HMS Sealion (72S)

HMS Sealion was a second-batch S-class submarine built during the 1930s for the Royal Navy. Completed in 1934, the boat fought in the Second World War.

Design and description
The second batch of S-class submarines were designed as slightly improved and enlarged versions of the earlier boats of the class and were intended to operate in the North and Baltic Seas. The submarines had a length of 208 ft overall, a beam of 24 ft and a mean draught of 11 ft. They displaced 768 LT on the surface and 960 LT submerged. The S-class submarines had a crew of 40 officers and ratings. They had a diving depth of 300 ft.

For surface running, the boats were powered by two 775 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 650 hp electric motor. They could reach 13.75 kn on the surface and 10 kn underwater. On the surface, the second-batch boats had a range of 6000 nmi at 10 kn and 64 nmi at 2 kn submerged.

The S-class boats were armed with six 21 in torpedo tubes in the bow. They carried six reload torpedoes for a total of a dozen torpedoes. They were also armed with a 3-inch (76 mm) deck gun.

Construction and career
Ordered on 23 December 1932, Sealion was laid down on 16 May 1933 in Cammell Laird's shipyard in Birkenhead and was launched on 16 March 1934. The boat was completed on 21 December. She had an eventful career after the outbreak of war. Under the command of Lieutenant Commander (later Rear Admiral) Benjamin Bryant, she attacked the GS U-21 (1936) off the Dogger Bank in November 1939, but failed to sink her. Her first success was the German merchant SS August Leonhardt (1922), sunk in April 1940 off the Danish island of Anholt. She later attacked the German merchant Moltkefels, but failed to hit her. She fired upon the beached Palime, and unsuccessfully attacked GS U-62 (1939) in July 1940. She finished her patrol by sinking the Norwegian merchant Toran and attacking but failing to sink the German merchant Cläre Hugo Stinnes in August.

On 5 February 1941 she shelled and sank the Norwegian Hurtigruten cargo-passenger ship SS Ryfylke (1916). In May of that year Sealion unsuccessfully attacked GS U-74 (1940). In July she attacked French shipping, sinking the French fishing vessels Gustav Eugene and Gustav Jeanne, and on succeeding days, Christus Regnat and St Pierre d'Alcantara.

She was one of a number of submarines ordered to track the GERMAN BATTLESHIP Bismarck before her eventual sinking.

Towards the end of 1941 she sank the Norwegian tanker Vesco and the Norwegian merchant SS Island (1918).

She was scuttled as an ASDIC target off the Isle of Arran, Firth of Clyde, on 13 March 1946.