This was a U-boat wolfpack operation, in tandem with ‘Amsel I’, ‘Amsel II’, ‘Fink’ and ‘Star’, in the Atlantic against the SC.127, SC.128 and ONS.5 convoys (22 April/6 May 1943).
The wolfpack first assembled with 17 U-boats on 22 April to attack the SC.127 convoy, but was unsuccessful and was then regrouped with 20 U-boats on 27 April with the task of attacking the HX.235 convoy. In overall terms, therefore, the pack comprised U-84, U-92, U-108, U-125, U-168, U-203, U-226, U-257, U-260, U-264, U-270, U-358, U-404, U-438, U-514, U-584, U-614, U-618, U-628, U-630, U-662, U-706, U-707 and U-732, and for the loss of Kapitänleutnant Ulrich Volkers’s U-125 sank the 4,737-ton British Lorient in attacks on the ONS.5 convoy.
On 27 April the ‘Specht’ pack, then comprising U-92, U-108, U-125, U-168, U-260, U-264, U-270, U-358, U-438, U-514, U-584, U-614, U-628, U-630, U-706, U-707 and U-732 (Kapitänleutnant Hermann Kottmann’s U-203 having been sunk on 25 April by aircraft from the escort carrier Biter and depth charges from the destroyer Pathfinder), was deployed in the area to the north-east of Newfoundland against the HX.235 convoy, which was supported by Commander G. N. Brewer’s Canadian Escort Group C4 (destroyers Restigouche and British Churchill, and the corvettes Baddeck, Brandon and Collingwood) was re-routed farther to the south with cover provided by Captain Giles E. Short’s US 6th Escort Group (escort carrier Bogue and destroyers Belknap, Greene, Osmond Ingram, and Lea).
After the B-Dienst’s 29 April location of the SC.128 convoy of 33 ships supported by the British 40th Escort Group (sloops Landguard, Lulworth and Hastings, frigates Moyola and Waveney, corvettes Poppy and Starwort, and anti-submarine trawler Northern Gift), the ‘Specht’ and ‘Amsel’ wolfpacks were positioned in a semi-circle along the convoy’s course. During the evening of 1 May U-628 sighted and reported the convoy’s smoke, but the U-boats ordered to the scene were diverted by the escorts’ tactics of firing flares on the convoy’s flank, and the SC.128 convoy thus avoided the wolfpacks by getting to the west of them.
The boats of the ‘Star’ and ‘Specht’ wolfpacks coming from the attack on the ONS.5 convoy were concentrated in a new patrol line ahead of SC.128 for 4 May, but the convoy passed to the west, and in the process a Boeing Canada Canso flying boat of the RCAF’s No. 5 Squadron damaged U-209, was lost on 8 May possibly as a result of this attack.
On 4 May most of the boats became part of the ‘Fink’ pack for attacks on the ONS.5 convoy.