U-Boat Operations

U-31	Type VIIA
Feldpost Number	M 28 961
Construction Yard	Deutsche Schiff- und Maschinenbau AG, (AG Weser) Bremen
Yard Number	912
Ordered	1st Apr 1935
Keel laid	1st Mar 1936
Launched	25th Sep 1936
Commissioned	28th Dec 1936
Baubelehrung	Marinelehr-und Reparaturwerkstatt, Wilhelmshaven / Lehrwerkstatt, Wilhelmshaven
Training, Flotillas and Duties
12.36 - 12.39	U-Flottille Saltzwedel, Wilhelmshaven Frontboot (operational)
01.40 - 03.40	2.U-Flottille, Wilhelmshaven Frontboot (operational)
	Decommissioned
07.40 - 11.40	2.U-Flottille, Wilhelmshaven Frontboot (operational)
Commanders
28.12.36 - 08.11.38	KL Rolf Dau see also: U-5 U-42
08.11.38 - 11.03.40	KL Johannes Habekost
08.07.40 - 02.11.40	OL Wilfried Prellberg see also: U-19

Operations information for U-31
27.08.1939 - 02.09.1939 First Sailing - active patrol U-31 left Memel under the command of Johannes Habekost on 27th Aug 1939 and arrived at return on 2nd Sep 1939 after six days.
09.09.1939 - 02.10.1939 Second Sailing - active patrol On the 9th Sep 1939, U-31 left Wilhelmshaven under the command of Johannes Habekost for operations in the North Atlantic and after over three weeks arrived at return on 2nd Oct 1939. Johannes Habekost hit two ships on this patrol, one was from convoy OB-4. On 16th Sep 1939 he sank the British 4,060 ton Aviemore, sailing with convoy OB-4. On 24th Sep 1939 he sank the British 4,646 ton Hazelside. It is thought that U-31 was the first U-Boat to sight a convoy during WW2, on 15th September KL Habecost sighted convoy OB-4
21.10.1939 - 31.10.1939 Third Sailing - active patrol U-31 departed under Johannes Habekost from Wilhelmshaven on 21st Oct 1939 for operations off Loch Ewe and arrived at return on 31st Oct 1939 after one and a half weeks. U-31 laid mines on this patrol. These mines were hit by 3 ships. The 33,950 ton British HMS Nelson was damaged by a mine on 4th Dec 1939. The 78 ton British HMS Promotive was sunk by a mine on 23rd Dec 1939. The 82 ton British HMS Glenalbyn was sunk by a mine on 23rd Dec 1939.U-31 had originally been detailed to lay mines within Loch Ewe but was unable to because of effective nets across the entrance. Therefore KL Habecost laid 18 TMB mines across the entrance instead.
19.11.1939 - 11.12.1939 Fourth Sailing - active patrol U-31 left Wilhelmshaven under the command of Johannes Habekost on 19th Nov 1939 for operations in the North Sea and after just over three weeks arrived at return on 11th Dec 1939. Johannes Habekost hit six ships on this patrol. On 1st Dec 1939 he sank the Norwegian 1,277 ton Arcturus. On 3rd Dec 1939 he sank the Danish 2,135 ton Ove Toft. On 4th Dec 1939 he sank the Norwegian 1,024 ton Primula. On 4th Dec 1939 he sank the Norwegian 1,271 ton Gimle. On 6th Dec 1939 he sank the Estonian 1,575 ton Agu. On 6th Dec 1939 he sank the Swedish 1,974 ton Vinga. Until recently it was believed that U 21 had sunk Arcturus and U 31 had sunk Mercator. However the times recorded in each boat's KTB and the location of Mercator - confirmed by the position of its wreck - leave little doubt that U 21 sank Mercator and U 31 sank Arcturus. Thanks to Jan-Olof Hending and Roland Berr for their assistance.You can read more about the Norwegian ships listed for this patrol at www.warsailors.com. Click the links for more information on Arcturus, Primula and Gimle.
15.01.1940 - 04.02.1940 Fifth Sailing - active patrol On the 15th Jan 1940, U-31 left Wilhelmshaven under the command of Johannes Habekost for operations off Loch Ewe and arrived at return on 4th Feb 1940 after nearly three weeks.U-31 once again attempted to lay mines within Loch Ewe, but failed to do so on the night of the 21st.
16.09.1940 - 08.10.1940 Sixth Sailing - active patrol U-31 departed under Wilfried Prellberg from Wilhelmshaven on 16th Sep 1940 and after just over three weeks arrived at return on 8th Oct 1940. Wilfried Prellberg hit two ships on this patrol. On 22nd Sep 1940 he sank the 81 ton Union Jack. On 27th Sep 1940 he sank the Norwegian 4,319 ton Vestvard. On OL Prellberg's return through the Bay of Biscay, the British submarine HMS Trident was waiting, it fired a torpedo at U-31 which missed. Both submarines ineffectively exchanged artillery fire for some minutes.You can read more about the Norwegian ship listed for this patrol at www.warsailors.com. Click the link for more information on Vestvard.
19.10.1940 - 02.11.1940 Seventh Sailing U-31 left Lorient under the command of Wilfried Prellberg on 19th Oct 1940 for operations in the North West approaches and arrived at return on 2nd Nov 1940 after two weeks. Wilfried Prellberg hit one ship on this patrol. On 29th Oct 1940 he sank the British 5,389 ton Matina.

Notes for U-31

U-31 was the only boat to be sunk twice by enemy action during the war. Between U-31's fifth and sixth patrols on 11th March 1940 she was being taken for trials by crew and dock workers in the shallow waters of the Jade Bay (North Sea) when she was sighted by 82 SQN Blenheim of RAF 2 Grp Bomber Command (SL M V Delap). The Blenheim attacked with 4 A/S bombs, and 2 hits were observed. The boat disappeared and a large quantity of oil was seen. 58 crew died including 10 dock workers, there were no survivors.

On 24th March 1940 U-31 was raised and thereafter recommissioned on 30th July 1940, only to be sunk on the 2nd of November 1940, NW of Ireland by D/C's from HMS Antelope. 2 men were killed in this attack, 44 survived.

We have 140 crew names for this boat. click here for crew names of U 31
You can perform other crew searches here. Note that the number of names we give possibly includes prior crew members.

You can discuss this boat or ask questions at the ubootwaffe.net forums

We have a position of 53°37N 08°10E for where this boat went down the first time, mapped below. U 31 was later raised. The cross represents where the boat had gone down.