HMS H51 was sold for scrapping on 6 June 1924 and was then resold on 17 July 1924 to the ship breakers.
Like all post-H20 British H-class submarines, H51 had a displacement of 423LT at the surface and 510LT while submerged.[2] It had a total length of 171feet,[3] a beam of 15feet, and a draught of . It contained a diesel engines providing a total power of and two electric motors each providing power.[4] The use of its electric motors made the submarine travel at 11kn. It would normally carry 16.4LT of fuel and had a maximum capacity of 18LT.[5]
The submarine had a maximum surface speed of 13kn and a submerged speed of 10.5kn. Post-H20 British H-class submarines had ranges of 2985nmi at speeds of 7.5kn when surfaced.[2] [4] H51 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.[2] It is a Holland 602 type submarine but was designed to meet Royal Navy specifications. Its complement was twenty-two crew members.[2]