HMS Spur was a S-class submarine of the third batch built for the Royal Navy during World War II. She survived the war and was sold to Portugal in 1948.
The last 17 boats of the third batch were significantly modified from the earlier boats. They had a stronger hull, carried more fuel and their armament was revised. The submarines had a length of 217feet overall, a beam of 23feet and a draft of 14feet. They displaced 814LT on the surface and 990LT submerged.[1] The S-class submarines had a crew of 48 officers and ratings. They had a diving depth of 350feet.[2]
For surface running, the boats were powered by two 9500NaN0 diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 650hp electric motor.[3] They could reach 14.75kn on the surface and underwater.[1] On the surface, the third batch boats had a range of 7500nmi at and 120nmi at submerged.[2]
Spur was armed with six 21 inch (533 mm) torpedo tubes in the bow. She carried six reload torpedoes for a grand total of a dozen torpedoes. Twelve mines could be carried in lieu of the torpedoes. The boat was also equipped with a 4-inch (102 mm) deck gun.[1]
HMS Spur was built by Cammell Laird and launched on 17 November 1944. So far she has been the only ship of the Royal Navy to bear the name Spur. During her wartime career, Spur claimed to have sunk a total of eleven junks in the Strait of Malacca, during her service in the Far East.[4] The boat survived the Second World War and was sold to the Portuguese navy in November 1948, where she was renamed NRP Narval. She was broken up on 1 October 1969.