German submarine ''U-100'' was a Type VIIB

U-boat U-boats were naval submarines operated by Germany, particularly in the First and Second World Wars. Although at times they were efficient fleet weapons against enemy naval warships, they were most effectively used in an economic warfare ro ...

Nazi Germany Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...

's '' Kriegsmarine'' during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

Design

German Type VIIB submarines were preceded by the shorter Type VIIA submarines. ''U-100'' had a displacement of when at the surface and while submerged. She had a total length of , a

pressure hull A submarine hull has two major components, the ''light hull'' and the ''pressure hull''. The light hull (''casing'' in British usage) of a submarine is the outer non-watertight hull which provides a hydrodynamically efficient shape. The pressure ...

length of , a

beam Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-ca ...

s producing a total of for use while surfaced, two BBC GG UB 720/8 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to . The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . ''U-100'' was fitted with five

torpedo tube A torpedo tube is a cylindrical device for launching torpedoes. There are two main types of torpedo tube: underwater tubes fitted to submarines and some surface ships, and deck-mounted units (also referred to as torpedo launchers) installed aboa ...

s (four fitted at the bow and one at the stern), fourteen

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, s ...

es, one SK C/35 naval gun, 220 rounds, and one anti-aircraft gun. The boat had a

complement A complement is something that completes something else. Complement may refer specifically to: The arts * Complement (music), an interval that, when added to another, spans an octave ** Aggregate complementation, the separation of pitch-clas ...

of between forty-four and sixty.

Service history

First patrol

The boat was launched on 10 April 1940, with a crew of 53, under the command of ''

Kapitänleutnant ''Kapitänleutnant'', short: KptLt/in lists: KL, ( en, captain lieutenant) is an officer grade of the captains' military hierarchy group () of the German Bundeswehr. The rank is rated OF-2 in NATO, and equivalent to Hauptmann in the Heer an ...

Joachim Schepke Joachim Schepke (8 March 1912 – 17 March 1941) was a German U-boat commander during World War II. He was the seventh recipient of the Knight's Cross of the Iron Cross with Oak Leaves. Schepke is credited with having sunk 36 Allied ships. Durin ...

. On her first active patrol, ''U-100'' came into contact with two Allied

convoys A convoy is a group of vehicles, typically motor vehicles or ships, traveling together for mutual support and protection. Often, a convoy is organized with armed defensive support and can help maintain cohesion within a unit. It may also be used ...

, OA-198 and OA-204. She shadowed both convoys.

Second patrol

''U-100'' departed for her second active patrol on 11 September 1940, coming into contact with the Allied

convoy HX 72 HX 72 was a North Atlantic convoy of the HX convoys, HX series which ran during the battle of the Atlantic in World War II. The convoy comprised 43 ships of which 11 were sunk and another damaged by German U-boats who suffered no losses. Backg ...

. 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.

Third patrol

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

''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

''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

''U-100'' departed on her sixth and what would be her final patrol on 9 March 1941. She approached

convoy HX 112 HX 112 was a North Atlantic convoy of the HX series which ran during the battle of the Atlantic in the Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 19 ...

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 Radar is a detection system that uses radio waves to determine the distance ('' ranging''), angle, and radial velocity of objects relative to the site. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, we ...

aboard .Rohwer & Hummelchen (1992) p. 54 ''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.Macintyre, Donald, CAPT RN "Shipborne Radar" ''United States Naval Institute Proceedings'' September 1967 pp. 78–79 Another destroyer, , was also present.. 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

References

Bibliography

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External links

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Canonesa, Convoy HX72 & ''U-100''
{{DEFAULTSORT:U0100 German Type VIIB submarines U-boats commissioned in 1940 U-boats sunk in 1941 World War II submarines of Germany World War II shipwrecks in the Atlantic Ocean 1940 ships Ships built in Kiel U-boats sunk in collisions U-boats sunk by British warships Maritime incidents in March 1941