German submarine U-100 (1940)

German submarine U-100 was a Type VIIB U-boat of Nazi Germany's Kriegsmarine during World War II.

U-100
History
Nazi Germany
NameU-100
Ordered15 December 1937
BuilderGermaniawerft, Kiel
Yard number594
Laid down22 May 1939
Launched10 April 1940
Commissioned30 May 1940
FateSunk 17 March 1941 by HMS Vanoc
General characteristics
Class and typeType VIIB submarine
Displacement
Length
Beam
  • 6.20 m (20 ft 4 in) o/a
  • 4.70 m (15 ft 5 in) pressure hull
Height9.50 m (31 ft 2 in)
Draught4.74 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
Speed
  • 17.9 kn (33.2 km/h; 20.6 mph) surfaced
  • 8 knots (15 km/h; 9.2 mph) submerged
Range
  • 8,700 nmi (16,100 km; 10,000 mi) at 10 knots (19 km/h; 12 mph) surfaced
  • 90 nmi (170 km; 100 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth
  • 220 m (720 ft)
  • Crush depth: 230–250 m (750–820 ft)
Complement4 officers, 40–56 enlisted
Sensors and
processing systems
Gruppenhorchgerät
Armament
Service record
Part of:
Identification codes: M 01 800
Commanders:
  • Kptlt. Joachim Schepke[1]
  • 30 May 1940 – 17 March 1941
Operations:
  • 6 patrols:
  • 1st patrol:
  • 9 August – 1 September 1940
  • 2nd patrol:
  • 11 – 25 September 1940
  • 3rd patrol:
  • 12 – 23 October 1940
  • 4th patrol:
  • 7 – 27 November 1940
  • 5th patrol:
  • 2 December 1940 – 1 January 1941
  • 6th patrol:
  • 9 – 17 March 1941
Victories:
  • 25 merchant ships sunk
    (135,614 GRT)
  • 1 merchant ship total loss
    (2,205 GRT)
  • 4 merchant ships damaged
    (17,229 GRT)

Design

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German Type VIIB submarines were preceded by the shorter Type VIIA submarines. U-100 had a displacement of 753 tonnes (741 long tons) when at the surface and 857 tonnes (843 long tons) while submerged.[2] 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).[2]

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).[2] 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-100 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.[2]

Service history

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First patrol

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The boat was launched on 10 April 1940, with a crew of 53, under the command of Kapitänleutnant Joachim Schepke. On her first active patrol, U-100 came into contact with two Allied convoys, OA-198 and OA-204. She shadowed both convoys.

Second patrol

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U-100 departed for her second active patrol on 11 September 1940, coming into contact with the Allied convoy HX 72. HX 72 lost 11 ships in total, with U-100 accounting for 7 ships of 50,340 GRT. In the attack on this convoy, while other U-boats stood off to the side and fired their torpedoes to little or no success, U-100 penetrated inside the convoy before attacking, a tactic soon adopted by the C-in-C of U-boats, Admiral Karl Donitz.[citation needed]

Third patrol

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After resupplying, U-100 departed for her third active patrol on 12 October 1940. She came into contact with two Allied convoys, HX 79 and SC 7.

Fourth patrol

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U-100 departed on her fourth patrol on 7 November 1940. On 22 November she came into contact with the Allied convoy SC 11 and began to shadow it.

Fifth patrol

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U-100 left for her fifth active patrol on 2 December 1940, sinking two vessels from Convoy OB 256, then a third solo vessel.

Sixth and final patrol

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U-100 departed on her sixth and what would be her final patrol on 9 March 1941. She approached convoy HX 112 from astern in the pre-dawn hours of 17 March, but was detected at a range of 1,000 meters by the Type 286 radar aboard HMS Vanoc.[3] U-100 was the first U-boat to be so discovered during World War II; she was rammed and sunk by Vanoc while attempting to submerge.[4] Another destroyer, HMS Walker, was also present.[5] Six of the boat's 53 crew members survived, spending the remainder of the war as POWs. Schepke was not one of them.

Summary of raiding history

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Date Ship Flag Tonnage
(GRT)
Fate[6]
16 August 1940 Empire Merchant   United Kingdom 4,864 Sunk
25 August 1940 Jamaica Pioneer   United Kingdom 5,471 Sunk
29 August 1940 Dalblair   United Kingdom 4,608 Sunk
29 August 1940 Hartismere   United Kingdom 5,498 Damaged
29 August 1940 Astra II   United Kingdom 2,393 Sunk
29 August 1940 Alida Gorthon   Sweden 2,373 Sunk
29 August 1940 Empire Moose   United Kingdom 6,103 Sunk
21 September 1940 Canonesa   United Kingdom 8,286 Sunk
21 September 1940 Torinia   United Kingdom 10,364 Sunk
21 September 1940 Dalcairn   United Kingdom 4,608 Sunk
22 September 1940 Empire Airman   United Kingdom 6,586 Sunk
22 September 1940 Scholar   United Kingdom 3,940 Sunk
22 September 1940 Frederick S. Fales   United Kingdom 10,525 Sunk
22 September 1940 Simla   Norway 6,031 Sunk
18 October 1940 Shekatika   United Kingdom 5,458 Damaged
18 October 1940 Boekelo   Netherlands 2,118 Damaged
19 October 1940 Blairspey   United Kingdom 4,155 Damaged
20 October 1940 Caprella   United Kingdom 8,230 Sunk
20 October 1940 Sitala   United Kingdom 6,218 Sunk
20 October 1940 Loch Lomond   United Kingdom 5,452 Sunk
23 November 1940 Justitia   United Kingdom 4,562 Sunk
23 November 1940 Bradfyne   United Kingdom 4,740 Sunk
23 November 1940 Ootmarsum   Netherlands 3,628 Sunk
23 November 1940 Bruse   Norway 2,205 Total Loss
23 November 1940 Salonica   Norway 2,694 Sunk
23 November 1940 Leise Maersk   United Kingdom 3,136 Sunk
23 November 1940 Bussum   Netherlands 3,636 Sunk
14 December 1940 Kyleglen   United Kingdom 3,670 Sunk
14 December 1940 Euphorbia   United Kingdom 3,380 Sunk
18 December 1940 Napier Star   United Kingdom 10,116 Sunk
Sunk: 135,614
Total loss: 2,205
Damaged: 17,229
Total: 155,048

References

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  1. ^ Helgason, Guðmundur. "Joachim Schepke (Knight's Cross with Oak Leaves)". German U-boats of WWII - uboat.net. Retrieved 17 May 2015.
  2. ^ a b c d Gröner 1991, pp. 43–44.
  3. ^ Rohwer & Hummelchen (1992) p. 54
  4. ^ Macintyre, Donald, CAPT RN "Shipborne Radar" United States Naval Institute Proceedings September 1967 pp. 78–79
  5. ^ Helgason, Guðmundur. "The Type VIIB boat U-100". German U-boats of WWII - uboat.net..
  6. ^ Helgason, Guðmundur. "Ships hit by U-100". German U-boats of WWII - uboat.net. Retrieved 11 December 2013.

Bibliography

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  • 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). German Warships 1815–1945, U-boats and Mine Warfare Vessels. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.
  • Rohwer, J.; Hummelchen, G. (1992). Chronology of the War at Sea 1939–1945. Naval Institute Press. ISBN 1-55750-105-X.
  • Kemp, Paul (1997). U-Boats Destroyed – German Submarine Losses in the World Wars. Arms and Armour Press. p. 69. ISBN 1-85409-321-5.
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61°04′N 11°30′W / 61.067°N 11.500°W / 61.067; -11.500