Dock landing ship
A dock landing ship (also called landing ship, dock or LSD) is an amphibious warfare ship with a well dock to transport and launch landing craft and amphibious vehicles. Some ships with well decks, such as the Soviet Ivan Rogov class, also have bow doors to enable them to deliver vehicles directly onto a beach (like a tank landing ship). Modern dock landing ships also operate helicopters.
A ship with a well deck (docking well) can transfer cargo to landing craft in rougher seas far more easily than a ship which has to use cranes or a stern ramp. The U.S. Navy hull classification symbol for a ship with a well deck depends on its facilities for aircraft—a (modern) LSD has a helicopter deck, a landing platform dock also has a hangar, and a landing helicopter dock or landing helicopter assault has a full-length flight deck.