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.
Like all post-H20British H-class submarines, H21 had a displacement of 423 long tons (430 t) at the surface and 510 long tons (520 t) while submerged.[1] It had a total length of 171 feet (52 m),[2] a beam of 15 feet 4 inches (4.67 m), and a draught of 12 metres (39 ft).[3] It contained a diesel engines providing a total power of 480 horsepower (360 kW) and two electric motors each providing 320 horsepower (240 kW) power.[3] The use of its electric motors made the submarine travel at 11 knots (20 km/h; 13 mph). It would normally carry 16.4 long tons (16.7 t) of fuel and had a maximum capacity of 18 long tons (18 t).[4]
The submarine had a maximum surface speed of 13 knots (24 km/h; 15 mph) and a submerged speed of 10.5 knots (19.4 km/h; 12.1 mph). Post-H20 British H-class submarines had ranges of 2,985 nautical miles (5,528 km; 3,435 mi) at speeds of 7.5 knots (13.9 km/h; 8.6 mph) when surfaced.[1][3]H21 was fitted with an anti-aircraft gun and four 21 inches (530 mm) torpedo tubes. Its torpedo tubes were fitted to the bows and the submarine was loaded with eight 21 inches (530 mm) 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]
Referencesedit
^ abcdGardiner, Robert; Gray, Robert (1985). Conway's All the World's Fighting Ships 1906-1921. London: Conway Maritime Press. p. 92. ISBN0-85177-245-5.
^Derek Walters (2004). The History of the British 'U' Class Submarine. Casemate Publishers. pp. 2–. ISBN978-1-84415-131-8.
^J. D. Perkins (1999). "Building History and Technical Details for Canadian CC-Boats and the Original H-CLASS". Electric Boat Company Holland Patent Submarines. Retrieved 20 August 2015.
Bibliographyedit
Hutchinson, Robert (2001). Jane's submarines : war beneath the waves from 1776 to the present day. London: HarperCollins. ISBN9780007105588.
April 11, 2024
british, class, submarine, built, vickers, limited, barrow, furness, first, batch, class, submarines, launched, october, 1917, commissioned, january, 1918, improved, design, class, which, produced, larger, displacement, latest, inch, torpedo, tubes, replacing,. 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 HMS H4 another submarine of the same classHistoryUnited KingdomNameH21BuilderVickers Limited Barrow in FurnessLaunched20 October 1917Commissioned28 January 1918FateSold 13 July 1926General characteristicsClass and typeH class submarineDisplacement423 long tons 430 t surfaced 510 long tons 518 t submergedLength171 ft 0 in 52 12 m Beam15 ft 4 in 4 67 m Propulsion1 480 hp 358 kW diesel engine 2 620 hp 462 kW electric motorsSpeed11 5 knots 21 3 km h 13 2 mph surfaced 9 knots 17 km h 10 mph submergedRange2 985 nmi 5 528 km at 7 5 kn 13 9 km h 8 6 mph surfaced 130 nmi 240 km at 2 kn 3 7 km h 2 3 mph submergedComplement22Armament4 21 in 533 mm bow torpedo tubes 8 21 inch torpedoesDesign editLike all post H20 British H class submarines H21 had a displacement of 423 long tons 430 t at the surface and 510 long tons 520 t while submerged 1 It had a total length of 171 feet 52 m 2 a beam of 15 feet 4 inches 4 67 m and a draught of 12 metres 39 ft 3 It contained a diesel engines providing a total power of 480 horsepower 360 kW and two electric motors each providing 320 horsepower 240 kW power 3 The use of its electric motors made the submarine travel at 11 knots 20 km h 13 mph It would normally carry 16 4 long tons 16 7 t of fuel and had a maximum capacity of 18 long tons 18 t 4 The submarine had a maximum surface speed of 13 knots 24 km h 15 mph and a submerged speed of 10 5 knots 19 4 km h 12 1 mph Post H20 British H class submarines had ranges of 2 985 nautical miles 5 528 km 3 435 mi at speeds of 7 5 knots 13 9 km h 8 6 mph when surfaced 1 3 H21 was fitted with an anti aircraft gun and four 21 inches 530 mm torpedo tubes Its torpedo tubes were fitted to the bows and the submarine was loaded with eight 21 inches 530 mm 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 References edit a b c d Gardiner Robert Gray Robert 1985 Conway s All the World s Fighting Ships 1906 1921 London Conway Maritime Press p 92 ISBN 0 85177 245 5 Derek Walters 2004 The History of the British U Class Submarine Casemate Publishers pp 2 ISBN 978 1 84415 131 8 a b c Colledge J J Warlow Ben 2006 1969 Ships of the Royal Navy The Complete Record of all Fighting Ships of the Royal Navy Rev ed London Chatham Publishing ISBN 978 1 86176 281 8 Retrieved from Naval History on 20 August 2015 J D Perkins 1999 Building History and Technical Details for Canadian CC Boats and the Original H CLASS Electric Boat Company Holland Patent Submarines Retrieved 20 August 2015 Bibliography editHutchinson Robert 2001 Jane s submarines war beneath the waves from 1776 to the present day London HarperCollins ISBN 9780007105588 Retrieved from https en wikipedia org w index php title HMS H21 amp oldid 1147437611, wikipedia, wiki, book, books, library,
