J3 battlecruiser

The J3 class battlecruiser was a design study conducted during the Royal Navy's 1921 Fleet modernization programme. As a follow-on to the Admiral-class battlecruiser, the J3 class incorporated all the lessons learned from the First World War, specifically the battle of Jutland. The design was seen as an improvement to the Admiral class by virtue of its heavier and improved armouring scheme, specifically the deck armour, although the offensive armament remained roughly the same. The design was superseded by the I3 and G3 battlecruiser designs, as both mounted a heavier main armament, and further improved the protection scheme, on roughly the same tonnage. The 1921 fleet program was cancelled due to signing of the Washington Naval Treaty in 1922, which limited the size and armament of battleships to 35,000 long tons (36,000 t) and no gun bigger than 16 inches (406 mm).

Background

In 1916 the US had declared its intention to create a Navy "second to none"; Congress had authorized the building of a large number of battleships and battlecruisers. In response, the Japanese government also began a large programme of warship building (the 8-8 fleet). Two improved Revenge-class battleship hulls were rebuilt into the two Renown-class battlecruisers by the Royal Navy during the war. The only new capital ships laid down during the war were the Admiral-class battlecruisers. Their design had been called into question after the Battle of Jutland in 1916, and three ships of this class were cancelled, leaving only Hood to be completed to a modified design.