America-class amphibious assault ship

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.[8] The gas turbines of Makin Island, America, and her possible successors use JP-5 fuel which is the same fuel used by their helicopters, the jet engines of their AV-8B Harrier and MV-22 Osprey 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 multi-role 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.[4] The exact make-up of the ship's aircraft complements may vary according to her mission. She can carry about 20 AV-8Bs or F-35Bs, and two MH-60Ss,[4] to serve as a small aircraft carrier as demonstrated by landing helicopter dock (LHD) operations in Operation Iraqi Freedom.[9]

The U.S. Marine Corps is now more concerned about anti-ship missile attacks from fast attack craft and long-range precision fires from land. To counter such attacks the Marine Corps wants to keep amphibious ships farther offshore. For this Marines will be transported ashore in larger and longer range MV-22 V/STOL aircraft. To accommodate these requirements, America has twice the displacement of the retired Iwo Jima-class amphibious assault ships.[10]

The America-class amphibious assault ships are engineered with a (CODLOG) hybrid-electric propulsion system derived from the one used on Makin Island. The ships can use gas-turbines for high speeds and the diesel-electric engines when required.[11] 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 if before 2040 the price of oil reached and remained above $140 per barrel then the use of nuclear propulsion for LH(X)-class ships would be more cost-effective.[12]

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).[13] The MPF(F) is the Navy's concept for a "sea base" to support operations ashore starting in about 2025.[14] These two ships would hypothetically be manned by a civilian crew from the Military Sealift Command and not armed with weapons.[13] Funding for the MPF(F) and the LHA(R) was tabled by the Senate Armed Services Committee in the fiscal year 2008 budget.[13] The U.S. Navy now intends to buy more ships of the America class for its fleet of amphibious warfare ships.[14]

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.[15] 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.[15] 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,[15] 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 Bougainville under construction, which will allow them to perform "complete unrestricted operations."[16] Minor modifications to America are as small as putting covers over life rafts and refueling stations and moving antennas.[17]

Launch of USS Tripoli (LHA-7) at Huntington Ingalls Industries in Pascagoula, Mississippi in 2017

The program started in July 2001, with development beginning in October 2005, the production decision was made in January 2006, and construction of LHA-6 began in December 2008. The keel-laying ceremony was on 17 July 2009 with delivery originally planned for August 2012.[9] As of 2009, delivery was planned for February 2013 and initial capability for February 2014, but delivery has now been further delayed into FY2014.[8][18]

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.[19] It was scheduled for delivery in 2017. In January 2011, development problems led to the F-35B program being delayed two years, and plans for LHA-7 could change if the F-35B were to be canceled.[20]

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 is to be laid down in April 2013 and her commission is planned in 2018.[21]

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).[22] On 20 June 2014, Ingalls Shipyards, authenticated Tripoli's keel in ceremony by the ship's sponsor, Lynne Mabus, wife of Secretary of the Navy, Ray Mabus.[23] Tripoli was officially delivered to the U.S. Navy on 28 February 2020.[24]

On 13 June 2014, the U.S. Department of Defense announced that it had awarded a contract worth for $23.5 million to General Dynamics National Steel and Shipbuilding Co., San Diego, California for design and development work on LHA-8.[25]

On 6 May 2020, Huntington Ingalls Industries' Ingalls Shipbuilding division received a $187.46 million contract for long-lead-time material and advance procurement activities for amphibious assault ship LHA-9.[26]

• US Navy.mil NewsStand LHA(R) page with image
• LHA-6 America Global Security Info Page
• LHX/LHA(R)
• America Class project on naval-technology.com