First patrol In preparation for the
German invasion of Poland and potential war with the United Kingdom and France, Admiral
Karl Dönitz, commander of Germany's submarine forces, ordered a deployment of U-boats to the Atlantic in August 1939.
U-37 left
Wilhelmshaven, with Heinrich Schuch in command, on 19 August 1939, passing north of the British Isles while en-route to the submarine's patrol area off Spain and Portugal rather than via the
English Channel. The boat operated for nearly four weeks in the
North Atlantic, returning to port on 15 September 1939.
Second patrol U-37 left Wilhelmshaven on 5 October 1939 to conduct operations in the North Atlantic now under the command of
Werner Hartmann. It was intended that Hartmann would direct a group of German submarines (known as a
wolfpack) against allied
convoys.
Hartmann's wolfpack consisted of six submarines, three Type IX submarines and three smaller
Type VIIs, from two different flotillas which had never exercised together. On the way to the patrol area,
U-37 sank two merchant ships, the Swedish
Vistula on 8 October and the Greek
Aris on 12 October. The wolfpack was then ordered to attack the Anglo-French convoy
KJF3, inbound from Jamaica, but
U-37 was too far away to direct the operation as intended, and was unable to catch the convoy, although
U-37 did manage to sink a straggler from the convoy, the French cargo ship
Vermont. The group was then ordered to attack
Convoy HG 3, sailing from
Gibraltar to
Liverpool, England.
U-37 sank the British cargo steamship
Yorkshire from the convoy, with two more ships being sunk by and .
U-37 continued her patrol further south, sinking three ships to the west of the
Straits of Gibraltar on 24 October, the British
Menin Ridge,
Ledbury and
Tafna, before being attacked by the British
destroyers and with
depth charges before the submarine managed to escape. On 4 February 1940,
U-37 sank two ships east of
Sumburgh Head,
Shetland, the Norwegian
steamship Hop and the British
Leo Dawson. On 8 February the submarine landed two agents at
Donegal Bay, Ireland, These agents were soon arrested, however. On the way to the assigned patrol area
U-37 sank the Norwegian merchant ship
Silja on 10 February and the British trawler
Togimo on 11 February, before being diverted to the Western end of the English Channel in an unsuccessful attempt to intercept the
aircraft carrier . After being released from this attempt,
U-37 sank the Danish steamship
Aase on 15 February. After reaching the patrol area,
U-37 was directed against a convoy detected by German signal intelligence, sinking three ships in two days, the
Pyrrhus on 17 February and the Greek
Ellin and the French
P.L.M. 15 on 18 February, although
Pyrrhus and
P.L.M. 15 were stragglers from separate convoys, and
Ellin was sailing independently.
U-37 returned to Wilhelmshaven on 27 February. As on his previous patrol, Hartmann sank eight ships, this time three British, two Norwegian, one Danish, one French and one Greek. with the submarine's initial duty being escorting the auxiliary cruiser as the raider broke out into the Atlantic. After leaving
Atlantis,
U-37 reverted to a normal patrol, sinking two ships, the Swedish
tanker Sveaborg and the Norwegian
Tosca north of the
Faroe Islands on 10 April and the British steamship
Stancliffe north-east of
Unst, Shetland, on 12 April. On 13 April,
U-37 attempted to attack a British
cruiser, but torpedo defects caused the attack to fail. After patrolling for over two weeks, the U-boat returned to Wilhelmshaven on 18 April. On 19 May,
U-37 sank the Swedish merchant ship
Erik Frisell with gunfire, and on the night of 22/23 May attacked the British
Dunster Grange. Several torpedoes were fired at the merchant ship, but torpedo failures meant that none of the torpedoes struck home.
U-37 then attacked with her gun, hitting
Dunster Grange, but return fire from the British ship caused
U-37 to break off the attack. Oehrn reported the torpedo failures by radio, and in response, Dönitz ordered all U-boats to switch from magnetic to impact detonators. The contact detonators were more successful, and
U-37 torpedoed and sank the Greek steamship
Kyma the next day. On 27 May
U-37 torpedoed and sank the steamship
Sheaf Mead. Observing that
Sheaf Mead was painted gray and was fitted with deck guns, Oehrn concluded that the ship was an auxiliary cruiser or a
Q-ship, and made no attempt to assist the survivors of the sinking. This refusal to assist the survivors was later cited by prosecutors at the
Nuremberg trials as an example of German brutality. Later that day,
U-37 stopped the Argentinean cargo ship
Uruguay, sailing from
Rosario to
Limerick with a cargo of
maize. After examining
Uruguays papers,
U-37 sank her with scuttling charges.
Uruguays crew of 28 were left in their
lifeboats. 15 died, 13 survived.
U-37 sank the French
cargo liner and trawler
Julien on 28 May, and on 29 May sank the French steamship
Marie José and the British tanker
Telena. On 1 June
U-37 sank the Greek steamship
Ioanna and on 3 May the Finnish
Snabb.
U-37 returned to Wilhelmshaven on 9 June, having used up all her torpedoes. This was the submarine's most successful mission, hitting eleven ships, sinking ten of them. Three French ships were sunk, two Greek, two British, one Swedish, one Argentinian, one Finnish; one British ship was damaged.
Seventh patrol For the first time,
U-37 began a patrol from a location other than Germany, at Lorient on 17 August, with Oehrn in command once more. The submarine was to focus on operations in the mid-Atlantic. On 23 August,
U-37 sank the Norwegian steamship
Keret and the British
Severn Leigh, and early on 24 sank the British steamship
Brookwood. Later that day,
U-37 attacked
Convoy SC 1, sinking the British
sloop and then
Blairmore from the same convoy early on 25 August. Attacks by air and surface escorts forced the patrol to be abandoned early, but this did not stop
U-37 from sinking the steamship
Yewcrest later on 25 August and the Greek
Theodoros T on 27 August.
U-37 returned to Lorient on 30 August 1940, having sunk seven ships during this voyage, including
Penzance (which Oehrn identified as a destroyer). On 27 September,
U-37 sank the Egyptian
Georges Mabro and on 28 September, the submarine encountered SS
Corrientes, which had been torpedoed by on 26 September while part of a westbound convoy, and whose crew had abandoned her, but remained afloat.
U-37 sunk the abandoned wreck with a torpedo and shellfire.
U-37 was then directed to operate as a weather reporting boat further to the west, where the submarine sank the steamships
Samala and
Heminge on 30 September. for operations in the South Atlantic, with the submarine to refuel from a German
supply ship in the
Canary Islands. On 1 December 1940,
U-37 sank the steamship
Palmella, a straggler from the Gibraltar-bound
Convoy OG 46, which had separated from the convoy in heavy weather, west-north-west of
Lisbon. On the next day, the submarine attacked the convoy itself, sinking the Swedish
Gwalia and the British
Jeanne M. On 4 December,
U-37 sank the Swedish
Daphne, another straggler from OG 46.
U-37 then headed southwards towards Morocco and the
Canary Islands, but the plans to refuel from a supply ship were unsuccessful owing to the presence of British forces. On 16 December,
U-37 sank the Spanish trawler
San Carlos off
Cape Juby, Morocco. On 19 December 1940,
U-37 torpedoed and sank the
Vichy French naval
oil tanker Rhône and the submarine , between Cape Juby and
Fuerteventura, with Clausen not realising that the ships were Vichy French until after the sinking. On reporting the attack to
U-boat command two days later, it was ordered that the involvement of any German or Italian submarine in the sinking be denied, and
U-37s
logbooks were altered to remove record of the attack, with the submarine's location at the time of the attack being changed to a position inland. After five weeks on the high seas,
U-37 returned to Lorient on 14 January 1941. It was decided that
U-37 would be transferred to training duties in the
Baltic Sea. Leaving Lorient for the final time on 27 February 1941,
U-37s last patrol took her to the waters south of Iceland. On 7 March 1941
U-37 sank the Greek cargo ship
Mentor, and was directed against
Convoy OB 293 but failed to make contact. On 12 March the submarine sank the Icelandic trawler
Pétursey. On 16 March,
U-37 was ordered against
Convoy HX 112, making contact at about noon and sending out contact signals to home in other submarines. As night fell,
U-37 closed to attack the convoy, but was spotted on the surface by a British destroyer (probably ), which turned to ram.
U-37 crash-dived just ahead of the destroyer, which responded by dropping a pattern of depth charges, badly damaging the submarine, which broke off the attempt to attack the convoy. Later that night,
U-37 picked up the last radio message from , commanded by
Otto Kretschmer, which had been forced to the surface and forced to scuttle herself, and relayed it to U-Boat Command. After spending 24 days at sea,
U-37 entered the port of
Kiel on 22 March.
Training boat On 1 May 1941
U-37 was reassigned to the
26th U-boat Flotilla, based at
Pillau (now Baltiysk, Russia) as a training U-boat. She was transferred to the
22nd U-boat Flotilla, based at
Gotenhafen (now Gdynia, Poland) on 1 April 1942, remaining in the training role. On 1 July 1944,
U-37 was transferred to the
4th U-boat Flotilla, where she was used as an experimental boat until the end of the war. She was
scuttled on 5 May 1945 off the east coast of
Schleswig-Holstein. The submarine's wreck was raised and broken up in 1946. ==Summary of raiding history==