German submarine U-480
|Career (Nazi Germany)|
|Ordered:||April 10, 1941|
|Builder:||Deutsche Werke, Kiel, yard 311|
|Laid down:||December 8, 1942|
|Launched:||August 14, 1943|
|Commissioned:||October 6, 1943|
|Fate:||Sunk between January 29 and February 20, 1945 in minefield Brazier D2 in the English Channel, with the loss of the entire crew of 48.|
|Type:||Type VIIC submarine|
|Displacement:||769 tonnes (757 long tons) surfaced
871 t (857 long tons) submerged
|Length:||67.1 m (220 ft 2 in) o/a
50.5 m (165 ft 8 in) pressure hull
|Beam:||6.2 m (20 ft 4 in) o/a
4.7 m (15 ft 5 in) pressure hull
|Draft:||4.74 m (15 ft 7 in)|
|Propulsion:||2 × supercharged Germaniawerft 6-cylinder 4-stroke F46 diesel engines, totalling 2,800–3,200 bhp (2,100–2,400 kW). Max rpm: 470-490
2 × electric motors, totalling 750 shp (560 kW) and max rpm: 296
|Speed:||17.7 kn (32.8 km/h; 20.4 mph) surfaced
7.6 knots (14.1 km/h; 8.7 mph) submerged
|Range:||15,170 km (8,190 nmi) at 10 kn (19 km/h) surfaced
150 km (81 nmi) at 4 kn (7.4 km/h) submerged
|Test depth:||230 m (750 ft)
Crush depth: 250–295 m (820–968 ft)
|Complement:||44–52 officers and ratings|
|Armament:||5 × 53.3 cm (21 in) torpedo tubes (four bow, one stern)
14 × G7e torpedoes or 26 TMA mines
1 × 8.8 cm (3.46 in) deck gun (220 rounds)
Various AA guns
|Part of:||5th U-boat Flotilla (October 6, 1943-May 31, 1944)
9th U-boat Flotilla (June 1-October 14, 1944)
11th U-boat Flotilla (October 15, 1944-February 20, 1945)
|Identification codes:||M 53 621|
|Commanders:||Oblt.z.S.. Hans-Joachim Förster|
|Operations:||1st patrol: June 7-July 7, 1944
2nd patrol: August 3-October 4, 1944
3rd patrol: January 6-February 20, 1945
|Victories:||Four ships sunk|
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 coating (codenamed "Alberich", probably after the German mythological character who had the ability to become invisible), that made it difficult to detect with British ASDIC (sonar).
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. The Alberich worked; U-480 was never detected by sonar.
World War II service
On the second patrol, Förster departed from Brest in occupied France on August 3, 1944, and sank two warships and two merchantmen:
- the Canadian Flower class corvette HMCS Alberni (925 tons) on August 21
- the British Algerine class minesweeper HMS Loyalty (850 tons) on August 22
- the Fort Yale (7134 GRT), sailing in convoy ETC-72, on August 23
- the Orminister (5712 GRT) on August 25
U-480 left Trondheim, Norway on January 6, 1945 for its third and last patrol. It did not return. In 1997, the wreck of a Type VIIC U-boat discovered by accident by divers at , 20 kilometres (12 mi) southwest of the Isle of Wight. The following year, it was correctly identified as the Alberich-coated U-480 by nautical archaeologist Innes McCartney. Subsequent research by the Naval Historical Branch established that it had fallen victim to the secret minefield 'Brazier D2' some time between January 29 and February 20. A mine had damaged the tail of U-480, sending it to the bottom 55 metres (180 ft) down. The entire crew of 48 was lost. Helmsman Horst Rösner only survived because he had been left behind in Norway for training.
The Germans developed a 4-millimetre (0.16 in) thick sheet of synthetic rubber that attenuated sound in the 10 to 18 kHz range to 15% of its normal strength. This frequency range matched the operating range of the early ASDIC active sonar used by the Allies. ASDIC's operating range would have been correspondingly reduced from its optimal range of 2,000 metres (6,600 ft) to somewhere around 300 metres (980 ft). 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. 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.
Summary of ships sunk
|21 August 1944||HMCS Alberni||Royal Canadian Navy||925|
|22 August 1944||HMS Loyalty||Royal Navy||850|
|23 August 1944||Fort Yale||United Kingdom||7,134|
|25 August 1944||Orminster||United Kingdom||5,712|
- "U-480". uboat.net. Retrieved April 13, 2011.
- "Operations information for U-480". uboatwaffe.net. Retrieved April 13, 2011.
- 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 Miltaer-Verlag. ISBN 978-3-938845-17-2. p. 313
- "Anti Sonar Coating / Alberich". uboataces.com. Retrieved April 15, 2011.
- Innes McCartney (2002). Lost Patrols: Submarine Wrecks of the English Channel.
- "Stealth Submarine", part of a National Geographic Channel documentary television episode on U-480