Amphibious transport dock ships are warships that embark, transport and land elements of a landing force for a variety of expeditionary warfare missions.
LPDs are used to transport and land Marines, their equipment, and supplies by embarked Landing Craft Air Cushion (LCAC) or conventional landing craft and amphibious assault vehicles (AAV) augmented by helicopters or vertical take-off and landing aircraft (MV 22). These ships support amphibious assault, special operations, or expeditionary warfare missions and serve as secondary aviation platforms for amphibious operations.
The LPD 17 San Antonio class is the functional replacement for over 41 ships including the LPD 4 Austin class, LSD 36 Anchorage class, LKA 113 Charleston class, and LST 1179 Newport class amphibious ships. The newly designated LPD Flight II ships (formerly LX(R)) will be the functional replacement for the LSD 41/49 Whidbey Island Class. The San Antonio class provides the Navy and Marine Corps with modern, sea-based platforms that are networked, survivable, and built to operate in the 21st century, with the MV-22 Osprey, the upgraded Amphibious Assault Vehicle, and future means by which Marines are delivered ashore.
Construction on USS San Antonio (LPD 17), the first ship of the class, commenced in June 2000 and was delivered to the Navy in July 2005. USS New York (LPD 21) was the first of three LPD 17class ships built in honor of the victims of the Sept. 11, 2001 terrorist attacks. The ship's bow stem was cast using 7.5 tons of steel salvaged from the World Trade Center. The Navy named the eighth and ninth ships of the class Arlington and Somerset, in honor of the victims of the attacks on the Pentagon and United Flight 93, respectively. Materials from those sites were also incorporated into the construction of each ship. USS Portland (LPD 27), the eleventh ship of the class, delivered in 2017. LPDs 28 and 29 are currently under construction at Huntington Ingalls Industries (HII) on the Gulf Coast. As the 12th and 13th San Antonio class ships, LPDs 28 and 29 will perform the same missions as the previous 11 ships of the class while incorporating technically feasible cost reduction initiatives and class lessons learned. In 2018 the Navy made the decision to transition to the LX(R) effort to a second flight of the LPD 17 design. LPD 30 will be the first of 13 planned LPD Flight II ships, for a total complement of 26 ships in the LPD 17 class.
General Characteristics, San Antonio Class LPD Flights I and II
Builder: Huntington Ingalls Industries
Propulsion: Four sequentially turbocharged marine Colt-Pielstick Diesels, two shafts, 41,600 shaft horsepower
Length: 684 feet
Beam: 105 feet
Displacement: Approximately 24,900 long tons (25,300 metric tons) full load
Draft: 23 feet
Speed: In excess of 22 knots (24.2 mph, 38.7 kph)
Crew: Ship's Company: 383 Sailors and 3 Marines. Embarked Landing Force: Flight I: 699 with surge capacity of 800; LPD 28/29:650; Flight II: 631.
Armament: Two Mk 46 30 mm Close in Guns, fore and aft; two Rolling Airframe Missile launchers, fore and aft: ten .50 caliber machine guns
Aircraft: Launch or land two CH-53E Super Stallion helicopters or two MV-22 Osprey tilt rotor aircraft or up to four AH-1Z or UH-1Y or MH-60 helicopters
Landing/Attack Craft: Two LCACs or one LCU; and 14 Amphibious Assault Vehicles
USS San Antonio (LPD 17), Norfolk, Virginia
USS New Orleans (LPD 18), San Diego, California
USS Mesa Verde (LPD 19), Norfolk, Virginia
USS Green Bay (LPD 20), Sasebo, Japan
USS New York (LPD 21), Mayport, Florida
USS San Diego (LPD 22), San Diego, California
USS Anchorage (LPD 23), San Diego, California
USS Arlington (LPD 24), Norfolk, Virginia
USS Somerset (LPD 25), San Diego, California
USS John P. Murtha (LPD 26), San Diego, California
USS Portland (LPD 27), San Diego, California
Fort Lauderdale (LPD 28) - under construction
Richard M. McCool (LPD 29) - under construction
Harrisburg (LPD 30) - under contract