HMS B9

HMS B9 was one of 11 B-class submarines built for the Royal Navy in the first decade of the 20th century. Completed in 1906, she was initially assigned to the Home Fleet, before the boat was transferred to the Mediterranean six years later. After the First World War began in 1914, B9 played a minor role in the Dardanelles Campaign. The boat was transferred to the Adriatic Sea in 1916 to support Italian forces against the Austro-Hungarian Navy. She was converted into a patrol boat in 1917 and was sold for scrap in 1919. The B class was an enlarged and improved version of the preceding A class. The submarines had a length of overall, a beam of and a mean draft of . They displaced on the surface and submerged. The boats could dive to a depth of . The B-class submarines had a crew of two officers and thirteen ratings. For surface running, the boats were powered by a single 16-cylinder Vickers petrol engine that drove one propeller shaft. When submerged the propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, the B class had a range of at . The boats were armed with two 18-inch (450 mm) 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. Ordered as part of the 1904–1905 Naval Programme, B9 was built by Vickers at their Barrow-in-Furness shipyard. She was launched on 26 January 1906 and completed on 28 April at a cost of £47,000. The B-class submarines were initially assigned to the Third Division of the Home Fleet, based at Portsmouth and Devonport, and were tasked with coastal-defence duties and defending the Straits of Dover in wartime. In 1912, HMS B9, and were transferred to Malta. After the start of the First World War and the unsuccessful pursuit of the German ships Goeben and Breslau in August 1914, the B-class submarines were transferred to the Dardanelles area in mid-September to prevent any breakout attempt by the German ships.