Convoy SC 143
Part ofWorld War II
Date October 1943 Location North Atlantic Result Allied operational victory
Belligerents
United Kingdom  Canada Poland	Germany
Commanders and leaders
Comm: Escort	AdmiralKarl Dönitz
Strength
SC 143: 39 ships 8 escorts SG 10 : 4 warships	Rossbach: 14 U-boats
Casualties and losses
1 ship sunk 1 warship sunk	3 U-boats

SC 143 was aNorth Atlanticconvoy of theSC series which ran during thebattle of the Atlantic inWorld War II.It was the second battle in theKriegsmarine's autumn offensive in the North Atlantic.

Following the attack on convoysONS 18 andON 202 by thewolfpackLeuthen, U-boat Control (Befehlshaber der Unterseeboote (BdU) was convinced of success and eager to continue the offensive.Accordingly, they re-organized the boats then in the North Atlantic into a new patrol line, the 12 remainingLeuthen boats being joined by 9 newcomers, from bases inFrance andGermany. Code-namedRossbach, the group was stationed at the western edge of theGreenland Air Gap to intercept the expected east-bound convoys, carryingmateriel for theinvasion of Europe.

For their part, theAllies were also encouraged by the outcome of the battle for ONS 18/ON 202, and were keen to seek battle with groupRossbach.

While forming,Rossbach came under attack by air patrols; four boats were destroyed, and another four were damaged and forced to return to base. Three others were damaged, but were able to continue operations, while a further two boats arrived from base as re-inforcement.

SC 143 leftHalifax on 28 September 1943 bound forLiverpool It was composed of 39 ships and was escorted by C-2 escort group comprising the destroyerHMS Icarus, frigateDuckworth and 5 corvettes. Also accompanying the convoy was theMAC carrierRapana.

By 6 OctoberRossbach, comprising fourteen U-boats at this point, was deployed to intercept the expected west-bound convoys, HX 259 and SC 143.

Western Approaches Command became aware ofRossbach's position via intelligence, principallyEnigma decrypts, but decided to engage the wolfpack and force a battle.Diverting HX 259 to the south, SC 143 was reinforced with 10th Support Group, of four destroyers,Musketeer, Oribi,Orkan andOrwell, and allowed to continue towardsRossbach asbait.

SC 143 was sighted on 8 October byU-731, which was returning to base following an air attack; she sent a sighting report, and throughout the day theRossbach boats converged on the position.

Seven boats had gathered by evening, and at nightfall mounted their attack.

During the night of 8/9 October the sevenRossbach boats were able to attack;U-645 torpedoed and sankYorkmar, andU-378 hitORP Orkan which sank with the loss of 157 men. This was the worst naval loss suffered by thePolish Navy during the war.^[1]

During the day the convoys air cover was able to mount several successful attacks; three U-boats were attacked by aircraft during the day.U-419 was attacked and sunk by aLiberator fromNo. 86 Squadron RAF;U-643 was damaged by 2 other Liberators, from 86 Sqdn RAF andNo. 120 Squadron RAF; it was later caught on the surface by another Liberator of RAF 86 Sqdn and sunk.U-610 was attacked by aSunderland from423 Sqdn RCAF and sunk.

Two other boats were damaged in air attacks and forced to return to base;U-539 by an unidentified aircraft, andU-762 by a Liberator ofNo. 120 Squadron RAF.

Following this the attack was discontinued by BdU andRossbach, now reduced to six boats, was disbanded. SC 143 continued its voyage, and arrived without further loss atLiverpool on 12 October 1943.

Undeterred by the poor result of this attack, and the losses suffered byRossbach, BdU wished to press on with the offensive; the remainingRossbach boats were reinforced to form a new group code-namedSchlieffen.

Date	Name	Flag	Casualties	Tonnage	Sunk by...
9 Oct 1943	Yorkmar	United States	13	5,612	U-645

Date	Name	Flag	Casualties	Type	Sunk by...
8 Oct 1943	Orkan	Poland	157	Destroyer	U-378

• Blair, Clay (1998).Hitler's U-Boat War: The Hunted 1942-1945.ISBN 0-304-35261-6.
• Arnold Hague :The Allied Convoy System 1939–1945 (2000) ISBN (Canada) 1 55125 033 0 : ISBN (UK) 1 86176 147 3
• 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 (1960) ISBN (none)
• Jak P M Showell :U-Boat Warfare: The Evolution of the Wolf-Pack (2002)ISBN 0-7110-2887-7

• SC 143 on convoyweb
• SC 143 at warsailors

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

• CS1 Polish-language sources (pl)
• Articles with short description
• Short description matches Wikidata
• Use dmy dates from January 2018
• Pages using gadget WikiMiniAtlas