The Wasp-Class Amphibious Assault Ship

The United States Navy operates 11 nuclear-powered supercarriers — the most powerful warships ever built. But when the mission is to put Marines ashore on a hostile beach, the carrier stays offshore. The ship that does the actual work — launching helicopters, deploying landing craft, and carrying nearly 1,900 Marines with their tanks, trucks, and ammunition — is the Wasp-class amphibious assault ship. At 844 feet long and 40,500 tons, each Wasp-class Landing Helicopter Dock is larger than most countries' aircraft carriers. Eight were built between 1989 and 2009, and they remain the backbone of America's ability to project power from the sea to the shore. When loaded with F-35B stealth fighters instead of Marines, they become something even more versatile: light aircraft carriers that can operate independently anywhere in the world.

Purpose: The Ship That Does Everything

An amphibious assault ship is not a single-purpose vessel. It is a floating military base that combines the capabilities of an aircraft carrier, a troop transport, a vehicle ferry, a landing craft dock, and a hospital — all in one hull. The Wasp-class was designed to carry a Marine Expeditionary Unit of approximately 1,894 Marines and land them on a hostile shore using every available method: by air, by sea, and by hovercraft.

The flight deck operates helicopters and short-takeoff/vertical-landing aircraft. The well deck at the stern floods with seawater to launch landing craft and amphibious vehicles. The vehicle decks carry tanks, armored personnel carriers, trucks, and artillery. The ammunition magazines store everything the Marines need to fight once ashore. And if casualties occur, the ship's 600-bed hospital — with six operating rooms — provides medical care that would be the envy of many small cities.

The Ships

Eight Wasp-class ships were built by Ingalls Shipbuilding (now Huntington Ingalls Industries) in Pascagoula, Mississippi, replacing the earlier Tarawa-class. The average cost was approximately $750 million in 1989 dollars — roughly $1.6 billion today.

USS Wasp (LHD-1) was commissioned on July 29, 1989. USS Essex (LHD-2) followed in October 1992, USS Kearsarge (LHD-3) in October 1993, USS Boxer (LHD-4) in February 1995, USS Bataan (LHD-5) in September 1997, USS Bonhomme Richard (LHD-6) in August 1998, USS Iwo Jima (LHD-7) in June 2001, and USS Makin Island (LHD-8) in October 2009.

Seven remain in service. USS Bonhomme Richard was destroyed by fire on July 12, 2020, while undergoing maintenance at Naval Base San Diego. The blaze burned for four days, injured 63 sailors and civilians, and caused damage too extensive to repair cost-effectively. She was decommissioned on April 14, 2021, and scrapped.

Engineering: Steam and Gas

The first seven ships (LHD-1 through LHD-7) are powered by two Westinghouse steam turbines fed by two boilers, producing 70,000 shaft horsepower through two shafts. This conventional steam plant drives the ship at speeds exceeding 22 knots with a range of 9,500 nautical miles at 18 knots.

USS Makin Island (LHD-8) introduced a revolutionary change: a hybrid propulsion system combining two General Electric LM2500+ gas turbines for high-speed operations with auxiliary diesel-electric motors for cruising. The gas turbines produce 70,000 horsepower for sprint speeds, while the diesel-electric drive handles economical cruising at lower speeds. This was the first hybrid-electric drive installed in a U.S. Navy large-deck amphibious ship.

The fuel savings are dramatic. Makin Island burns approximately 15,000 gallons per day compared to 35,000 to 40,000 gallons for her steam-powered sisters. On a single seven-month deployment, the ship saved $15 million in fuel costs. Over the vessel's lifetime, the Navy projects $250 million in savings. The hybrid drive proved so successful that every subsequent large-deck amphibious ship — the America-class — uses the same propulsion concept.

The Air Wing

In a standard Marine Expeditionary Unit configuration, a Wasp-class ship carries approximately 30 aircraft: six AV-8B Harrier II jump jets or F-35B Lightning II stealth fighters, 12 MV-22B Osprey tiltrotors, four CH-53E Super Stallion heavy-lift helicopters, three to four UH-1Y Venom utility helicopters, and four AH-1Z Viper attack helicopters. The flight deck and hangar deck can accommodate different mixes depending on the mission — up to 20 F-35Bs or 20 Ospreys in alternative configurations.

The transition from the AV-8B Harrier to the F-35B Lightning II has transformed the Wasp-class from an amphibious assault ship that carried some aircraft into something approaching a light aircraft carrier. The F-35B brings stealth, advanced sensors, and network-centric warfare capabilities that the Harrier could never provide. USS Wasp was the first ship to operate F-35Bs, and USS Kearsarge achieved its first F-35B flight operations in February 2026.

The Lightning Carrier

When loaded primarily with F-35Bs — up to 20 — the Wasp-class functions as a "Lightning Carrier," a light aircraft carrier capable of sea control and power projection missions traditionally reserved for the Navy's supercarriers. The Marines tested this concept in October 2019, controlling 13 F-35Bs from multiple amphibious ships simultaneously.

The Lightning Carrier concept gives the Navy additional flattops beyond its 11 supercarriers. A Wasp-class ship loaded with F-35Bs can operate independently in a crisis zone, providing air power where a supercarrier is not available or not needed. The limitation is survivability — an LHD lacks the armor, escorts, and damage control capability of a 100,000-ton nuclear carrier — but for lower-threat environments or as a supplement to carrier strike groups, the concept extends America's reach significantly.

The Well Deck

The well deck — 266 feet long, 50 feet wide, and 28 feet high — is the Wasp-class's other major capability. Located at the stern, it can be flooded with seawater to allow landing craft to float out and head for the beach. The well deck accommodates three Landing Craft Air Cushion (LCAC) hovercraft, or 12 Landing Craft Mechanized, or 40 Amphibious Assault Vehicles. The LCACs can cross the beach at 40 knots, carrying a 60-ton payload — including an M1 Abrams tank — from ship to shore in minutes.

Above the well deck, 20,000 square feet of vehicle storage space typically carries five M1 Abrams tanks, 25 Amphibious Assault Vehicles, eight M198 howitzers, 68 trucks, and a dozen support vehicles. An additional 30,800 square feet of cargo space holds ammunition, supplies, and equipment. The Wasp-class carries everything a Marine Expeditionary Unit needs to fight — and the means to deliver it all to the beach.

Self-Defense

While the Wasp-class relies primarily on its escort ships for defense, it carries its own layered self-defense systems. Two Mark 29 octuple launchers fire RIM-7 Sea Sparrow surface-to-air missiles (upgraded to Evolved Sea Sparrow on some ships). Two Mark 49 launchers fire RIM-116 Rolling Airframe Missiles for close-in defense against anti-ship missiles. Three 20mm Phalanx Close-In Weapon Systems provide last-ditch defense with radar-guided Gatling guns. Four 25mm Mark 38 chain guns and four .50-caliber machine guns handle surface threats and small boats.

The Floating Hospital

The Wasp-class carries the largest medical facility of any combatant ship — exceeded only by the dedicated hospital ships USNS Mercy and USNS Comfort. The 600-bed hospital includes four main operating rooms and two emergency surgical suites, a 15-bed intensive care unit, a 44-bed hospital ward with 500 overflow beds, four dental operating rooms, X-ray rooms, a blood bank, laboratories, and a pharmacy. Three battle dressing stations are distributed throughout the ship, and a casualty collecting area at flight deck level allows rapid triage of wounded Marines arriving by helicopter. Medical elevators transfer casualties from the flight deck and hangar deck directly to the medical spaces below.

This medical capability is not just for combat. In humanitarian disasters — earthquakes, typhoons, tsunamis — the Wasp-class becomes a floating hospital that can provide surgical care, trauma treatment, and mass casualty management at a scale that overwhelmed local infrastructure cannot match.

Combat and Humanitarian Service

Wasp-class ships have served in every major U.S. military operation since 1991. During Operation Desert Storm, USS Wasp and USS Essex supported the amphibious operations in Kuwait. In Somalia, the class participated in Operation Restore Hope. During Operation Iraqi Freedom in 2003, multiple Wasp-class ships deployed to the Persian Gulf. USS Wasp made history in October 2007 as the first ship to deploy the MV-22 Osprey to a combat zone.

The humanitarian record is equally significant. After Hurricane Katrina in 2005, USS Bataan and USS Iwo Jima provided disaster relief along the Gulf Coast. Following the 2010 Haiti earthquake, multiple ships delivered medical aid and supplies. After Typhoon Haiyan struck the Philippines in 2013, Wasp-class ships and their embarked Marines provided critical relief.

The Successor

The America-class (LHA-6) is gradually replacing both the Tarawa-class and eventually the Wasp-class. The first two America-class ships — USS America (LHA-6) and USS Tripoli (LHA-7) — eliminated the well deck entirely, using the space for an enlarged hangar deck and increased aviation support. This proved controversial: the Marines wanted their landing craft back. Starting with LHA-8 (USS Bougainville), the well deck has been restored, acknowledging that aviation capability alone cannot replace the ability to put heavy equipment on a beach.

The America-class uses the same GE LM2500+ hybrid-electric propulsion that USS Makin Island pioneered. The Wasp-class ships are expected to serve into the 2030s and 2040s as the America-class gradually takes over. The fact that the Navy had to reverse course on the well deck — removing it, then putting it back — underscores the enduring logic of the Wasp-class design: a ship that can do everything the Marines need, all from a single hull.

The Wasp-class was not designed to fight other navies. It was designed to bring a Marine Expeditionary Unit — infantry, armor, artillery, helicopters, and stealth fighters — from the open ocean to a hostile shore, land them under fire, support them from the air, and treat their wounded. No other class of ship in any navy combines these capabilities in a single platform. Eight were built. Seven remain in service. And the concept they embody — power projection from sea to shore — remains as relevant today as it was when USS Wasp first put to sea in 1989.