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Washington Naval Treaty

The Washington Naval Treaty limited the naval armaments of its five signatories. It was signed by the United States of America, the British Empire, France, Italy, and Japan at Washington, DC, on February 6, 1922. The US Senate advised ratification on March 29, 1922; the President of the United States ratified it on June 9, 1923; the ratifications were deposited with the Government of the United States on August 17, 1923, and were proclaimed on August 21, 1923.


The text of the Washington treaty can be read at " class="external">

After specifying some exceptions for ships in current use and under construction, the treaty limited the total capital ship tonnage of each of the signatories: the United States Navy and the Royal Navy could not exceed 525,000 tons, the French Navy and the Italian Navy were limited to 175,000 tons, and the Japanese Navy to 315,000 tons. No single ship could exceed 35,000 tons, and no ship could carry a gun in excess of 16 inches.

Aircraft carriers were addressed specifically: the total tonnage for carriers of the United States and the British Empire was limited to 135,000 tons; for France and Italy 60,000 tons; and for Japan 81,000 tons. Only two carriers per nation could exceed 27,000 tons, and those two were limited to 33,000 tons each. The number of large guns carried by an aircraft carrier was sharply limited -- it was not legal to put a small aircraft on a battleship and call it an aircraft carrier.

As to fortifications and naval bases, the United States, the British Empire, and Japan agreed to maintain the status quo at the time of the signing. No new fortifications or naval bases could be established, and existing bases and defences could not be improved in the territories and possessions specified. In general, the specified areas allowed construction on the main coasts of the countries, but not on smaller island territories. For example, the United States could build on Hawaii and the Alaskan mainland, but not on the Aleutian Islands. Britain could build on Australia or New Zealand, but not Hong Kong. Japan could build on the home islands, but not Formosa.

On December 29, 1934, the Japanese government gave notice that it intend to terminate the treaty. Its provisions remained in force until the end of 1936, and it was not renewed.


The Treaty was a major cause of the United States Navy's conversion from a battleship fleet to an aircraft carrier-based force.

The United States was over the limits in capital ships when the treaty was ratified, and had to decommission or disarm several older ships to comply. However, the only aircraft carrier in the US fleet before the treaty was signed was USS Langley (CV-1) (11,500 tons), a converted collier. Not only did carriers have separate limits, but as an experimental vessel, Langley did not count against the tonnage restrictions. The US Navy had a free rein to build carriers.

In the 1920s The Department of the Navy had a low opinion of the concept of naval aviation despite (or perhaps because of) Billy Mitchell's 1921 success in using Army bombers to sink the captured German battleship Ostfriesland). However, to comply with the treaty, two newly constucted battlecruisers, USS Lexington (CV-2) (41,000 tons) and USS Saratoga (CV-3) (33,000 tons), had to be disposed of. They were converted into carriers, although that choice was only slightly preferred over scrapping.

In 1931, the United States was still well under the treaty's limit on carriers. USS Ranger (CV-4) (14,500 tons) was the first US carrier designed as such -- no other class of capital ship could be built -- and the Navy began incorporating the lessons from those first four carriers into the design of two more. In 1933, Congress passed Franklin Roosevelt's "New Deal" package of legislation, which included nearly $40 million for the two new carriers: USS Yorktown (CV-5) (19,800 tons) and USS Enterprise (CV-6) (19,800 tons). The US carrier fleet now totalled 128,100 tons and there it remained until the treaty was terminated by Japan in 1936.

By then, the US Navy had overcome its antipathy toward carriers. The keel of USS Wasp (CV-7) (14,700 tons) was laid down on April 1, 1936.