HMS H47 was a British H class submarine built by William Beardmore and Company, Dalmuir. She was laid down on 20 November 1917 and was commissioned on 25 February 1919. It had a complement of twenty-two crew members. HMS H47 was sunk in a collision with British L class submarine L12 off Milford Haven, Wales on 9 July 1929. Twenty one of the crew were lost with only three survivors.
Design
Like all post-H20 British H-class submarines, H47 had a displacement of at the surface and while submerged. It had a total length of , a beam of , and a draught of . It contained a diesel engines providing a total power of and two electric motors each providing power. The use of its electric motors made the submarine travel at . It would normally carry of fuel and had a maximum capacity of .
The submarine had a maximum surface speed of and a submerged speed of . Post-H20 British H-class submarines had ranges of at speeds of when surfaced. H47 was fitted with an anti-aircraft gun and four torpedo tubes. Its torpedo tubes were fitted to the bows and the submarine was loaded with eight torpedoes. It is a Holland 602 type submarine but was designed to meet Royal Navy specifications. Its complement was twenty-two crew members.