This was a U-boat wolfpack operation against the OG.75 and HG.75 convoys on the Atlantic route between the UK and Gibraltar (17/29 October 1941).
The wolfpack comprised six boats 1, and for the loss of Kapitänleutnant Walter Kell’s U-204 sank nine ships (24,576 tons) including the British destroyer Cossack and corvette Fleur de Lys, and damaged the 6,746-ton catapult-armed merchant ship Ariguani.
On 2 October a pair of Focke-Wulf Fw 200 Condor long-range maritime reconnaissance bombers of the I/Kampfgeschwader 40 sighted and reported the OG.75 convoy of 25 merchant vessels and nine escorting warships west of the North Channel. The convoy was again sighted from the air during 3 and 4 October, but the outbound U-71, U-83, U-206 and U-563 and the inbound U-204 and U-564 (released from escorting the outbound blockade runner Rio Grande) failed to intercept. On 5, 6 and 7 October air reconnaissance located only a small 744-ton freighter, which they bombed and sank, and on the following day another Fw 200 sighted and reported the convoy, which was by now off Cape Finisterre.
U-83 approached during the day and U-71 briefly during the night, but on 9 October contact was again lost in bad weather. On 10 October an Fw 200 again reported the convoy but the U-boats fell astern because the convoy’s speed had been underestimated. Kapitänleutnant Hans-Werner Kraus’s U-83 sank a large floating crane and, on 12 October, the 2,044-ton Portuguese Corte Real. U-563 again approached the convoy on 12 October, but was forced to submerge when an aeroplane appeared. Kapitänleutnant Herbert Opitz’s U-206 sank Fleur de Lys off the Strait of Gibraltar just as she was about o enter port. U-204 and U-564 put into Cadiz during the night to take on fuel from a German tanker.
On 17 October the 'Breslau' wolfpack was deployed with U-206, U-563 and U-564 near Cape Trafalgar in expectation of the departure of the HG.75 convoy from Gibraltar, while U-204, U-71 and U-83 patrolled off Cape Spartel and, farther to the west, the Italian boats Archimede, Galileo Ferraris and Guglielmo Marconi were also available. On 19 October, U-206 and Kell’s U-204 each sank one ship, the 3,081-ton British Baron Kelvin and 9,158-ton British tanker Inverlee respectively, but the latter boat was then sunk by the sloop Rochester and corvette Mallow. U-71 attacked but missed a destroyer.
The HG.75 convoy, supported by Lieutenant Commander C. B. Allen’s British 37th Escort Group (sloop Rochester and corvettes Campion, Carnation, Heliotrope, Mallow and Free French Malouine and Commandant Duboc) bolstered by a support group comprising the destroyers Cossack, Legion, Lamerton, Duncan and Vidette, finally sailed during the afternoon of 22 October.
The convoy was reported shortly after 24.00 on 23 October by U-71. Attacks by U-206 and U-564 failed, but the boats were able to maintain contact in spite of the strong escort. During the night 23/24 October Fregattenkapitän Reinhard Suhren’s U-564 sank the 1,352-ton British Alhama and Oberleutnant Klaus Bargsten’s U-563 torpedoed and damaged the destroyer Cossack, which went down on 26 October, and U-564 sank the 2,176-ton British Ariosto and 3,670-ton British Carsbreck.
The U-boats then lost contact, but in the afternoon of 24 October the convoy was spotted by an aeroplane of the I/KG 40, and in the evening by U-71. On 25 October, U-71, U-83, U-206 and Archimede were all driven off, partly by aircraft and partly by the escorting warships. Galileo Ferraris sprang a leak in a fuel tank as a result of the bombing of a Consolidated Catalina flying boat and, forced to surface, was approached by the destroyer Lamerton and sunk after a long gun duel on 25 October. During the night of 25/26 October, U-83 and U-563 gained attack positions, and Kraus’s U-83 torpedoed and damaged the 6,746-ton CAM-ship Ariguani. U-71 and U-564 maintained contact during the following day, but the attacks by U-563 and U-564 during the night of 26/27 October were unsuccessful. On 28 October Marconi was sunk by the destroyer Duncan. U-564 and U-563 maintained contact until 28 October and directed Kapitänleutnant Heinz-Otto Schultze’s returning U-432, which sank the 1,574-ton British Ulea. On 29 October the three German boats, having expended all their torpedoes, started their return to base.