| History | |
|---|---|
 United Kingdom | |
| Name | HMS C21 |
| Builder | Vickers, Barrow |
| Laid down | 4 February 1908 |
| Launched | 26 September 1908 |
| Commissioned | 18 May 1909 |
| Fate | Sold, 5 December 1921 |
| General characteristics | |
| Class and type | C-class submarine |
| Displacement |
|
| Length | 142 ft 3 in (43.4 m) |
| Beam | 13 ft 7 in (4.1 m) |
| Draught | 11 ft 6 in (3.5 m) |
| Installed power | |
| Propulsion |
|
| Speed |
|
| Range | 910 nmi (1,690 km; 1,050 mi) at 12 kn (22 km/h; 14 mph) on the surface |
| Test depth | 100 feet (30.5 m) |
| Complement | 2 officers and 14 ratings |
| Armament | 2 × 18 in (450 mm) bow torpedo tubes |
HMS C21 was one of 38 C-class submarines built for the Royal Navy in the first decade of the 20th century. The boat survived the First World War and was sold for scrap in 1921.
Design and description
The C-class boats of the 1907–08 and subsequent Naval Programmes were modified to improve their speed, both above and below the surface. The submarine had a length of 142 feet 3 inches (43.4 m) overall, a beam of 13 feet 7 inches (4.1 m) and a mean draft of 11 feet 6 inches (3.5 m). They displaced 290 long tons (290 t) on the surface and 320 long tons (330 t) submerged. The C-class submarines had a crew of two officers and fourteen ratings.[1]
For surface running, the boats were powered by a single 12-cylinder[2] 600-brake-horsepower (447 kW) Vickers petrol engine that drove one propeller shaft. When submerged the propeller was driven by a 300-horsepower (224 kW) electric motor.[1] They could reach 13 knots (24 km/h; 15 mph) on the surface and 8 knots (15 km/h; 9.2 mph) underwater. On the surface, the C class had a range of 910 nautical miles (1,690 km; 1,050 mi) at 12 knots (22 km/h; 14 mph).[3]
The boats were armed with two 18-inch (45 cm) torpedo tubes in the bow. They could carry a pair of reload torpedoes, but generally did not as they would have to remove an equal weight of fuel in compensation.[4]
Construction and career
C21 was laid down on 4 February 1908 by Vickers at their Barrow-in-Furness shipyard, launched on 26 September and was completed on 18 May 1909. During World War I, the boat was generally used for coastal defence and training in home waters. C21 was sold for scrap on 5 December 1921.
Notes
References
- Akermann, Paul (2002). Encyclopaedia of British Submarines 1901–1955 (reprint of the 1989 ed.). Penzance, Cornwall: Periscope Publishing. ISBN 1-904381-05-7.
- Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8.
- Gardiner, Robert & Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN 0-85177-245-5.
- Harrison, A. N. (January 1979). "The Development of HM Submarines From Holland No. 1 (1901) to Porpoise (1930) (BR3043)". RN Subs. Retrieved 27 September 2022.