SM_U-XX_(Austria-Hungary)
SM U-20 (Austria-Hungary)
Lead boat of U-20 class
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 that of the submarines of the Royal Danish Navy's Havmanden class (which had been designed by Whitehead & Co. in Fiume), and was largely obsolete by the beginning of the war.
The design for U-20 was based on that of the Havmanden class built for the Royal Danish Navy (Havmanden pictured) | |
| History | |
|---|---|
 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: |
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| Victories: | None[5] |
| General characteristics | |
| Class and type | U-20-class submarine |
| Displacement |
|
| Length | 127 ft 2 in (38.76 m)[2] |
| Beam | 13 ft (4.0 m)[2] |
| Draft | 9 ft (2.7 m)[2] |
| Propulsion |
|
| Speed |
|
| Range |
|
| Complement | 18[2] |
| Armament |
|
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.
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] which had been designed by Whitehead & Co. in Fiume, who had built three units.[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 a coastal 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 (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]
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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]
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, 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]
- Halpern, p. 382.
- Gardiner, p. 343.
- "Tengeralattjárók" (PDF) (in Hungarian). Imperial and Royal Navy Association. p. 20. Archived from the original (PDF) on 11 October 2021. Retrieved 2 February 2009.
- Grant, p. 163.
- Helgason, Guðmundur. "WWI U-boats: KUK U20". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 29 November 2008.
- Gardiner, p. 354.
- Gardiner, p. 344.
- Halpern, p. 383.
- Gardiner, p. 341.
- 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; 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.
- 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.