Convoy SC 100 was a North Atlantic convoy, one of the SC series which ran during the battle of the Atlantic in World War II. It was the 100th of the numbered series of slow convoys of merchant ships from Sydney, Cape Breton Island to Liverpool. It came under attack, one of several convoy battles that occurred during the autumn and winter of 1942, losing five ships.
Background SC 100, comprised twenty six merchant ships and departed Halifax for the UK under local escort on 12 September 1942. The Convoy Commodore was Capt. NH Gale in Athelsultan. SC 100 was met by its Ocean Escort, Group A-3, led by US Coast Guard cutter , under Cdr. P Heineman. Also in the group was the cutter and four RCN corvettes. A-3 was joined by the corvette , escorting ships from Wabana, and by three corvettes travelling in convoy for refit in the UK.Blair p.32 During the action SC 100 was joined by several units as reinforcement, including the newly formed convoy support group, 20EG, led by Comm. FJ Walker.Roskill p. 201
SC 100 was attacked by units of two U-boat patrol lines, Lohs, of 18 boats, and Pfiel, of 11 Uboats, under the guidance of U-boat Commander (BdU) Adm K Dönitz.
Action The convoy departed Halifax on 12 September 1942 and was joined on 16 September by Mid-Ocean Escort Force Group A-3. Ahead of the convoy were three U-boat patrol lines; Vorwarts, of 18 boats, off the east of North America; Lohs, of 19 boats, south of Greenland, and Pfeil, 11 boats, moving west from bases in Occupied France. SC 100 passed through the Vorwarts patrol line without being detected, and these boats took no further part in the action, but on 18 September the convoy was found and reported by , of Lohs. U-599 commenced shadowing, while other U-boats of the group joined; first , which had sunk the USCG weather ship Muskeget the previous week, then and . These boats began their attack, but U-259 collided with a merchant ship and was forced to break off. Both boats were vigorously attacked by escort ships, but suffered no damage. Two more Lohs boats, and joined; the latter attacked and sank the freighter Empire Hartebeeste, but a claim by U-373 to have torpedoed a corvette was not substantiated.Blair p.33
At this point a massive storm blew up (described by U-boat reports as "a hurricane"), making further attempts impossible. Faced with this BdU called off the operation, but several boats remained in contact and on the third day , of Pfeil made contact and torpedoed Athelsultan, the commodores ship. U-617 also sank the stragglers Tennessee and Roumanie, which had become separated in the storm. Meanwhile, SC 100 had been re-inforced by ships from nearby convoys, and from 20 EG, bringing the total number of warships to 15. On 24 September two more U-boats made contact; sank the freighter Penmar, but a claim by of two freighters sunk was mistaken. The next day, as the weather cleared, aircraft of RAF Coastal Command were able to give saturation cover, forcing all U-boats still in contact to break off contact. With this BdU dropped plans to re-engage with SC 100 and moved the U-boats present to other tasks. With no further attacks SC 100 arrived safely at Liverpool on 28 September.Hague p. 135
Assessment Despite the number of U-boats called to this action few were able to make contact, due to the storm. Those that did were driven off by the escorts; of the five ships sunk by enemy action only two were in convoy at the time. It has been suggested that the ships of Group A-3 were not fast enough to catch surfaced U-boats;Willoughby, p.198 but Donitz attributed the failure of the attack on the aggressive handling of the escorts as well as the appalling weather.Blair p. 34 The U-boats sank five scattered ships before losing contact on 25 September;Rohwer & Hummelchen, pp.144&162 another was lost in a collision.Hague p. 137 Twenty ships arrived safely.
SC 100 was one of three North Atlantic convoys attacked during September; in the same period the Allies sailed nineteen convoys comprising some 580 ships. Total losses were 19 ships and two escorts, (some 3% of ships involved); the cost to the U-Boat Arm was five boats lost, and another four damaged sufficiently to be returned to base.Blair p.36
Ships in convoy
Allied merchant ships NameFlagCasualtiesTonnage (GRT)CargoFateNotes Ary Lensen 3,214Sugar Athelsultan51 8,882Molasses, alcoholSunk by on 23 September SE of Cape Farewell, Greenland.Convoy commodore's ship, Capt N H Gale DSO Rd RNR. Survivors picked up by and and landed at Londonderry Port. Atland 5,203Wabana iron ore Atlantic 5,414Steel, lumber Belgian Fisherman 4,714General cargo Boris 5,166Wabana iron ore Dux 1,590Lumber Empire Guinevere 7,072Steel and tobacco Empire Hartebeeste0 5,676General cargoSunk by on 20 September SE of Cape Farewell, Greenland. Empire Opal 9,811Benzene, paraffin Empire Razorbill 5,118Steel, tobacco Empire Soldier 4,539General cargo Marine accident Sunk in a collision with tanker Hague p.137Empire Stour 4,696General cargo Esturia 6,968Fuel oil Greylock 7,460General cargo Gunvor Maersk 1,977Sydney lumber Innesmoor 4,392General cargo Mount Evans 5,598General cargo Norhauk 6,086General cargo Rescued crew from Empire HartebeestePanama 6,650Sugar Pennmar2 5,868General cargoStraggled and was sunk by on 24 September. Survivors picked up by Rio Verde 3,223General cargo Roumanie42 3,658General cargoStraggled and was sunk by on 24 September. Sole survivor was picked up by U-617 as a PoW and landed at St Nazaire.Spurt 2,061Lumber Turned backTennessee15 2,342Sydney grainStraggled and sunk by on 23 September SE of Cape Farewell, Greenland.Survivors picked up by and Tore Jarl 1,514Lumber
Convoy escorts NameFlagTypeJoinedLeft 16 September 194228 September 194216 September 194226 September 1942 cutter 16 September 194216 September 1942 sloop25 September 194225 September 1942 12 September 194226 September 1942ASW naval trawler27 September 194227 September 1942 21 September 194226 September 1942 21 September 194227 September 1942 12 September 194216 September 1942 16 September 194228 September 1942 12 September 194216 September 1942ASW naval trawler27 September 194228 September 1942 16 September 194227 September 1942HMCS Niagara 12 September 194216 September 1942 21 September 194226 September 1942 25 September 194225 September 1942 25 September 194225 September 1942 cutter 16 September 194216 September 1942 15 September 194228 September 1942 16 September 194227 September 1942 21 September 194226 September 1942
U-boats The convoy was attacked by both Wolfpack Lohs comprising 9 U-boats, and 8 U-boats from Wolfpack Pfeil, namely
Wolfpack Lohs
Wolfpack Pfeil
References
Bibliography Clay Blair : Hitler's U-Boat War Vol II:The Hunted 1942-1945 (1998).
Willoughby, Malcolm F. The U.S. Coast Guard in World War II (1957) United States Naval Institute
External links SC 100 at convoyweb 100 at uboat.net