docks Amphibious transport docks, also known as landing platform dock or LPD, is an amphibious warfare ship, a warship that embarks, transports, and lands elements of a landing force for expeditionary warfare missions. Several navies currently operate this kind of ship. The ships are generally designed to transport troops into a war zone by sea, primarily using landing craft, although invariably they also have the capability to operate transport, utility and attack helicopters and multi-mission tilt-rotor aircraft. (12 in active service of 17 planned) Dock landing ships Dock landing ships, also known as landing ship, dock or LSD, are amphibious warfare ships with well docks 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 Landing Ship, Tank). Modern dock landing ships also operate helicopters. A ship with a well deck (docking well) can transfer cargo to landing craft in rougher seas than a ship that has to use cranes or a stern ramp. The US 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 LPD also has a hangar, and a LHD or LHA has a full-length flight deck. (6 in active service) (4 in active service) Expeditionary mobile base Expeditionary mobile bases are semi-submersible, flexible, modular platforms providing that perform large-scale logistics movements such as the transfer of vehicles and equipment from sea to shore. These ships significantly reduce the dependency on foreign ports and provide support in the absence of port availability. (2 in active service of 6 planned) Cruisers Cruisers and guided missile cruisers CG are a type of warship. The term has been in use for several hundred years, and has had different meanings throughout this period. During the Age of Sail, the term cruising referred to certain kinds of missions – independent scouting, raiding or commerce protection – fulfilled by a frigate or sloop, which were the cruising warships of a fleet. In the middle of the 19th century, cruiser came to be a classification for the ships intended for this kind of role, though cruisers came in a wide variety of sizes, from the small protected cruiser to armored cruisers that were as large (although not as powerful) as