'Siegfried' (v) was a U-boat wolfpack operation in the Atlantic (24/27 October 1943).
The wolfpack comprised U-91, U-212, U-226, U-231, U-267, U-281, U-309, U-373, U-405, U-413, U-426, U-437, U-552, U-575, U-592, U-608, U-648, U-709, U-762, U-842, U-963, U-967 and U-969, and neither lost any of its own number nor sank any ship.
The wolfpack was established in response to B-Dienst intelligence that the HX.262 convoy was expected. This was supported by Commander H. F. Pullen’s Canadian Escort Group C5 (destroyers Ottawa and British Burnham, and corvettes Arvida, Dauphin and Wetaskiwin) bolstered by the advent from service with the ON.207 convoy of Captain F. J. Walker’s British 2nd Support Group (sloops Starling, Kite, Woodcock, Wild Goose and Magpie together with the escort carrier Tracker).
U-413 was able to take several bearings on the radio traffic of the escorts, but it was 25/26 October before the wolfpack approached the convoy, which had been rerouted into the area to the south of the German patrol line. U-212 and U-608 were both bombed, and a Consolidated Liberator long-range patrol bomber of the RCAF’s No. 10 Squadron damaged U-91. U-420 was reported as missing from 20 October.
The 'Siegfried' (v) wolfpack was now operating in three sections as 'Siegfried I' with U-212, U-231, U-405, U-608, U-967 and U-969, 'Siegfried II' with U-267, U-281, U-413, U-426, U-437, U-552, U-592 and U-963, and 'Siegfried III' with U-226, U-373, U-575, U-648, U-709 and U-842.
From 28 October these three smaller wolfpacks established shorter patrol lines in the area to the east of Newfoundland against the now-expected SC.145 convoy of 32 ships supported by Commander R. A. Currie’s British Escort Group B6 (destroyers Fame and Vanquisher, frigate Deveron, and Free Norwegian corvettes Eglantine, Potentilla and Rose) bolstered by Captain W. W. P. Shirley-Rollason’s British 8th Support Group (escort carrier Fencer, and destroyers Inconstant and Free Polish Burza and Garland). As the convoy approached, U-714 transmitted several radio messages on the flank to make the convoy turn away from it and thus run straight into the main U-boat formation. On 29 October U-405 and U-608 drove off Fairey Swordfish anti-submarine aircraft from Fencer with anti-aircraft fire, but in the event the convoy passed by the U-boats without being detected.
Farther to the east, Oberleutnant Rudolf Müller’s approaching U-282 was located on radar by Vidette, which was part of Commander P. W. Gretton’s British Escort Group B7 (destroyers Duncan and Vidette, and corvettes Loosestrife, Pink and Sunflower) which had been ordered to provide addition support for the ON.208 convoy escorted by Commander M. J. Evans’s British Escort Group B3 (frigate Towy, destroyer Keppel and corvettes Narcissus, Orchis and Free French Lobélia, Renoncule and Roselys). U-282 was sunk by Sunflower, and the Escort Group B7 was then detached from the ON.208 convoy to aid the HX.263 convoy, which was currently supported by Lieutenant Commander E. H. Chavasse’s British 4th Escort Group (frigates Bentinck, Bazely, Blackwood, Burgess, Byard, Drury and Berry).