The C class was essentially a repeat of the preceding B class, albeit with better performance underwater. 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 287 long tons (292 t) on the surface and 316 long tons (321 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 16-cylinder 600-brake-horsepower (447 kW) Vickerspetrol engine that drove one propeller shaft. When submerged the propeller was driven by a 300-horsepower (224 kW) electric motor.[1] They could reach 12 knots (22 km/h; 14 mph) on the surface and 7 knots (13 km/h; 8.1 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).[2]
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.[3]
Akermann, Paul (2002). Encyclopaedia of British Submarines 1901–1955 (reprint of the 1989 ed.). Penzance, Cornwall: Periscope Publishing. ISBN1-904381-05-7.
Gardiner, Robert & Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN0-85177-245-5.