America-class amphibious assault ship

USS America (LHA-6) during trials in 2013
Class overview
Builders:
Operators:  United States Navy
Preceded by: Wasp class
Cost: US$10.094 billion - initial program cost for 3 ships ($3.4B/unit[1]FY15)
Built: 2008–
Building: 1[2]
Planned: 11[3]
Completed: 1
Active: 1
General characteristics
Type: Amphibious assault ship
Displacement: 44,971 long tons (45,693 t)[4] full load
Length: 844 ft (257 m)
Beam: 106 ft (32 m)
Propulsion:
  • Two gas turbines, two shafts, with 70,000 bhp (52,000 kW) total,
  • Two 5,000 hp (3,700 kW) auxiliary propulsion engines.
Speed: 20 knots (37 km/h; 23 mph) plus
Complement:
Sensors and
processing systems:
Electronic warfare
& decoys:
  • AN/SLQ-32B(V)2
  • two Mk53 Nulka decoy launchers[5]
Armament:
Aircraft carried:
Aviation facilities: hangar deck

The America-class amphibious assault ships (formerly the LHA(R) class) of the U.S. Navy are designed to put ashore a Marine Expeditionary Unit using helicopters and MV-22B Osprey V/STOL transport aircraft, supported by AV-8B Harrier II or F-35 Lightning II V/STOL aircraft and various attack helicopters. The first of these warships was commissioned by the U.S. Navy in 2014 to replace the USS Peleliu (LHA-5) of the Tarawa-class amphibious assault ships; as many as eleven will be built.[3] The design of the America class is based on that of USS Makin Island (LHD-8), the last ship of the Wasp class, but the "Flight 0" ships of the America class will not have well decks, and they have smaller on-board hospitals in order to give more space for aviation uses.

Although they only carry helicopters and V/STOL aircraft, USS America, with a displacement of about 45,000 long tons (46,000 t), is similar in size to the French Charles de Gaulle and the Indian Vikramaditya fixed-wing aircraft carriers. Also, while more than 120 feet (37 m) shorter, they are of comparable displacement to the former US Navy Midway-class aircraft carriers.

USS America can be used as a small aircraft carrier with a squadron of jet fighters plus several multipurpose helicopters, such as the SH-60 Seahawk. It can carry about 20 AV-8Bs, F-35Bs, or a mixture of the two, but the future ships of this class, starting with LHA-8, will have smaller aircraft hangars to leave room for larger amphibious warfare well decks.[6]

Design

America is based on the design of USS Makin Island, herself an improved version of the Wasp-class amphibious assault ships with gas turbine power. About 45 percent of the "Flight 0" design of this class is based on that of Makin Island, but with her well deck omitted to allow more room for aircraft, their spare parts and weapons, and their fuel.[7] The gas turbines of Makin Island, America, and her possible successors burn the same kind of fuel (JP-5) that is burned in the gas turbines of their helicopters, the jet engines of their AV-8B Harrier and MV-22 Osprey fixed–wing aircraft and, in future ships, the gas turbines of the Landing Craft Air Cushions (LCACs) that they could carry in their well decks. This commonality greatly simplifies the storage, distribution, and use of the fuels.

The typical aircraft complement for the first two vessels is expected to be 12 MV-22B Osprey transports, six F-35B Lightning II STOVL multirole jet aircraft, four CH-53K heavy transport helicopters, seven AH-1Z/UH-1Y attack/utility helicopters, and two Navy MH-60S "Knighthawks" for air-sea rescue.[5] The exact make-up of the ship's aircraft complements will vary according to her mission. She can carry about 20 AV-8Bs or F-35Bs, and two MH-60Ses[5] to serve as a small aircraft carrier as demonstrated by Landing Helicopter Dock (LHD) operations in Operation Iraqi Freedom.[8]

The U.S. Marine Corps is now more concerned about anti-ship missile attacks from fast attack craft, hence the Commandant of the Marine Corps wants to keep the amphibious ships farther offshore. In that case, Marines would be sent ashore in long-ranged MV-22 V/STOL aircraft. The MV-22 is significantly larger than the largest helicopters used by the U.S. Marine Corps and the U.S. Navy in the past. Hence, America has twice the displacement of the much older Iwo Jima-class amphibious assault ships (all of which are now decommissioned).[9]

The America-class amphibious assault ships are engineered with a hybrid-electric propulsion system derived from the one used on Makin Island. The ships can use diesel-electric propulsion for slow speeds and use gas-turbines for high speeds. The amphibious ships can use the diesel-electric engines when operating close to shores in situations that require lower speeds.[10] Setting the beam of America at 106 feet (32 m) was dictated by the need for these ships to pass through the Panama Canal. The Congressional Budget Office found that LH(X)-class ships would be more cost-effective if they were built with nuclear power—if the price of oil reached and stayed above $140 per barrel by 2040.[11]

A modified version of the design of America, designated the MPF(F), LHA(R), or T-LHA(R), was proposed for two ships of the Maritime Prepositioning Force (Future).[12] The MPF(F) is the Navy's concept for a "sea base" to support operations ashore starting in about 2025.[13] These two ships would hypothetically be manned by a civilian crew from the Military Sealift Command, and hence not armed with weapons.[12] Funding for the MPF(F) and the LHA(R) was tabled by the Senate Armed Services Committee in the fiscal year 2008 budget.[12] The U.S. Navy now intends to buy more ships of the America class for its fleet of amphibious warfare ships.[13]

The so-called "LHX" was a warship that was proposed in the late 1990s to replace the Tarawa-class amphibious assault ships, but with a dry deck for hovercraft rather than a floodable "well deck". After 2000, the LHX, the so-called "Amphibious Assault Ship Future Replacement", was put forward to replace all of the LHDs.[14] The new LHX could be a Flight 2 design of the America class built with a well deck and a smaller island superstructure, which would give it 20 percent more capacity on the flight deck.[14] This would remove the current restriction on MV-22s to land on spots 5 and 6, and also giving room for four MV-22B, three F-35B Lightning IIs, or three CH-53Ks to use the flight deck. In 2008, the procurement of Flight 2 ships was tentatively planned for 2024,[14] but that might not be practical or affordable by then.

In January 2014, the U.S. Navy began taking measures on America in order to reduce damage from excessive heat given off by the F-35B and MV-22 to prolong the life of the flight deck. The F-35B engine gives off much more heat than the previous AV-8B Harrier STOVL fighter and the MV-22 Osprey's heat exhaust has been known to damage flight decks. Plans include 14 different modifications to the ship and limiting the number of flight operations that are conducted off the deck. The U.S. Navy is looking for cost-effective solutions that will not affect the combat effectiveness of America. Restricting the number of flight operations is not expected to decrease its usefulness as amphibious assault ships are made to support quick assaults, while full-sized aircraft carriers have the mission of conducting sustained air operations. Lessons learned from these measures will be applied to Tripoli and LHA-8 under construction, which will allow them to perform "complete unrestricted operations."[15] Some changes to America are as small as putting covers over life rafts and refueling stations and moving antennas.[16]

Well deck

Further warships in this class will have a well deck for amphibious warfare[17] in their sterns to contain landing craft, such as the Landing Craft Air Cushion (LCAC), as in Tarawa-class LHAs and Wasp-class amphibious assault ships.

The addition of a well deck will leave less space for aircraft on board the ships, but the "Early Operational Assessment" of 2005 criticized the "Flight 0" design because the expanded aviation facilities gave no space for a well deck. Also, USS America has reduced stowage space for military vehicles, and the size of her hospital was reduced by two-thirds with respect to the Wasp-class ships.[5]

Before he became the Under Secretary of the Navy, Robert O. Work also brought into question the usefulness of an amphibious warfare ship without a well deck. The concept of the Landing Platform Helicopter (LPH) had failed when their helicopters met anti-aircraft systems off the coast of Lebanon during the late 1970s. In that case, Marines first had to be moved onto ships that had well decks.[9]

The third ship of the class (LHA-8) will be the first in its class with a well deck for deploying amphibious vehicles. While there was emphasis on lighter ground vehicles in the late 1990s, up-armored and heavier vehicles were used during operations in Iraq and Afghanistan. Future counterinsurgency operations require ships that can carry and deliver those vehicles, including through use of shore connectors; cargo lift requirements are met more expensively by aircraft airlifting equipment. Adding the well deck will require the ship's island to be slightly smaller compared to its two predecessors. Early design work with funds will begin in 2015, detailed design work and construction will start in 2017, and the LHA-8 will enter service in 2024.[16]

History

The program started in July 2001,[7] with development beginning in October 2005,[7] the production decision was made in January 2006,[7] and construction of LHA-6 began in December 2008.[7] The keel-laying ceremony was on 17 July 2009[8] with delivery originally planned for August 2012.[7] As of 2009, delivery was planned for February 2013[7] and initial capability for February 2014,[7] but delivery has now been further delayed into FY2014.[17]

Northrop Grumman Shipbuilding was awarded $48.1M for "additional planning and advanced engineering services in support of the LHA replacement (LHA[R]) Flight 0 amphibious assault ship (LHA 7)" on 28 October 2010, to run until May 2012.[18] It is tentatively scheduled for delivery in 2017. In January 2011 development problems led to the F-35B program being placed on probation for two years, and plans for LHA-7 could change if the F-35B is canceled.[19]

In April 2012, Contract N00024-10-C-2229 was issued to Huntington Ingalls Industries, in which funding for steel plate purchase for LHA-7 is planned, and announced requirement for additional four ships (to LHA-10). LHA-7 will be laid down in April 2013 and her commission is planned in 2018.[20]

On 4 May 2012, Secretary of the Navy Ray Mabus announced the selection of USS Tripoli as the name for the Navy's next large-deck amphibious assault ship (LHA-7).[21][22]

On 13 June 2014 the U.S. Department of Defense announced on their website, that DOD had rewarded General Dynamics National Steel and Shipbuilding Co., San Diego, California modification to the reward as part design/development work on LHA-8 for $23,500,000.[23]

On 20 June 2014, PCU Tripoli's shipyard, Ingalls Shipyards, is set to authenticate the ship's keel in ceremony by the ship's sponsor, Lynne Mabus, wife of Secretary of the Navy, Ray Mabus.[24]

Ships in class

Ship Hull Number Builder Laid down Launched Commissioned Status
America LHA-6 Huntington Ingalls Industries, Pascagoula 17 July 2009 4 June 2012 11 October 2014[25] Active, in service
Tripoli LHA-7 22 June 2014 Under construction

References

Notes

  1. ↑ "GAO-15-342SP DEFENSE ACQUISITIONS Assessments of Selected Weapon Programs" (PDF). US Government Accountability Office. March 2015. p. 105. Retrieved 15 July 2015.
  2. ↑ http://www.wlox.com/story/25833222/keel-laying-ceremony-held-for-amphibious-assault-ship-tripoli
  3. 1 2 http://defensetech.org/2013/06/04/first-america-class-amphib-nears-completion/
  4. ↑ Cavas, Christopher P. (4 November 2013). "New big-deck amphib AMERICA (LHA 6) takes to the sea for the first time". Defense News. Retrieved 2013-11-15.
  5. 1 2 3 4 5 "LHA 6 (formerly LHA(R)) New Amphibious Assault Ship" (pdf). FY2008 Annual Report for the Office of the Director, Operational Test & Evaluation. DOT&E. 2008. p. 149.
  6. ↑ Freedberg, Sydney J. Jr. "Navy's Newest, LHA-6, A Dead End For Amphibious Ships?" 3 October 2012.
  7. 1 2 3 4 5 6 7 8 GAO-09-326SP 'Defense Acquisitions: Assessments of Selected Weapon Programs', U.S. Government Accountability Office, 30 March 2009
  8. 1 2 "Keel Laid for Latest Addition to Multimission-Capable Amphibious Fleet". United States Navy. 18 July 2009. Retrieved 20 July 2009.
  9. 1 2 Jean, Grace V. (September 2008). "Marines Question the Utility of Their New Amphibious Warship". National Defense Magazine (National Defense Industrial Association).
  10. ↑ Navy to Test Hybrid-Propulsion on Destroyers - Defensetech.org, 6 August 2013
  11. ↑ "The Cost-Effectiveness of Nuclear Power for Navy Surface Ships". CBO, May 2011.
  12. 1 2 3 "National Defense Authorization Act for Fiscal Year 2008". Library of Congress. 5 June 2007.
  13. 1 2 Stackley, Sean J. (25 May 2011). "Statement before the Subcommittee on Seapower and Projection Forces of the House Armed Forces Committee on Navy Shipbuilding" (pdf).
  14. 1 2 3 "Systematic approach to an enduring requirement" (PPT). US Marines Corps. 26 August 2008. Retrieved 19 January 2012.
  15. ↑ SNA 2014: Heat From F-35, MV-22 Continue to Plague Big Deck Amphibs - News.USNI.org, 15 January 2014
  16. 1 2 Navy Bringing Well Decks Back to Amphibs - DoDBuzz.com, 18 January 2014
  17. 1 2 Stackley, Sean J. (16 March 2011). "Statement before the Subcommittee on Seapower and Projection Forces of the House Armed Forces Committee on Amphibious Operations".
  18. ↑ "Contract". Office of the Assistant Secretary of Defense (Public Affairs), U.S. Department of Defense. 28 October 2010.
  19. ↑ Cavas, Christopher P. (8 January 2011). "Fleet will feel effects of major Corps cuts". Navy Times.
  20. ↑ http://flotprom.ru/news/?ELEMENT_ID=109511
  21. ↑ http://www.defense.gov/releases/release.aspx?releaseid=15247
  22. ↑ "Future Multipurpose Amphibious Assault ship USS Tripoli (LHA 7) Keel Authenticated". 23 June 2014.
  23. ↑ Defense.gov Contract Announcements include General Dynamic's award for LHA-8's development research for Flight I version of LHA-8.
  24. ↑ Tripoli's Keel Authentication Ceremony announced for 20 June 2014.
  25. ↑ "Amphibious Assault Ship USS America (LHA 6) Commissioned into U.S. Navy". 12 October 2014.

External links

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