HMS C18

HMS C18 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 was essentially a repeat of the preceding B class, albeit with better performance underwater. The submarine had a length of 142 ft overall, a beam of 13 ft and a mean draft of 11 ft. They displaced 287 LT on the surface and 316 LT submerged. The C-class submarines had a crew of two officers and fourteen ratings.

For surface running, the boats were powered by a single 16-cylinder 600 bhp Vickers petrol engine that drove one propeller shaft. When submerged the propeller was driven by a 300 hp electric motor. They could reach 12 kn on the surface and 7 kn underwater. On the surface, the C class had a range of 910 nmi at 12 kn.

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.

Construction and career
C18 was laid down on 11 March 1907 at the Royal Dockyard, Chatham, launched on 10 October 1908, and completed on 23 July 1909. During World War I, the boat was generally used for coastal defence and training in home waters. HMS C18 was sold for scrap on 26 May 1921 in Sunderland.