HMS H21 explained
HMS H21 was a
British H class submarine built by
Vickers Limited, Barrow-in-Furness, as the first of the Batch 3 H class submarines. She was launched on 20 October 1917 and was commissioned on 28 January 1918.
H21 was an improved design of the H class which produced a larger displacement and the latest 21 inch torpedo tubes replacing the old 18 inch torpedo tubes. This would be incorporated into all batch 3 H class submarines. HMS
H21 was sold to
John Cashmore Ltd on 13 July 1926 for scrapping at
Newport.
Design
Like all post-H20 British H-class submarines, H21 had a displacement of 423LT at the surface and 510LT while submerged.[1] It had a total length of 171feet,[2] 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.[3] 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.[4]
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.[1] [3] H21 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.[1] It is a Holland 602 type submarine but was designed to meet Royal Navy specifications. Its complement was twenty-two crew members.[1]
Bibliography
- Book: Hutchinson . Robert . Jane's submarines : war beneath the waves from 1776 to the present day . 2001 . HarperCollins . London . 9780007105588.
Notes and References
- Book: Gardiner . Robert . Gray . Robert . Conway's All the World's Fighting Ships 1906-1921 . 1985 . Conway Maritime Press . London . 0-85177-245-5 . 92.
- Book: Derek Walters. The History of the British 'U' Class Submarine. 2004. Casemate Publishers. 978-1-84415-131-8. 2–.
- Retrieved from Naval-History on 20 August 2015.
- Web site: Building History and Technical Details for Canadian CC-Boats and the Original H-CLASS. Electric Boat Company Holland Patent Submarines. J. D. Perkins. 1999. 20 August 2015.
