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.[1] The submarines had a length of 208feet overall, a beam of 24feet and a mean draught of 11feet. They displaced 768LT on the surface and 960LT submerged.[2] The S-class submarines had a crew of 40 officers and ratings. They had a diving depth of 300feet.[3]
For surface running, the boats were powered by two 7750NaN0 diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 650hp electric motor. They could reach 13.75kn on the surface and underwater.[4] On the surface, the second-batch boats had a range of 6000nmi at and 64nmi at submerged.[3]
The S-class boats were armed with six 21 inch (533 mm) 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.[2]
Ordered on 18 February 1935, Spearfish was laid down on 23 May 1935 in Cammell Laird's shipyard in Birkenhead and was launched on 21 April 1936. The boat was completed on 11 December 1936.[5]
Her wartime career started inauspiciously, when on 24 September 1939, she was heavily damaged by German warships off Horns Reef. She managed to escape despite being unable to submerge. A rescue mission was undertaken by the British Humber force and Home Fleet, including the aircraft carrier, and the battleship, which performed escort duty whilst search and rescue attempts were made. The fleet was attacked by Junkers Ju 88 bombers of the Luftwaffe's Kampfgeschwader 30, and a bomb caused slight damage to the battlecruiser . Spearfish safely put in Rosyth on 26 September, and repairs were completed in early March 1940.
Another notable action occurred on 11 April 1940, whilst patrolling in the Kattegat, under the command of Lieutenant Commander John Hay Forbes, she torpedoed and damaged the German heavy cruiser Lützow, putting her out of action for over a year.[6] [7] At the time it was reported that she sank her sister ship, .[8] Later that year, on 20 May, she sank two Danish fishing vessels S.130 and S.175 with gunfire in the North Sea.[6]
Spearfish sailed from Rosyth on 31 July 1940, still under the command of "Jock" Forbes, to patrol off the Norwegian coast. On 1 August she was spotted on the surface by the under the command of Wilhelm Rollmann who attacked and sank her, about 180miles west-southwest of Stavanger.[9] There was only one survivor, Able Seaman William Pester, who was taken about the U-34 as a prisoner of war.[10]