U-9, a typical Type IIB boat
History
Nazi Germany
NameU-23
Ordered2 February 1935
Builder
Yard number553
Laid down11 April 1936
Launched28 August 1936
Commissioned24 September 1936
FateScuttled 11 September 1944, off the coast of Turkey in the Black Sea
General characteristics
Class and typeType IIB coastal submarine
Displacement
  • 279 t (275 long tons) surfaced
  • 328 t (323 long tons) submerged
Length
Beam
  • 4.08 m (13 ft 5 in) (o/a)
  • 4.00 m (13 ft 1 in) (pressure hull)
Height8.60 m (28 ft 3 in)
Draught3.90 m (12 ft 10 in)
Installed power
  • 700 PS (510 kW; 690 bhp) (diesels)
  • 410 PS (300 kW; 400 shp) (electric)
Propulsion
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 depth80 m (260 ft)
Complement3 officers, 22 men
Armament
Service record
Part of:
Identification codes: M 01 984
Commanders:
  • Kptlt. / K.Kapt. Eberhard Godt
  • 1 September 1936 – 3 January 1938
  • Kptlt. Hans-Günther Looff
  • 1936 / 37 – 30 September 1937
  • Oblt.z.S. / Kptlt. Otto Kretschmer
  • 1 October 1937 – 1 April 1940
  • Kptlt. Heinz Beduhn
  • 8 April – 19 May 1940
  • Oblt.z.S. Heinrich Driver
  • 20 May – 30 September 1940
  • Oblt.z.S. Kurt Reichenbach-Klinke
  • 1 October 1940 – 20 March 1941
  • Oblt.z.S. Ernst-Ulrich Brüller
  • 21 March – 23 September 1941
  • Oblt.z.S. Ulrich Gräf
  • 24 September 1941 – 26 March 1942
  • Oblt.z.S. / Kptlt. Rolf-Birger Wahlen
  • 27 March – 26 August 1942
  • 3 June 1943 – 19 June 1944
  • Oblt.z.S. Rudolf Arendt
  • 20 June – 10 September 1944
Operations:
  • 16 patrols:
  • 1st patrol:
  • 25 August – 4 September 1939
  • 2nd patrol:
  • a. 9 – 21 September 1939
  • b. 29 – 30 September 1939
  • 3rd patrol:
  • 1 – 16 October 1939
  • 4th patrol:
  • 1 – 9 November 1939
  • 5th patrol:
  • 5 – 15 December 1939
  • 6th patrol:
  • 8 – 15 January 1940
  • 7th patrol:
  • 18 – 29 January 1940
  • 8th patrol:
  • a. 9 – 25 February 1940
  • b. 26 – 28 February 1940
  • c. 9 – 10 April 1940
  • 9th patrol:
  • 13 April – 3 May 1940
  • 10th patrol:
  • a. 27 June – 16 July 1943
  • b. 18 – 19 July 1943
  • 11th patrol:
  • 10 August – 9 September 1943
  • 12th patrol:
  • 10 October – 11 November 1943
  • 13th patrol:
  • 14 December 1943 – 7 January 1944
  • 14th patrol:
  • 30 March – 24 April 1944
  • 15th patrol:
  • 17 May – 7 June 1944
  • 16th patrol:
  • 16 August – 10 September 1944
Victories:
  • 7 merchant ships sunk
    (11,179 GRT)
  • 2 warships sunk
    (1,410 tons)
  • 3 merchant ships total loss
    (18,199 GRT)
  • 1 warship damaged
    (56 tons)
  • 1 auxiliary warship damaged
    (1,005 GRT)

German submarine U-23 was a Type IIB U-boat of Nazi Germany's Kriegsmarine, built in Germaniawerft, Kiel. She was laid down on 11 April 1936 and commissioned on 24 September.

Design

German Type IIB submarines were enlarged versions of the original Type IIs. U-23 had a displacement of 279 tonnes (275 long tons) when at the surface and 328 tonnes (323 long tons) while submerged. Officially, the standard tonnage was 250 long tons (250 t), however.[1] The U-boat had a total length of 42.70 m (140 ft 1 in), a pressure hull length of 28.20 m (92 ft 6 in), a beam of 4.08 m (13 ft 5 in), a height of 8.60 m (28 ft 3 in), and a draught of 3.90 m (12 ft 10 in). The submarine was powered by two MWM RS 127 S four-stroke, six-cylinder diesel engines of 700 metric horsepower (510 kW; 690 shp) for cruising, two Siemens-Schuckert PG VV 322/36 double-acting electric motors producing a total of 460 metric horsepower (340 kW; 450 shp) for use while submerged. She had two shafts and two 0.85 m (3 ft) propellers. The boat was capable of operating at depths of up to 80–150 metres (260–490 ft).[1]

The submarine had a maximum surface speed of 12 knots (22 km/h; 14 mph) and a maximum submerged speed of 7 knots (13 km/h; 8.1 mph).[1] When submerged, the boat could operate for 35–42 nautical miles (65–78 km; 40–48 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 3,800 nautical miles (7,000 km; 4,400 mi) at 8 knots (15 km/h; 9.2 mph). U-23 was fitted with three 53.3 cm (21 in) torpedo tubes at the bow, five torpedoes or up to twelve Type A torpedo mines, and a 2 cm (0.79 in) anti-aircraft gun. The boat had a complement of twentyfive.[1]

Service history

At 04:45 on 4 October 1939, U-23 scored one of the Kriegsmarine's early successes of the war when she torpedoed and sank with gunfire, the merchant ship Glen Farg about 60 nmi (110 km; 69 mi) south-southwest of Sumburgh Head (southern Shetland). One person died, while 16 survivors were picked up by HMS Firedrake and landed at Kirkwall the next day.

In 16 patrols U-23 sank seven ships for a total of 11,179 gross register tons (GRT) including two warships, as well as damaging a warship and an auxiliary warship.

Over the course of her service with the Kriegsmarine, U-23 had ten commanding officers, the most famous of whom was Kapitänleutnant Otto Kretschmer, who went on to become the top scoring U-boat ace. After service in the Atlantic with the 1st U-boat Flotilla, U-23 served as a training boat with the 21st U-boat Flotilla from July 1940 until September 1942. U-23 was then transported in sections along the Danube to the Romanian port of Galați. She was then re-assembled by the Romanians at the Galați shipyard and sent to the Black Sea port of Constanţa, Romania, with the 30th U-boat Flotilla until September 1944.[2]

Fate

U-23 was scuttled by her crew on 10 September 1944, off the coast of Turkey in the Black Sea at position 41°11′N 30°00′E / 41.183°N 30.000°E / 41.183; 30.000 to prevent her capture by the advancing Soviets.

On 3 February 2008, The Daily Telegraph newspaper reported that U-23 had been discovered by Selçuk Kolay, a Turkish marine engineer, in 160 ft (49 m) of water, three miles from the town of Ağva.[3][4]

Summary of raiding history

Date Name Nationality Tonnage[Note 1] Fate[5]
4 October 1939 Glen Farg  United Kingdom 876 Sunk
8 December 1939 Scotia  Denmark 2,400 Sunk
11 January 1940 Fredville  Norway 1,150 Sunk
12 January 1940 Danmark  Denmark 10,517 Total loss
23 January 1940 Varild  Norway 1,085 Sunk
18 February 1940 HMS Daring  Royal Navy 1,375 Sunk
19 February 1940 Tiberton  United Kingdom 5,225 Sunk
22 February 1940 Loch Maddy  United Kingdom 4,996 Total loss
24 August 1943 Shkval  Soviet Navy 35 Sunk
15 October 1943 TSC-486 Sovetskja Rossiya  Soviet Navy 1,005 Damaged
23 October 1943 Tanais  Soviet Union 372 Sunk
5 April 1944 SKA-099  Soviet Navy 56 Damaged
29 May 1944 Smelyj  Soviet Union 71 Sunk
1 September 1944 Oituz  Romania 2,686 Sunk

References

Notes

  1. ↑ Merchant ship tonnages are in gross register tons. Military vessels are listed by tons displacement.

Citations

  1. 1 2 3 4 Gröner 1991, pp. 39–40.
  2. ↑ Steel and Ice: The U-boat Battle in the Arctic and Black Sea 1941-45, Chapter 5 - The Black Sea: War in the South 1942-43, page 5
  3. ↑ Jasper Copping (3 February 2008). "Adolf Hitler's 'lost fleet' found in Black Sea". The Daily Telegraph. Retrieved 15 July 2010.
  4. ↑ Andy McSmith (11 February 2008). "Hitler's 'lost fleet' of U-boats found in Black Sea". The Independent. London. Retrieved 15 July 2010.
  5. ↑ Helgason, Guðmundur. "Ships hit by U-23". German U-boats of WWII - uboat.net. Retrieved 29 December 2014.

Bibliography

  • Busch, Rainer; Röll, Hans-Joachim (1999). German U-boat commanders of World War II : a biographical dictionary. Translated by Brooks, Geoffrey. London, Annapolis, Md: Greenhill Books, Naval Institute Press. ISBN 1-55750-186-6.
  • Busch, Rainer; Röll, Hans-Joachim (1999). Deutsche U-Boot-Verluste von September 1939 bis Mai 1945 [German U-boat losses from September 1939 to May 1945]. Der U-Boot-Krieg (in German). Vol. IV. Hamburg, Berlin, Bonn: Mittler. ISBN 3-8132-0514-2.
  • Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.
  • Helgason, Guðmundur. "The Type IIB boat U-23". German U-boats of WWII - uboat.net. Retrieved 6 December 2014.
  • Hofmann, Markus. "U 23". Deutsche U-Boote 1935-1945 - u-boot-archiv.de (in German). Retrieved 6 December 2014.
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