Were the USS America to cruise alongside the French nuclear-powered aircraft carrier Charles de Gaulle, the average Joe might struggle to distinguish their purposes. Both flat-tops measure longer than two-and-half football fields in length and carry jet fighters and helicopters.
But the America and her sistership Tripoli are technically “Landing Helicopter Assault” vessels numbered LHA-6 and LHA-7 respectively: super-sized members of the “gator navy” of amphibious assault ships designed to deploy the expeditionary units of the U.S. Marine Corps onto hostile shores. In addition to the Navy crew of 1,000-1,200 sailors and officers, each LHA can carry nearly 1,700 Marines.
Unlike the catapult-launched Rafale-M jet fighters on the Charles de Gaulle, the America and Tripoli can only deploy short-takeoff and vertical-lift capable jump jets from their decks. You can see a video of an F-35B hovering down for a landing on the America here.
Rather than using nuclear reactors to achieve brisk speeds of 30 knots, 45,000-ton LHAs use an innovative hybrid electric/gas-turbine propulsion system pioneered in the final Wasp-class LHD, USS Makin Island. The electric propulsion is used for slower cruising speeds while the gas-turbine becomes more efficient near the more modest maximum speed of twenty knots.
However, unlike the Wasp-class Landing Helicopter Docks (LHDs) they were based upon, America and Tripoli lack floodable “well deck” which can carry landing craft to ferry troops ashore. (This video shows how the Wasp’s cavernous well deck works.)
All that space has instead gone to dramatically expanded aviation facilities and fuel stores. The ship’s medical facilities were also reduced by two-thirds.
Instead of watercraft, the LHAs rely on squadrons of MV-22B Osprey tilt-rotors, sophisticated hybrid aircraft combining the vertical lift ability of a helicopter and the speed and range of an airplane—to insert troops by air.
Officially, a “typical” air wing on the America would include a dozen Ospreys, six Harrier or F-35B jump jets, seven AH-1Z “Viper” attack and four CH-53K heavy transport helicopters to support troops ashore, and two MH-60S choppers for anti-submarine and search-and-rescue duties.
But if the Navy wants to, it could instead cram up to twenty fighters on the LHDs, turning them effectively into light aircraft carriers—a class of ship the Navy hasn’t built since World War II. Like the lower-end escort carrier, the concept was that there were many missions like aircraft delivery and convoy escort that would benefit from air support, but didn’t require the massive firepower of a full carrier air wing with seventy to a hundred warplanes.
Indeed, during the invasion of Iraq in 2003 the Navy used the LHDs Bataan and Bonhomme Richard as pocket carriers primarily to launch Harrier airstrikes in Iraq.
However, the subsonic Harrier, though a versatile support platform, was substantially inferior in performance to equivalent land-based or catapult-launched fighters.
The new supersonic-capable F-35B Lightning II stealth jets entering service with the Marine Corps are far more capable of taking on fourth- and fifth-generation fighters and launching longer-range strikes. Combined with the F-35’s surveillance capabilities, this means future air wings on LHDs and LHAs will be far more versatile.
As the Pentagon’s chief strategic contingency is preparing for the possibility of conflict with China, the Marine Corps sees the Pacific Ocean as its most important likely battleground.
A U.S.-China conflict might play out over small islands in the South China Sea in which the Chinese military has installed airfields, missile batteries and naval bases. And it may prove inefficient or risky to delegate a full-sized supercarrier to operations targeting these islands, or defend islands to which Marine and Army forces have deployed their own missile batteries.
Indeed, the LHD USS Wasp deployed in April 2019 with ten F-35Bs onboard and buzzed Chinese troops deployed at Scarborough Shoal, an occupied by Chinese troops but claimed by the Philippines.
Light carriers might also be appropriate in scale for protecting vital convoys traversing the vastness of the Pacific against sporadic air and submarine attacks using their onboard fighters and helicopters respectively.
The cost of the America-class LHAs reflects the efficiency argument well: the three ships ordered together were developed and built for $10 billion. That’s less than a single $13 billion Gerald Ford-class supercarrier.
Bringing Back the Well Deck
Nonetheless, Marines have understandable objections to the removal of the ability to deploy landing craft from a nominally “amphibious” ship.
Afterall, air-cushion landing craft (LCAC) can carry up to 180 soldiers, 60-75 tons of supplies on each load, and vehicles as large as an Abrams main battle tank. Meanwhile, an Osprey can only carry 10-15 tons or thirty-two personnel. The only vehicle the MV-22B is certified to carry internally is a Growler jeep.
The Marine Corps, however, is increasingly convinced that D-Day style amphibious landings on defended beachheads are less and less likely to be viable in modern warfare.
Strategists worry that long-range shore-launched anti-ship missiles will make it unlikely that landing craft, and even the larger LHDs and LHA carrying those landing craft, will be able to approach close enough to even deposit their troops in the first place. Surely, giant amphibious ships stuffed full with over a thousand Marines would be particularly tempting targets.
America-class LHAs can at least thin out threats up to thirty miles away with their two Evolved Sea Sparrow missile launchers before having to rely on Phalanx gatling cannons and Rolling Airframe Missile launchers and Nulka decoys for point defense. But none of these systems can even hope to stop anti-ship ballistic missiles entering service in Iran and China.
Thus, the Marine Corps recently abandoned its former objective of maintaining thirty-eight amphibious assault ships in service (it currently has thirty-two) which can deployed two full brigades into battle between them, in favor of dispersing troops amongst more numerous, though less capable, auxiliary and even robotic ships.
That may explain why the Navy prioritized the ability to launch additional troop-carrying Ospreys from over a hundred miles away which can land behind enemy lines rather than exposed beachheads.
But that doesn’t change the issue of logistical throughput: if you need to rapidly reinforce a beachhead with heavy weapons, vehicles and supplies, landing craft are preferable—especially once nearby enemy defenses are suppressed.
The Ospreys themselves, while highly flexible, are also expensive to maintain and operate per flight hour. Furthermore, exhaust from both the Osprey and, especially, the F-35Bs inflict heat damage to the flight deck over time, limiting the advisability and increasing the cost of surging high-intensity flight operations over prolonged periods. The Navy has been continuously adapting the ships to prevent heat damage for years.
Therefore, in a bid to restore flexibility, the third America-class ship, Bouganville (LHA-8) which was laid down in March 2019 in Mississippi, will see the well-deck restored with a capacity for two LCACS. The island is trimmed down to allow more flight deck parking spot in compensation for lost hangar space. Armament and sensors are re-situated onto the vessel’s “island” superstructure, including a brand-new EASR radar also destined to equip future Gerald Ford-class carriers.
The new configuration inevitably requires tradeoffs. According to a chart at Navy Recognition, Bougainville falls squarely in between the Wasp-class LHD and the first two America-class boats with 38,000 square feet of deck space dedicated to aviation, but has less than half the aviation fuel capacity of her sister ships and more limited vehicle stowage.
Despite these downsides, the restoration of the ability to carry landing craft should improve the America class’s flexibility. Still, naval planners will hopefully bear in mind the carrier’s secondary potential to serve as economy-size aircraft carriers for missions that don’t require $13 billion supercarriers.
Sébastien Roblin holds a master’s degree in conflict resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.
Image: U.S. Navy via Wikimedia Commons.