K-class submarine

K-class submarine, a revolutionary submarine design produced by the British Navy between 1916 and 1923. The basis of its design was the requirement in the British Grand Fleet for a submarine fast enough on the surface to accompany the fleet in its searches for the German High Seas Fleet and to dive and attack the enemy fleet with torpedoes when contact had been made. Since the normal diesel engine could not produce the required surface speed, around 21 knots, a steam turbine (see steam propulsion) seemed the only answer, and steam, of course, requires a boiler to produce it.

Admiral Fisher, the First Sea Lord in October 1914, was fiercely opposed to the principle of steam-driven submarines, an opinion reinforced by the unfortunate experiences of the Archimède, a steam-driven French submarine temporarily attached to a British naval force. While in the Heligoland Bight, she was struck by such a heavy sea that it bent her funnel so that it could not be retracted. Unable to dive she was exposed to enemy surface ships, and matters were made worse when the heavy seas started to pour down the buckled funnel. Luckily, she managed to make port, but Fisher told his director of naval construction to concentrate on designing a diesel submarine which had the required surface speed. However, when 19 knots was the fastest the latest design could be expected to achieve, Fisher gave in and in 1916, after Fisher had resigned as First Sea Lord, two prototype steam-driven submarines were launched. Neither was a success, but it was from these two boats that the K-class was produced. The class needed to be very large in order to accommodate boiler, fuel tanks, and turbine for surface propulsion, coupled with electric batteries and motors for submerged propulsion. They were, therefore, 103 metres (338 ft) in length overall with a submerged displacement of 2,500 tons. They had two collapsible funnels to carry away the boiler fumes, and these were shut down, and the boiler room completely sealed off, when the submarine dived. Their surface speed was 24 knots, their submerged speed 10 knots, and they were fitted with ten torpedo tubes.

Eighteen K-class submarines were completed during the First World War (1914–18), and they had a disastrous history. Their main failure was their initial high diving speed, but they were also difficult to steer on the surface and were liable to mechanical failures. Out of the eighteen, K1, K4, K17, and K18 sank in separate collisions, K5 disappeared during exercises, K13 sank on her acceptance trials, and K15 sank in Portsmouth harbour. Between November 1919 and May 1923 three more were commissioned (K19, K20, and K26). These, with K18, were renamed the M-class (Monitor Class). Their record was equally disastrous: M1 (K18) sank after a collision and M2 (K19) sank on exercises, and the other two were scrapped. Yet in their use of steam propulsion, the K-class were, in a way, the forerunners of today's nuclear-powered submarines.

Bibliography

Everett, D. , The K Boats (1963).