German submarine U-20 (1936)

U-9, a typical Type IIB boat
History
Nazi Germany
Name:	U-20
Ordered:	2 February 1935
Builder:	Germaniawerft, Kiel
Yard number:	550
Laid down:	1 August 1935
Launched:	14 January 1936
Commissioned:	1 February 1936
Fate:	Scuttled 10 September 1944, off the coast of Turkey in the Black Sea
General characteristics
Class & type:	IIB coastal submarine
Displacement:	279 t (275 long tons) surfaced 328 t (323 long tons) submerged
Length:	42.70 m (140 ft 1 in) o/a 27.80 m (91 ft 2 in) pressure hull
Beam:	4.08 m (13 ft 5 in) (o/a) 4.00 m (13 ft 1 in) (pressure hull)
Height:	8.60 m (28 ft 3 in)
Draught:	3.90 m (12 ft 10 in)
Installed power:	700 PS (510 kW; 690 bhp) (diesels) 410 PS (300 kW; 400 shp) (electric)
Propulsion:	2 shafts 2 × diesel engines 2 × electric motors
Range:	1,800 nmi (3,300 km; 2,100 mi) at 12 knots (22 km/h; 14 mph) surfaced 35–43 nmi (65–80 km; 40–49 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth:	80 m (260 ft)
Complement:	3 officers, 22 men
Armament:	3 × 53.3 cm (21 in) torpedo tubes 5 × torpedoes or up to 12 TMA or 18 TMB 1 × 2 cm (0.79 in) anti-aircraft gun
Service record
Part of:	Kriegsmarine 1st U-boat Flotilla 3rd U-boat Flotilla 21st U-boat Flotilla 30th U-boat Flotilla
Identification codes:	M 29 241
Commanders:	Hans Eckermann Karl-Heinz Moehle Harro von Klot-Heydenfeldt Heinrich Driver Hans-Jürgen Zetzsche Ottokar Arnold Paulshen Herbert Schauenburg Wolfgang Sträter Kurt Nölke Clemens Schöler Karl Grafen
Operations:	16; 1st patrol: 24–31 August 1939 2nd patrol: 29 September – 17 October 1939 3rd patrol: 18–24 November 1939 4th patrol: 7–13 December 1939 5th patrol: 6–16 January 1940 6th patrol: a. 21–21 January 1940 b. 23–31 January 1940 c. 4–4 February 1940 7th patrol: 27 February – 4 March 1940 8th patrol: 14–20 March 1940 9th patrol: 22–29 June 1943 10th patrol: 11 July – 7 August 1943 11th patrol: a. 16–22 September 1943 b. 24 September–12 October 1943 12th patrol: 8 November – 9 December 1943 13th patrol: 1–26 January 1944 14th patrol: a. 22 February – 1 March 1944 b. 2–27 March 1944 15th patrol: 11 June – 11 July 1944 16th patrol: 19 August – 10 September 1944
Victories:	13 ships sunk for a total of 30,067 GRT One ship damaged, of 1,846 GRT. Two ships declared a total loss for a total of 8,446 GRT

German submarine U-20 was a Type IIB U-boat of Nazi Germany's Kriegsmarine. Her keel was laid down on 1 August 1935, by Germaniawerft of Kiel as yard number 550. She was commissioned on 1 February 1936. During World War II, she conducted operations against enemy shipping.

U-20 went on 16 war patrols, sinking 16 ships totalling 39,637 GRT and damaging one more of 1,846 GRT.

Design

German Type IIB submarines were enlarged versions of the original Type IIs. U-20 had a displacement of 279 tonnes (275 long tons) when at the surface and 328 tonnes (323 long tons) while submerged. Officially, the standard tonnage was 250 long tons (250 t), however. The U-boat had a total length of 42.70 m (140 ft 1 in), a pressure hull length of 28.20 m (92 ft 6 in), a beam of 4.08 m (13 ft 5 in), a height of 8.60 m (28 ft 3 in), and a draught of 3.90 m (12 ft 10 in). The submarine was powered by two MWM RS 127 S four-stroke, six-cylinder diesel engines of 700 metric horsepower (510 kW; 690 shp) for cruising, two Siemens-Schuckert PG VV 322/36 double-acting electric motors producing a total of 460 metric horsepower (340 kW; 450 shp) for use while submerged. She had two shafts and two 0.85 m (3 ft) propellers. The boat was capable of operating at depths of up to 80–150 metres (260–490 ft).

The submarine had a maximum surface speed of 12 knots (22 km/h; 14 mph) and a maximum submerged speed of 7 knots (13 km/h; 8.1 mph). When submerged, the boat could operate for 35–42 nautical miles (65–78 km; 40–48 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 3,800 nautical miles (7,000 km; 4,400 mi) at 8 knots (15 km/h; 9.2 mph). U-20 was fitted with three 53.3 cm (21 in) torpedo tubes at the bow, five torpedoes or up to twelve Type A torpedo mines, and a 2 cm (0.79 in) anti-aircraft gun. The boat had a complement of twentyfive.

Operational history

1st, 2nd and 3rd patrols

U-20's first three patrols involved observation (in August 1939) and the laying of mines in the North Sea and off the British east coast. She would start in Kiel and finish in Wilhelmshaven; then reverse the process.

4th and 5th patrols

She sank Magnus about 40 nmi (74 km; 46 mi) east northeast of Peterhead in Scotland. The ship went down in 90 seconds; there was only one survivor. She also sank Ionian and Willowpool in November and December respectively, with mines laid in November.

The boat sank Sylvia northeast of Aberdeen on her fifth sortie on 13 October 1940.

6th - 8th patrols

U-20 sank a steady number of ships on her sixth and seventh patrols, (her eighth foray was relatively quiet), but a series of changes were on the way.

She was transferred to the U-Ausbildungsflottille as a school boat on 1 May 1940, then the Black Sea, avoiding the heavy British presence at Gibraltar and throughout the Mediterranean by moving overland and along the Danube to her new home with the 30th U-boat Flotilla at Constanta in Romania.

9th and 10th patrols

The boat's first patrol in the new environment, but her ninth overall, almost ended in disaster when she tried to torpedo a Soviet submarine chaser; the vessel responded by dropping eight depth charges. U-20 was obliged to stay submerged for four hours and returned to base with various mechanical failures.

Near the end of sally number ten, a crew member from U-19 who had been taken sick, was transferred to U-20 on 4 August 1943. The boat docked at Constanta on the 7th.

11th - 14th patrols

These patrols were conducted between Constanta and Sevastopol. U-20 sank the Soviet Vaijan Kutur'e on 16 January 1944 off Cape Anakria.

15th patrol

The boat sank Pestel on 19 June 1944 off Trabzon. The Soviets reported that this ship was sunk in Turkish territorial waters.

She also sank the Soviet landing craft DB-26 on 26 June with gunfire and demolition charges.

16th patrol and fate

She was scuttled on 10 September 1944, in the Black Sea off the coast of Turkey.

On 3 February 2008, The Daily Telegraph newspaper reported that U-20 had been discovered by Selçuk Kolay, a Turkish marine engineer, in 80 feet (24 m) of water off the coast of the Turkish city of Karasu.

Summary of raiding history

Date	Name	Nationality	Tonnage (GRT)	Fate
29 November 1939	Ionian	United Kingdom	3,114	Sunk (mine)
9 December 1939	Magnus	Denmark	1,339	Sunk
10 December 1939	Føina	Norway	1,674	Sunk
10 December 1939	Willowpool	United Kingdom	4,815	Sunk (mine)
13 January 1940	Sylvia	Sweden	1,524	Sunk
27 January 1940	England	Denmark	2,319	Sunk
27 January 1940	Faro	Norway	844	Total loss
27 January 1940	Friedensborg	Denmark	2,094	Sunk
27 January 1940	Hosanger	Denmark	1,591	Sunk
29 February 1940	Maria Rosa	Italy	4,211	Sunk
1 March 1940	Mirella	Italy	5,340	Sunk
29 November 1943	Peredovik	Soviet Union	1,846	Damaged
16 January 1944	Vaijan Kutur'e	Soviet Union	7,602	Total loss
7 April 1944	Rion	Soviet Union	184	Sunk (mine)
19 June 1944	Pestel	Soviet Union	1,850	Sunk
24 June 1944	DB-26	Soviet Union	9	Sunk