German submarine U-21 (1936)

U-9, a typical Type IIB boat
History
Nazi Germany
Name	U-21
Ordered	2 February 1935
Builder	Germaniawerft, Kiel
Yard number	551
Laid down	4 March 1936
Launched	31 July 1936
Commissioned	3 August 1936
Fate	Decommissioned on 5 August 1944 at Pillau and cannibalized for spare parts
General characteristics
Class and type	Type IIB coastal submarine
Displacement	279 t (275 long tons) surfaced 328 t (323 long tons) submerged
Length	42.70 m (140 ft 1 in) o/a 27.80 m (91 ft 2 in) pressure hull
Beam	4.08 m (13 ft 5 in) (o/a) 4.00 m (13 ft 1 in) (pressure hull)
Height	8.60 m (28 ft 3 in)
Draught	3.90 m (12 ft 10 in)
Installed power	700 PS (510 kW; 690 bhp) (diesels) 410 PS (300 kW; 400 shp) (electric)
Propulsion	2 shafts 2 × diesel engines 2 × electric motors
Speed	13 knots (24 km/h; 15 mph) surfaced 7 knots (13 km/h; 8.1 mph) submerged
Range	1,800 nmi (3,300 km; 2,100 mi) at 12 knots (22 km/h; 14 mph) surfaced 35–43 nmi (65–80 km; 40–49 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	80 m (260 ft)
Complement	3 officers, 22 men
Armament	3 × 53.3 cm (21 in) torpedo tubes 5 × torpedoes or up to 12 TMA or 18 TMB mines 1 × 2 cm (0.79 in) anti-aircraft gun
Service record
Part of:	1st U-boat Flotilla 1 August 1936 – 1 August 1939 1 September 1939 – 30 June 1940 21st U-boat Flotilla 1 July 1940 – 5 August 1944
Identification codes:	M 08 360
Commanders:	Kptlt. Kurt Freiwald 18 July 1935 – 3 October 1937 Kptlt. Werner Lott September 1936 – 31 March 1937 Kptlt. Wilhelm Ambrosius 1937 Kapt.z.S. Erwin Sachs 1937 Oblt.z.S. / Kptlt. Fritz Frauenheim 1 October 1937 – 6 January 1940 Kptlt. Wolf-Harro Stiebler 6 January – 28 July 1940 Oblt.z.S. Hans Heidtmann 1 August – 20 December 1940 Kptlt. Ernst-Bernard Lohse 21 December 1940 – 18 May 1941 Oblt.z.S. Karl-Heinz Herschleb 19 May 1941 – 3 January 1942 Oblt.z.S. Hans-Heinrich Döhler 4 January – 24 September 1942 Lt.z.S. / Oblt.z.S. Hans-Ferdinand Geisler 25 September 1942 – 28 January 1943 Oblt.z.S.d.R Rudolf Kugelberg 29 January 1943 – 11 May 1944 Oblt.z.S. Wolfgang Schwarzkopf 12 May – 5 August 1944
Operations:	7 patrols: 1st patrol: 25 August – 5 September 1939 2nd patrol: a. 9 September – 1 October 1939 b. 2 – 3 Oct 1939 3rd patrol: 22 October – 8 November 1939 4th patrol: 27 November – 5 December 1939 5th patrol: 17 – 24 December 1939 6th patrol: 27 January – 9 February 1940 7th patrol: a. 21 – 27 March 1940 b. 16 – 20 April 1940
Victories:	5 merchant ships sunk (10,706 GRT) 1 warship damaged (11,500 tons)

German submarine U-21 was a Type IIB U-boat of Nazi Germany's Kriegsmarine. Her keel was laid down 4 March 1936, by Germaniawerft of Kiel as yard number 551. She was commissioned on 3 August 1936. During World War II, she conducted operations against enemy shipping.

U-21 went on seven war patrols, sinking five merchant ships and damaging one warship.