German submarine U-480

History
Nazi Germany
Name	U-480
Ordered	10 April 1941 [1]
Builder	Deutsche Werke, Kiel
Yard number	311 [1]
Laid down	8 December 1942 [1]
Launched	14 August 1943 [1]
Commissioned	6 October 1943 [1]
Fate	Sunk between 29 January and 20 February 1945 in minefield "Brazier D2" in the English Channel, with the loss of the entire crew of 48. [1]
General characteristics
Class and type	Type VIIC submarine
Displacement	769 tonnes (757 long tons) surfaced 871 t (857 long tons) submerged
Length	67.23 m (220 ft 7 in) o/a 50.50 m (165 ft 8 in) pressure hull
Beam	6.20 m (20 ft 4 in) o/a 4.70 m (15 ft 5 in) pressure hull
Height	9.60 m (31 ft 6 in)
Draught	4.74 m (15 ft 7 in)
Installed power	2,800–3,200 PS (2,100–2,400 kW; 2,800–3,200 bhp) (diesels) 750 PS (550 kW; 740 shp) (electric)
Propulsion	2 shafts 2 × diesel engines 2 × electric motors
Speed	17.7  kn (32.8 km/h; 20.4 mph) surfaced 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range	8,500 nmi (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph) surfaced 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	230 m (750 ft) Crush depth: 250–295 m (820–968 ft)
Complement	4 officers, 40–56 enlisted
Armament	5 × 53.3 cm (21 in) torpedo tubes (four bow, one stern) 14 × torpedoes or 26 TMA mines 1 × 8.8 cm (3.46 in) deck gun (220 rounds) 1 × 3.7 cm (1.5 in) Flak M42 AA gun 2 × twin 2 cm (0.79 in) C/30 anti-aircraft guns
Service record [1]
Part of:	5th U-boat Flotilla 6 October 1943 – 31 May 1944 9th U-boat Flotilla 1 June – 14 October 1944 11th U-boat Flotilla 15 October 1944 – 29 January 1945
Identification codes:	M 53 621
Commanders:	Oblt.z.S. Hans-Joachim Förster 6 October 1943 – 29 January 1945
Operations:	3 patrols: 1st patrol: 7 June – 7 July 1944 2nd patrol: 3 August – 4 October 1944 3rd patrol: 6 – 29 January 1945
Victories:	2 merchant ships sunk (12,846  GRT) 2 warships sunk (1,775 tons)

German submarine U-480 was an experimental Kriegsmarine Type VIIC U-boat of World War II.

Considered by many to be the first stealth submarine, it was equipped with a special rubber skin of anechoic tiles (codenamed Alberich, after the German mythological character who had the ability to become invisible), that made it difficult to detect with the Allies' ASDIC (sonar). She was one of about six Type VIIs so equipped. ^[2]

The U-boat was laid down in the Deutsche Werke in Kiel as yard number 311 on 8 December 1942, launched on 14 August 1943 and commissioned on 6 October 1943 under Oberleutnant zur See Hans-Joachim Förster. U-480 carried out three war patrols, all under Förster's command. Because of its coating, the boat was sent to the heavily defended English Channel.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-480 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged. ^[3] She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two Siemens-Schuckert GU 343/38–8 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft). ^[3]

The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). ^[3] When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-480 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, (220 rounds), one 3.7 cm (1.5 in) Flak M42 and two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty. ^[3]

Anechoic coating

A close-up view of an Alberich tile, illustrating patterns of multiple holes with different diameters

Alberich tiles as they appear on U-480

Rubber foil containing air holes can be used to reduce the sound waves reflected under water by structures when foil thickness is small by comparison with the sound wavelength in water, providing a low reflectivity over a narrow frequency range. ^{[4] [5] [6]}

The leading German acoustician Erik Meyer and his team developed a 4-millimetre (0.16 in) thick tile consisting of two 2-millimetre thick foils of synthetic rubber. ^{[7] [8] [9] [10]} The anechoic tile reduced echoes by 15% in the 10 to 18 kHz range. ^{[11] [12]} This frequency range matched the operating range of the early ASDIC active sonar used by the Allies. The ASDIC types 123, 123A, 144 and 145 all operated in the 14 to 22 kHz range. ^{[13] [14]} However, this degradation in echo reflection was not uniform at all diving depths due to the voids being compressed by the water pressure. ^[15] An additional benefit of the coating was it acted as a sound dampener, containing the U-boat's own engine noises. ^{[11] [16]}

The rubber contained a series of holes, which helped break up sound waves. There were problems with this technology: the material performed differently at different depths, due to the holes being compressed by water pressure, and securing the tiles to the submarine's hull required a special adhesive and careful application. ^[17]

The first tests were conducted in 1940, but it was not used operationally until 1944, with U-480. According to the Naked Science television episode "Stealth Submarine", U-480 had a perforated inner rubber layer covered by a smooth outer one. This formed air pockets with the right separation and size to muffle sonar waves.

Other U-boats with the anechoic tiles coating include: U-11, U-485, U-486, U-1105, U-1106, U-1107, U-1304, U-1306, U-1308, U-4704, U-4708 and U-4709. ^{[18] [19] [20] [21]}

With the exception of U-480 and U-486, none of the other German submarines of this type with this equipment was lost in combat.

Service history

On its first patrol, the boat was attacked by a Canadian PBY Catalina flying boat of 162 Squadron RCAF, piloted by Laurance Sherman. ^[1] The aircraft was shot down. ^[1]

On the second patrol, Förster departed from Brest in occupied France on 3 August 1944, and sank two warships and two merchantmen: ^[22]

For his success, Förster was awarded the Knight's Cross on 18 October 1944. ^[23]

Fate

U-480 left Trondheim, Norway, on 6 January 1945 for its third and last patrol. It did not return. In 1997, the wreck of a Type VIIC U-boat was discovered by accident by divers at 50°22′4″N1°44′10″W / 50.36778°N 1.73611°W / 50.36778; -1.73611 , 20 kilometres (12 mi) southwest of the Isle of Wight. ^[24] The following year, it was identified as U-480 by nautical archaeologist Innes McCartney. ^[25] Subsequent research by the Naval Historical Branch established that it had fallen victim to the secret minefield 'Brazier D2' sometime between 29 January and 20 February. ^[26] A mine had damaged the stern of U-480, sending it to the bottom 55 metres (180 ft) down. ^[27] The entire crew of 48 was lost. Helmsman Horst Rösner only survived because he had been left behind in Norway for training.

Summary of raiding history

Date	Ship Name	Nationality	Tonnage [Note 1]	Notes [28]
21 August 1944	HMCS Alberni	Royal Canadian Navy	925	Flower-class corvette
22 August 1944	HMS Loyalty	Royal Navy	850	Algerine-class minesweeper
23 August 1944	Fort Yale	United Kingdom	7,134	Sailing in convoy ETC-72
25 August 1944	Orminster	United Kingdom	5,712

References

Notes

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

Citations

1. Helgason, Guðmundur. "The Type VIIC boat U-480". German U-boats of WWII – uboat.net. Retrieved 13 April 2011.
2. Sgarlato, Nico; Sgarlato, Alessio (2022). Secret projects of the Kriegsmarine : unseen designs of Nazi Germany's navy. Alessio Sgarlato. Barnsley, S. Yorkshire. ISBN   978-1-78438-687-0. OCLC   1260821096.
3. Gröner 1991, pp. 43–46.
4. Lane, R. (1981). "Absorption mechanisms for waterborne sound in Alberich anechoic layers". Ultrasonics. 19 (1): 28–30. doi:10.1016/0041-624X(81)90029-9. ISSN   0041-624X.
5. Oberst, Hermann (1953). "Resonant Sound Absorbers". In Richardson, Edward Gick (ed.). Technical Aspects of Sound: Ultrasonic range, underwater acoustics. Vol. II. Elsevier Publishing Company.
6. Gaunaurd, G. (1977). "One‐dimensional model for acoustic absorption in a viscoelastic medium containing short cylindrical cavities". The Journal of the Acoustical Society of America. 62 (2): 298–307. Bibcode:1977ASAJ...62..298G. doi:10.1121/1.381528. ISSN   0001-4966.
7. Meyer, Erwin; Oberst, Hermann (1952). "Resonanzabsorber für Wasserschall" [Resonance absorbers of water-borne sound]. Acta Acustica United with Acustica. 2 (3): 149–170.
8. Guicking, Dieter (2015), Xiang, Ning; Sessler, Gerhard M. (eds.), "Research on Underwater Acoustics in Göttingen", Acoustics, Information, and Communication, Cham: Springer International Publishing, pp. 241–276, doi:10.1007/978-3-319-05660-9_13, ISBN   978-3-319-05659-3 , retrieved 18 December 2022
9. "Anti Sonar Coating / Alberich". uboataces.com. Retrieved 15 April 2011.
10. Guicking, Dieter (1 September 2013). "Erwin Meyer – A Great German Acoustician. Biographical Notes". Acta Acustica United with Acustica. 99 (5): 816–821. doi:10.3813/AAA.918659.
11. "Anti Sonar Coating". www.uboataces.com. Retrieved 17 December 2010.
12. U.S. Naval Technical Mission in Europe (20 September 1945). Rubber Covering of German Submarines Anti-Asdic (German code name "Alberich'). Series IV, Technical Reports #351-45 thru #370-45. Vol. Report No. 352-45. US Navy.
13. "ASDIC Equipment Types – Section A". Jerry Proc. Archived from the original on 17 December 2010. Retrieved 17 December 2010.
14. "ASDIC Equipment Types – Section B". Jerry Proc. Archived from the original on 17 December 2010. Retrieved 17 December 2010.
15. Rössler, Eberhard (2001). The U-boat : the evolution and technical history of German submarines. London: Cassell. ISBN   0-304-36120-8. OCLC   47868026.
16. Hamilton, Aaron S. (30 May 2020). "Acoustic camouflage". Total Undersea War: The Evolutionary Role of the Snorkel in Dönitz's U-Boat Fleet, 1944–1945. Seaforth Publishing. pp. 104–118. ISBN   978-1-5267-7883-3.
17. Meyer, Erwin; Oberst, Hermann (1950). "Introduction to the physics and technology of resonance sound – absorbers for underwater sound". In Meyer, Erwin (ed.). Sound absorption and sound absorbers in water. (Dynamic properties of rubber and rubberlike substances in the acoustic frequency region). NavShips900, 164. Translated by Mongan, Charles E. Washington, D.C.: Dept. of the Navy, Bureau of Ships. pp. 293–309. hdl:2027/uc1.31822010310829.
18. Wynn, Kenneth G. U-Boat Operations of the Second World War: Career Histories, U1-U510. Naval Institute Press (1998). ISBN   1-55750-860-7.
19. Rössler, Eberhard. Die Sonaranlagen der deutschen Unterseeboote: Entwicklung, Erprobung, Einsatz und Wirkung akustischer Ortungs- und Täuschungseinrichtungen der deutschen Unterseeboote. Bernard & Graefe. ISBN   3-7637-6272-8
20. "Recubrimiento Anti-Sonar". u-historia.com. Retrieved 17 December 2010.
21. Llewellyn-Jones, Malcolm (8 December 2005). The Royal Navy and Anti-Submarine Warfare, 1917–49. Routledge. ISBN   978-1-134-17272-6.
22. "Operations information for U-480". uboatwaffe.net. Archived from the original on 22 July 2004. Retrieved 13 April 2011.
23. Scherzer, Veit (2007). Die Ritterkreuzträger Die Inhaber des Ritterkreuzes des Eisernen Kreuzes 1939 von Heer, Luftwaffe, Kriegsmarine, Waffen-SS, Volkssturm sowie mit Deutschland verbündeter Streitkräfte nach den Unterlagen des Bundesarchives (in German). Jena, Germany: Scherzers Militaer-Verlag. ISBN   978-3-938845-17-2. p. 313
24. Niestlé, Axel (2010). The 'Atlas' Survey Zone: Deep-sea Archaeology & U-boat Loss Reassessments (Report). Odyssey Marine Exploration. Retrieved 18 December 2022.
25. McCartney, Innes (2002). Lost Patrols: Submarine Wrecks of the English Channel. Periscope Publishing Ltd. pp. 99–100. ISBN   978-1-904381-04-4.
26. Simner, Mark (31 August 2019). "U-480: The Kriegsmarine's Stealth Submarine". Mark Simner. Retrieved 17 December 2022.
27. McCartney, Innes (2 January 2020). "The Archaeology of Second World War U-boat Losses in the English Channel and its Impact on the Historical Record". The Mariner's Mirror. 106 (1): 62–81. doi: 10.1080/00253359.2020.1692578 . ISSN   0025-3359. S2CID   220326970.
28. Helgason, Guðmundur. "Ships hit by U-480". German U-boats of WWII – uboat.net. Retrieved 28 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.
• McCartney, Innes (2002). Lost patrols : submarine wrecks of the English Channel. Penzance: Periscope. ISBN   978-1-904381-04-4.

External links

• Helgason, Guðmundur. "The Type VIIC boat U-480". German U-boats of WWII – uboat.net. Retrieved 28 December 2014.
• "Stealth Submarine", part of a National Geographic Channel documentary television episode on U-480
• Bardehle, Peter; Ruthven, John, eds. (2008). Vom Jaeger zum Gejagten – Das erste Stealth UBoot der Welt [From hunter to hunted – The world's first stealth submarine] (Television production) (in German). The world's first stealth submarine, developed and used by the German Kriegsmarine during World War II, was completely covered with rubber. The rubber had small holes in it that made the submarine invisible to British sonar. Until then, warships could use sound waves to locate any submarine underwater and fight it with depth charges. Thus, submarines had been rendered largely ineffective by sonar. U 480 proved for the first time that a so-called "Alberich" camouflage – named after the eponymous character in the Saga of the Nibelungs – worked. On its first voyage into the well-protected English Channel, U 480 sank four ships at once. The British were able to intercept and decode the Germans' secret radio communications, but it took them several weeks to realize what weapon the Germans had developed. Once they knew, a dramatic hunt began for the stealth submarine, using a simple stratagem of war to sink it. The wreck of U 480 was not discovered until 1998. The documentary by John Ruthven and Peter Bardehle accompanies the first diving expedition with Berlin submarine historian Axel Niestlé and reconstructs the fate of hunters and hunted in the winter of 1944/1945.
• Nazi Secrets | Drain the Oceans on YouTube