat‐shaped flotation hull; it was propelled in water by a stern propeller and on land by its truck wheels.

U.S. wartime developments included attack transports (APA), attack cargo ships (AKA), and amphibious command ships (AGC), all more suitable for operating in forward battle areas than prewar troop transports; the APA and AKA were capable of carrying large numbers of deck‐loaded landing craft. Many other modifications to ships and craft throughout the war added a variety of guns, armor, communications, and other special capabilities. In all, some fourteen types of personnel landing craft, twenty‐one types of vehicle and tank landing craft, twenty types of landing ships, and three types of amphibian vehicles were in use by the Allies by the end of the war.

After World War II, amphibious forces were retained, and, with embarked Marine combat units, soon became a standard feature of the forward‐deployed naval forces of the Cold War. The most notable use of amphibious forces was the dramatic landing at Inchon, which reversed the course of the Korean War. Other operations were Lebanon in 1958, the Dominican Republic in 1965, and the initial combat troop deployments to Vietnam. Throughout that war, special landing forces were employed in the I Corps area and numerous landing craft were adapted for riverine warfare in IV Corps. Early in the war, a new class of dock transport (LPD) was developed to add a small helicopter flight deck and hangar, allowing it to carry up to six medium helicopters. Ultimately, fifteen of this class were built.

The most important postwar development in amphibious ships was the creation of three new classes of assault ships: the seven‐ship, 18,000‐ton Iwo Jima class (LPH) in 1961; the five‐ship, 39,300‐ton Tarawa class (LHA) in 1976; and—the world's largest amphibious ships—the five‐ship, 40,500‐ton Wasp class (LHD) in 1989. All are fully capable aircraft carriers, with hangar decks and elevators able to operate twenty medium helicopters in the Iwo Jima and Tarawa classes and thirty in the Wasp class. The latter two classes have well decks to accommodate the navy's new air cushion landing craft (LCAC). Rapid surface assault to complement helicopter assault is now a reality with the 40‐knot, 60‐ton payload LCAC.

The U.S. Navy plans a total of ninety‐one LCACs. Four of the Tarawa‐ and all of the Wasp‐class ships can accommodate up to eight Harrier jet attack aircraft, as well as helicopters, adding a new dimension. These amphibious assault ships with their embarked Marines have proved important in every large operation of the 1990s and their role into the next century seems assured.
[See also Amphibious Warfare.]

Bibliography

James C. Fahey , The Ships and Aircraft of the U.S. Fleet, 6th ed., 1950.
Kenneth J. Clifford , Progress and Purpose: A Developmental History of the United States Marine Corps, 1973.
Kenneth J. Clifford , Amphibious Warfare Development in Britain and America 1920–1940, 1983.
Samuel E. Morison and and John S. Rowe , The Ships and Aircraft of the U.S. Fleet, 10th ed., 1975.
Norman Polmar , Ships and Aircraft of the U.S. Fleet, 16th ed., 1996.

Gerald C. Thomas, Jr.