Amphibious warfare ship
An amphibious warfare ship (or amphib) is a warship employed to land and support ground forces, such as marines, on enemy territory during an amphibious assault. The largest fleet of these types is operated by the United States Navy, including the Tarawa class amphibious assault ships dating back to the 1970s and the newer and larger Wasp class ships that debuted in 1989.
World War I and interwar period 
The history of the specialist amphibious assault vessel really begins during World War II. Prior to World War I, amphibious assaults had taken place using conventional boats. The disastrous Gallipoli landings of 1915 showed that this type of operation was impossible in the face of modern weapons, especially the machine gun. The 1920s and 1930s did not see much progress in most of the world, the exception being by the United States Marine Corps. Small-scale operations conducted by the Marine Corps in Latin America in the 1920s and 1930s, known as the Banana Wars, led to the development of advanced amphibious assault doctrine. By the late 1930s, concrete plans were beginning to form to build the first true specialized amphibious assault ships.
Specialized shipping can be divided into two types, most crudely described as ships and craft. In general the ships carry the troops from the port of embarkation to the drop point for the assault and the craft carry the troops from the ship to the shore. Amphibious assaults taking place over short distances can also involve the shore-to-shore technique where landing craft go directly from the port of embarkation to the assault point.
World War II developments 
|Amphibious Force Flagship|
|Attack cargo ship|
|High speed transport|
|Landing Ship, Dock|
|Landing Ship, Medium|
|Landing Ship, Tank|
|Landing Ship, Vehicle|
|WWII British terminology|
|Amphibious Force Flagship|
Many of the early types of shipping were converted cargo vessels. However, the Landing Ship, Tank (LST) stands out. As the name suggests it is a specialized type for getting tanks or other large vehicles ashore. Unlike the other large ships, LSTs could beach and discharge directly onto shore. Beyond the ships carrying the troops, other vessels were needed. It was quickly appreciated that amphibious assaults were such complicated operations that a specialized flagship was needed, with facilities that a normal naval vessel simply could not provide. It was also realized that battleships, cruisers and destroyers could not necessarily provide all the fire support (including suppressive fire) that an assault would need. Therefore specialized vessels were developed that incorporated various direct and indirect fire weapons. These included guns and rockets which could be mounted on landing craft and landing ships. As part of the final barrage before an assault, the landing area would be plastered by these types. Despite all the progress that was seen during World War II, there were still fundamental limitations in the types of coastline that were suitable for assault. Beaches had to be relatively free of obstacles, and have the right tidal conditions and the correct slope. However, the development of the helicopter fundamentally changed the equation.
Early Cold War developments 
The first use of helicopters in an amphibious assault came during the Anglo-French-Israeli invasion of Egypt in 1956 (the Suez War). Two British light fleet carriers were pressed into service to carry helicopters, and a battalion-sized airborne assault was made. Two of the other carriers involved, HMS Bulwark (R08) and Albion (R07), were converted in the late 1950s into dedicated "commando carriers." The techniques were developed further by American forces in the Vietnam War and refined during training exercises. The modern amphibious assault can take place at virtually any point of the coast, making defending against them extremely difficult.
Earlier ships which played a similar role to the current vessels as the heart of an amphibious assault included five Iwo Jima class Landing Platform Helicopter vessels, built in the 1950s and 1960s, and various converted fleet and escort carriers. The first of the type envisaged was the escort aircraft carrier USS Block Island (CVE-106/LPH-1), which never actually saw service as an amphibious assault ship. Delays in the construction of the Iwo Jima class saw other conversions made as a stopgap measure; three Essex-class aircraft carriers (USS Boxer (CV-21/LPH-4), Princeton (CV-37/LPH-5), and Valley Forge (CV-45/LPH-8)) and one Casablanca class escort carrier (USS Thetis Bay (CVE-90/CVHA-1/LPH-6)) were converted into Boxer and Thetis Bay class amphibious assault vessels.
The Tarawa and Wasp types and their Iwo Jima class forebears resemble aircraft carriers. However, the role of an amphibious assault ship is fundamentally different from that of an aircraft carrier. Its aviation facilities are not to support strike or air defense aircraft, but for hosting helicopters to support forces ashore.
Future developments 
One of the most recent innovations is the LCAC (Landing Craft Air Cushioned). These large hovercraft further expand the range of conditions under which an amphibious assault can take place and increase the speed of transfer of assets from ship to shore. Ground effect vehicles, which straddle the line between aircraft and ship, have also been proposed for the role in the past.
Amphibious assault submarines, while proposed during the 1950s, and almost brought to actual construction by the Soviet Union in the 1960s, are currently not being designed. However, if the predictions of military experts such as John Keegan or others hold true, and surface shipping becomes extremely dangerous during future wars of evenly matched powers (due to satellite reconnaissance and anti-ship missiles), then transport and amphibious assault submarines might deserve another look.
- LHA: Landing Helicopter Assault (USS Tarawa class)
- LHD: Landing Helicopter Dock (USS Wasp class)
- LPH: Landing Platform Helicopter (HMS Ocean (L12))
- LPD: Landing Platform Dock
- LSD: Landing Ship Dock
- LSI: Landing Ship, Infantry was previously designated as Landing Craft, Infantry
- LSL: Landing Ship Logistics
- LSM: Landing Ship Medium
- LST: Landing Ship Tank
- LCC: Amphibious Command Ship, unrelated to the Landing Craft, Control (LCC)
- AGF: Auxiliary Command Ship
- AKA/LKA: Attack cargo ship
- AP/APA/LPA: Auxiliary Personnel Assault
- ARL: Landing Craft Repair Ship (USS Achelous (ARL-1) class)
See also 
- Submarine aircraft carriers (uneven-quality private website, but has third-party citations in support)