Even before the massive amphibious operations dotting the World War 2 battlescape came to pass and prior to the American entry into the conflict proper, thought was already being given by Allied warplanners to the development of large ocean-going assault ships capable of moving man, machine, and supplies from offshore staging points to unprepared beaches. There were various types of these vessels eventually created for warfare - dedicated troop ships, tank transports and the like - and a myriad of variants appeared in-between. The British made steady progress in the field and eventually produced the "Landing Ship, Tank Mk I" (LST(1)) series based on its experiences at Dunkirk in 1940 - the purpose to bring armor to within reach of the beach line and help carry the fight directly to the enemy where they waited. Three Mk I series ships were completed before attention then turned to the definitive assault ship of the war - "Landing Ship, Tank Mk II" (LST(2)).
Understanding the importance of large-scale production in bringing these ships to pass, a British attache was sent to the United States to secure manufacture of the new class. With the details ironed out from late-1941 to early-1942, an order for the ships was placed during February of 1942.
Unlike the original LST(1) vessels - which were simply modifications of existing oil tankers, useful because of their ocean-going capabilities and shallow draughts - the LST(2) was a purpose-designed warship and, therefore, given creative freedom in its eventual make-up. The relatively compact twin-diesel engine arrangement sat at the rear of the hull and under the tank cargo deck (the Third Deck of four total) resulting in full use of the boat's length for cargo management and storage. Dimensions were more contained than in the previous offering, improving water-handling and speeds, while the shallow draught design was continued. Doors were set at the bow and hinged to open outwards from centerline. Within the bow was the loading ramp to facilitate the crossing of vehicles from ship to water. The lower deck was sectioned off for tanks of medium and light class weight while the upper deck (Second Deck) was devised to support lighter-weight vehicles. Beyond this, the ships could also support 150 men and their related supplies. Berthing for the troops was along the edges of the Second Deck.
As completed, the LST(2) weighed 3,800 long tons under full load and showcased a length of 328 feet, a beam of 50 feet, and a draught of 14 feet (8 feet at the bow). The ramp provided some run-off into the tide until 1943 when floating pontoon sections were used to aid vehicles coming off the ship (creating a "ship-to-shore causeway" of sorts). The General Motors 12-567 diesel engines outputted 1,800 horsepower (each) and drove two shafts under stern at speeds up to 12 knots. Internally, the cargo hold held space for eighteen tanks (30-ton class) or thirty military trucks. For self-defense the ship was outfitted with 1 x 76mm Dual-Purpose (DP) gun, 6 x 40mm Bofors Anti-Aircraft (AA) guns, 6 x 20mm Oerlikon AA guns, 2 x 0.50 caliber Heavy Machine Guns (HMGs), and 4 x .30 caliber machine guns.
The LST(2) production effort was part of the larger naval construction initiative pushed by the American congress in the early war years and the first keel of the series was laid on June 10th, 1942 at Newport News, Virginia. Twenty-three ships were readied before the end of the year. Such was the need for LSTs that production vehicles were being constructed even before a prototype had been completed and tested. Since the draught of the LST(2) was shallow, the ships could be built inland away from already-committed coastal shipyards of the United States.
In the end, 1,051 LST ships were built between 1942 and 1945 and 113 of these were passed to Britain via Lend-Lease while a further 101 were cancelled as the war progressed. The ships proved so critical to Allied actions that their priority never waned during the course of the war. A vessel could be completed in under two months and modifications were accordingly added to the series as war time use showcased the need in streamlining the ship-to-shore process. For their part in the war, the large movers proved themselves strong, reliable, and robust with only a few lost to enemy action (26 officially noted). They were nicknamed "Large Slow Target" ("LST") by some. Operators included both Britain and the United States as well as Canada.
LST(2) ships were used in every theater that the Allies fought in and saw post-war use for a time - including action in the Korean War (1950-1953) that followed. By this time, the revised design was capable of reaching speeds over 17 knots.