Fast Battleship - Other Designs, 1912-1923

Other Designs, 1912-1923

During the First World War, the Royal Navy was unique in operating both a Fast Division of purpose-built battleships and a separate force of battlecruisers. However, the period 1912-1923 period saw a series of advances in marine engineering which would eventually lead to a dramatic increase in the speeds specified for new battleship designs, a process terminated only by the advent of the Washington Naval Treaty. These advances included:

• small-tube boilers, allowing more efficient transfer of heat from boiler to propulsive steam;
• increases in steam pressure;
• reduction gearing, which allowed propellers to rotate at a slower, and more efficient, speed than the turbines that powered them;

By the early 1920s, the wealth of the USA and the ambition of Japan (the two Great Powers least ravaged by World War I) were forcing the pace of capital ship design. The Nagato class set a new standard for fast battleships, with 16-inch (406 mm) guns and a speed of 26.5 knots (49.1 km/h). The Japanese appear to have shared Fisher’s aspiration for a progressive increase in the speed of the whole battlefleet, influenced partly by their success at outmanoeuvring the Russian fleet at Tsushima, and partly by the need to retain the tactical initiative against potentially larger hostile fleets. The immediate influence of the Nagatos was limited by the fact that the Japanese kept their actual speed a closely guarded secret, admitting to only 23 knots (43 km/h). As a result, the US Navy, which had hitherto adhered steadily to a 21-knot (39 km/h) battlefleet, settled for a modest increase to 23 knots (43 km/h) in the abortive South Dakota class of 1920.

The Japanese planned to follow up the Nagatos with the Kii class, (ten 16-inch (406 mm) guns, 29.75 knots, 39,900 tons) described as "fast capital ships" and, according to Conway’s, representing a fusion of the battlecruiser and battleship types. Meanwhile, the Royal Navy, alarmed at the rapid erosion of its pre-eminence in capital ships, was developing even more radical designs; the 18-inch (457 mm) gunned N3 battleship and the 32-knot (59 km/h), 16-inch (406 mm) gunned G3 class both of some 48,000 tons. Officially described as battlecruisers, the G3s were far better protected than any previous British capital ship, and have generally been regarded, like the Kiis, as true fast battleships. The G3s were given priority over the N3s, showing that they were considered fit for the line of battle, and orders were actually placed. However, both the British and the Japanese governments baulked at the monstrous cost of their respective programmes, and ultimately were forced to accede to US proposals for an arms limitation conference; this convened at Washington DC in 1921, and resulted in the 1922 Washington Naval Treaty. This treaty saw the demise of the giant fast battleship designs, although the British used a scaled-down version of the G3 design to build two new battleships permitted under the treaty; the resulting Nelson class vessels were completed with the modest speed of 23 knots (43 km/h).