1 Ibid pp. 218–223.
CHAPTER III
The Atlantic Battle, 1941
IN THE late spring and early summer of 1941 it was plain to the British authorities that events in the Atlantic were moving towards a crisis. Though the Germans had not yet decided to place U-boat construction at the top of their list of priorities, we were aware that their rate of production was increasing far more rapidly than in 1940, and that we were not sinking them nearly as fast as new boats were taking the water. In fact between 1st January and 1st April, 1941, thirty new boats were commissioned, compared with twenty-two in the previous quarter, and the enemy’s total strength rose from 89 to 113. Furthermore the U-boats and long-range bombers were beginning to make full use of the bases in western France which they had acquired in June, 1940, and this greatly shortened the distance to the Atlantic convoy routes and so increased the time which each boat could spend on patrol. It was not surprising that our shipping losses in the north Atlantic should have risen from 42 ships (214,382 tons) in January to 69 ships (317,378 tons) in February, and to 63 ships (364,689 tons) in March; and the proportion of these losses caused by the U-boats was also rising steeply. With 195 ships of 687,901 tons sunk by all types of enemy action in April our losses reached the highest point so far touched during the war—not even excepting the very heavy casualties sustained during the withdrawal from Europe in June, 1940. Small wonder that the Admiralty was anxious !
But if the situation during that second spring of the war looked grave, the auguries for the not too distant future were by no means all unfavourable to the British cause. In the first place, by the occupation of Iceland in May, 1940, we had to some extent offset the advantage the enemy had gained by the invasion of Norway. It was true that the invisible barrier of British sea power, through which commerce raiders had to break, had been forced back from the historic line between the Shetland Islands and Norway to the middle of the Atlantic, which made it far easier for the enemy’s surface and underwater craft to evade our sea and air patrols; but the possession of bases in Iceland enabled our Atlantic escorts to extend their protection much farther out into the ocean. Instead of having to leave the convoys with sufficient fuel to return to bases in Northern Ireland, they could now carry on to a point south of Iceland, and then steam the much shorter distance to one of its harbours to replenish; and it was possible for other escorts based on Iceland to come south to meet the convoys, and take over their protection from the ships which had started out from Britain. These measures enabled us to extend the protecting shield of the convoy escorts from about 19° West, which was the farthest point to which they had been able to reach at the end of 1940, to about 35° West, which was half-way across the northern ocean. Nor was the extension of surface escort the only benefit derived from the occupation of Iceland; for it also enabled the Royal Air Force to establish bases there, and so extend the range of Coastal Command’s shore-based aircraft much farther out into the ocean. By 1941 we fully realised the vital importance of air escort in the struggle against the U-boats, and were making every endeavour to strengthen No. 15 Group of Coastal Command, which was responsible for the North Atlantic. In April of that year the Air Ministry established a separate wing (No. 30) in Iceland under the control of No. 15 Group, and in the same month the Admiralty assumed operational control of all Coastal Command aircraft. These measures greatly strengthened our sea-air co-operation, and by sending our Atlantic convoys by northerly routes they were able to gain the maximum protection from the Iceland-based aircraft.
By the spring of 1941 we had also got over the first shock of the “ wolf pack ” tactics introduced by the Germans in the previous autumn, when their night attacks on the surface had found a weak spot in our defensive organisation and training; and early in the following year we had dealt the U-boat command a heavy blow by depriving it of three of its most famous “ aces.” The death of Prien, who had penetrated into Scapa and sunk the Royal Oak on 14th October, 1939, in U.47 and of Schepke in U.100, and the capture of Kretsch-mer from U.99, all of which took place within a few days in March, 1941, were more important accomplishments than we could possibly have realised at the time.1 Other developments favourable to our cause owed an enormous debt to the vision and drive of Admiral Sir Percy Noble, who had taken over the Western Approaches command when its headquarters were shifted from Plymouth to Liverpool in February, 1941; for it was he who introduced permanent escort groups, who organised thorough training in anti-submarine tactics, who standardised our practices and procedure, and also achieved the intimate collaboration between the Western Approaches escorts and the aircraft of Coastal Command’s No. 15 Group, which was to yield such decisive results at the crisis of the battle in May, 1943. From the very beginning Air Vice-Marshal Robb, commander of No. 15 Group, established himself in the next door room to Admiral Noble in the Western Approaches Command headquarters in Derby House, Liverpool; and the close contact between the sea and air forces engaged in the Atlantic battle thereby established was of immense benefit to the Allied cause.
Once the permanent escort groups, two of which played the leading parts in our story, had been formed, we made every endeavour not to break them up. The reason was that a close understanding between individual Captains was found to be far more important in convoy work than the homogeneity of the types of vessel forming a group. Thus a group might consist of two or three destroyers, which formed the main striking force, four or five of the war-built corvettes, one or two sloops and a number of fishing trawlers which had been converted for anti-submarine work. In early 1941 the total strength of an escort group might, on paper, have been as many as fifteen ships; but the constant need for refits and for dockings to repair the damage caused by the violence of the Atlantic storms, generally kept the actual operational strength down to little more than half that figure.
Though the formation of the permanent escort groups marked a big step in the right direction, formidable difficulties still had to be surmounted before they could be regarded as anything like efficient anti-submarine forces. In the first place, for all the lessons we had learnt in the 1914–18 war, none of the ships which comprised them was well designed for the work they had to carry out. The destroyers, though possessed of a good turn of speed and comparatively powerful armaments, were all old ships, for the more modern ones were all needed to work with our main fleets at home and in the Mediterranean; and those which we had recently taken over from the Americans had undergone even less modernisation than our own. But the most serious weakness of the escort destroyers lay in the fact that none of them had sufficient endurance to cross the Atlantic without refuelling, and we had not yet developed the technique of replenishing them from a tanker in the convoy they were escorting. Thus they always had to leave their convoys with sufficient fuel in hand to reach a shore base. The corvettes had better endurance, but were lightly armed and so lively in a seaway that they taxed their crews very severely indeed. Moreover they were so slow (about 15 knots maximum) that they could not catch a surfaced U-boat. The sloops were comparatively long-endurance ships, and for that reason were more generally employed on the route between Britain and Sierra Leone than in the North Atlantic; while the coal-burning trawlers, though they could keep the sea longer than any other class, were slower and still livelier than the corvettes.
Second only to the deficiencies from which the ships themselves suffered was the problem of finding trained and experienced officers to command them. Astonishing though it may seem in the light of our 1914–18 war experiences, anti-submarine technique and the problems of convoy protection were regarded between the wars as very secondary matters, and little study was devoted to them. Nearly all our fleet exercises were framed to represent engagements between squadrons of heavy ships, and if trade protection entered into them at all it was approached from the point of view of countering surface raiders rather than submarines. Furthermore the anti-submarine branch of the Service was regarded as very much the poor relation of the older b
ranches—gunnery, torpedo or navigation. It thus came to pass that in 1939 we had practically no fund of common experience and doctrine in convoy work to fall back on. Everything had to be studied from the beginning, and experience had to be gained the hard way—from our own mistakes. The Admiralty appointed Commanders, most of whom had experience of small ship work, as Senior Officers of the escort groups, and Lieutenant-Commanders of similar background to the sloops and destroyers; but it fell mostly to R.N.R. and R.N.V.R. Officers to command the corvettes and trawlers, and they of course had even less experience of convoy work than their R.N. colleagues. A further difficulty arose through the constant shortage of escort vessels making it extremely difficult for senior officers to arrange a programme of steady training for their groups. As soon as one convoy had been brought home they had to prepare to take another one out. Only very rarely could a group exercise as a whole in between convoys, or while on passage by itself. The lack of any common doctrine led, moreover, to senior officers devising their own screening formations, and issuing their own orders on how to deal with any emergency. This may not have mattered if an escort was drawn entirely from one group. But it was, as will be seen later in our story, a common event for ships of two or more groups to have to work together during some stages of a convoy’s progress; and when that took place it was all too easy for misunderstandings to arise in, for example, the confused conditions of a night attack by several U-boats. Admiral Noble and his staff well understood the need to standardise practice throughout the ships of his command, and he ultimately issued the Western Approaches Convoy Instructions with that purpose; but at the date with which we are concerned that still lay in the future, and there were still wide variations in the tactical practices of all escort groups.
The group commanders knew full well the need to foster and encourage a strong esprit de corps in their ships; and it is a remarkable fact that, even to-day, the group spirit survives among the junior officers and men who served in them. Each group developed its own personality, and there was a healthy rivalry between groups; but in spite of the inadequacies of ships and armaments, and the knowledge that officers and men still had much to learn about their work, all felt completely confident that, if only they could gain contact with their elusive adversaries, they would come out on top. There is indeed no doubt at all that the carefully fostered group spirit had a great deal to do with the success achieved in encounters such as that which led to the capture of U.110.
One recent development which, although still in its infancy in 1941, had greatly increased the confidence of the groups was the advent of an elementary surface radar set. Only a few ships, and those mostly the destroyers, had so far been fitted; but the crews regarded the equipment as little short of magical, and knew that it put them on far more level terms with the surfaced submarine, attacking in darkness, than had been the case when they had to rely solely on visual sighting by lookouts. The radar aerial of those days resembled a bedstead, and was about that size; and as it had to be fitted on the mast it reduced the stability of the ships, and made them roll still more heavily. It even caused the dismasting of several ships which encountered exceptionally violent weather; yet all knew that the scientists and technicians had placed in their hands perhaps the most important anti-submarine development of the whole war. Little could it have been foreseen in those days that, before the war was over, a Group Commander would be able to conduct a search and attack entirely by radar and voice radio from his “ plot,” without ever emerging on to his bridge.
In the spring of 1941 the homeward North Atlantic traffic was organised into fast (9-knot) convoys from Halifax (HX), and slow (7-knot) convoys from Sydney, Cape Breton Island (SC). In a normal month four of the former and two of the latter would sail for British ports, and four outward convoys (OB) would leave for North America, dispersing in about 35° West to proceed to their several destinations. The main assembly and arrival ports in Britain were Liverpool and the Clyde; for after the fall of France we could make less use of London and the other east coast ports. Such ships as had to proceed to and from the east coast were organised into subsidiary convoys, which were taken round the north of Scotland. Not until July, 1941, were we able to organise end-to-end escort for all outward as well as homeward Atlantic shipping.
To give an idea of the size of the traffic which the Western Approaches Command had to protect, in the first three months of 1941, 687 ships sailed in HX convoys, 306 in SC convoys, and 1,282 in the OB outward series; and in addition to the North Atlantic traffic the same command also had to look after the convoys running to and from Gibraltar and Sierra Leone while they were within its area of responsibility. The north Atlantic escort groups worked mainly from Liverpool and the Clyde, but Londonderry was developing into a very important advanced base, and several groups were based on Hvalfiord in Iceland to relieve the original escorts when they reached the limit of their fuel endurance in about 24° West.
Though the U-boats were reaching ever farther out into the Atlantic from their new bases in western France, in early 1941 none had yet been contacted beyond about 30° West. In consequence it was our practice for an outward convoy only to be escorted to about 35° West, and for the homeward convoys to be given only an anti-raider escort from the east coast of America to that point. In some cases battleships or cruisers fulfilled the latter duty, for the pocket battleship Scheer’s attack on convoy HX.84 on 5th November, 1940, and the foray of the battle cruisers Scharnhorst and Gneisenau in the Atlantic in early 1941 had shown us that only heavy warships could protect the convoys against such enemies. But in many cases only a converted liner, officially and somewhat optimistically described as an Armed Merchant Cruiser, could be provided. These ships called themselves the “ suicide squad,” and in fact many of them fell victims to the enemy, and especially to the U-boats, against which they were virtually defenceless. In early 1941 they generally broke off from their convoys when the anti-submarine escort was met in mid-Atlantic, steamed to Iceland to refuel and then proceeded west again to pick up another convoy at Halifax. We shall encounter one ship of that type, the former P. & O. liner Ranpura later in our story.
1 For an account of the sinking of U.99 and U.100 by the destroyers Walker and Vanoc on 17th March, 1941, see Captain Donald Macintyre U-boat Killer (Weidenfeld and Nicolson, 1956). According to post-war statistics prepared in Germany (see Marine Rundschau for October 1957) Kretschmer’s successes place him first on the list of outstanding U-boat commanders with 44 ships totalling 266,629 tons sunk while in command of U.23 and U.99. Prien’s name stands 10th on the same list with 28 ships totalling 160,935 tons sunk by U.47, and Schepke is nth with 39 ships of 159,130 tons to his credit while in command of U.3, U.19 and U.100.
CHAPTER IV
The Convoy
ONE OF the unchanging features of maritime war is that convoys always draw enemy commerce raiders to themselves like bees to honey. The reason is the simple one that, once the greatest part of a nation’s shipping is sailed in convoy, it is only by finding and attacking one of them that the raiders can fulfil the purpose for which they were fitted out and sent to sea. Nor has the entry of either the submarine or the aircraft into sea warfare altered this feature in the slightest; for both wars of this century have demonstrated very clearly not only how the convoy system enables us to know where to look for the commerce raiders, but how it also produces the opportunity for the escorts to strike back hard at them. Indeed it is true to say that most of the successful actions fought against U-boats took place around convoys, whose slow progress across the ocean often took the form of a continuous battle lasting several days and nights. It is thus inevitable that the story of the capture of U.110 should be closely interwoven with the fate of the convoy which she tried to attack; and to understand how the British success was achieved it is necessary to follow the adventures of the convoy in some detail.
OB.318 was a very typical example of the outward convoys mentioned in the last chapter. The largest section, whic
h finally consisted of seventeen ships, assembled at Liverpool late in April, 1941; and they were to be joined by subsidiary sections assembling at Loch Ewe in north-west Scotland (12 ships), the Clyde (5 ships), and Milford Haven (4 ships). The ships in Loch Ewe had come from ports on the east coast of Britain, and had already been convoyed round the north of Scotland. All the subsidiary sections were to be sailed to rendezvous with the main convoy at pre-arranged times and positions, and during the passage across the Atlantic three ships were to be detached to Iceland, whence four others would come south to join the convoy. The successful interlocking of all these movements, and the organisation of the necessary sea and air escorts, plainly demanded very skilful staff work at all the bases concerned. Yet—for the North Atlantic convoys alone—the whole process was carried out at least a dozen times in every month throughout the war.
Throughout the war the Ministry of Transport kept the Admiralty informed regarding the dates when individual merchantmen would be ready to sail, what were their cargoes and whither they were bound; and as all convoys sailed on regular “ cycles ”—the number of days between the departure of similar convoys—the Admiralty was thus able to start planning each movement well in advance. The preliminary orders for OB.318 were actually issued on the evening of 25th April, 1941, when the Naval authorities in all ports concerned were told the names of the ships detailed for the convoy, their cargoes and their destinations; and in the same message the Admiralty also laid down the route which the convoy was to follow. It was to proceed up the Minches, the sheltered stretch of water between the Hebrides and the west coast of Scotland, and then turn north-west into the Atlantic, passing through a succession of named positions until it reached 50° 50′ North 35° West (about midway between Iceland and the southern point of Greenland1), where the convoy would break formation, and ships would proceed independently to their several destinations. This first message from the Admiralty set in motion the far-flung and intricate machinery for the organisation of yet another convoy. Next day the Naval Control Service Officer in the Mersey, who was the authority responsible to the Admiralty for convoy organisation in that port, signalled that the main section of OB.318 would sail at 3 p.m. (local time) on the 2nd May1; and his message was quickly followed by others from the N.C.S.O.s at Milford Haven, the Clyde, and Aultbea (Loch Ewe) stating their intentions with regard to sailing the subsidiary convoys for which they were each responsible. Meanwhile the operational authorities in the naval bases were detailing the escorts for the main convoy and its sub-sections. The destroyer Vanity, two anti-submarine trawlers, and an anti-submarine yacht were to bring the Milford Haven section to the rendezvous with the main convoy; the destroyer Campbeltown (formerly the U.S. Navy’s Buchanan), which was to achieve undying fame later in the raid on St. Nazaire on 27th-28th March, 1942) and the A/S trawler Angle were to leave with the Clyde section2, while the destroyer Newmarket (the former American Robinson) would look after the twelve ships from Loch Ewe for the short distance they had to travel to meet the main convoy in the North Minch shortly before it emerged into the Atlantic. The Flag Officer, Liverpool, had meanwhile nominated the 7th Escort Group to take charge of the convoy for the first part of the ocean passage, and the sloop Rochester, with the corvettes Primrose, Marigold and Nasturtium of that group, were to leave with the Liverpool section. The Senior Officer of the group, Commander I. H. Bockett-Pugh, in the destroyer Westcott, one of the “ Admiralty W ” class designed for the 1914–18 war and completed in 1918, and the corvettes Dianthus and Auricula would leave Liverpool about 24 hours after the merchantmen and overtake them off Cape Wrath. By the time the convoy headed out into the Atlantic it would thus be escorted by Bockett-Pugh’s full strength, comprising three destroyers, one sloop, five corvettes and a trawler. The destroyers were to top up their fuel tanks in Loch Ewe, and so have the maximum endurance for the westward passage. OB.318’s escort was unusually strong in numbers for that period of the war, but only the Westcott was fitted with radar, and hers was of a somewhat rudimentary type. Furthermore the two ex-American destroyers, which were the only ships with direction-finding wireless, had not had time to calibrate their sets, and the group thus lacked one of the most valuable means of locating enemy submarines, by taking bearings of their wireless transmissions. But if its technical equipment was far from perfect, in Commander Bockett-Pugh the 7th Escort Group had recently acquired an outstanding leader. He had entered the Navy from Christ’s Hospital in 1918, and had served most of the inter-war years in small ships or in naval training establishments. He had been lucky enough to gain early experience of command in a West River gunboat in China, and in 1940 took command of the sloop Wellington, which did excellent work on the Gibraltar convoy route. From her he transferred to the Westcott early in 1941, and between that date and the end of the war he was awarded three D.S.O.s and once mentioned in despatches.1 It is hardly surprising that, with such a leader, the 7th Escort Group should quickly gain a reputation for efficient convoy work, and for striking hard blows at any enemy which came within its reach.
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