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 423 LT at the surface and 510 LT while submerged. It had a total length of 171 ft, a beam of 15 ft, and a draught of 12 m. It contained a diesel engines providing a total power of 480 hp and two electric motors each providing 320 hp power. The use of its electric motors made the submarine travel at 11 kn. It would normally carry 16.4 LT of fuel and had a maximum capacity of 18 LT. The submarine had a maximum surface speed of 13 kn and a submerged speed of 10.5 kn. Post-H20 British H-class submarines had ranges of 2985 nmi at speeds of 7.5 kn when surfaced. H47 was fitted with an anti-aircraft gun and four 21 in torpedo tubes. Its torpedo tubes were fitted to the bows and the submarine was loaded with eight 21 in torpedoes. It is a Holland 602 type submarine but was designed to meet Royal Navy specifications. Its complement was twenty-two crew members.