Engineering:Type XVII submarine

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Short description: Class of German U-boat
U-1406.jpg
Type XVIIB submarine U-1406, partially dismantled shortly after the end of World War II
Class overview
Builders:
  • Blohm + Voss, Hamburg
  • Friedrich Krupp Germaniawerft, Kiel
Operators:
Preceded by:
  • Type II (Conventional coastal submarine)
  • V-80 (AIP testbed)
Succeeded by: Type XXIII (conventional coastal submarine)
Built: 1942 – 1945
In commission: 1943 – 1949
Planned: 16
Completed: 7
Cancelled: 9
General characteristics [1][2][3]
Type: Coastal submarine
Displacement:
  • Type XVIIA
  • Wa 201 :
    • 277 tonnes (273 long tons) surfaced
    • 309 t (304 long tons) submerged
    • 372 t (366 long tons) total
  • Wk 202 :
    • 236 t (232 long tons) surfaced
    • 259 t (255 long tons) submerged
    • 312 t (307 long tons) total
  • Type XVIIB
    • 312 t (307 long tons) surfaced
    • 337 t (332 long tons) submerged
    • 415 t (408 long tons) total
Length:
  • Type XVIIA
  • Wa 201 :
  • Wk 202 :
    • 36.60 m (120 ft 1 in) o/a
  • Type XVIIB
    • 41.45 m (136 ft 0 in) o/a
    • 27.30 m (89 ft 7 in) pressure hull
Beam:
  • 4.50 m (14 ft 9 in) o/a
  • Type XVIIA Wa 201 & Type XVIIB :
    • 3.30 m (10 ft 10 in) pressure hull
  • Type XVIIA Wk 202 :
    • 3.40 m (11 ft 2 in) pressure hull
Draft:
  • Type XVIIA Wa 201 & Type XVIIB :
    • 4.30 m (14 ft 1 in)
  • Type XVIIA Wk 202 :
    • 4.55 m (14 ft 11 in)
Propulsion:
  • 1 × Deutz SAA SM517 supercharged 8-cylinder Diesel engine, 210 PS (210 shp; 150 kW)
  • 1 × AEG Maschine AWT98 electric motor, 77 PS (76 shp; 57 kW)
  • 1 shaft
  • Type XVIIA Wa 201 U-792 & Wk 202 :
    • 2 × Walter gas turbines, 5,000 PS (4,900 shp; 3,700 kW)
  • Type XVIIA Wa 201 U-793 & Type XVIIB :
    • 1 × Walter gas turbine, 2,500 PS (2,500 shp; 1,800 kW)
Speed:
  • Type XVIIA
    • 9 knots (17 km/h; 10 mph) surfaced
    • 5 knots (9.3 km/h; 5.8 mph) submerged (electric drive)
    • 25 knots (46 km/h; 29 mph) submerged (HTP drive)
  • Type XVIIB
    • 8.8 knots (16.3 km/h; 10.1 mph) surfaced
    • 5 knots (9.3 km/h; 5.8 mph) submerged (electric drive)
    • 25 knots (46 km/h; 29 mph) submerged (HTP drive)
Range:
  • Type XVIIA, Wa 201 :
    • 2,910 nmi (5,390 km; 3,350 mi) at 8.5 knots (15.7 km/h; 9.8 mph) surfaced
    • 50 nmi (93 km; 58 mi) at 2 knots (3.7 km/h; 2.3 mph) submerged (electric drive)
    • 127 nmi (235 km; 146 mi) at 20 knots (37 km/h; 23 mph) submerged (HTP drive)
  • Wk 202 :
    • 1,840 nmi (3,410 km; 2,120 mi) at 9 knots (17 km/h; 10 mph) surfaced
    • 76 nmi (141 km; 87 mi) at 2 knots (3.7 km/h; 2.3 mph) submerged (electric drive)
    • 117 nmi (217 km; 135 mi) at 20 knots (37 km/h; 23 mph) submerged (HTP drive)
  • Type XVIIB
    • 3,000 nmi (5,600 km; 3,500 mi) at 8 knots (15 km/h; 9.2 mph) surfaced
    • 76 nmi (141 km; 87 mi) at 2 knots (3.7 km/h; 2.3 mph) submerged (electric drive)
    • 123 nmi (228 km; 142 mi) at 25 knots (46 km/h; 29 mph) submerged (HTP drive)
Complement:
  • Type XVIIA : 12
  • Type XVIIB : 19
Armament:
  • 2 × 53.3 cm (21 in) torpedo tubes (bow)
  • 2 × reserve torpedoes stored on the torpedo room floor.

The Type XVII U-boats were small coastal submarines that used a high-test peroxide propulsion system, which offered a combination of air-independent propulsion and high submerged speeds.

Background

In the early 1930s Hellmuth Walter had designed a small, high-speed submarine with a streamlined form propelled by high-test peroxide (HTP) and in 1939 he was awarded a contract to build an experimental vessel, the 80 ton V-80, which achieved an underwater speed of 28.1 knots (52.0 km/h; 32.3 mph) during trials in 1940. In November 1940 Admirals Erich Raeder and Werner Fuchs (head of the Kriegsmarine's Construction Office) witnessed a demonstration of the V-80; Raeder was impressed, but Fuchs was slow to approve further tests.

Following the success of the V-80's trials, Walter contacted Karl Dönitz in January 1942, who enthusiastically embraced the idea and requested that these submarines be developed as quickly as possible. An initial order was placed in summer 1942 for four Type XVIIA development submarines.

Construction

Of these, U-792 and U-793, designated Wa 201, were built by Blohm + Voss, achieved 20.25 kn (37.50 km/h; 23.30 mph) submerged. The other pair of Type XVIIA submarines, U-794 and U-795, designated Wk 202, were constructed by Friedrich Krupp Germaniawerft, Kiel.

The U-793 achieved a submerged speed of 22 kn (41 km/h; 25 mph) in March 1944 with Admiral Dönitz aboard. In June 1944 U-792 achieved 25 kn (46 km/h; 29 mph) over a measured mile.[4]

The Type XVIIA submarines were found to be very hard to handle at high speed, and were plagued by numerous mechanical problems, low efficiency, and the fact that a significant amount of power was lost due to increased back pressure on the exhaust at depth. Also, the length to beam ratio was too low, resulting in an unnecessarily high drag.[4]

Admiral Fuchs argued that introducing a new type of U-boat would hinder current production efforts, but Dönitz argued the case for them and on 4 January 1943 the Kriegsmarine ordered 24 Type XVII submarines.[5]

Construction of operational Type XVII submarines – the Type XVIIB – was begun at the Blohm + Voss yard in Hamburg. The Type XVIIB, unlike the XVIIA, had only a single turbine. The initial order was for 12 submarines, U-1405 through U-1416.[6] However, Blohm + Voss were already struggling to cope with orders for Type XXI submarines and the Kriegsmarine reduced the order to six.

Projected types

Twelve Type XVIIG of slightly improved design, U-1081 through U-1092, were at the same time ordered from Germaniawerft.[6]

A projected Type XVIIK would have abandoned the Walter system for closed-cycle Diesel engines using pure oxygen from onboard tanks. The only boat, U 798, was still unfinished at the Krupp Germaniawerft at the end of the war.

Completed boats

Three Type XVIIB boats were completed by Blohm + Voss of Hamburg between 1943 and 1945: U-1405, U-1406 and U-1407. U-1405 was completed in December 1944, U-1406 in February 1945, and U-1407 in March 1945.[7]

A further three boats (U-1408 to U-1410) were under construction, but were not complete when the war ended. Another six Type XVIIB's (U-1411 to U-1416) were cancelled during the war in favour of the Type XXI submarine.[2]

Post war

Type XVIIB boat (probably U-1406 or U-1407) raised by floating crane in Bremerhaven, August, 1945

All three completed Type XVIIB boats were scuttled by their crews at the end of World War II, U-1405 at Flensburg, and U-1406 and U-1407 at Cuxhaven, all in the British Zone of Occupation.[7] U-1406 and U-1407 were scuttled on 7 May 1945 by Oberleutnant zur See Gerhard Grumpelt, even though a superior officer, Kapitän zur See Kurt Thoma, had prohibited such actions. Grumpelt was subsequently sentenced to 7 years imprisonment by a British military court.[8]

At the Potsdam Conference in July 1945 U-1406 was allocated to the United States and U-1407 to Britain, and both were soon salvaged. The uncompleted U-1408 and U-1410 were discovered by British forces at the Blohm + Voss yard in Hamburg.[7]

The United States Navy did not repair and operate U-1406 as it had with the two Type XXI submarines it had captured. She travelled to the United States as deck cargo, having been stripped after being damaged by fire and twice flooded. Portsmouth Naval Shipyard estimated it would cost $1 million to put her into service, but plans to do so were rejected due to the perceived fire hazard and high cost of HTP, and she was broken up in New York harbour some time after 18 May 1948.[9]

The Royal Navy repaired U-1407 and recommissioned her on 25 September 1945 as HMS Meteorite. She served as the model for two further HTP boats, HMS Explorer and HMS Excalibur.

List of boats

Type XVIIA

Wa 201 — Blohm + Voss, Hamburg

Wk 202 — Germaniawerft, Kiel

Type XVIIB — Blohm + Voss, Hamburg

  • U-1405 — scuttled on 5 May 1945
  • U-1406 — scuttled on 7 May 1945, raised, and transported to the U.S.; broken up some time after 18 May 1948
  • U-1407 — scuttled on 7 May 1945, raised, repaired and served as HMS Meteorite until September 1949
  • U-1408 – 1410 — incomplete when the war ended
  • U-1411 – 1416 — contract cancelled before construction began

References

  1. Helgason, Guðmundur. "Type XVIIA Walter boats". http://uboat.net/types/xviia.htm. 
  2. 2.0 2.1 Helgason, Guðmundur. "Type XVIIB Walter boats". http://www.uboat.net/types/xviib.htm. 
  3. "This page contains details on the German U-Boat Type III, Type IV, Type V, Type VI, Type VIII, Type XI, Type XII, Type XIII, XV, XVI, VB60, V80, U-179, XVII.". www.sharkhunters.com. http://www.sharkhunters.com/typeadditional.htm. 
  4. 4.0 4.1 Polmar, p. 33
  5. Grier, Howard D (2007). Hitler, Dönitz, and the Baltic Sea. Naval Institute Press. p. 174. ISBN 978-1-59114-345-1. 
  6. 6.0 6.1 Akermann, Paul (2002). Encyclopedia of British Submarines 1901–1955. Periscope Publishing. p. 471. ISBN 1-904381-05-7. 
  7. 7.0 7.1 7.2 Polmar, p. 35
  8. Madsen, Chris (1998). The Royal Navy and German Naval Disarmament, 1942-1947. Routledge. p. 180. ISBN 0-7146-4823-X. 
  9. Friedman, Norman (1994). U.S. Submarines Since 1945: An Illustrated Design History. Naval Institute Press. p. 249. ISBN 1-55750-260-9. 

Bibliography

  • Gröner, Erich; Jung, Dieter; Maass, Martin (1991). German Warships 1815–1945, U-boats and Mine Warfare Vessels. 2. London: Conway Maritime Press. ISBN 0-85177-593-4. 
  • Polmar, Norman; Kenneth J. Moore (2004). Cold War Submarines: The Design and Construction of U.S. and Soviet Submarines. Brassey's. pp. 35–36. ISBN 1-57488-594-4.