'Streitaxt' was a U-boat wolfpack operation in the Atlantic off the Strait of Gibraltar against the SL.125 convoy (20 October/2 November 1942).
The wolfpack comprised U-103, U-134, U-203, U-409, U-440, U-509, U-510, U-572, U-604 and U-659, and for the loss of none its own number sank 12 ships (80,005 tons) and damaged one 6,405-ton ship.
Freetown, Sierra Leone, was the collection point for Allied merchant ships from South America, Africa and the Indian Ocean, and after these had arrived independently in Freetown these were grouped into convoys for the last leg of their passages to the UK. The SL.125 convoy of 42 ships had departed Freetown on 16 October under the notably weak escort of the corvettes Cowslip, Crocus, Petunia and Woodruff.
The B-Dienst naval signals intercept and analysis service decoded message traffic containing tactical information about the convoy, and the 'Streitaxt' wolfpack was assembled on 23 October to intercept the convoy in the area to the west of the Canary islands group. From 23 October the 'Streitaxt' wolfpack, initially comprising U-134, U-203, U-409, U-509, U-510, U-572, U-604 and U-659, headed to the south in an east/west patrol line. On 25 October U-510 sighted a single ship, U-659 two escorts and Kapitänleutnant Hermann Kottmann’s U-203 an escorted tanker, and was depth-charged and slightly damaged while attempting an attack. The tanker was subsequently shadowed by Korvettenkapitän Rudolf Schendel’s U-134 and damaged by Korvettenkapitän Werner Witte’s U-509. Oberleutnant Hanns-Ferdinand Massmann’s U-409 found and reported the main convoy of 37 ships on 27 October, and Korvettenkapitän Hans Stock’s U-659 was depth-charged and damaged while attempting to attack the convoy.
After moonrise, Korvettenkapitän Horst Höltring’s U-604 sank the damaged 7,705-ton Anglo Maersk, and U-509 torpedoed and sank the 7,591-ton British Pacific Star and 6,148-ton British Stentor. This led to the deaths of 44 merchant seamen and well as 6,000 tons of West African produce and 5,037 tons of refrigerated meat and general cargo. After unsuccessful submerged daylight attacks on 28 October, U-509 sank the 5,283-ton British Nagpore and damaged the 5,178-ton British Hopecastle after sunset. U-203 sank the damaged Hopecastle before dawn. This resulted in the deaths of 23 merchant seamen as well as the loss of 1,500 tons of copper and 11,000 tons of general cargo. U-509 sank the 4,772-ton British Britanny during foul weather on the night of 29/30 October with the loss of 14 merchant seamen and 7,132 tons of general cargo.
Another 50 merchant seamen were killed when the 7,519-ton British tanker Bullmouth, in ballast, was damaged by U-409 and sunk by U-659. The 7,131-ton British Corinaldo was damaged by both U-509 and U-659 before being sunk by U-203, going down with eight merchant seamen and 5,141 tons of frozen meat.
On 30 October U-103 missed a corvette and two ships of the now-scattered convoy, and U-659 was depth-charged and damaged. The advent of better weather now paved the way to co-ordinated attacks on the night of 30/31 October. U-409 torpedoed the 6,373-ton British Silverwillow, and U-604 torpedoed the 11,898-ton British troop transport Président Doumer and 3,642-ton British Baron Vernon: 265 merchant seamen died, and 9,000 tons of general cargo and 550 tons of iron ore were lost. The 6,405-ton British Tasmania was damaged by U-659 and sunk by Kapitänleutnant Gustav-Adolf Janssen’s U-103 with the loss of 8,500 tons of food and iron and two merchant seamen. The 5,700-ton Norwegian Tasmania was damaged by Fregattenkapitän Karl Neitzel’s U-510, but managed to keep station.
On 31 October U-509 and U-604 maintained contact, but toward the fall of night all the U-boats were driven off when air escort arrived and the naval escort was strengthened. Admiral Karl Dönitz, the Befehlshaber der Unterseeboote, cancelled operations on the morning of 1 November as the detection of Allied convoys for the 'Torch' landings in French North Africa persuaded him to relocate all available boats from the Mediterranean and the waters to the west of Morocco.
The convoy therefore reached Liverpool on 9 November without further loss, but had nonetheless suffered greater losses than any other convoy of the SL series. However, the convoy’s timing, and the attacks on it, had for a critical period drawn the U-boat arm’s focus, and many of the available U-boats, well away from the 'Torch' convoys.