For other ships named German submarine U-20, see German submarine U-20 (disambiguation).
UC-20
CountryGerman Empire
Ordered29 August 1915[1]
BuilderBlohm & Voss, Hamburg[2]
Yard number270[1]
Launched1 April 1916[1]
Commissioned7 September 1916[1]
FateSurrendered, 16 January 1919; broken up, 1919 – 20[1]
SM UC-20
ClassType 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
SM UC-20
Partof
  • Pola / Mittelmeer / Mittelmeer I Flotilla
  • 11 December 1916 – 11 November 1918
Commanders
  • Kptlt. Franz Becker[3]
  • 8 September 1916 – 8 May 1917
  • Oblt.z.S. Hans Adalbert von der Lühe[4]
  • 9 May – 12 December 1917
  • Oblt.z.S. Otto Kümpel[5]
  • 13 December 1917 – 10 January 1918
  • Oblt.z.S. Heinrich Kukat[6]
  • 1 April – 18 June 1918
  • Oblt.z.S. Hermann Rohne[7]
  • 19 June – 29 November 1918
Operations13 patrols
Victories
  • 21 merchant ships sunk
    ()
  • 3 merchant ships damaged
    ()

SM UC-20[Note 1] 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 1 April 1916. She was commissioned into the German Imperial Navy on 7 September 1916 as SM UC-20. In 13 patrols UC-20 was credited with sinking 21 ships, either by torpedo or by mines laid. UC-20 was surrendered on 16 January 1919 and broken up at Preston in 1919–20.[1]

Design

Like all pre-UC-25 Type UC II submarines, UC-20 had a displacement of 417 tonnes (410 long tons) when at the surface and 493 tonnes (485 long tons) while submerged. She had a total length 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 hp) (a total of 500 metric horsepower (370 kW; 490 hp)), two electric motors producing 460 metric horsepower (340 kW; 450 hp), 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).[8]

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-20 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.[8]

Summary of raiding history

DateNameNationalityTonnage[Note 2]Fate[9]
19 October 1916Frits EmilDenmark194Sunk
17 November 1916EmiliaPortugal1,159Sunk
10 April 1917Abd RazikTunisia25Sunk
11 April 1917CandiaKingdom of Italy1,045Sunk
14 April 1917Cinque OttobreKingdom of Italy39Sunk
14 April 1917ProgressoKingdom of Italy31Sunk
15 April 1917Alessio CoccoKingdom of Italy29Sunk
18 May 1917Millicent KnightUnited Kingdom3,563Sunk
25 May 1917ArgentinaKingdom of Italy97Sunk
25 May 1917IdaKingdom of Italy46Sunk
26 May 1917Unione SalvatoreKingdom of Italy57Sunk
26 May 1917Abd es SalemFrance25Sunk
26 May 1917DandoloFrance50Sunk
26 May 1917ManoubiaFrance50Sunk
26 May 1917MessaoudaFrance50Sunk
26 May 1917San FrancescoKingdom of Italy47Sunk
27 May 1917BoldwellUnited Kingdom3,118Sunk
26 August 1917Maurizio P.Kingdom of Italy558Sunk
4 January 1918Regina ElenaKingdom of Italy7,940Sunk
13 April 1918GioveKingdom of Italy5,037Damaged
28 April 1918VerdunFrance2,769Sunk
4 May 1918MergellinaKingdom of Italy354Damaged
4 June 1918StrombusUnited Kingdom6,163Damaged
12 June 1918PoincareTunisia35Sunk

References

Notes

  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. ^ Tonnages are in gross register tons

Citations

  1. ^ UC+20. Retrieved 22 February 2009.
  2. ^ Tarrant, p. 173.
  3. ^ 18. Retrieved 10 February 2015.
  4. ^ 188. Retrieved 10 February 2015.
  5. ^ 167. Retrieved 10 February 2015.
  6. ^ 165. Retrieved 10 February 2015.
  7. ^ 270. Retrieved 10 February 2015.
  8. ^ Gröner 1991, pp. 31–32.
  9. ^ uc20. Retrieved 10 February 2015.

Bibliography

  • 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. Vol. 2. German Warships 1815–1945. Translated by Thomas, Keith & Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.
  • Conway's All the World's Fighting Ships 1906–1921. Annapolis, Maryland: Naval Institute Press. 1985. 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