SM U-20 (Austria-Hungary)

The design for U-20 was based on the Havmanden class of the Royal Danish Navy (Havmanden pictured)
Career (Austria-Hungary)
Name: SM U-20
Ordered: 27 March 1915[1]
Builder: Pola Navy Yard, Pola[2]
Laid down: 29 September 1915[3]
Launched: 18 September 1916[2]
Commissioned: 20 October 1917[3]
Fate: sunk by Italian submarine F-12, 4 July 1918, raised and partially scrapped in 1962, remaining parts donated to museum[4]
Service record
Commanders:
  • Klemens Ritter von Bezard (May 1916 – Apr 1917)[5]
  • Franz Rzemenowsky von Trautenegg (Jul–Nov 1917)
  • Hermann Rigele (Nov 1917 – Mar 1918)
  • Ludwig Müller (Mar–Jul 1918)
Victories: None[5]
General characteristics
Class and type:U-20-class submarine Imported from Wikidata (?)
Type:U-20-class submarine
Displacement:173 t, surfaced
210 t, submerged[2]
Length:127 ft 2 in (38.76 m)[2]
Beam:13 ft (4.0 m)[2]
Draft:9 ft (2.7 m)[2]
Propulsion:1 × shaft
1 × diesel engine, 450 bhp (340 kW)
1 × electric motor, 160 shp (120 kW)[2]
Speed:12 knots (22 km/h) surfaced
9 knots (17 km/h) submerged[2]
Range:
  • 1,400 nautical miles (2,600 km) at 10 knots (19 km/h) surfaced[6]
  • 23 nautical miles (43 km) at 8 knots (15 km/h) submerged
Complement:18[2]
Armament:2 × 45 cm (17.7 in) torpedo tubes (both in front); 2 torpedoes
1 × 66 mm/26 (2.6 in) deck gun
1 × 8 mm (0.31 in) machine gun[2]

SM U-20 or U-XX was the lead boat of the U-20 class of submarines or U-boats built for and operated by the Austro-Hungarian Navy (German: Kaiserliche und Königliche Kriegsmarine or K.u.K. Kriegsmarine) during the First World War. The design for U-20 was based on submarines of the Royal Danish Navy's Havmanden class (three of which had been built in Austria-Hungary), and was largely obsolete by the beginning of the war.

U-20 was just over 127 feet (39 m) long and was armed with two bow torpedo tubes, a deck gun, and a machine gun. U-20 had no wartime successes and was sunk in early July 1918 by the Italian submarine F-12. The wreck of U-20 was located in 1962 and salvaged. A portion of her conning tower is on display in a military museum in Vienna.

Design and construction

When it became apparent to the Austro-Hungarian Navy that the First World War would not be a short war,[1] they moved to bolster their U-boat fleet by seizing the plans for Denmark's Havmanden class submarines,[7] three of which had been built at Whitehead & Co. in Fiume.[6] Although the Austro-Hungarian Navy was not happy with the design, which was largely obsolete,[8][9] it was the only design for which plans were available and which could be begun immediately in domestic shipyards.[9] The Austro-Hungarian Navy unenthusiastically placed orders for U-20 and her three sister boats on 27 March 1915.[1]

U-20 was one of two boats of the class to be built at the Pola Navy Yard.[7] Due to demands by the Hungarian government,[1] subcontracts for the class were divided between Hungarian and Austrian firms,[2] but this politically expedient solution worsened technical problems with the design and resulted in numerous modifications and delays for the class in general.[7]

U-20 was an ocean-going submarine that displaced 173 tonnes (191 short tons) surfaced and 210 tonnes (231 short tons) submerged and was designed for a complement of 18. She was 127 feet 2 inches (38.76 m) long with a beam of 13 feet (4.0 m) and a draft of 9 feet (2.7 m). For propulsion, she featured a single propeller shaft, a single 450 bhp (340 kW) diesel engine for surface running, and a single 160 shp (120 kW) electric motor for submerged travel.[2] She was capable of 12 knots (22 km/h) while surfaced and 9 knots (17 km/h) while submerged. Although there is no specific notation of a range for U-20, the Havmanden class, upon which the U-20 class was based, had a range of 1,400 nautical miles (2,600 km) at 10 knots (19 km/h), surfaced, and 23 nautical miles (43 km) at 8 knots (15 km/h) submerged.[6]

U-20 was armed with two 45 cm (17.7 in) torpedo tubes located in the front and carried a complement of two torpedoes. She was also equipped with a 66 mm/26 (2.6 in) deck gun and an 8 mm (0.31 in) machine gun.[2]

U-20 was laid down on 29 September 1915,[3] six months after she was ordered,[1] and was launched on 18 September 1916.[2]

Service career

Upon completion, U-20 began diving trials. On her 15 March 1917 trial, she was accidentally rammed by Admiral Spaun in the Fasana Channel. The collision with the Austro-Hungarian light cruiser twisted U-20‍ '​s periscope, extensively damaged the conning tower, and knocked off her deck gun. After seven months of reconstruction, U-20 was commissioned into the Austro-Hungarian Navy on 20 October.[3]

The conning tower of U-20 on display at the Heeresgeschichtliches Museum in Vienna

After initially operating out of Pola, U-20 was transferred to Trieste in February 1918. Over the next three months, the U-boat patrolled in the northern Adriatic between the Tagliamento estuary and Venice. U-20 had an encounter with an enemy submarine on 7 April but was not able to successfully launch an attack.[3]

On 3 July, Linienschiffsleutnant Ludwig Müller sailed U-20 out from Trieste for the Gulf of Venice. A day later, U-20 was spotted by the Italian submarine F-12, which was on patrol in the northern Adriatic. F-12 initially pursued U-20 underwater, and then on the surface. At a range of 650 yards (590 m), F-12 torpedoed U-20 at position 45°29′N 13°05′E / 45.483°N 13.083°E, sinking her with all hands. There was no wreckage on the surface, only an oil slick.[4][Note 1] Like all of her sister boats,[7] U-20 had no wartime successes.[5]

In mid 1962, the wreck of U-20 was discovered in the northern Adriatic. Italian salvage crews raised the boat's rear portion on 22 July and her front section on 21 November.[4] The conning tower and a small midships section of U-20 were donated to the Heeresgeschichtliches Museum in Vienna, where they are on display, while the rest of the boat was scrapped.[7] The remains of the crewmen were buried on the grounds of the Theresian Military Academy at Wiener Neustadt.[10]

Notes

  1. ↑ Grant (p. 163) gives the date of U-20‍ '​s loss as 4 July 1918. Compton-Hall (p. 235) reports it on 9 July, while Baumgartner and Sieche report it on 6 July.
    For Baumgartner and Sieche, see excerpt here (reprinted and translated into English by Sieche). Retrieved 29 November 2008.

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 Halpern, p. 382.
  2. ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 Gardiner, p. 343.
  3. ↑ 3.0 3.1 3.2 3.3 3.4 "Tengeralattjárók" (DMY) (in Hungarian). Imperial and Royal Navy Association. p. 20. Retrieved 2 February 2009.
  4. ↑ 4.0 4.1 4.2 Grant, p. 163.
  5. ↑ 5.0 5.1 5.2 Helgason, Guðmundur. "WWI U-boats: U KUK U20". U-Boat War in World War I. Retrieved 29 November 2008.
  6. ↑ 6.0 6.1 6.2 Gardiner, p. 354.
  7. ↑ 7.0 7.1 7.2 7.3 7.4 Gardiner, p. 344.
  8. ↑ Halpern, p. 383.
  9. ↑ 9.0 9.1 Gardiner, p. 341.
  10. ↑ Baumgartner and Sieche, as excerpted here (reprinted and translated into English by Sieche). Retrieved 17 November 2008.

Bibliography

  • Baumgartner, Lothar; Erwin Sieche (1999). Die Schiffe der k.(u.)k. Kriegsmarine im Bild = Austro-Hungarian warships in photographs (in German). Wien: Verlagsbuchhandlung Stöhr. ISBN 978-3-901208-25-6. OCLC 43596931.
  • Compton-Hall, Richard (2004) [1991]. Submarines at War, 1914–18. Penzance: Periscope Publishing. ISBN 978-1-904381-21-1. OCLC 57639764.
  • Gardiner, Robert, ed. (1985). Conway's All the World's Fighting Ships, 1906–1921. Annapolis, Maryland: Naval Institute Press. ISBN 978-0-87021-907-8. OCLC 12119866.
  • Grant, Robert M. (2002) [1964]. U-boats Destroyed: The Effect of Anti-submarine Warfare, 1914–1918. Penzance: Periscope. ISBN 978-1-904381-00-6. OCLC 50215640.
  • Halpern, Paul G. (1994). A Naval History of World War I. Annapolis, Maryland: Naval Institute Press. ISBN 978-0-87021-266-6. OCLC 28411665.