'Sturmbock' was a U-boat wolfpack operation in the Atlantic against the ONS.167 convoy (21/23 February 1943).
The wolfpack comprised U-84, U-432, U-591, U-664 and U-758, and for the loss of none of its own number sank two ships (13,446 tons).
After sighting and reporting the ONS.167 convoy, supported by Commander A. A. Tait’s British Escort Group B3 (destroyers Escapade, Harvester and Free Polish Burza and Garland, and corvettes Narcissus and Free French Aconit, Renoncule and Roselys), during the evening of 21 February Oberleutnant Adolf Graef’s U-664 sank the 8,807-ton Panamanian H. H. Rogers and 4,659-ton US Rosario from the convoy.
U-84, U-432, U-591 and U-758, which were on passage through the area, were deployed with U-664 as the 'Sturmbock' wolfpack and during the night 21/22 February and during the following morning U-664 and U-758 established brief contact with the convoy before being driven off.
For 25 February the Germans established a new patrol line on the basis of the 'Wildfang' wolfpack.