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The ''San Antonio'' class is a class of amphibious transport dock (LPD) warships used by the United States Navy. These warships replace the older ''Austin'' class LPDs (including ''Cleveland'' and ''Trenton'' sub-classes), as well as the ''Newport'' class tank landing ships, and the ''Charleston'' class amphibious cargo ships that have already been retired.〔 Twelve ships of the ''San Antonio'' class were proposed, but only eleven were funded. Their original target price was $890 million; as built, their average cost is $1.6 billion.〔 Defense Authorization for Fiscal Year 2015 included partial funding for a twelfth ''San Antonio'' class ship. nine warships of this class are in service with the U.S. Navy with an additional three ships under construction or authorized. ==History== The ''San Antonio'' class was designed to provide the Navy and U.S. Marine Corps with modern, sea-based platforms that are networked, survivable, and built to operate with 21st century transformational platforms, such as the MV-22 Osprey, the (since canceled) Expeditionary Fighting Vehicle (EFV), air-cushioned landing craft (LCACs), and future means by which Marines are delivered ashore.〔 The ship is more than 45 percent larger than the ''Austin'' class, displacing more than 25,000 tons at full load. It carries fewer troops, but has twice as much space for vehicles, landing craft, and aircraft. The project embraced a "Design for Ownership" philosophy; a concurrent engineering approach that injects operator, maintainer, and trainer input into the design development process. The goal was to ensure that operational realities are considered throughout the total ship design, integration, construction, test and life cycle support of the new ships and their systems. This process was intended to improve combat readiness, enhance quality of life, and reduce Total Ownership Costs, and resulted in numerous changes during the project. The ''San Antonio'' class has significant survivability features and computer technology. In addition to Rolling Airframe Missile (RAM) protection from air threats, the class was designed to minimize radar signature. Radar cross-section (RCS) reduction techniques make the ships more difficult to locate and target.〔 Enhanced survivability features include improved nuclear blast and fragmentation protection and a shock-hardened structure. The fiber-optic shipboard-wide area network (SWAN) connects onboard-integrated systems. The network will allow "plug in and fight" configuration, updating and replacing hardware more easily when newer technology becomes available. Moreover, the class has extensive communications, command, control, and intelligence systems to support current and projected expeditionary warfare missions of the 21st century.〔 The Advanced Enclosed Mast/Sensors (AEM/S) System mast, a 93-foot-high hexagonal structure 35 feet in diameter, is constructed of a multi-layer frequency-selective composite material. It is designed to permit the ship's own sensor frequencies with very low loss while reflecting other frequencies. The tapered hexagonal shape of the AEM/S is designed to reduce the radar cross section, and enclosing the antennas provides improved performance and greatly reduces maintenance costs. The ''San Antonio'' class also incorporates the latest quality of life standards for the embarked Marines and sailors, including sit-up berths, a ship services mall, a learning resource center, and a fitness center. Medical facilities include two operating rooms and 124 beds. Additionally, they are the first USN ships designed to accommodate sailors and Marines of both sexes as part of the crew and embarked troops. Following the extended problems and incidents experienced by the USS ''San Antonio'', the U.S. Department of Defense's Director, Operational Test and Evaluation (DOT&E), stated in 2010 that the ships are "capable of operating 'in a benign environment', but not effective, suitable and not survivable in a combat situation".〔Capaccio, Tony (Northrop Navy Ships `Not Survivable' in Combat, Official Says ) Bloomberg, 28 October 2010〕 The DOT&E found in 2011 that the class's first ship, USS ''San Antonio'', had several deficiencies which rendered it "not operationally effective, suitable, or survivable in a hostile environment".〔("LPD-17 San Antonio Class Amphibious Transport Dock" ). DOT&E〕 U.S. senator Kay Hagan has asked if the LPD-17 construction line should be extended to a 12th ship as a bridge to building the LX(R) (formerly LSD(X)) on the same hull, but the USN has indicated that the requirements of the LX(R) have not yet been settled and that the LPD-17 hull might be too large for such a mission.〔O'Rourke, Ronald. ("Navy LPD-17 Amphibious Ship Procurement: Background, Issues, and Options for Congress." ) ''Congressional Research Service'', 16 March 2011.〕 However, Commandant James F. Amos had also endorsed dropping LSD in favor of continued LPD production.〔("Navy League Conference 2013 speeches on the future of the maritime services." )〕 In October 2014, Secretary of the Navy Ray Mabus signed an internal memo recommending that the LX(R) warship be based on the existing San Antonio-class design. The LPD-17 design was selected over a foreign variant and an entirely new design to meet required capability, capacity, and cost parameters. Official selection of basing the LX(R) off the LPD-17 design still has to come with Milestone A approval.〔(Memo: Hull Based on San Antonio Design is Navy’s Preferred Option for Next Generation Amphib ) - USNI.org, 20 October 2014.〕 The National Defense Authorization Act for Fiscal Year 2015 included partial funding for a twelfth ''San Antonio'' class ship (LPD-28).〔http://www.defensenews.com/article/20141212/DEFREG/312120029/Navy-Gains-Ship-15-Growlers-Defense-Bill〕 Chief of Naval Operations Greenert is considering using some of the extra space in the San Antonio class to mount modular equipment in the same fashion as the Littoral combat ship.〔Freedberg, Sydney J. Jr. ("Modular 'Trucks' Will Rule The Waves: CNO." ) ''Aol Defense''. 18 April 2012.〕 As part of their bid to offer "Flight II" LPD-17s for the Dock landing ship replacement contract, HII has suggested fitting out the ships to carry the Aegis Ballistic Missile Defense System.〔("HII Pitching BMD Role For LPD-17 Hull." )〕〔("LPD Flight II." )〕 In early 2014, HII displayed its Flight IIA version of the LPD-17 hull for the Navy's LX(R) amphibious ship. The design is further modified by removing some of the higher-end capabilities of the San Antonio to create an "amphibious truck" to replace the Whidbey Island and Harpers Ferry landing ship docks. The Flight IIA has improved command and control (C2) features over the LSDs, half the medical spaces of the LDP-17 and a smaller hangar for stowing two MV-22s, no composite masts, two unspecified main propulsion diesel engines (MPDE), two spots for LCACs or one LCU, a reduced troop capacity (500) and a crew of about 400 sailors.〔(What the Navy’s Next Generation Amphibious Ship Could Look Like ) - News.USNI.org, 21 November 2014〕 In April 2015, the USN proposed adding a 12th ship to the class. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「San Antonio-class amphibious transport dock」の詳細全文を読む スポンサード リンク
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