SM UC-23 was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. The U-boat was ordered on 29 August 1915 and was launched on 29 February 1916. She was commissioned into the German Imperial Navy on 17 July 1916 as SM UC-23.[Note 1] In 17 patrols UC-23 was credited with sinking 46 ships, either by torpedo or by mines laid. UC-23 was surrendered at Sevastopol on 25 November 1918 and broken up at Bizerta in August 1921.[1]

History
German Empire
NameUC-23
Ordered29 August 1915[1]
BuilderBlohm & Voss, Hamburg[2]
Yard number273[1]
Launched29 February 1916[1]
Commissioned17 July 1916[1]
FateSurrendered, 25 November 1918; broken up, August 1921[1]
General characteristics [3]
Class and typeType UC II submarine
Displacement
  • 417 t (410 long tons), surfaced
  • 493 t (485 long tons), submerged
Length
Beam
  • 5.22 m (17 ft 2 in) o/a
  • 3.65 m (12 ft) pressure hull
Draught3.68 m (12 ft 1 in)
Propulsion
Speed
  • 11.6 knots (21.5 km/h; 13.3 mph), surfaced
  • 7.0 knots (13.0 km/h; 8.1 mph), submerged
Range
  • 9,430 nmi (17,460 km; 10,850 mi) at 7 knots (13 km/h; 8.1 mph) surfaced
  • 55 nmi (102 km; 63 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth50 m (160 ft)
Complement26
Armament
Notes35-second diving time
Service record
Part of:
  • Constantinople Flotilla
  • 6 December 1916 – 11 November 1918
Commanders:
  • Oblt.z.S. Johannes Kirchner[4]
  • 28 July 1916 - 6 July 1917
  • Kptlt. Freiherr Volkhard von Bothmer[5]
  • 5 July – 14 December 1917
  • Kptlt. Hans Georg Lübbe[6]
  • 15 December 1917 – 14 November 1918
Operations: 17 patrols
Victories:
  • 41 merchant ships sunk
    (37,752 GRT)
  • 5 auxiliary warships sunk
    (4,089 GRT)
  • 1 merchant ship damaged
    (35 GRT)
  • 2 merchant ships taken as prize
    (1,232 GRT)
  • 1 auxiliary warship taken as prize
    (327 GRT)

Design

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Like all pre-UC-25 Type UC II submarines, UC-23 had a displacement of 417 tonnes (410 long tons) when at the surface and 493 tonnes (485 long tons) while submerged. She had a length overall of 49.35 m (161 ft 11 in), a beam of 5.22 m (17 ft 2 in), and a draught of 3.65 m (12 ft). The submarine was powered by two six-cylinder four-stroke diesel engines each producing 250 metric horsepower (180 kW; 250 shp) (a total of 500 metric horsepower (370 kW; 490 shp)), two electric motors producing 460 metric horsepower (340 kW; 450 shp), and two propeller shafts. She had a dive time of 35 seconds and was capable of operating at a depth of 50 metres (160 ft).[3]

The submarine had a maximum surface speed of 11.6 knots (21.5 km/h; 13.3 mph) and a submerged speed of 7 knots (13 km/h; 8.1 mph). When submerged, she could operate for 55 nautical miles (102 km; 63 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 9,430 nautical miles (17,460 km; 10,850 mi) at 7 knots (13 km/h; 8.1 mph). UC-23 was fitted with six 100 centimetres (39 in) mine tubes, eighteen UC 200 mines, three 50 centimetres (20 in) torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8 cm (3.5 in) Uk L/30 deck gun. Her complement was twenty-six crew members.[3]

Summary of raiding history

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Date Name Nationality Tonnage[Note 2] Fate[7]
29 November 1916 Minnewaska   United Kingdom 14,317 Sunk
31 December 1916 Venus   French Navy 281 Sunk
21 February 1917 HMS Princess Alberta   Royal Navy 1,586 Sunk
10 June 1917 Kleopatra   Greece 160 Sunk
13 June 1917 Aghios Nicolaos   Greece 120 Sunk
14 June 1917 New Zealand Transport   United Kingdom 4,481 Sunk
18 June 1917 Pannomitis   Greece 11 Sunk
18 June 1917 Xiphias   Greece 483 Sunk
19 June 1917 Jakobus   Greece 304 Sunk
19 June 1917 Maria   Greece 35 Sunk
19 June 1917 Raxiarchos   Greece 30 Sunk
2 August 1917 HMS Ermine   Royal Navy 1,777 Sunk
6 September 1917 HMT Helgian   Royal Navy 220 Sunk
7 September 1917 HMT By George   Royal Navy 225 Sunk
21 September 1917 Santo Nicola   Kingdom of Italy 159 Sunk
21 September 1917 Spiridon   Greece 128 Sunk
23 September 1917 Nicolaos   Greece 104 Sunk
19 January 1918 Trocas   United Kingdom 4,129 Sunk
22 January 1918 Evangelistria   Greece 21 Sunk
23 January 1918 Birkhall   United Kingdom 4,541 Sunk
24 January 1918 Aghia Arene   Greece 16 Sunk
24 January 1918 Aghios Johannes   Greece 14 Sunk
20 February 1918 Hagios Nicolaos   Greece 18 Sunk
20 February 1918 Maria Archis   Greece 13 Sunk
20 February 1918 Taxi Arches   Greece 3 Sunk
23 February 1918 Aspasia   Greece 105 Sunk
28 February 1918 Hagios Triast   Greece 22 Sunk
11 April 1918 Trud   Imperial Russian Navy 610 Captured as prize
14 April 1918 Unidentified lighter   Russian Empire 100 Sunk
14 April 1918 Kazak   Imperial Russian Navy 622 Captured as prize
14 April 1918 Olga   Imperial Russian Navy 327 Captured as prize
15 April 1918 Rostov   Imperial Russian Navy 1,280 Sunk
3 October 1918 Blasios   Greece 181 Sunk
3 October 1918 Evangelistria   Greece 35 Damaged
5 October 1918 Hagios Marcos   Greece 45 Sunk
5 October 1918 Maria   Spain 2,159 Sunk
5 October 1918 Marigo   Greece 48 Sunk
5 October 1918 Reventazon   United Kingdom 4,050 Sunk
13 October 1918 Aghion Spiridon   Greece 21 Sunk
13 October 1918 Aghios Georgios   Greece 130 Sunk
13 October 1918 Biolleta   Greece 99 Sunk
13 October 1918 Evangelistria   Greece 41 Sunk
13 October 1918 Evangelistrios   Greece 121 Sunk
13 October 1918 Glaros   Greece 43 Sunk
13 October 1918 Iphigenia   Greece 75 Sunk
13 October 1918 Panaghia   Greece 26 Sunk
13 October 1918 Urania   Greece 23 Sunk
15 October 1918 Evangelistria   Greece 24 Sunk
15 October 1918 Georgios   Greece 29 Sunk
15 October 1918 Maria   Greece 43 Sunk

References

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Notes

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  1. ^ "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.
  2. ^ Merchant ship tonnages are in gross register tons. Military vessels are listed by tons displacement.

Citations

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  1. ^ a b c d e f Helgason, Guðmundur. "WWI U-boats: UC 23". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 22 February 2009.
  2. ^ Tarrant, p. 173.
  3. ^ a b c Gröner 1991, pp. 31–32.
  4. ^ Helgason, Guðmundur. "WWI U-boat commanders: Johannes Kirchner". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 15 February 2015.
  5. ^ Helgason, Guðmundur. "WWI U-boat commanders: Freiherr Volkhard von Bothmer". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 15 February 2015.
  6. ^ Helgason, Guðmundur. "WWI U-boat commanders: Hans Georg Lübbe". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 15 February 2015.
  7. ^ Helgason, Guðmundur. "Ships hit by UC 23". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 15 February 2015.

Bibliography

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  • Bendert, Harald (2001). Die UC-Boote der Kaiserlichen Marine 1914-1918. Minenkrieg mit U-Booten (in German). Hamburg, Berlin, Bonn: Mittler. ISBN 3-8132-0758-7.
  • 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.
  • Gardiner, Robert; Gray, Randal, eds. (1985). Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN 978-0-87021-907-8. OCLC 12119866.
  • Tarrant, V. E. (1989). The U-Boat Offensive: 1914–1945. Annapolis, Maryland: Naval Institute Press. ISBN 978-0-87021-764-7. OCLC 20338385.