Shadow over the Atlantic

by Robert Forsyth

  Stabskompanie

  Staff Company

  Technisches Amt

  Technical Office

  Unterseebootsflottille

  U-boat flotilla

  Verbandsführerschule

  Unit Leaders’ School

  VLR Very Long Range

  Wetterwarte Atlantik

  Atlantic Weather Station

  CONVOY PREFIXES

  HX Halifax–UK

  KMS UK–North Africa–Port Said (Slow)

  MKS Mediterranean–North Africa–UK (Slow)

  ON UK–North America

  ONS UK–North America

  OS UK–West Africa

  SC Halifax–UK (Slow)

  SL Sierra Leone–UK

  FERNAUFKLÄRUNGSGRUPPE 5 / JU 290 AND AR 234 RANGES AND BASES: 1943–1945.

  CHAPTER ONE

  DARK WATERS

  The Luftwaffe can raise not only the diminishing number of ships sunk by U-boats, but can strike a decisive blow against British sea power by paralysing her supplies. The Luftwaffe would fulfil its true purpose if so used.

  ‘The Operational Use of the Luftwaffe in the War at Sea 1939–1943’, Luftwaffe 8.Abteilung Historical Report, January 1944

  In January 1944, in a report on the operational use of the German Air Force in the war at sea, an officer of the Luftwaffe historical research section wrote:

  The Luftwaffe is particularly mobile. It is the Luftwaffe that as a rule locates a convoy and directs U-boats to it. It is the Luftwaffe that seeks out aircraft carriers in order to sink them first. It is the Luftwaffe that fights the U-boats’ worst enemy, the fighter, and destroys enemy shipping unaided. But the engagements of the Luftwaffe are only of short duration. If an attack is unsuccessful, then the U-boats are at an advantage because they can lurk along the convoy route for a long period and make another attack later. The U-boat can also summon the Luftwaffe to make surprise attacks. If contact with the enemy is lost, it can again call on the Luftwaffe to carry out reconnaissance so that this may be restored. Both services accordingly help each other as well as possible. From this it is understood that the commands of the Luftwaffe and the U-boats must be closely connected.1

  Some 30 years before, Imperial Germany was quick to recognize the tactical value of cooperation between the first U-boats and early military aeroplanes. A photograph from World War I shows a military seaplane resting on the surface of the water, while its observer stands on one of the aircraft’s floats, clutching the leading edge of the wing to steady himself, as he passes the commander of a surfaced U-boat what is described as an ‘important report.’2

  Following the end of the war in 1918, Germany, despite being a vanquished naval power, never let go of its belief in the submarine as an effective weapon, and as the Weimar Republic gave way to the Nazi era and the process of rearmament, there were those who worked hard to drive forward a renewed U-boat construction programme. The man upon whose shoulders this task was chiefly placed was Karl Dönitz. The son of an optical engineer for Karl Zeiss at Jena, he had joined the Kaiserliche Marine (Imperial Navy) in 1910, receiving a commission three years later. His first years in the Navy were spent on board the cruiser Breslau, mostly in the Mediterranean.

  Between 1916 and 1918 Dönitz served in the U-boat arm, but was captured after the sinking of his boat off Malta at the end of the war. In 1919 he joined the Reichsmarine, the small navy allowed Germany under the terms of the Treaty of Versailles. During the 1930s, he embraced National Socialism, and in 1935 was appointed by Generaladmiral Erich Raeder to (re)build the U-boat fleet.3

  Dönitz held firmly to two principles; that in order to use U-boats effectively against enemy shipping in what he believed would be ‘convoy’ warfare, large numbers or ‘packs’ of boats would need to be deployed. This ‘pack’ philosophy envisaged groups of U-boats smashing through a convoy’s defences, the convoy having first been located, with the boats assembled in the optimum position to launch a simultaneous attack. However, a prerequisite for this was the need for the best possible reconnaissance, preferably from the air. Indeed, as early as 1937, Dönitz recognized that air reconnaissance would, in fact, be vital to the efficacy of submarine warfare, especially since the U-boat in itself had little reconnaissance capability: ‘it must act in cooperation with a branch of the armed forces more suited to reconnaissance duties. And for these, the best instrument is the aeroplane.’4

  However, this requirement was at odds with fundamental Luftwaffe doctrine; in the years immediately before the outbreak of war in 1939, senior German military planners had envisaged and prepared for a ‘strategic’ deployment of the Luftwaffe in a war on land, mounted against enemies who were seen as potential threats to the ‘security of the Reich’. Indeed, in January 1944, a Luftwaffe historical report noted that ‘there had never been any doubt of the possibility and necessity of using the bulk of the Luftwaffe in full force for strategic purposes on land.’

  Consequently, in technical terms, priority was placed on the development of aircraft suited for war over land against land forces. As such, aircraft and equipment intended for use in direct cooperation with the other branches of the armed services received lesser attention. The ‘weaker’ development was for cooperation with the Navy, for example, the stronger would be the strategic (land) force, which would benefit from better development and training. In such an environment the Kriegsmarine could expect support only from coastal reconnaissance in the Baltic and the North Sea, although it was also the intention to form air units for the aircraft carrier, Graf Zeppelin, then under construction.5

  For some 20 years, the German Navy and Army had competed to build their own, autonomous air arms. German naval aviation had undergone a foundational and acrimonious change between 1935 and 1939, when General Hermann Göring, as commander of the new Luftwaffe, had grasped effective control of the Luftwaffenkommando-See, the small naval air arm operated by the Kriegsmarine, and in doing so responsibility for aerial reconnaissance and the air support of naval units when in contact with an enemy. This left tensions simmering between the Luftwaffe and the Kriegsmarine and, in reality, neither force could field significant assets under the prevailing infrastructure. Then, in 1937 a conference was held to agree the respective zones of operation for the air force and naval air units. The Kriegsmarine retained control only of those units deemed to be an extension of the fleet as well as some coastal aviation.6

  In command of this revised air organization was the Oberbefehlshaber der Luftwaffe – Führer der Seeluftstreitkräfte (Commander of Naval Units on the Staff of the Ob.d.L.). In March 1939, this was redesignated as the General der Luftwaffe beim Oberbefehlshaber der Marine (Luftwaffe General to the Commander in Chief of the Navy) who reported directly to Göring (and who acted as the main liaison with the Kriegsmarine).7 Under this arrangement, the Luftwaffe controlled the shadowing and reporting of enemy convoys and their locations, and all other shipping at sea and in coastal waters.

  Joint air and naval exercises in the mid- to late 1930s conducted in the North Sea and the Baltic, involving reconnaissance aircraft, had shown that cooperation was possible, and the potential for Atlantic reconnaissance was also examined. During a major wargame manoeuvre in the winter of 1938/39, which included officers from the staff of the General der Luftwaffe beim Oberbefehlshaber der Marine, daily reconnaissance sorties had been despatched boldly across the North Sea and the Shetlands, to fly around the coasts of Britain and Ireland, returning over France.8 By all accounts they were successful.

  New aircraft deemed to be suitable for long-range maritime reconnaissance had been expected to become available during the late 1930s, but it was always an uphill struggle because Generalmajor Ernst Udet, the extrovert World War I fighter ace in charge of the Luftwaffe Technisches Amt (Technical Office), was an advocate of small, fast aircraft. Both he and General der Flieger Erhard Milch, the Secretary of State for Aviation, shared an aversion to long-range military aircraft because of their cost and the drain they placed o
n metal and other vital raw materials. Indeed, Göring had scrapped the four-engined Dornier Do 19 long-range bomber in April 1937, while the prototype Junkers Ju 89 was converted to become the Ju 90 transport (see Chapter Two).

  When, however, in August 1938, a four-engined Focke-Wulf Fw 200 Condor airliner landed in New York on its record-breaking, non-stop propaganda flight across the Atlantic, for a while at least, a delighted Udet forgot his aversion to four-engined, long-range aircraft.

  Whatever the motives of either side in the unsettled arrangement between the Luftwaffe and the Kriegsmarine, over the following years, and as the war progressed, the relationship that developed was never easy, a situation that was reflected in the very processes of ‘cooperation’. Offensive operations against the British Home Fleet in October 1939 highlighted major shortcomings in the ability of Luftwaffe crews to fly in bad weather over the sea, resulting in a lack of reconnaissance, ‘shadowing’ and attack. On another occasion in the same month, in an operation off the east coast of England, a tactical plan failed between new Ju 88 Luftwaffe bombers and He 115 floatplanes of a naval Küstenfliegergruppe (coastal air group), resulting in the loss of four of the latter aircraft with damage to another. But worse was to come in February 1940, when Luftwaffe bombers erroneously sank two German destroyers engaged in an operation against British fishing vessels off Dogger Bank. Not surprisingly, Grossadmiral Raeder, Commander-in-Chief of the Kriegsmarine, was livid.9

  The main long-range reconnaissance aircraft used by the Luftwaffe for maritime work at this time was the tandem-engined Dornier Do 18 flying boat, which equipped the small number of Küstenfernaufklärungsstaffeln (long-range coastal reconnaissance squadrons) of the Küstenfliegergruppen (coastal air groups). The Do 18 had originally been developed as a transocean mailplane for Lufthansa in 1934, and four years later one example had achieved a seaplane record for flying non-stop in a straight line for 8800 km between England and Brazil. However, according to German opinion, it offered no real comparison to contemporary British aircraft and, aside from reconnaissance, even in terms of offensive capability, it had a restricted payload with no provision for carrying torpedoes or mines. At the end of October 1939, the Kriegsmarine admitted that the 56 Do 18s then available to it had achieved a total patrol range of 500,000 km, or just over 150 km per day. Furthermore, ten of the flying boats had been lost, with replacements arriving at a rate of only three per month. In an ominous portent of things to come, Admiral Alfred Saalwächter, commander of Marinegruppe West, noted that no increase in the supply of such aircraft could be expected.10

  In 1939, Konteadmiral Dönitz held discussions with Major Edgar Petersen, a Luftwaffe staff officer who had also commanded the Fernaufklärungsstaffel Ob.d.L. Petersen was an advocate of long-distance and night flying and served as an adviser on the staff of Generalleutnant Hans Geisler, the commander of X. Fliegerkorps and one-time Führer der Marineluftstreitkräfte. In September 1939, Petersen had suggested to Geisler that existing Fw 200s could and should be converted for long-range reconnaissance purposes.11 He believed that the Focke-Wulf would be able to fly from Germany, across France to the main U-boat operational area to the west of the English Channel, and back. The problem was that the first Gruppe of Fw 200s would not commence (bombing) operations until the spring of 1940.

  By June 1940 the invasion of France had given the Germans airfields on the Atlantic coast and the U-Boat Staff Officer in the Naval Staff Operations Division was enthused:

  ...the possibility arises of air reconnaissance of the enemy convoy routes and disposition in the area south and south-west of Ireland and perhaps even in the remoter areas to the west and north. The task of the aircraft will be to intercept enemy convoys and other valuable ships, shadow them and, even if contact should be lost, regain it on the following morning.

  At the same time, Dönitz was requested to produce his plans for direct cooperation between Befehlshaber der Unterseeboote (BdU) and the Naval Air Commander, and to ascertain from Göring what his intentions were in terms of rendering support for Atlantic reconnaissance. The reality was that for most of 1940, the only aircraft available for such a task were those of Kü.Fl. Gr.406 (Do 18s) and 506 (He 115s) and such ‘cooperation’ that there was, was invariably hit and miss.12

  When, in January 1941, the Fw 200 Condor bombers of 1./KG 40 based at Bordeaux-Mérignac were placed under the operational control of the BdU, things were still hit and miss. There was only a small number of aircraft available and they suffered from technical problems. On two early attempts to locate convoys in January 1941, the Condors lost contact, and generally the U-boats had to maintain their own reconnaissance.13 When the U-boats were moved north, from west of the North Channel, to track diverted convoys, their zone of operations stretched as far as the coast of Iceland, a point which the Fw 200s struggled to reach. The main issue however, was that there were too few aircraft, and when a shadower was observed, the British simply diverted their ships. As Günter Hessler describes:

  With a view to keeping air shadowers unobserved, they were ordered on 3rd March not to bomb the convoys. Flag Officer U-boats took this step reluctantly, being aware of the tonic effect of successful air attacks on aircrews engaged in long and wearying reconnaissance. But the large Condors found unobserved shadowing impossible, and on 31st March, general freedom of bomber attack on all targets was restored.14

  From March 1941, leadership of Luftwaffe maritime reconnaissance over the North Sea between 52° and 58° North remained the responsibility of the Führer der Seeluftstreitkräfte, while north of this parallel it was in the hands of the Fliegerführer Nord (Air Commander North). The English Channel and the area west of the Scilly Isles and Ushant (Ouessant) was the jurisdiction of the recently formed Fliegerführer Atlantik (Air Commander Atlantic).15 Indeed, this latter tactical command had been established by order of the Führer – probably as a result of pressure from Dönitz and others – and was subordinated to Luftflotte 3. Its first commander was the highly decorated anti-shipping specialist Oberstleutnant Martin Harlinghausen, whose brief was to work closely with the BdU in operations against enemy supply shipping in the Atlantic which, effectively, meant the convoy routes to and from Britain and the Mediterranean and the US East Coast, as well as those passing over the eastern, southern and western coasts of the British Isles.16

  But from the autumn of 1940, the air-naval chain of communication proved cumbersome and slow to function. Response to the sighting of enemy shipping by the Condors of KG 40, which added, inherently, the role of reconnaissance to their anti-shipping operations, meant that a report on the sighting of enemy shipping was first transmitted to the Geschwader base at Bordeaux-Mérignac. It was then passed to the headquarters of the tactical command, IV. Fliegerkorps at Dinard. The Korps then transferred the information to Luftflotte 3 in Paris, which then relayed it to Marinegruppe West and finally to the BdU at Sengwarden near Wilhelmshaven (later Paris). This procedure frequently took a day to complete, resulting in missed opportunities and a devaluation of KG 40’s ‘raw’ reconnaissance intelligence.17

  That year, the Navy requested that a flying unit be formed for the specific task of carrying out long-range maritime reconnaissance and rendering support for the U-boats and surface ships, rather than just a Gruppe that was also committed to offensive missions. From the second half of 1941, Dönitz began to beat the drum again and again: any lack of success against convoys was attributable fairly and squarely to a lack of boats and a lack of ‘eyes’ in the air.18 Until these ‘eyes’ became widely available, the U-boat itself would continue to be the main instrument of reconnaissance, but even in good visibility the best range of vision from a U-boat was some 30 km.19

  In mid-1941, as the strength of I./KG 40 increased and the U-boats had returned to more easterly waters, BdU hoped for at least two to three Condors to be made available daily for reconnaissance (still in addition to the primary bombing operations of the Gruppe). But at just this point, control of the Gruppe had been removed fro
m the BdU and assigned to Fliegerführer Atlantik, where Harlinghausen did his best to ensure smooth cooperation – something in itself that suspicious minds within U-boat command believed was a measure by Göring to illustrate how KG 40’s assignment to BdU was not an acceptable state of affairs.20

  In the period 15 March to 31 October 1941, Luftwaffe reconnaissance reported 56 convoys and shadowed many of them for several days at a time, thus enabling the U-boats to close in for attack. As a result of this all too brief period of close cooperation with Luftwaffe reconnaissance, the U-boats claimed to have sunk ‘74 merchant vessels totalling 390,000 tons, one aircraft carrier and one destroyer’. Unless this is a chronologically inaccurate reference to HMS Audacity (the escort carrier sunk by a U-boat on 21 December 1941 having been shadowed by Fw 200s), this is not correct. In the period 13 March to 31 December 1942, the bomber force of the Fliegerführer Atlantik claimed to have accounted for 161 vessels totalling 903,000 Gross Registered Tonnage (GRT) sunk, seven vessels probably sunk, totalling 31,000 GRT and 113 vessels damaged totalling 590,000 GRT.21

  However, the inescapable fact was that from the summer of 1941, by far the bulk of the Luftwaffe was committed to the east for the invasion of the Soviet Union – a land campaign. This meant that Luftwaffe commands in the West found it increasingly difficult to carry out the tasks allotted to them, including that of maritime reconnaissance, anti-shipping and minelaying operations.22 Such duties became ever more peripheral.

  By late 1941, the convoys were receiving regular destroyer escort as well as cover from aircraft and thus the task of the U-boats became ever harder. Subsequently, the main point of U-boat effort was moved west, farther out into the Atlantic, targeting the eastbound Atlantic convoys, well beyond the range of the relatively few Fw 200s that there were. The plan was that by the late autumn of 1941, operations were to be conducted exclusively in North American waters, which provided favourable attack conditions along with plentiful targets.23 As the Luftwaffe historical branch noted, ‘in the middle of December 1941 cooperation with the C.-in.C. U-boats in the joint campaign against enemy shipping in the eastern Atlantic came practically to a standstill.’24