Aircraft carrier

An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a sea going air base. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations. They have evolved from wooden vessels used to deploy balloons into nuclear-powered warships that carry dozens of fixed-wing and rotary-wing aircraft.

Aircraft carriers are typically the capital ship of a fleet, and are extremely expensive to build and important to protect. Of the ten nations that possess an aircraft carrier, eight possess only one. Twenty aircraft carriers are currently active throughout the world with the U.S. Navy operating 10 as of February 2013 though some of these nations no longer have carrier-capable aircraft in inventory and have re-purposed these ships.

History

The 1903 advent of heavier-than-air, fixed-wing aircraft was closely followed in 1910 by the first experimental take-off of such an airplane from the deck of a United States Navy vessel (cruiser USS Birmingham), and the first experimental landings were conducted in 1911. On 4 May 1912 the first plane to take-off from a ship underway flew from the deck of the British Royal Navy's HMS Hibernia.

Seaplane tender support ships came next; in September 1914, the Imperial Japanese Navy Wakamiya conducted the world's first successful naval-launched air raids. Used against German forces during World War I, it carried four Maurice Far-man seaplanes, which took off and landed on the water and were lowered from and raised to the deck by crane. On 6 September 1914 a Farman aircraft launched by Wakamiya attacked the Austro-Hungarian cruiser Kaiserin Elisabeth and the German gunboat Jaguar in Qiaozhou Bay off Tsingtao; neither were hit.

   He development of flat top vessels produced the first large fleet ships. In 1918, HMS Argus became the world's first carrier capable of launching and landing naval aircraft. Carrier evolution was well underway by the mid-1920s, resulting in the commissioning of ships such as Hōshō (1922), HMS Hermes (1924), and Béarn (1927). Most early aircraft carriers were conversions of ships that were laid down (or had served) as different ship types: cargo ships, cruisers, battlecruisers, or battleships. The Washington Naval Treaty of 1922 affected aircraft carrier plans. The U.S. and UK were permitted up to 135,000 tons of carriers each, while specific exemptions on the upper tonnage of individual ships permitted conversion of capital ship hulls to carriers such as the Lexington-class aircraft carriers(1927).