Convoy SC 107

Convoy SC 107 was the 107th of the numbered series of World War II Slow Convoys of merchant ships from Sydney, Cape Breton Island to Liverpool. The ships departed New York City on 24 October 1942 and were found and engaged by a wolfpack of U-boats which sank fifteen ships. It was the heaviest loss of ships from any trans-Atlantic convoy through the winter of 1942-43.

Background
As western Atlantic coastal convoys brought an end to the "Second Happy Time", Admiral Karl Dönitz, the Befehlshaber der U-Boote (BdU) or commander in chief of U-Boats, shifted focus to the mid-Atlantic to avoid aircraft patrols. Although convoy routing was less predictable in the mid-ocean, Dönitz anticipated that the increased numbers of U-boats being produced would be able to effectively search for convoys with the advantage of intelligence gained through B-Dienst decryption of British Naval Cypher Number 3. However, only 20 percent of the 180 trans-Atlantic convoys sailing from the end of July 1942 until the end of April 1943 lost ships to U-boat attack.

Discovery
Convoy SC 107 was found and reported by U-522 on 29 October as the Western Local Escort Force turned the convoy over to Mid-Ocean Escort Force Group C-4 consisting of the Canadian River class destroyer Restigouche with the Flower class corvettes Amherst, Arvida, Sherbrooke, Celandine, Algoma, Moose Jaw, and the Convoy rescue ship Stockport. As wolfpack Veilchen assembled to intercept the convoy, U-520 was sunk by a No. 10 Squadron RCAF Digby bomber, and U-658 was sunk by a RCAF Lockheed Hudson.

First attack on 1/2 November
Stockport and Restigouche located 25 HF/DF transmissions on the afternoon of 1 November, but the single destroyer was unable to investigate all of them. While Arvida had a RADAR malfunction, U-boat Ace Kapitänleutnant Siegfried von Forstner's U-402 penetrated the starboard side on the convoy screen about midnight to torpedo the British freighter Empire Sunrise. Restigouche narrowly avoided torpedoes launched a short time later by U-381. While Celandine dropped astern to screen Stockport rescuing survivors from Empire Sunrise, U-402 twice more penetrated the convoy screen where Celadine had been and torpedoed the Greek freighter Rinos and British freighters Dalcroy, SS Empire Antelope, and Empire Leopard. U-522 torpedoed the Greek freighter Mount Pelion and British freighters Hartington and Maratima. Kapitänleutnant von Forstner would receive the Knight's Cross of the Iron Cross for his work in U-402 during this convoy and in Convoy SC-118 on the next patrol.

2 November
Stormy weather caused the U-boats to lose contact after U-522 torpedoed Greek freighter Parthenon in a daylight attack. The escort was reinforced by the V class destroyer Vanessa from convoy HX-213 before nine U-boats regained contact when visibility improved on 3 November.



Second attack on 3/4 November
U-521 torpedoed the American tanker Hahira in a daylight attack on 3 November. U-89 torpedoed the convoy commodore's freighter Jeypore after sunset on 3 November while U-132 torpedoed the Dutch freighter SS Hobbema and British freighters Empire Lynx and Hatimura. U-132 is believed to have been destroyed by the detonation of the ammunition cargo of the latter ship.

On 4 November, Arvida and Celandine were detached to Iceland with Stockport and two tugs overcrowded with 240 survivors. U-89 torpedoed the British freighter Daleby shortly before the convoy escort was reinforced by the USCG Treasury Class Cutter Ingham and the Wickes class destroyers Leary and Schenck from Iceland. No. 120 Squadron RAF B-24 Liberators scrambled from Iceland drove off the remaining U-boats, and the convoy reached Liverpool on 10 November.