The C class was essentially a repeat of the preceding B class, albeit with better performance underwater. The submarine had a length of 142feet overall, a beam of 13feet and a mean draft of 11feet. They displaced 287LT on the surface and 316LT 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 6000NaN0 Vickers petrol engine that drove one propeller shaft. When submerged the propeller was driven by a 300hp electric motor.[1] They could reach 12kn on the surface and underwater. On the surface, the C class had a range of 910nmi at .[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]
C3 was built by Vickers at their Barrow-in-Furness shipyard, laid down on 13 November 1905 and was commissioned on 23 February 1906. The obsolete C3 was packed full of explosives for her last mission, which was to destroy a viaduct connecting the mole to the shore during the Zeebrugge Raid on 23 April 1918. Her commanding officer, Richard Douglas Sandford, received the Victoria Cross for the successful action.