U-52, a typical Type VIIB boat
|Ordered:||15 December 1937|
|Laid down:||31 March 1939|
|Launched:||12 March 1940|
|Commissioned:||18 April 1940|
|Fate:||Scuttled, 17 March 1941, south-east of Iceland. Three dead and 40 survivors|
|Class and type:||Type VIIB submarine|
|Height:||9.50 m (31 ft 2 in)|
|Draught:||4.74 m (15 ft 7 in)|
|Complement:||4 officers, 40–56 enlisted|
|Identification codes:||M 17 046|
German submarine U-99 was a Type VIIB U-boat of Nazi Germany's Kriegsmarine during World War II. She was laid down on 31 March 1939 at the Friedrich Krupp Germaniawerft in Kiel as yard number 593. She was launched on 12 March 1940 under the command of Korvettenkapitän Otto Kretschmer and was assigned to the 7th U-boat Flotilla based in Kiel and later in St Nazaire.
U-99 was one of the most successful German U-boats in the war, sinking 38 ships for a total tonnage of 244,658 gross register tons (GRT) of Allied shipping in eight patrols. She damaged five more ships and took one vessel as a prize.
German Type VIIB submarines were preceded by the shorter Type VIIA submarines. U-99 had a displacement of 753 tonnes (741 long tons) when at the surface and 857 tonnes (843 long tons) while submerged. She had a total length of 66.50 m (218 ft 2 in), a pressure hull length of 48.80 m (160 ft 1 in), a beam of 6.20 m (20 ft 4 in), a height of 9.50 m (31 ft 2 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 BBC GG UB 720/8 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).
The submarine had a maximum surface speed of 17.9 knots (33.2 km/h; 20.6 mph) and a maximum submerged speed of 8 knots (15 km/h; 9.2 mph). When submerged, the boat could operate for 90 nautical miles (170 km; 100 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,700 nautical miles (16,100 km; 10,000 mi) at 10 knots (19 km/h; 12 mph). U-99 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, and one 2 cm (0.79 in) anti-aircraft gun The boat had a complement of between forty-four and sixty.
From April to June 1940, the crew of U-99 were under training, based at Kiel and St. Nazaire.
On 18 June, U-99 departed Kiel for operations in the North Sea west of Norway. She was attacked by an Arado Ar-196 seaplane from the German battleship Scharnhorst, having been mistaken for a British submarine. Two days later, U-99 was attacked by two aircraft; minor damage was inflicted. She returned to Kiel on 25 June.
U-99 departed Wilhelmshaven on 27 June to patrol southwest of Ireland. On 29 June, she was attacked by British aircraft. A crash dive was carried out with the result that the boat hit the seabed, causing some damage which was able to be repaired. During this patrol, U-99 sank six ships. A seventh was captured. An attack on the 5,360 GRT Manistee was called off on 7 July, when the armed merchant ship fired upon the U-boat. On 8 July, over 100 depth charges were dropped by the escorts of Convoy HX 53, but U-99 escaped undamaged. The patrol ended on 21 July.
|5 July 1940||Magog †||Canada||2,053||Sunk|
|7 July 1940||Bissen||Sweden||1,514||Sunk|
|HMS Manistee||Royal Navy||5,360||Escaped|
|Sea Glory||United Kingdom||1,964||Sunk|
|8 July 1940||Humber Arm ‡||United Kingdom||5,758||Sunk|
|12 July 1940||Ia||Greece||4,861||Sunk|
|18 July 1940||Woodbury||United Kingdom||4,434||Sunk|
† Convoy HX 52, ‡ Convoy HX 53, * sunk by German bombing, 15 July 1940
On 25 July, U-99 departed Lorient for the North Atlantic. Four ships were sunk and three others damaged. On the 31st, the escorts of Convoy OB 191 dropped 20 depth charges on the boat without effect. Later that evening, a flying boat also attacked her, again without causing any damage. The patrol ended on 5 August.
|28 July 1940||Auckland Star||UK||13,212||Sunk|
|29 July 1940||Clan Menzies||UK||7,226||Sunk|
|31 July 1940||Jamaica Progress||UK||5,475||Sunk|
|Jersey City †||UK||6,322||Sunk|
|2 August 1940||Alexia †, ‡||UK||8,016||Damaged|
|Lucerna †, ‡||UK||6,556||Damaged|
|Strinda †, ‡||Norway||10,973||Damaged|
† Convoy OB 191, ‡ Damaged
|11 September 1940||Albionic||UK||2,468||Sunk|
|15 September 1940||Kenordoc †||Canada||1,780||Sunk|
|16 September 1940||Lotos †||Norway||1,327||Sunk|
|17 September 1940||Crown Arun ‡||UK||2,372||Sunk|
|21 September 1940||Baron Blythswood *||UK||3,668||Sunk|
† Convoy SC 3, ‡ Convoy HX 71, * Convoy HX 72
On 13 October, U-99 departed Lorient to patrol the North West Approaches. Six ships from Convoy SC 7 were sunk and another was damaged. The patrol ended on 22 October.
|18 October 1940||Empire Miniver||UK||6,055||Sunk|
|19 October 1940||Clintonia †||UK||3,106||Damaged|
U-99 departed Lorient for the North West Approaches on 30 October 1940; four ships were sunk. The patrol ended on 8 November.
|3 November 1940||Casanare||UK||5,376||Sunk|
|HMS Laurentic||Royal Navy||18,724||Sunk|
|4 November 1940||Patroclus||UK||11,314||Sunk|
|5 November 1940||Scottish Maiden †||UK||6,993||Sunk|
† Convoy HX 83
On 27 November, U-99 departed Lorient for the North Atlantic. Four ships were sunk. The patrol ended on 12 December.
|2 December 1940||HMS Forfar (F30)||Royal Navy||16,402||Sunk|
|3 December 1940||Conch †||UK||8,376||Sunk|
|7 December 1940||Farmsum ‡||Netherlands||5,237||Sunk|
† Convoy HX 90, ‡ Convoy OB 252
U-99 departed Lorient on 22 February 1941 to patrol in the North Atlantic; eight ships were sunk. U-99 was attacked herself, with severe damage inflicted. Kretschmer surrendered and scuttled the submarine with the loss of three lives.
|7 March 1941||Athelbeach †||UK||6,568||Sunk|
|16 March 1941||Beduin ‡||Norway||8,136||Sunk|
|J. B. White||Canada||7,375||Sunk|
On 17 March 1941, U-99 had just fired the last of her torpedoes and sunk Korshamn when the Watch Officer spotted a destroyer, south-east of Iceland in approximate position . He immediately ordered a dive, contrary to Kretschmer's standing orders, but once the boat was under it was quickly fixed on ASDIC and attacked by HMS Walker and Vanoc. U-99 was driven deep by the attack but was nonetheless severely damaged. Kretschmer had no choice but to surface; immediately a barrage of fire greeted the boat. Kretschmer sent a message to Donald Macintyre, Walker's captain, "CAPTAIN TO CAPTAIN. I AM SUNKING [sic] PLEASE RESCUE MY CREW." He then ordered that the boat should be scuttled. 40 crew, including Kretschmer, were rescued to become POWs, while three crewmen lost their lives. Macintyre took Kretschmer's binoculars as a souvenir.
U-99 operated with the following Wolfpacks during her career:
- Wolfpack 1 (20–22 September 1940)
- Wolfpack 2 (17–19 October 1940)
- Kemp 1997, p. 69.
- Gröner 1991, pp. 43–44.
- Helgason, Guðmundur. "The Tpye IVVB boat U-99". German U-boats of WWII - uboat.net. Retrieved 17 November 2009.
- Helgason, Guðmundur. "Merisaar". German U-boats of WWII - uboat.net. Retrieved 17 November 2009.
- Helgason, Guðmundur. "HMS Manistee (F104)". German U-boats of WWII - uboat.net. Retrieved 17 November 2009.
- Fairbank White 2006, p. 79.
- Fairbank White 2006, p. 81.
- Fairbank White 2006, p. 82–83.
- Busch, Rainer; Röll, Hans-Joachim (1999). Deutsche U-Boot-Verluste von September 1939 bis Mai 1945. Der U-Boot-Krieg (in German) IV (Hamburg, Berlin, Bonn: Mittler). ISBN 3-8132-0514-2.
- Edwards, Bernard (1996). Dönitz and the Wolf Packs - The U-boats at War. Cassell Military Classics. pp. 23, 27, 28, 32, 35, 42–44, 48–49. ISBN 0-304-35203-9.
- Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945 2. Translated by Thomas, Keith; Magowan, Rachel (London: Conway Maritime Press). ISBN 0-85177-593-4.
- Fairbank White, David (2006). Bitter Ocean – The dramatic story of the Battle of the Atlantic 1939–1945. Headline Publishing Group. ISBN 9-780-7553-1089-0.
- Kemp, Paul (1997). U-Boats Destroyed, German Submarine Losses in the World Wars. Arms and Armour. ISBN 1-85409-515-3.
- Hofmann, Markus. "U 99". Deutsche U-Boote 1935-1945 - u-boot-archiv.de (in German). Retrieved 8 December 2014.
- uboataces.com webpage with insignia for U-99
- uboatarchive.net U-99 Interrogation of Survivors, Naval Intelligence Division, April 1941