German submarine U-997

Last updated
U995 2004 1.jpg
U-995 Type VIIC/41 at the Laboe Naval Memorial. This U-boat is almost identical to U-997.
History
War ensign of Germany (1938-1945).svg Nazi Germany
NameU-997
Ordered14 October 1941
Builder Blohm & Voss AG, Hamburg
Yard number197
Laid down7 December 1942
Launched18 August 1943
Commissioned23 September 1943
Fate
General characteristics [1]
Class and type Type VIIC/41 submarine
Displacement
Length
Beam
  • 6.20 m (20 ft 4 in) o/a
  • 4.70 m (15 ft 5 in) pressure hull
Height9.60 m (31 ft 6 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
  • 17.7 knots (32.8 km/h; 20.4 mph) surfaced
  • 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range
  • 8,500  nmi (15,700  km; 9,800  mi) at 10 knots (19 km/h; 12 mph) surfaced
  • 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth
  • 230 m (750 ft)
  • Calculated crush depth: 250–295 m (820–968 ft)
Complement44-52 officers & ratings
Armament
Service record
Part of:
Identification codes: M 55 164
Commanders:
Operations:
  • 7 patrols:
  • 1st patrol:
  • a. 25 May – 22 June 1944
  • b. 18 – 20 July 1944
  • 2nd patrol:
  • 6 August – 2 September 1944
  • 3rd patrol:
  • a. 13 September – 2 October 1944
  • b. 8 – 10 October 1944
  • 4th patrol:
  • 14 October – 9 November 1944
  • 5th patrol:
  • a. 21 November – 26 December 1944
  • b. 27 – 29 December 1944
  • c. 22 – 26 February 1945
  • d. 7 – 8 March 1945
  • 6th patrol:
  • 12 – 24 March 1945
  • 7th patrol:
  • a. 17 – 30 April 1945
  • b. 12 May 1945
  • c. 15 – 19 May 1945
Victories:
  • 1 merchant ship sunk
    (1,603  GRT)
  • 1 warship sunk
    (105 tons)
  • 1 merchant ship damaged
    (4,287  GRT)

German submarine U-997 was a Type VIIC/41 U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 7 December 1942 by Blohm & Voss, Hamburg as yard number 197, launched on 18 August 1943 and commissioned on 23 September 1943 under Oberleutnant zur See Hans Lehmann.

Contents

Design

Like all Type VIIC/41 U-boats, U-977 had a displacement of 759 tonnes (747 long tons) when at the surface and 860 tonnes (850 long tons) while submerged. She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), and a draught of 4.74 m (15 ft 7 in). [3] The submarine was powered by two Germaniawerft F46 supercharged six-cylinder four-stroke 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) and 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. The boat was capable of operating at a depth of 250 metres (820 ft). [3]

The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). [3] U-997 was fitted with three anti-aircraft guns, five 53.3 cm (21 in) torpedo tubes (four on the bow and one on the stern) and fourteen torpedoes. Its complement was between forty-four and sixty. [3]

Sensors

Passive sonar

U-997 was one of only ten Type VIIC's to be fitted with a Balkongerät (literally 'Balcony apparatus or equipment'). The Balkongerät was used on U-boats (U-682, U-788, U-799, U-1021, U-1105, U-1172, U-1306, U-1307 and U-1308). [4] The Balkongerät was standard on the Type XXI and the Type XXIII. Nonetheless, it was also fitted to several Type IXs and one Type X. The Balkongerät was an improved version of Gruppenhorchgerät (GHG) (group listening device). The GHG had 24 hydrophones, the Balkongerät had 48 hydrophones and improved electronics, which enabled more accurate readings to be taken. [5]

Service history

The boat's service career began on 23 September 1943 with the 5th Training Flotilla, followed by 12 months active service, with a succession of three flotillas, namely 9th Flotilla on 1 May 1944, then 13th Flotilla on 1 June 1944, and finally with 14th Flotilla on 1 March 1945.

Wolfpacks

U-997 took part in seven wolfpacks, namely:

Fate

U-997 was surrendered on 9 May 1945 and was sunk by aircraft on 13 December 1945 in the North Atlantic, in position 55°50′N10°05′W / 55.833°N 10.083°W / 55.833; -10.083 , as part of Operation Deadlight.

Summary of raiding history

DateShip NameNationalityTonnage [Note 1] Fate [6]
7 December 1944 BO-229 Naval Ensign of the Soviet Union (1950-1991).svg  Soviet Navy 105Sunk
22 April 1945 Idefjord Flag of Norway.svg  Norway 4,287Damaged
22 April 1945 Onega Flag of the Soviet Union.svg  Soviet Union 1,603Sunk

See also

Related Research Articles

German submarine U-1021 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

German submarine U-712 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. Commissioned on 5 November 1942, she served with the 8th U-boat Flotilla until 31 October 1943 as a training boat, and as a front boat in the 3rd U-boat Flotilla under Oberleutnant zur See Walter Pietschmann until 14 December, before being replaced by Oberleutnant zur See Walter-Ernst Koch.

German submarine U-565 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 30 March 1940 by Blohm & Voss in Hamburg as yard number 541, launched on 20 February 1941 and commissioned on 10 April 1941 under Oberleutnant Johann Jebsen.

German submarine <i>U-245</i> German World War II submarine

German submarine U-245 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 18 November 1942 at the Friedrich Krupp Germaniawerft yard at Kiel as yard number 679, launched on 25 November 1943 and commissioned on 18 December under the command of Korvettenkapitän Friederich Schumann-Hindenberg.

German submarine U-310 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 30 January 1942 at the Flender Werke yard at Lübeck as yard number 310, launched on 3 January 1943 and commissioned on 24 February under the command of Leutnant zur See Klaus Friedland.

German submarine U-311 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 21 March 1942 at the Flender Werke yard at Lübeck as yard number 311, launched on 20 January 1943 and commissioned on 23 March under the command of Kapitänleutnant Joachim Zander.

German submarine U-775 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 22 January 1943 by Kriegsmarinewerft Wilhelmshaven as yard number 158, launched on 11 February 1944 and commissioned on 23 March 1944 under Oberleutnant zur See Erich Taschenmacher.

German submarine U-989 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 17 October 1942 by Blohm & Voss, Hamburg as yard number 189, launched on 16 June 1943 and commissioned on 22 July 1943 under Oberleutnant zur See Hardo Rodler von Roithberg.

German submarine U-1051 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 8 February 1943 by Friedrich Krupp Germaniawerft, Kiel as yard number 685, launched on 3 February 1944 and commissioned on 4 March 1944 under Oberleutnant zur See Heinrich von Holleben.

German submarine <i>U-1004</i> German World War II submarine

German submarine U-1004 was a Type VIIC/41 U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 15 January 1943 by Blohm & Voss, Hamburg as yard number 204, launched on 27 October 1943 and commissioned on 16 December 1943 under Oberleutnant zur See Hartmuth Schimmelpfennig.

German submarine <i>U-1017</i> German World War II submarine

German submarine U-1017 was a Type VIIC/41 U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 19 April 1943 by Blohm & Voss, Hamburg as yard number 217, launched on 1 March 1944 and commissioned on 13 April 1944 under Kapitänleutnant Victor Graf von Reventlow-Criminil.

German submarine <i>U-1172</i> German World War II submarine

German submarine U-1172 was a Type VIIC/41 U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 7 June 1943 by Danziger Werft, Danzig as yard number 144, launched on 3 December 1943 and commissioned on 20 April 1944 under Oberleutnant zur See Jürgen Kuhlmann.

German submarine <i>U-1274</i> German World War II submarine

German submarine U-1274 was a Type VIIC/41 U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was ordered on 13 June 1942, and was laid down on 21 June 1943 by Vegesacker Werft AG, Bremen as yard number 69, launched on 25 January 1944 and commissioned on 1 March 1944 under Oberleutnant zur See Fedor Kuscher.

German submarine <i>U-992</i> German World War II submarine

German submarine U-992 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 30 October 1942 by Blohm & Voss, Hamburg as yard number 192, launched on 24 June 1943 and commissioned on 2 August 1943 under Oberleutnant zur See Hans Falke.

German submarine U-1203 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 15 May 1943 by Schichau-Werke, Danzig as yard number 1573, launched on 9 December 1943 and commissioned on 10 February 1944 under Oberleutnant zur See Erich Steinbrink.

German submarine U-825 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 19 July 1943 by Schichau-Werke, Danzig as yard number 1588, launched on 16 February 1944 and commissioned on 4 May 1944 under Oberleutnant zur See Gerhard Stoelker.

German submarine U-979 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 10 August 1942 by Blohm & Voss, Hamburg as yard number 179, launched on 15 April 1943 and commissioned on 20 May 1943 under Oberleutnant zur See Johannes Meermeier.

German submarine U-682 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 21 December 1942 at the Howaldtswerke yard at Hamburg, launched on 7 March 1944, and commissioned on 17 April 1944 under the command of Leutnant zur See d.R. Sven Thienemann.

German submarine <i>U-1306</i> German World War II submarine

German submarine U-1306 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

German submarine <i>U-1307</i> German World War II submarine

German submarine U-1307 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

References

Notes

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

Citations

  1. Helgason, Guðmundur. "Type VIIC/41". German U-boats of WWII - uboat.net. Retrieved 23 March 2015.
  2. Helgason, Guðmundur. "Hans Lehmann (Knight's Cross)". German U-boats of WWII - uboat.net. Retrieved 23 March 2015.
  3. 1 2 3 4 Gröner 1991, pp. 43–46.
  4. Base on war-time photographs.
  5. "Hydrophones". U-boats Aces - uboataces.com. Retrieved 20 May 2016.
  6. Helgason, Guðmundur. "Ships hit by U-997". German U-boats of WWII - uboat.net. Retrieved 26 March 2015.

Bibliography