G3 Class Battlecruisers - Background

Background

In 1916 the US had declared its intention to create a Navy "second to none"; the United States Congress had authorized the building of a large number of battleships and battlecruisers. In the aftermath of the First World War, the Japanese government were also embarking on a large programme of warship building. Meanwhile, in Great Britain, the needs of the First World War had led to the pre-war Queen Elizabeth-class battleships being followed by the slower and cheaper Revenge-class battleships. Two improved Revenge class hulls were converted during construction into the two Renown-class battlecruisers as emergency builds during the war. The only new capital ships laid down in the war were the Admiral-class battlecruisers. Their design had been called into question after the Battle of Jutland in 1916. Three of this class were cancelled, leaving only Hood to be completed to an altered design.

The US plan had been delayed by the wartime need to build smaller vessels. Nevertheless, estimates by the Admiralty were that by the early 1920s the UK would be behind in ships. The British did have access to German technology through ships such as the battleship Baden which had been saved from the scuttling of the interned German High Seas Fleet in Scapa Flow and the experiences of the war. A committee concluded that any new ship should be able to match the speed of the new US Lexington-class battlecruisers, expected to make 32 knots. Consequently a series of designs was prepared of ships with displacements ranging from 53,100 to 44,500 long tons (54,000 to 45,200 t), the only limitations being the ability to use British dockyards and passage through the Suez Canal. These designs were given letters of the alphabet running backwards from K to G. The related battleship designs under consideration at the same time had design letters from L upwards.

The first two design proposals, 'K2' and 'K3', had a general layout similar to Hood, but were armed with either eight or nine 18-inch guns, in four twin or three triple gun turrets, respectively. The numeral in the designation came from the number of guns in each turret. These ships were very large, displacing 52,000 to 53,100 long tons (53,000 to 54,000 t), could only reach 30 knots (56 km/h; 35 mph), and could only be docked in a single ex-German floating dock and one dock in Liverpool. 'J3', the next proposal, saved nearly 10,000 long tons (10,000 t) by reducing the main armament to nine 50-calibre 15-inch (381 mm) guns and the main deck armour to 4 inches (102 mm). This reduction in size allowed the ship to dock anywhere that Hood could dock and to pass through the Suez and Panama Canals. 'I3' took another route in saving weight and concentrated the main armament amidships with 'X' turret placed between the forward superstructure and the funnels. The consequent weight savings were negated by additional hull and machinery weights and the ship displaced only slightly less than 'K3'. It had the advantage, however, that it could be docked in Rosyth and Portsmouth and pass through both canals, once the Suez Canal had been deepened. The primary drawback was that the main armament had a blind spot towards the rear of the ship of no less than 40°. Several variations were evaluated of the 'H3' design with the number of turrets reduced. In 'H3a' both turrets were forward of the superstructure while in 'H3b' one was forward and the other was aft of the forward superstructure. 'H3c' retained the layout of 'H3b', but lowered the turrets by one deck and saved 1,250 long tons (1,270 t) over the 45,000 long tons (46,000 t) of 'H3b'. All three 'H3' designs had a maximum speed of 33 knots (61 km/h; 38 mph), but the reduced number of main guns was disliked so the 'G3' was proposed with the three triple turrets, armed with 16.5-inch (419 mm) guns to save weight.

This design was accepted at the end of 1920, but changes were made as the design was finalized in early 1921, including the reduction of the ship's horsepower from 180,000 to 160,000 and the reduction of the main armament from 16.5 inches to 16 inches (406 mm).