上陸用舟艇
The 'Landing Ship Dock' or LSD developed from a British staff requirement for a type of self-propelled drydock to transport beaching craft over long distances, that would in turn deliver trucks and supplies onto the beach. A flooding deck aft capable of holding either two of the larger British Landing craft tanks (LCTs) or three of the new US LCTs was included in the designs. With the option of fitting extra decks, large numbers of vehicles could be transported, and loaded into landing craft via ramps. Despite an initial specification for a speed of , the LSDs were capable of only .