This was a U-boat wolfpack operation in the Atlantic against convoys plying between the USA and Gibraltar (1 June/15 July 1943).
Formed from U-boats withdrawing from the North Atlantic and initially deployed against the GUS.7A convoy, this wolfpack was replenished on 7/13 June by the ‘milch cow’ U-488, and at maximum strength comprised U-92, U-193, U-211, U-217, U-221, U-228, U-232, U-336, U-435, U-488, U-558, U-603, U-608, U-641, U-642, U-666, U-951 and U-953, and for the loss of Kapitänleutnant Kurt Reichenbach-Klinke’s U-217 sank no Allied ships.
On its formation during 1 June, the ‘Trutz’ (i) wolfpack was deployed to the south-west of the Azores islands group to locate and attack the GUS.7A convoy of 45 ships, supported by Commander John W. Bays’s US Task Force 65 (destroyers Parker, Boyle, Kendrick, Laub, MacKenzie, McLanahan and Nields), which had departed Gibraltar on 23 May. The Allies learned of the German deployment from ‘Ultra’ decrypts, however, and therefore re-routed the convoy, detecting the patrol line with HF/DF and avoiding it by passing farther to the south.
On 4 June aircraft of Captain Giles E. Short’s US support group (escort carrier Bogue and destroyers Clemson, George E. Badger, Greene and Osmond Ingram) compelled U-228, U-603 and U-641 to dive, but only after the last’s anti-aircraft guns had shot down one of the US aircraft. Reichenbach-Klinke’s U-217 was sunk on 5 June by two aircraft of the US Navy’s VC-9 squadron operating from Bogue.
As U-488 replenished 14 of the ‘Trutz’ (i) wolfpack’s boats without molestation between 7 and 13 June, the group centred on Bogue passed to the south with the UGS.9 convoy of 74 ships supported by TF69 (destroyers Stevenson, Stockton, Thorn and Paul Jones, and the US Coast Guard cutter Campbell) in an easterly direction. The outbound U-758 managed to hold off eight carrierborne aircraft and indeed inflict severe damage on several of them with its 20-mm quadruple cannon mounting in the first successful use of this equipment on a U-boat.
U-758 then made rendezvous with another ‘milch cow’ boat, Korvettenkapitän Werner Czygan’s U-118, but the latter succumbed on 12 June to an attack by eight aircraft of the VC-9 squadron. From 16 June the replenished ‘Trutz’ (i) boats were divided into three smaller wolfpacks and established overlapping patrol lines. ‘Trutz I’ comprised U-228, U-558, U-608 and U-642, ‘Trutz II’ comprised U-135, U-232, U-336, U-603, U-641, U-666, U-951 and U-953, and ‘Trutz III’ comprised U-193, U-211, U-221 and U-435, and the three wolfpacks were intended to locate and attack the expected GUS.8 convoy, which was supported by the US TF66 (US Coast Guard cutters Bibb and Ingham, destroyers Doyle, Greer, Hamilton and Upshur, minesweepers Pioneer, Portent and Threat, Free French destroyer Malin, and Free French sloops Commandant Delage and Graçieuse) and Captain Arnold J. Isbell’s Support Group 21.3 (escort carrier Card and destroyers Herbert, Dickerson and Dupont).
The convoy evaded the German patrol line, as too did the UGS.10 convoy of 70 ships supported by the US TF61 (destroyers Livermore, Eberle, Ericsson, Kearny and McCormick, and minesweepers Parrott, Pilot and Prevail) and Captain H. F. Fick’s Support Group 21.11 (escort carrier Santee and destroyers Overton, Bainbridge and MacLeish) coming from the west.
To the south the outbound U-572 was overrun and sank the 4,220-ton French French naval oiler Lot.
As U-170, U-488, U-530, U-535 and U-536, in temporary service as tankers, replenished 10 boats and the ‘Trutz’ (i) wolfpacks searched farther to the east, the GUS.8A convoy of 43 ships supported by the US TF69 (US Coast Guard cutters Campbell, Duane and Spencer, and destroyers Stevenson, Mayo, Paul Jones, Stockton, Tarbell and Thorn) also passed to the south. From 29 June U-221 and U-558 went to the waters off Lisbon, and U-135 and U-193 to those off the Canary islands group, while the others boats were reconstituted from 2 July as the components of the three ‘Geier’ wolfpacks.