This was the designation of Allied slow convoys (together with a numerical suffix) initially plying the route from Sydney, Nova Scotia (generally called Cape Breton to avoid confusion with Sydney, Australia) to Liverpool in the UK, and as such reciprocals of the 'ON' (ii) series (August 1940/June 1945).
For a time after the USA’s December 1941 entry into the war following the Japanese ‘Ai’ attack on Pearl Harbor and the German declaration of war on the USA, the port of origin for the 'SC' (ii) convoys was shifted to New York City, but the resulting congestion from September 1942 led to another change in March 1943, this time to Halifax, Nova Scotia.
The convoys were temporarily suspended during the summer of 1944 when a number of the all-important escort and support groups were diverted to cover the ‘Neptune’ and follow-on landings in the ‘Overlord’ campaign in Normandy. During this period all eastbound traffic sailed in the HX series, which ran as Fast or Slow convoys, and whose sizes were effectively doubled.
A total of 177 'SC' (ii) convoys ran during the campaign, and saw 6,806 ship movements. Only three of the convoys failed to reach their destination: the SC.52 convoy suffered an attack shortly after leaving port and was forced to return, and the SC.62 and SC.63 convoys were each scattered by appalling weather conditions which forced their ships to proceed independently.
The first of the convoys was SC.1 of 15/29 August 1940 with 40 merchant vessels loaded primarily with timber, pit props, pulpwood, newsprint, scrap iron, iron ore, corn, grain, nitrates and phosphates. The convoy was escorted by six British ships in the form of the destroyers Havelock and Hurricane, sloops Leith and Penzance, corvette Clarkia, and armed yacht Reindeer. There were only a few attacks on this convoy by U-boats, whose successes included the 4,141-ton British Blairmore, which was sunk on 25 August by Kapitänleutnant Victor Oehrn’s U-37 while rescuing survivors, 3,868-ton Finnish Elle which straggled and was sunk on 28 August by Kapitänleutnant Fritz Frauenheim’s U-101, 1,599-ton Norwegian Eva which also straggled and was sunk on 27 August by Kapitänleutnant Günter Kuhnke’s U-28 while the boat was operating as a weather reporter, and the sloop Penzance which was also sunk by U-28 on 24 August.
The last of the convoys was SC.177 of 26 May/8 June 1945 with 31 merchant vessels (including the 8,016-ton British MAC-ship and escort oiler Alexia, 9,720-ton Norwegian escort oiler Velma and 1,637-ton British rescue ship St Clair) carrying cargo as diverse as timber, pit props, wood pulp, iron ore, grain, miscellaneous fuels, lubricating oil, whale oil, sugar, refrigerated meat, guano and ammunition. Canadian escort was provided by the corvettes Battleford, Celandine, Charlock, Morpeth Castle, Pimpernel and Primrose, and minesweepers Portage, Middlesex and Winnipeg. With the war over, none of the merchant vessels or warships came under attack
Of the 177 convoys, 29 came under attack, and lost 145 ships excluding those of stragglers (perhaps the same number again) and another 18 in accidents, suggesting an overall figure in the order of 340 ships lost. As the 'SC' (ii) movements were slow convoys of ships capable of making no more than 8 kt and therefore not eligible for inclusion in the slightly faster 9-kt 'HX' convoys, they were more vulnerable to U-boat interception, and were thus subject to a disproportionate number of attacks.
The 'SC' (ii) convoys were the subject of some of the major battles of the campaign. Of the 40 convoys which lost six or more ships, 11 were of the 'SC' (ii) series.
Some of the most notable 'SC' (ii) convoy battles were those of the SC.7 convoy, which was attacked in October 1940 and lost 20 ships in the worst day’s shipping losses of the entire campaign; the SC.42 convoy, in which two U-boats were sunk by reinforcements coming to the aid of the weak Canadian escort for this September 1941 convoy in which 14 merchant ships were lost in three days; the SC.94 convoy of August 1942, which marked the beginning of the climactic North Atlantic convoy battles following ‘Paukenschlag’ off the US east coast; the SC.104 convoy of October 1942, which lost seven ships while the Escort Group B6 sank two U-boats; the SC.107 convoy of November 1942, which lost 15 ships including five torpedoed by the U-boat ‘ace’ Kapitänleutnant Siegfried Freiherr von Forstner’s U-402; the SC.118 convoy of February 1943 in which von Forstner on 7/8 February torpedoed seven ships (1,571 British Toward, 6,625-ton US tanker Robert E. Hopkins, 9,272-ton Norwegian Daghild which was damaged and later sunk by Kapitänleutnant Rolf Struckmeier’s U-608, 8,597-ton British Afrika, 6,063-ton US Henry R. Mallory transporting troops to Iceland, 4,965-ton Greek Kalliopi and 4,625-ton British Newton Ash); the SC.121 convoy of March 1943 attacked by the ‘Westmark’ wolfpack after being scattered by a Force 10 storm, losing 14 ships sunk and one ship damaged (59,913 tons) out of 59 ships, with just 76 of the sunk ships’ 275 crew rescued; the SC.122 convoy of March 1943 attacked in a battle that merged with that around the HX.229 convoy to create the largest convoy battle of the Atlantic campaign; and the SC.130 convoy of May 1943 attacked but defended successfully in a battle that resulted in the sinking of five U-boats for the loss of no ships.
This last action culminated the period known to the Germans as schwarz Mai (black May), after which the Germans pulled their U-boats out of the North Atlantic to regroup, retrain and introduce new weapons before relaunching their U-boat offensive in September of the same year.
One of the most significant of these convoys was SC.7, whose passage led to a major battle with U-boats on 16/19 October 1940. The convoy comprised 35 ships which departed Sydney, Nova Scotia, for Liverpool and other British ports on 5 October 1940 and was escorted by six warships (sloops Fowey, Leith and Scarborough, corvettes Bluebell and Heartsease, and armed yacht Elk).
The convoy was attacked by a U-boat wolfpack and, in the battle that resulted, the escort was completely overwhelmed, demonstrating the potential of wolfpack tactics and the inadequacy of current British anti-submarine capabilities. SC.7 was designed to make 8 kt, but a number of its merchant vessels were in fact considerably slower than this. The convoy consisted of older, smaller ships, most of them carrying essential cargoes of bulk goods, and the largest ship was the 9,512-ton British tanker Languedoc, which was bound for the Clyde with fuel for the Royal Navy. Another ship, the 5,154-ton British Empire Brigade, was carrying a valuable cargo of trucks. Many of the ships were British, but the convoy also included Greek, Swedish, Norwegian and Dutch vessels. The convoy’s commodore was Vice Admiral L. D. I. Mackinnon, a retired naval officer who had volunteered for this civilian duty, and he sailed in the 2,962-ton British Assyrian.
The sloop Scarborough was the only naval escort for the first three-quarters of the passage, and would have stood no chance whatsoever in any action against a German surface raider. There was no air protection in 1940 for Allied ships beyond the eastern and western coastal regions of the Atlantic Ocean. Many of the merchant ship captains resented their instructions to sail in convoy, and would have preferred to take their chances on their own rather than risk such a slow crossing with a weak escort. Therefore they were often unco-operative: at one point early in the passage Scarborough’s captain was appalled to find a Greek merchant ship at night with her lights on. On the first day, the 6,197-ton US Winona dropped out with mechanical trouble and had to return. Adverse weather set in on 11 October, and several ships, after becoming separated, thereafter sailed independently. One of these, the British Trevisa, was a 1,813-ton Canadian Laker: she was sighted by Kapitänleutnant George-Wilhelm Schulz’s U-124 on 16 October and sunk. Another, the 3,554-ton Greek Aenos, was spotted and sunk by Kapitänleutnant Heinrich Liebe’s U-38 on the next day. But the 1,900-ton British Eaglescliff Hall, another Canadian Laker, avoided this fate and was able to rescue survivors from Aenos, before arriving safely at Rothesay on 19 October. A fourth straggler regained the convoy on 15 October.
On 17 October, as the convoy entered the Western Approaches, Scarborough was joined by the sloop Fowey and the new corvette Bluebell. Later that day they were sighted by Kapitänleutnant Heinrich Bleichrodt’s U-48, which attacked, sinking Languedoc and the 3,843-ton British Scoresby. Scarborough counterattacked, driving U-48 deep so she was unable to shadow or report. However the attack was maintained too long, and the convoy moved so far ahead that Scarborough was unable to rejoin.
On 18 October the convoy was joined by the sloop Leith and corvette Heartsease, the former’s captain assuming command. Later that day Kapitänleutnant Heinrich Liebe’s U-38 sighted the convoy and attacked, damaging the 3,670-ton British Carsbreck. Leith and Heartsease attacked without success, though U-38 was driven off, and Heartsease was detailed to escort Carsbreck into port, so weakening the escort further.
On the night of 18/19 October five U-boats made a concerted attack. These were the ‘ace’ Kapitänleutnant Engelbert Endrass’s U-46, the ‘ace’ Korvettenkapitän Otto Kretschmer’s U-99, the ‘ace’ Kapitänleutnant Joachim Schepke’s U-100, Kapitänleutnant Fritz Frauenheim’s U-101 and Kapitänleutnant Karl-Heinz Moehle’s U-123, and the attack was co-ordinated from his headquarters at Kerneval near Lorient in north-western France by Vizeadmiral Karl Dönitz, the commander of the U-boat arm. An early loss was the 3,917-ton British iron ore ship Creekirk, bound for Cardiff on the south coast of Wales. With her heavy cargo, the ship sank like a stone taking all 36 crew members with her. Later that night the SC.7 convoy lost many of its members, including the 5,154-ton British Empire Brigade with her cargo of trucks and six of her crew, and the 4,815-ton British Fiscus with her cargo of steel ingots. The latter also sank almost immediately, taking with her all but one of her 39-man crew. Also among the casualties was the commodore’s ship, Assyrian, which went down with 17 members of her crew, although Mackinnon was once of those rescued.
In all, 16 ships were lost in a six-hour period, and the escorts were wholly unable to prevent any of these losses. Their responses were unco-ordinated and ineffective, and their captains did not appreciate that the U-boats were not attacking submerged or from outside the convoy, but on the surface inside the convoy between the columns of merchant ships. The escorts were therefore unable to mount any serious attacks on the U-boats, and had to spend much of their time rescuing survivors.
During the daylight hours on 19 October, the escorts, loaded with survivors, gathered the surviving ships. Fowey collected eight ships and made for the Clyde river, arriving there a few days later. Scarborough passed through the scene of the battle later on 19 October, and found wreckage but no survivors. Later in the afternoon of the same day Leith met Heartsease, still escorting the damaged Carsbreck, and together the ships made for Gourock, collecting two more stragglers on the way. Bluebell, with more than 200 survivors on board, headed directly for the Clyde, arriving on 20/21 October.
Thus the SC.7 convoy had lost 20 ships (79,592 tons) out of 35, of which seven fell victim to Kretschmer’s U-99.
Meanwhile the arrival of the HX.79 convoy in the vicinity had diverted the U-boats, which went now sank 12 of HX.79’s ships during that night. No U-boats were lost in either engagement. The loss of 28 ships in 48 hours made 18/19 October the worst two days for shipping losses in the entire Atlantic campaign.
The SC.9 convoy was just the second to be attacked by a wolfpack, and used tactics that were rudimentary at this early stage of the war: the escorts’ responses were unco-ordinated as the ships were not used to working together in an established and well rehearsed common battle plan. Command fell to the senior officer present, and could change as each new ship arrived. The escorts were torn between staying with the convoy, abandoning survivors in the water, as Defensively Armed Merchant Ships regulations demanded, and picking them up, leaving the convoy unprotected and risking being torpedoed themselves.
Just under 30 months later, in March 1943, there occurred the largest battle of the North Atlantic war between the U-boats and the convoys, in this case HX.229 and SC.122, and U-boats. By this time the German tactics against the convoys were centred on the use of one or more wolfpacks controlling a comparatively large number of boats in nearly simultaneous night attacks by surfaced boats, the presence of ever-increasing numbers of Allied maritime patrol bombers having severely limited the ability of the U-boats to gather and attack by day. Thus the longer nights of the North Atlantic winter were preferred by the U-boats for movement and attack.
The winter of 1942/43 saw the war’s largest number of U-boats deployed to the mid-Atlantic before comprehensive anti-submarine air patrols could be extended into that area. March was characterised by a number of fierce convoy battles and was, for the Allies, the crisis point of the whole campaign.
In the case of the battle round the HX.229 and SC.122 convoys, some 110 Allied merchant ships encountered three wolfpacks, totalling 41 boats (12, 18 and 11 in the ‘Raubgraf’, ‘Stürmer’ (i) and ‘Dränger’ wolfpacks respectively) in a single wide-spread action. A British report later concluded that ‘The Germans never came so near to disrupting communications between the New World and the Old as in the first 20 days of March 1943.’
The SC.122 slow convoy of 60 ships, routed from New York to Liverpool, departed New York on 5 March under the initial protection of one destroyer and five corvettes of the Western Local Escort Force. On 6 March, off Cape Cod, two ships put back to New York as a result of heavy weather, and two days later another six abandoned the crossing and put into Halifax. The rest of the convoy pressed on, changing escorts on 13 March off Cape Race, when the group provided by the Western Local Escort Force was replaced by Commander R. C. Boyle’s British Escort Group B5 from St John’s, Newfoundland with eight warships in the form of the destroyers Havelock and US Upshur, frigate Swale, and corvettes Buttercup, Godetia, Lavender, Pimpernel and Saxifrage, together with 1,567-ton British Zamalek as rescue vessel.
The HX.229 convoy was also eastbound, and sailed from New York on 8 March, with 40 ships and the local escort. A further 34 ships which should have been included were by congestion in the port of New York, and sailed on the following day as the HX.229A convoy. The first few days of the convoy were uneventful. The HX.229 convoy met its mid-ocean escort force on 14 March and the local escort then departed. The ocean escort was Commander G. J. Luther’s British Escort Group B4 from St John’s, Newfoundland, and comprised the destroyers Beverley, Mansfield, Volunteer and Witherington, and corvette Anemone. Witherington had to detach on the following day, and was replaced by the corvette Pennywort.
Against these Allied merchant ships and escorts were mustered three wolfpacks: ‘Raubgraf’ of an initial eight boats had already been formed and had just been involved in a battle with the HX.228 convoy, and was now despatched to patrol east of Newfoundland at the western edge of the ‘air gap’. ‘Stürmer’ (i) was a new wolfpack of 18 boats that were to form in the middle of the ‘air gap’, and comprised boats from the ‘Westmark’ wolfpack, which had previously been in battle with the SC.121 convoy. ‘Dränger’ of 11 boats formed to the east of ‘Stürmer’ (i), and comprised some boats from the ‘Neuland’ wolfpack, which had also been in battle with the HX.228 convoy, and a number of newly arrived boats.
The German navy’s B-Dienst signals intercept and decryption service had given notice of an eastbound convoy, and by 08.00 on 13 March was able to provide the position of the SC.122 convoy. Grossadmiral Karl Dönitz,the commander-in-chief of the German navy but still in day-to-day control of the U-boat arm via Konteradmiral Eberhart Godt, his chief-of-staff, directed the ‘Raubgraf’ wolfpack to intercept along a new patrol line farther to the west. However, at this point a westerly gale increased the speed of the SC.122 convoy, which therefore passed through the patrol area of the ‘Raubgraf’ wolfpack during the morning of 15 March, one day before the patrol line was formed.
The ‘Ultra’ intelligence which had helped the Admiralty to divert convoys away from wolfpacks, had been ‘blinded’ on 10 March as the Germans introduced a new short weather report, which starved the British codebreakers of the ‘cribs’ necessary to break the ‘Shark’ code. The Admiralty’s U-boat tracking room was therefore unable to divert convoys round the wolfpacks. Fortunately for the British, any message transmitted by a U-boat revealed its position once that position had been fixed by HF/DF, and the SC.122 convoy was diverted around the estimated danger area. However, the Allied Cipher No. 3 used by the convoy escorts had been broken by the Germans, and this allowed then to position wolfpacks in the way of the HX.229 convoy, which was following a similar course. However, the convoy passed through the patrol line of the ‘Raubgraf’ wolfpack during the night of 15/16 March without being sighted because of bad weather.
On the morning of 16 March U-653,which had left the ‘Raubgraf’ wolfpack to return to base with mechanical problems, sighted the HX.229 convoy on its eastward course and sent a sighting report. Godt immediately ordered the ‘Raubgraf’ wolfpack to pursue and intercept, while the ‘Stürmer’ (i) and ‘Dränger’ wolfpacks were ordered to the west to form a line ahead of the convoy. In this Dönitz and Godt saw an opportunity to attack an eastbound convoy with ships carrying war matériel bound for the UK and with the full width of the ‘air gap’ yet to cross.
The ‘Raubgraf’ wolfpack caught the HX.229 convoy on the evening of 16 March and attacked that night, sinking three ships, and followed with another five during the morning of 17 March for a total of eight sinkings in just eight hours. The escort was reported to be weak as two of the warships had dropped out to pick up survivors The escorts pursued three contacts during the night, but without positive result.
During the rest of 17 March boats from the ‘Stürmer’ (i) wolfpack began to arrive. One of these was attacked by a destroyer, again fruitlessly. Meanwhile, at the north-eastern end of the ‘Stürmer’ (i) wolfpack’s patrol line, Kapitänleutnant Manfred Kinzel’s U-338 had sighted the eastbound SC.122 convoy about 120 miles (195 km) from the position of the HX.229 convoy. The boat sent a sighting report and attacked, sinking three ships in quick succession (7,886-ton Dutch Alderamin, 5,072-ton British King Gruffydd and 4,898-ton British Kingsbury) and damaging the 7,134-ton British Fort Cedar Lake, which was sunk later in the same day by Oberleutnant Hans-Jürgen Haupt’s U-665.
The HX.229 convoy lost another two ships during the day, when two boats of the ‘Stürmer’ (i) wolfpack managed to penetrate the defences at about 12.00, but the escorts were able to fend off any further attacks with the aid of Consolidated Liberator VLR (very long range) maritime patrol bombers flying at extreme range. The SC.122 convoy was also able to resist further attacks until evening. During the night of 17/18 March the attacks on both convoys, which were by now a mere 70 miles (115 km) apart, continued.
Kinzel’s U-338 sank the 4,071-ton Panamanian freighter Granville of the SC.122 convoy during the evening, and then survived a fierce counterattack by the escorts, and after 24.00 Kapitänleutnant Rufolf Bahr’s U-305 sank the 8,789-ton British Port Auckland and 4,256-ton British Zouave. The HX.229 convoy suffered no further losses during that night.
The HX.229 convoy’s escort was reduced as Mansfield was forced to detach during the night of 17/18 March, but assistance was on its way in the form of Commander E. C. L. Day’s destroyer Highlander, which arrived on 18 March. As the senior and more experienced officer, Day assumed command of the Escort Group B4 for the rest of the battle. Also en route from the Hvalfjörður in south-western Iceland were the destroyers Vimy and US Babbitt for the HX.229 convoy, and the US Coast Guard cutter Ingham for the SC.122 convoy. These had been despatched on the morning of 18 March and arrived on the following day.
During the afternoon of 18 March Kapitänleutnant Hans-Hartwig Trojer’s U-221 sank the the 7,191-ton US William Q. Gresham and 8,293-ton British Canadian Star of the HX.229 convoy, but the convoy avoided further losses. Highlander joined that afternoon, and was a notably a welcome addition as the Escort Group B4 was by this time reduced to five ships.
During the night of 18/19 March the two convoys were running in tandem though still independent of each other. The attacks on both convoys were repelled this night, and the escorts gained six firm contacts and attacked, but inflicted little damage. The 5,848-ton US Matthew Luckenbach, which had broken away from the HX.229 convoy to proceed independently, steamed into the melée round the SC.122 convoy and was torpedoed and damaged by U-523, and was sunk later on 19 March by Kapitänleutnant Herbert Uhlig’s U-527. A straggler from the SC.122 convoy, the 5,754-ton British Clarissa Radcliffe was also lost, and may have foundered or perhaps was torpedoed by Kapitänleutnant Heinrich Schmid’s U-663. On 19 March the escort was strengthened by the arrival of Vimy and Babbitt for the HX.229 convoy, and Ingham for the SC.122 convoy. The HX.229 convoy’s escort was also joined by corvette Abelia detached from another convoy. Also on the same day Oberleutnant Hans-Achim von Rosenberg-Gruszcynski’s U-384 was attacked and sunk by aircraft to the north of the SC.122 convoy. There were no further losses on either side during 19 March.
Faced with stiffening resistance and fearing losses that would be disproportionate with successes, Dönitz terminated the assault at this time. The two convoys continued to the east.
Further changes to the escort occurred on 20 March as reinforcement arrived in the form of Sherbrooke, while Upshur and Ingham were detached. The local escort groups joined on 23 March, and the HX.229 convoy, with 27 ships surviving, reached Liverpool on 23 March, while the SC.122 convoy, with 42 ships surviving, arrived later on the same day. The double battle had involved 90 merchant ships and 16 escort ships (though not all were present at the same time). A total of 22 merchant ships were sunk (13 and none from the HX.229 and SC.122 convoys respectively), representing a loss of 146,000 tons, and more than 300 merchant seaman died. In total, 38 U-boats had taken part (though throughout the battle not all had been in contact), and one U-boat had been lost with its entire crew.
This was the largest convoy battle of the Atlantic campaign, and was, for the Allies, the crucial point of the whole campaign.