Treaty battleship A treaty battleship was a battleship built in the 1920s or 1930s under the terms of one of a number of international treaties governing warship construction . Many of these ships played an active role in the Second World War , but few survived long after it . In the Washington Naval Treaty of 1922 , the world ' s five naval powers agreed to abide by strict restrictions on the construction of battleships and battlecruiser s , in order to prevent an arms race in naval construction such as preceded the Great War . The Treaty limited the number of capital ships possessed by each signatory , and also the total tonnage of each navy ' s battleships . New ships could only be constructed to replace the surviving ships as they retired after 20 years ' service . Furthermore , any new ship would be limited to guns of 16 - inch caliber and a displacement of 35 , 000 tons . The Washington Treaty limits were extended and modified by the London Naval Treaty of 1930 and the Second London Naval Treaty of 1936 . During the 1930s , however , the effectiveness of these agreements broke down , as some signatory powers ( in particular Japan ) withdrew from the treaty arrangements and others only paid lip service to them . By 1938 , Britain and the USA had both invoked an ' escalator clause ' in the Second London Treaty which allowed battleships of up to 45 , 000 tons displacement , and the Treaty was effectively defunct . The strict limits on displacement forced the designers of battleships to make compromises which they might have wished to avoid given the choice . The 1920s and 1930s saw a number of innovations in battleship design , particularly in engines , underwater protection , and aircraft . Washington Treaty and the 1920s . The Washington Naval Treaty was signed in 1922 by Britain , France , the USA , Japan and Italy , as the five powers which had any significant numbers of modern dreadnought battleships and battlecruisers . The Treaty was aimed at preventing an expensive arms race , principally between Britain , the USA and Japan . The Treaty established a definition of a capital ship , which was any ship with a displacement of 10 , 000 tons or more , or with guns above 8 in ( 203 mm ) calibre , apart from an aircraft carrier . Carriers were specifically constrained from having guns above 8 in calibre , in order to prevent confusion between the two types . Each signatory agreed to limit its total number of capital ships , and its total tonnage of capital ships . These measures meant that several classes of battleships and battlecruisers which were planned , or had even been begun , were scrapped or cancelled . In addition , each new ship was limited in size to 35 , 000 tons displacement , and to guns of calibre . Only one vessel already finished , the British battlecruiser , exceeded these limits ; however , many of the new ships planned or being built were significantly larger . The Treaty permitted the improvement of existing warships , but limited the resulting increase in displacement at 3 , 000 tons . The Treaty also introduced a ' building holiday ' . In general , a new ship could only be begun if one of the ships allowed by the Treaty had been in service for 20 years . This meant that for most signatory powers , no new ships could be begun until the 1930s . An exception was made for Britain ; the Royal Navy had no existing ships with 16 - inch guns , while both the U . S . Navy and Japan had 16 - inch ships already in commission which would be allowed to continue under the terms of the Treaty . These first British treaty battleships became the , which were begun in 1922 and launched in 1925 . The " Nelson " class solved the problem posed by the new weight restriction by placing all the heavy guns forward of the superstructure in three triple turrets , hence saving weight on the armour around them . London Treaties . These limits were reiterated by the London Naval Treaty of 1930 , and the Second London Naval Treaty of 1936 further limited guns to 14 - inch calibre . The Second London Treaty contained a clause which allowed construction of battleships with 16 - inch guns if any of the signatories of the Washington Treaty failed to ratify the new one . It contained an additional clause which allowed displacement restrictions to be relaxed if non - signatories built vessels more powerful than the treaty allowed . Virtually all battleships built subsequently obeyed the treaty limits . The Washington Naval Treaty was signed by the USA , UK , Japan , France and Italy - all the principal naval powers . At various stages Italy and France opted out of further negotiations ; however , their economic resources did not permit the development of super - battleships . Germany , while not permitted any battleships by the Treaty of Versailles , developed one in the 1930s ; this was legitimised by the Anglo - German Naval Agreement , which placed Germany under the same legal limits as Britain . Only Japan , which opted out of the Treaty system in 1934 , actually built mammoth treaty - busting battleships - the . The collapse of the treaty system led to the wartime construction of " post - treaty " battleships which exceeded the limitations : the German , the U . S . and the British and ( never completed ) . A number of designs , never finished , shattered the treaty limits ; the German H - class were scrapped on the outbreak of war , while the U . S . were canceled before being laid down . Technical change . Treaty battleships were technically superior to their predecessors . Naval technology developed in the 1920s and 1930s provided improved steel , better guns , more efficient engines , and more effective protection against torpedoes . The displacement limit also encouraged naval designers to think creatively about minimising displacement , meaning that the treaty battleships significantly increased their performance .