Convoy ON 207
Part ofWorld War II
Date 26–29 October 1943 Location North Atlantic Result Allied victory
Belligerents
United Kingdom Canada	Germany
Commanders and leaders
Comm: Escort:Cdr JA Burnett	AdmiralKarl Dönitz
Strength
52 ships 19 escorts	18U-boats
Casualties and losses
no losses	3 U-boats destroyed

ON 207 was aNorth Atlanticconvoy of theONS/ON series which ran during theBattle of the Atlantic inWorld War II. It was the subject of a majorU-boat attack in October 1943, the fourth battle in the German autumn offensive.

Still believing their new weapons and tactics gave them an advantage, despite the losses suffered bywolfpackSchlieffen and unaware of the poor results achieved during its attack onconvoys ONS 20 and ON 206,Befehlshaber der Unterseeboote (BdU) re-organized the boats then in the North Atlantic into patrol lineSiegfried to continue the offensive. The next convoy subjected to an attack was ON 207.

ON 207 departed Liverpool on 18 October 1943, bound forNew York.Composed of 52 ships it was escorted by Canadian escort group C-1, which comprised 3destroyers;HMS Forester (Cdr JA Burnett as Senior Officer Escort),HMCSSt Laurent andHMCS Assiniboine,frigateHMS Ettrick and 3corvettes;HMCS Agassiz,HMCS Galt andHMS Celandine. The escort was augmented by theescort carrierHMS Biter, with 3sloopsHMS Crane,HMS Pheasant andHMS Chanticleer as escort, and theMerchant aircraft carrierAmastra, though she had to return to base early in the voyage with storm damage.

BdU had established the patrol lineSeigfried of 18 boats.It consisted of 7 boats from the disbanded groupSchlieffen, plus 11 others from bases inFrance andGermany. All the reinforcements were commanded by new skippers; 6 from Norway were also new boats, while the 5 from France were experienced boats with new commanders. TheSiegfried boats had fuel problems, so a re-fueling group was established north of the Azores, of 3U-tankers and aflak boat as escort.

When Allied intelligence learned of the position ofSeigfried, it was decided to force an engagement with the wolfpack; severalHX andSC convoys in the area were diverted away, whilst ON 207 was left to continue on course, as a bait convoy for the U-boats. ON 207 was massively reinforced by two support groups, 2nd EG commanded byCapt FJ Walker, and B-7 EG, commanded by Cdr P Gretton, which detached from a successful trip with ON 206.2 EG comprised 4 sloopsHMS Starling,HMS Magpie,HMS Wild Goose andHMS Woodcock andwas accompanied by the escort carrierHMS Tracker. (Two of 2EG's sloops were absent at the time). B 7 group at this point comprised 2 destroyersHMS Duncan andHMS Vidette, and 2 corvettesLoosestrife andHMS Sunflower. B-7 also had 2 corvettes detached.

On 23 October 1943U-274 was sighted by aB-24 Liberator ofNo. 224 Squadron RAF attempting to make contact with the convoy. The Liberator attacked, and was joined by escortsVidette andDuncan of B-7. They also attacked with depth charges, andU-274 was destroyed with all hands.

On 26 OctoberU-91 was attacked by a Liberator ofNo. 10 Squadron RCAF, but she escaped with little damage. Later in the day, another Liberator of 10 Squadron attacked and destroyedU-420.

On 29 October B 7 detached to join ON 208, which was following several days behind; the group foundU-282 shadowing the convoy.Duncan,Vidette andSunflower attacked with depth charges andHedgehog, andU-282 was destroyed with all hands.

During the time ON 207 was inSiegfried's patrol area, none of its boats were able to launch an attack, and none of ON 207s ships were harmed by enemy action.

While this action was taking place,Siegfried's refuelling group was also under attack, from two USNHunter-killer groups centred on the escort carriersUSS Block Island andUSS Card.On the night of 25/26 October they attacked the U-tankerU-488, though she escaped with no damage; on 28 October they attacked two U-boats,U-220, which was destroyed, andU-256 which was damaged and forced to return to base.On 31 October two more boats were attacked,U-91, which escaped again, andU-584, which was destroyed. Later that day, the destroyerUSS Borie destroyedU-405 in a 72-minute duel, that also sawBorie fatally damaged, sinking later that day.

ON 207 continued to its destination, arriving at New York on 4 November 1943.

With 3 U-boats destroyed for no ships lost ON 207 was undoubtedly an Allied victory; but if Admiralty was hoping to inflict a crushing blow to UbW by wiping out an entire wolf pack, this success eluded them.Most of the U-boats were unable to make contact, and those that did were unable to shadow effectively in order to bring the pack together. Possibly the escorts were unfamiliar with their role as bait, and were too efficient at keeping the pack away from the convoy.

Following ON 207 BdU re-configuredSiegfried to form 3 sub-groups to cover a wider area, but this failed to produce results. Also BdU was realizing that the new weapons and tactics underpinning the Autumn offensive were not being successful; and following the attack on ON 207 no further North Atlantic convoys were seriously harmed.

U-boats destroyed

• Blair, Clay (1998).Hitler's U-Boat War: The Hunted 1942-1945.ISBN 0-304-35261-6.
• Peter Gretton :Convoy Escort Commander (1964).ISBN (none)
• Arnold Hague :The Allied Convoy System 1939–1945 (2000).ISBN 1-55125-033-0 (Canada).ISBN 1-86176-147-3 (UK)
• Kemp, Paul (1997).U-Boats Destroyed, German submarine losses in the World Wars. Arms and Armour.ISBN 1-85409-515-3.
• Niestle, Axel (1998).German U-Boat Losses During World War II. Greenhill.ISBN 1-85367-352-8.
• Stephen Roskill :The War at Sea 1939–1945 Vol III(1959).ISBN (none)

• ON 207 on Convoyweb

• North Atlantic convoys of World War II
• Naval battles of World War II involving Canada

• Use dmy dates from January 2018