HMS R9
HMS R9 was one of 10 R-class submarine built for the Royal Navy during the First World War. The boat was not completed before the end of the war and was sold for scrap in 1923. Design and description
The R-class submarine was designed to meet an Admiralty requirement for a specialised hunter-killer submarine with an emphasis on submerged performance. The boats had a length of  overall, a beam of  and a mean draft of . They displaced  on the surface and  submerged. The R-class submarines had a crew of 2 officers and 20 ratings. They had a diving depth of . For surface running, the boats were powered by a single eight-cylinder   diesel engine that drove the single propeller shaft. When submerged it was driven by a  electric motor. They could reach  on the surface and  underwater. On the surface, the R class had a range of  at  and  at  submerged. The boats were armed with six 18-inch (45 cm) torpedo tubes in the bow. They carried six reload torpedoes for a grand total of a dozen torpedoes. They were equipped with an array of five hydrophones in the bow to allow them to locate and engage targets while submerged. Construction and career
HMS R9 was laid down on 1 December 1917 by Armstrong Whitworth, launched on 12 August 1918 and commissioned on 26 July 1919. She came too late to see any combat in World War I, like most of the other R class submarines. She was sold on 21 February 1923 to E. Suren. Notes

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British R-class submarines
Royal Navy ship names
1918 ships
Ships built by Armstrong Whitworth