Design and description
The third batch was slightly enlarged and improved over the preceding second batch of the S-class. The submarines had a length of 217 feet (66.1 m) overall, a beam of 23 feet 9 inches (7.2 m) and a draft of 14 feet 8 inches (4.5 m). They displaced 842 long tons (856 t) on the surface and 990 long tons (1,010 t) submerged. The S-class submarines had a crew of 48 officers and ratings. They had a diving depth of 300 feet (91.4 m).
For surface running, the boats were powered by two 950- brake-horsepower (708 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 650-horsepower (485 kW) electric motor. They could reach 15 knots (28 km/h; 17 mph) on the surface and 10 knots (19 km/h; 12 mph) underwater. On the surface, the third batch boats had a range of 6,000 nautical miles (11,000 km; 6,900 mi) at 10 knots (19 km/h; 12 mph) and 120 nmi (220 km; 140 mi) at 3 knots (5.6 km/h; 3.5 mph) submerged.
The boats were armed with seven 21 inch (533 mm) torpedo tubes. A half-dozen of these were in the bow and there was one external tube in the stern. They carried six reload torpedoes for the bow tubes for a grand total of thirteen torpedoes. Twelve mines could be carried in lieu of the internally stowed torpedoes. They were also armed with a 3-inch (76 mm) deck gun.
Construction and career
HMS Shalimar was built at Chatham Dockyard and launched on 22 April 1943. Thus far she has been the only ship of the Royal Navy to bear the name Shalimar . She spent most of her wartime career in the Far East, where she caused significant losses amongst enemy shipping. She sank fourteen Japanese sailing vessels, the auxiliary minesweeper Choun Maru No.7 , two Japanese tugs and three barges, a coaster and an identified Japanese vessel. She also damaged five Japanese landing craft, and in conjunction with her sister HMS Sea Dog, she sank a Japanese coaster.  Shalimar survived the Second World War, and was sold in July 1950 to be broken up at Troon.
- Chesneau, p. 51
- McCartney, p. 7
- Bagnasco, p. 110
- Chesneau, pp. 51–52
- , Uboat.net