The O 21 class was a class of seven submarines, built for the Royal Netherlands Navy. The boats were still incomplete at the start of the German invasion of the Netherlands O 21, O 22, O 23 and O 24 were hastily launched and escaped to the United Kingdom. O 25, O 26 and O 27 were not able to escape and were captured by the German forces. The Kriegsmarine ordered the completion of the boats and they entered German service as UD-3, UD-4 and UD-5. The submarines diving depth was 100 meters (330 ft).
One of the requirements the Royal Netherlands Navy set for the O 21-class was that it had to be able to dive 20 m (66 ft) deeper than the previous class, which was the O 19-class submarine.[1]
Construction
The ships were built by three different shipyards. O 21 and O 22 were built by the Koninklijke Maatschappij. O 23, O 24, O 26 and O 27 by R.D.M, Rotterdam and O 25 also in Rotterdam at Fijenoord shipyard.
Jalhay, P.C.; Wijn, J.J.A. (1997). Ik nader ongezien! De onderzeeboten van de Koninklijke Marine. Amsterdam: De Bataafsche Leeuw. ISBN9067074624.
Gerretse, K.H.L.; Wijn, J.J.A. (1993). Drie-cylinders duiken dieper: de onderzeeboten van de dolfijn-klasse van de Koninklijke Marine. Amsterdam: Van Soeren. ISBN9068810278.
External links
Description of class
March 07, 2023
class, submarine, class, class, seven, submarines, built, royal, netherlands, navy, boats, were, still, incomplete, start, german, invasion, netherlands, were, hastily, launched, escaped, united, kingdom, were, able, escape, were, captured, german, forces, kri. The O 21 class was a class of seven submarines built for the Royal Netherlands Navy The boats were still incomplete at the start of the German invasion of the Netherlands O 21 O 22 O 23 and O 24 were hastily launched and escaped to the United Kingdom O 25 O 26 and O 27 were not able to escape and were captured by the German forces The Kriegsmarine ordered the completion of the boats and they entered German service as UD 3 UD 4 and UD 5 The submarines diving depth was 100 meters 330 ft HNLMS O 21Class overviewNameO 21 classBuildersRotterdamsche Droogdok Maatschappij 4 Koninklijke Maatschappij De Schelde 2 Wilton Fijenoord 1 Operators Royal Netherlands Navy KriegsmarinePreceded byO 19 classSucceeded byDolfijn classBuilt1937 1940Completed7Lost2Scrapped5General characteristicsTypeSubmarineDisplacement990 tons surfaced 1205 tons submergedLength77 7 m 255 ft Beam6 8 m 22 ft Draught3 95 m 13 ft Propulsion2 Sulzer 7QD42 7 cylinder diesel engines 2 500 bhp 1 864 kW each 2 500 bhp 373 kW electric motorsSpeed19 5 kn 36 1 km h 22 4 mph surfaced 9 kn 17 km h 10 mph submergedRange10 000 nmi 19 000 km 12 000 mi at 12 kn 22 km h 14 mph surfaced 28 nmi 52 km 32 mi at 8 5 kn 15 7 km h 9 8 mph submergedComplement39Armament8 21 in 530 mm torpedo tubes 4 bow 2 stern 2 traversing amidships Contents 1 Design 2 Construction 3 References 3 1 Bibliography 4 External linksDesign EditOne of the requirements the Royal Netherlands Navy set for the O 21 class was that it had to be able to dive 20 m 66 ft deeper than the previous class which was the O 19 class submarine 1 Construction EditThe ships were built by three different shipyards O 21 and O 22 were built by the Koninklijke Maatschappij O 23 O 24 O 26 and O 27 by R D M Rotterdam and O 25 also in Rotterdam at Fijenoord shipyard Name Laid down Launched Commissioned DecommissionedO 21 20 November 1937 21 October 1939 10 May 1940 uncompleted 2 November 1957O 22 20 November 1937 20 January 1940 10 May 1940 uncompleted 8 November 1940O 23 12 October 1937 5 December 1939 13 May 1940 uncompleted 1 December 1948O 24 12 November 1937 18 March 1940 13 May 1940 uncompleted 22 February 1954O 25Commissioned as UD 3 10 April 1939 1 May 1940 8 June 1941 13 October 1944 3 May 1945 scuttled O 26Commissioned as UD 4 20 April 1939 23 November 1940 28 January 1941 3 May 1945 scuttled O 27Commissioned as UD 5 3 August 1939 26 September 1941 30 January 1942 13 July 1945 Dutch navy 14 November 1959References Edit Gerretse and Wijn p 9 Bibliography Edit Jalhay P C Wijn J J A 1997 Ik nader ongezien De onderzeeboten van de Koninklijke Marine Amsterdam De Bataafsche Leeuw ISBN 9067074624 Gerretse K H L Wijn J J A 1993 Drie cylinders duiken dieper de onderzeeboten van de dolfijn klasse van de Koninklijke Marine Amsterdam Van Soeren ISBN 9068810278 External links EditDescription of class Retrieved from https en wikipedia org w index php title O 21 class submarine amp oldid 1091712785, wikipedia, wiki, book, books, library,
