German submarine U-870

Summary

German submarine U-870 was a Type IXC/40 U-boat of Nazi Germany's Kriegsmarine built for service during the Second World War. She was ordered on 25 August 1941, and laid down on 29 April 1943 at Bremen, Germany. She was launched on 29 October 1943 and commissioned on 3 February 1944.

History
Nazi Germany
NameU-870
Ordered25 August 1941
BuilderDeSchiMAG AG Weser, Bremen
Yard number1078
Laid down29 April 1943
Launched29 October 1943
Commissioned3 February 1944
FateSunk on 30 March 1945
General characteristics
Class and typeType IXC/40 submarine
Displacement
  • 1,144 t (1,126 long tons) surfaced
  • 1,257 t (1,237 long tons) submerged
Length
Beam
  • 6.86 m (22 ft 6 in) o/a
  • 4.44 m (14 ft 7 in) pressure hull
Height9.60 m (31 ft 6 in)
Draught4.67 m (15 ft 4 in)
Installed power
  • 4,400 PS (3,200 kW; 4,300 bhp) (diesels)
  • 1,000 PS (740 kW; 990 shp) (electric)
Propulsion
Speed
  • 18.3 knots (33.9 km/h; 21.1 mph) surfaced
  • 7.3 knots (13.5 km/h; 8.4 mph) submerged
Range
  • 13,850 nmi (25,650 km; 15,940 mi) at 10 knots (19 km/h; 12 mph) surfaced
  • 63 nmi (117 km; 72 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth230 m (750 ft)
Complement4 officers, 44 enlisted
Armament
Service record[1]
Part of:
Identification codes: M 49 432
Commanders:
Operations:
  • 1 patrol:
  • a. 10 November 1944 – 20 February 1945
  • b. 25 – 27 February 1945
Victories:
  • 2 warships sunk
    (1,960 tons)
  • 2 merchant ships total loss
    (11,844 GRT)
  • 1 warship damaged
    (1,400 tons)

Design edit

German Type IXC/40 submarines were slightly larger than the original Type IXCs. U-870 had a displacement of 1,144 tonnes (1,126 long tons) when at the surface and 1,257 tonnes (1,237 long tons) while submerged.[2] The U-boat had a total length of 76.76 m (251 ft 10 in), a pressure hull length of 58.75 m (192 ft 9 in), a beam of 6.86 m (22 ft 6 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.67 m (15 ft 4 in). The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 shaft horsepower (1,010 PS; 750 kW) for use while submerged. She had two shafts and two 1.92 m (6 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 18.3 knots (33.9 km/h; 21.1 mph) and a maximum submerged speed of 7.3 knots (13.5 km/h; 8.4 mph).[2] When submerged, the boat could operate for 63 nautical miles (117 km; 72 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 13,850 nautical miles (25,650 km; 15,940 mi) at 10 knots (19 km/h; 12 mph). U-870 was fitted with six 53.3 cm (21 in) torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm (4.13 in) SK C/32 naval gun, 180 rounds, and a 3.7 cm (1.5 in) Flak M42 as well as two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of forty-eight.[2]

Service history edit

For her one patrol, she had one commander, Korvettenkapitän Ernst Hechler, who was awarded the Knight's Cross of the Iron Cross.

Over her career she claimed two warships sunk, total of 1,960 tons, one warship damaged for a total of 1,400 tons, and two ships a total loss, total of 11,844 gross register tons (GRT).[1] On 20 December 1944, U-870 attacked a small group of landing ships, damaging USS Fogg and sinking the 1,625-tons vessel USS LST-359. The U-boat was then attacked by a British aircraft from No. 220 Squadron RAF but got away, also evading two hunter-killer groups of vessels.[1]

Fate edit

She was sunk on 30 March 1945 at Bremen by US bombs.[1]

Summary of raiding history edit

Date Ship Name Nationality Tonnage[Note 1] Fate[3]
20 December 1944 USS Fogg   United States Navy 1,400 Damaged at 43°02′N 19°19′W / 43.033°N 19.317°W / 43.033; -19.317 (USS Fogg (ship))
20 December 1944 USS LST-359   United States Navy 1,625 Sunk at 42°04′N 19°08′W / 42.067°N 19.133°W / 42.067; -19.133 (USS LST-359 (ship))
3 January 1945 Henry Miller   United States 7,207 Total loss at 35°51′N 06°24′W / 35.850°N 6.400°W / 35.850; -6.400 (Henry Miller (ship))
9 January 1945 FFL L´Enjoue   Free French Naval Forces 335 Sunk at 35°56′N 05°49′W / 35.933°N 5.817°W / 35.933; -5.817 (FFL L´Enjoue (W 44) (ship))
10 January 1945 Blackheath   United Kingdom 4,637 Total loss at 35°49′N 06°03′W / 35.817°N 6.050°W / 35.817; -6.050 (Blackheath (ship))

References edit

Notes edit

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

Citations edit

  1. ^ a b c d Helgason, Guðmundur. "The Type IXC/40 boat U-870". German U-boats of WWII – uboat.net. Retrieved 2 February 2015.
  2. ^ a b c d Gröner 1991, p. 68.
  3. ^ Helgason, Guðmundur. "Ships hit by U-870". German U-boats of WWII – uboat.net. Retrieved 13 February 2014.

Bibliography edit

  • 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). Der U-Boot-Krieg, 1939-1945: Deutsche U-Boot-Verluste von September 1939 bis Mai 1945 [German U-boat losses from September 1939 to May 1945] (in German). Vol. IV. Hamburg, Berlin, Bonn: Mittler. ISBN 3-8132-0514-2.
  • Gröner, Eric; 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.
  • Sharpe, Peter (1998). U-Boat Fact File, 1935-1945. Great Britain: Midland Publishing. ISBN 1-85780-072-9.

External links edit

  • Helgason, Guðmundur. "The Type IXC/40 boat U-870". German U-boats of WWII – uboat.net. Retrieved 2 February 2015.