15

Operation Sea Lion

Plan of the German Admiralty — Their Conditions Met by the Conquest of France and the Low Countries — Meeting with the Fuehrer of July 21 — Hitler Comprehends the Difficulties but Gives the Order — Controversy Between the German Navy and Army Staffs — Raeder and Halder at Variance – The Compromise Plan Agreed — Further Misgivings of the German Admiralty — Both German Navy and Army Chiefs Cast the Burden on Goering and the Air — Goering Accepts — Hitler Postpones D-Day — British Counter-Activities — The “Cromwell” Order of September 7 — A Healthy Tonic — German Ignorance of Amphibious Warfare — Service Disunion — The Germans Stake All on the Air Battle.

SOON AFTER WAR BROKE OUT on September 3, 1939, the German Admiralty, as we have learnt from their captured archives, began their staff study of the invasion of Britain. Unlike us, they had no doubt that the only way was across the narrow waters of the English Channel. They never considered any other alternative. If we had known this, it would have been an important relief. An invasion across the Channel came upon our best-defended coast, the old sea-front against France, where all the ports were fortified and our main flotilla bases, and in later times most of our airfields and air-control stations for the defence of London, were established. There was no part of the island where we could come into action quicker or in such great strength with all three Services. Admiral Raeder was anxious not to be found wanting should the demand to invade Britain be made upon the German Navy. At the same time he asked for a lot of conditions. The first of these was the entire control of the French, Belgian, and Dutch coasts, harbours, and river mouths. Therefore, the project slumbered during the Twilight War.

Suddenly all these conditions were surprisingly fulfilled, and it must have been with some misgivings but also satisfaction that on the morrow of Dunkirk and the French surrender he could present himself to the Fuehrer with a plan. On May 21 and again on June 20, he spoke to Hitler on the subject, not with a view to proposing an invasion, but in order to make sure that if it were ordered the planning in detail should not be rushed. Hitler was sceptical, saying that “he fully appreciated the exceptional difficulties of such an undertaking.” He also nursed the hope that England would sue for peace. It was not until the last week in June that the Supreme Headquarters turned to this idea, nor till July 2 that the first directive was issued for planning the invasion of Britain as a possible event. “The Fuehrer has decided that under certain conditions – the most important of which is achieving air superiority – a landing in England may take place.” On July 16, Hitler issued his directive: “Since England, in spite of her militarily hopeless position, shows no sign of coming to terms, I have decided to prepare a landing operation against England, and if necessary to carry it out…. The preparations for the entire operation must be completed by mid-August.” Active measures in every direction were already in progress.

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The German Navy Plan, of which it is clear I had received an inkling in June, was essentially mechanical. Under the cover of heavy-gun batteries firing from Gris-Nez towards Dover, and a very strong artillery protection along the French coast in the Straits, they proposed to make a narrow corridor across the Channel on the shortest convenient line and to wall this in by minefields on either side, with outlying U-boat protection. Through this the Army was to be ferried over and supplied in a large number of successive waves. There the Navy stopped, and on this the German Army Chiefs were left to address themselves to the problem.

Considering that we could, with our overwhelming naval superiority, tear these minefields to pieces with small craft under superior air power and also destroy the dozen or score of U-boats concentrated to protect them, this was at the outset a bleak proposition. Nevertheless, after the fall of France anyone could see that the only hope of avoiding a long war, with all that it might entail, was to bring Britain to her knees. The German Navy itself had been, as we have recorded, knocked about in a most serious manner in the fighting off Norway; and in their crippled condition they could not offer more than minor support to the Army. Still, they had their plan, and no one could say that they had been caught unawares by good fortune.

The German Army Command had from the first regarded the invasion of England with considerable qualms. They had made no plans or preparations for it; and there had been no training. As the weeks of prodigious, delirious victory succeeded one another, they were emboldened. The responsibility for the safe crossing was not departmentally theirs, and, once landed in strength, they felt that the task was within their power. Indeed, already in August Admiral Raeder felt it necessary to draw their attention to the dangers of the passage, during which perhaps the whole of the army forces employed might be lost. Once the responsibility for putting the Army across was definitely thrust upon the Navy, the German Admiralty became consistently pessimistic.

On July 21 the heads of the three Services met the Fuehrer. He informed them that the decisive stage of the war had already been reached, but that England had not yet recognised it and still hoped for a turn of fate. He spoke of the support of England by the United States and of a possible change in German political relations with Soviet Russia. The execution of “Sea Lion,” he said, must be regarded as the most effective means of bringing about a rapid conclusion of the war. After his long talks with Admiral Raeder, Hitler had begun to realise what the crossing of the Channel, with its tides and currents, and all the mysteries of the sea, involved. He described “Sea Lion” as “an exceptionally bold and daring undertaking.” “Even if the way is short, this is not just a river crossing, but the crossing of a sea which is dominated by the enemy. This is not a case of a single-crossing operation, as in Norway; operational surprise cannot be expected; a defensively prepared and utterly determined enemy faces us and dominates the sea area which we must use. For the Army operation forty divisions will be required. The most difficult part will be the material reinforcements and stores. We cannot count on supplies of any kind being available to us in England.” The prerequisites were complete mastery of the air, the operational use of powerful artillery in the Dover Straits, and protection by minefields. “The time of year,” he said, “is an important factor, since the weather in the North Sea and in the Channel during the second half of September is very bad, and the fogs begin in the middle of October. The main operation must therefore be completed by September 15, for after that date co-operation between the Luftwaffe and the heavy weapons becomes too unreliable. But as air co-operation is decisive, it must be regarded as the principal factor in fixing the date.”

A vehement controversy, conducted with no little asperity, arose in the German staffs about the width of the front and the number of points to be attacked. The Army demanded a series of landings along the whole English southern coast from Dover to Lyme Regis, west of Portland. They also desired an ancillary landing north of Dover at Ramsgate. The German Naval Staff now stated that the most suitable area for the safe crossing of the English Channel was between the North Foreland and the western end of the Isle of Wight. On this the Army Staff developed a plan for a landing of 100,000 men, followed almost immediately by 160,000 more at various points from Dover westward to Lyme Bay. Colonel-General Halder, Chief of the Army Staff, declared that it was necessary to land at least four divisions in the Brighton area. He also required landings in the area Deal-Ramsgate; at least thirteen divisions must be deployed, as far as possible simultaneously, at points along the whole front. In addition, the Luftwaffe demanded shipping to transport fifty-two A.A. batteries with the first wave.

The Chief of the Naval Staff, however, made it clear that nothing like so large or rapid a movement was possible. He could not physically undertake to escort a landing fleet across the whole width of the area mentioned. All he had meant was that within these limits the Army should pick the best place. The Navy had not enough strength, even with air supremacy, to protect more than one passage at a time, and they thought the narrowest parts of the Straits of Dover the least difficult. To carry the whole of the 160,000 men of the second wave and their equipment in a single operation would require two million tons of shipping. Even if this fantastic requirement could have been met, such quantities of shipping could not have been accommodated in the area of embarkation. Only the first echelons could be thrown across for the formation of narrow bridgeheads, and at least two days would be needed to land the second échelons of these divisions, to say nothing of the second six divisions which were thought indispensable. He further pointed out that a broad-front landing would mean three to five and a half hours’ difference in the times of high water at the various points selected. Either, therefore, unfavourable tide conditions must be accepted at some places, or simultaneous landings renounced. This objection must have been very difficult to answer.

Much valuable time had been consumed in these exchanges of memoranda. It was not until August 7 that the first verbal discussion took place between General Halder and the Chief of the Naval Staff. At this meeting Halder said: “I utterly reject the Navy’s proposals. From the Army viewpoint I regard it as complete suicide. I might just as well put the troops that have been landed straight through the sausage-machine.” The Naval Chief of Staff rejoined that he must equally reject the landing on a broad front, as that would lead only to a sacrifice of the troops on the passage over. In the end a compromise decision was given by Hitler which satisfied neither the Army nor the Navy. A Supreme Command Directive, issued on August 27, decided that “the Army operations must allow for the facts regarding available shipping space and security of the crossing and disembarkation.” All landings in the Deal-Rams-gate area were abandoned, but the front was extended from Folkestone to Bognor. Thus it was nearly the end of August before even this measure of agreement was reached; and of course everything was subject to victory being gained in the air battle, which had now been raging for six weeks.

On the basis of the frontage at last fixed, the final plan was made. The military command was entrusted to Rundstedt, but shortage of shipping reduced his force to thirteen divisions, with twelve in reserve. The Sixteenth Army, from ports between Rotterdam and Boulogne, were to land in the neighbourhood of Hythe, Rye, Hastings, and Eastbourne; the Ninth Army, from ports between Boulogne and Havre, attacking between Brighton and Worthing. Dover was to be captured from the landward side; then both armies would advance to the covering line of Canterbury-Ashford-Mayfield-Arundel. In all, eleven divisions were to be landed in the first waves. A week after the landing it was hoped, optimistically, to advance yet farther, to Gravesend, Reigate, Petersfield, Portsmouth. In reserve lay the Sixth Army, with divisions ready to reinforce, or, if circumstances allowed, to extend the frontage of attack to Weymouth. It would have been easy to increase these three armies, once the bridgeheads were gained, “because,” says General Halder, “no military forces were facing the Germans on the Continent.” There was indeed no lack of fierce and well-armed troops, but they required shipping and safe conveyance.

On the Naval Staff fell the heaviest initial task. Germany had about 1,200,000 tons of seagoing shipping available to meet all her needs. To embark the invasion force would require more than half this amount, and would involve great economic disturbance. By the beginning of September the Naval Staff were able to report that the following had been requisitioned:

All this armada had to be manned, and brought to the assembly ports by sea and canal. Meanwhile, since early July we had made a succession of attacks on the shipping in Wilhelmshaven, Kiel, Cuxhaven, Bremen, and Emden; and raids were made on small craft and barges in French ports and Belgian canals. When on September 1 the great southward flow of invasion shipping began, it was watched, reported, and violently assailed by the Royal Air Force along the whole front from Antwerp to Havre. The German Naval Staff recorded:

The enemy’s continuous fighting defence off the coast, his concentration of bombers on the “Sea Lion” embarkation ports, and his coastal reconnaissance activities, indicate that he is now expecting an immediate landing.

And again:

The English bombers, however, and the mine-laying forces of the British Air Force … are still at full operational strength, and it must be confirmed that the activity of the British forces has undoubtedly been successful even if no decisive hindrance has yet been caused to German transport movement.

Yet, despite delays and damage, the German Navy completed the first part of their task. The ten per cent margin for accidents and losses they had provided was fully expended. What survived, however, did not fall short of the minimum they had planned to have for the first stage.

Both Navy and Army now cast their burden on the German Air Force. All this plan of the corridor, with its balustrades of minefields to be laid and maintained under the German Air Force canopy against the overwhelming superiority of the British flotillas and small craft, depended upon the defeat of the British Air Force and the complete mastery of the air by Germany over the Channel and Southeast England, and not only over the crossing but over the landing points. Both the older Services passed the buck to Reichsmarshal Goering.

Goering was by no means unwilling to accept this responsibility, because he believed that the German Air Force, with its large numerical superiority, would, after some weeks of hard fighting, beat down the British air defence, destroy their airfields in Kent and Sussex, and establish a complete domination of the Channel. But apart from this, he felt assured that the bombing of England, and particularly of London, would reduce the decadent peace-loving British to a condition in which they would sue for peace, more especially if the threat of invasion grew steadily upon their horizon.

The German Admiralty were by no means convinced, indeed their misgivings were profound. They considered “Sea Lion” should be launched only in the last resort, and in July they had recommended the postponement of the operation till the spring of 1941, unless the unrestricted air attack and the unlimited U-boat warfare should “cause the enemy to negotiate with the Fuehrer on his own terms.” But Feldmarshal Keitel and General Jodl were glad to find the Air Supreme Commander so confident.

These were great days for Nazi Germany. Hitler had danced his jig of joy before enforcing the humiliation of the French Armistice at Compiègne. The German Army marched triumphantly through the Arc de Triomphe and down the Champs Elysées. What was there they could not do? Why hesitate to play out a winning hand? Thus each of the three Services involved in the operation “Sea Lion” worked upon the hopeful factors in their own theme and left the ugly side to their companions.

As the days passed, doubts and delays appeared and multiplied. Hitler’s order of July 16 had laid down that all preparations were to be completed by the middle of August. All three Services saw that this was impossible. And at the end of July, Hitler accepted September 15 as the earliest D-Day, reserving his decision for action until the results of the projected intensified air battle could be known.

On August 30, the Naval Staff reported that owing to British counteraction against the invasion fleet preparations could not be completed by September 15. At their request D-Day was postponed to September 21, with a proviso of ten days’ previous warning. This meant that the preliminary order had to be issued on September 11. On September 10, the Naval Staff again reported their various difficulties from the weather, which is always tiresome, and from British counter-bombing. They pointed out that, although the necessary naval preparations could in fact be completed by the 21st, the stipulated operational condition of undisputed air superiority over the Channel had not been achieved. On the 11th, therefore, Hitler postponed the preliminary order by three days, thus setting back the earliest D-Day to the 24th; on the 14th he further put it off.

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On the 14th, Admiral Raeder expressed the view that:

(1) The present air situation does not provide conditions for carrying out the operation, as the risk is still too great.

(2) If the “Sea Lion” operation fails, this will mean a great gain in prestige for the British; and the powerful effect of our attacks will thus be annulled.

(3) Air attacks on England, particularly on London, must continue without interruption. If the weather is favourable an intensification of the attacks is to be aimed at, without regard to “Sea Lion.” The attacks must have a decisive outcome.

(4) “Sea Lion,” however, must not yet be cancelled, as the anxiety of the British must be kept up; if cancellation became known to the outside world, this would be a great relief to the British.

On the 17th, the postponement became indefinite, and for good reason, in their view as in ours. Raeder continues:

(1) The preparations for a landing on the Channel coast are extensively known to the enemy, who is increasingly taking counter-measures. Symptoms are, for example, operational use of his aircraft for attacks and reconnaissances over the German operational harbours, frequent appearance of destroyers off the south coast of England, in the Straits of Dover, and on the Franco-Belgian coast, stationing of his patrol vessels off the north coast of France, Churchill’s last speech, etc.

(2) The main units of the Home Fleet are being held in readiness to repel the landing, though the majority of the units are still in western bases.

(3) Already a large number of destroyers (over thirty) have been located by air reconnaissance in the southern and southeastern harbours.

(4) All available information indicates that the enemy’s naval forces are solely occupied with this theatre of operations.

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During August the corpses of about forty German soldiers were washed up at scattered points along the coast between the Isle of Wight and Cornwall. The Germans had been practising embarkations in the barges along the French coast. Some of these barges put out to sea in order to escape British bombing and were sunk, either by bombing or bad weather. This was the source of a widespread rumour that the Germans had attempted an invasion and had suffered very heavy losses either by drowning or by being burnt in patches of sea covered with flaming oil. We took no steps to contradict such tales, which spread freely through the occupied countries in a wildly exaggerated form, and gave much encouragement to the oppressed populations. In Brussels, for instance, a shop exhibited men’s bathing-suits marked “For Channel swimming.”

On September 7, the information before us showed that the westerly and southerly movement of barges and small ships to posts between Ostend and Havre was in progress, and as these assembly harbours were under heavy British air attack, it was not likely the ships would be brought to them until shortly before the actual attempt. The striking strength of the German Air Force between Amsterdam and Brest had been increased by the transfer of a hundred and sixty bomber aircraft from Norway; and short-range dive-bomber units were observed on the forward airfields in the Pas de Calais area. Four Germans captured a few days earlier after landing from a rowing-boat on the southeast coast had confessed to being spies, and said that they were to be ready at any time during the next fortnight to report the movement of British reserve formations in the area Ipswich-London-Reading-Oxford. Moon and tide conditions between the 8th and 10th of September were favourable for invasion on the southeast coast. On this the Chiefs of Staff concluded that the possibility of invasion had become imminent and that the defence forces should stand by at immediate notice.

There was, however, at that time no machinery at General Headquarters, Home Forces, by which the existing eight hours’ notice for readiness could be brought to “readiness for immediate action” by intermediate stages. The code-word “Cromwell,” which meant “invasion imminent,” was therefore issued by Home Forces at 8 P.M., September 7, to the eastern and southern commands, implying action stations for the forward coastal divisions. It was also sent to all formations in the London area and to the 4th and 7th Corps in G.H.Q. Reserve. It was repeated for information to all other commands in the United Kingdom. On this, in some parts of the country, the Home Guard commanders, acting on their own initiative, called out the Home Guard by ringing the church bells. This led to rumours of enemy parachutist landings, and also that German E-boats were approaching the coast. Neither I nor the Chiefs of Staff were aware that the decisive code-word “Cromwell” had been used, and the next morning instructions were given to devise intermediate stages by which vigilance could be increased on future occasions without declaring an invasion imminent. Even on receipt of the code-word “Cromwell,” the Home Guard were not to be called out except for special tasks; and also church bells were to be rung only by order of a Home Guard who had himself seen as many as twenty-five parachutists landing, and not because other bells had been heard or for any other reason. As may be imagined, this incident caused a great deal of talk and stir, but no mention of it was made in the newspapers or Parliament. It served as a useful tonic and rehearsal for all concerned.

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Having traced the German invasion preparations steadily mounting to a climax, we have seen how the early mood of triumph changed gradually to one of doubt and finally to complete loss of confidence in the outcome. Confidence was in fact already destroyed in 1940, and, despite the revival of the project in 1941, it never again held the imagination of the German leaders as it had done in the halcyon days following the fall of France. During the fateful months of July and August, we see the Naval Commander, Raeder, endeavouring to teach his military and air colleagues about the grave difficulties attending large-scale amphibious war. He realised his own weakness and the lack of time for adequate preparation, and sought to impose limits on the grandiose plans advanced by Halder for landing immense forces simultaneously over a wide front. Meanwhile, Goering with soaring ambition was determined to achieve spectacular victory with his air force alone and was disinclined to play the humbler rôle of working to a combined plan for the systematic reduction of opposing sea and air forces in the invasion area.

It is apparent from the records that the German High Command were very far from being a co-ordinated team working together with a common purpose and with a proper understanding of each other’s capabilities and limitations. Each wished to be the brightest star in the firmament. Friction was apparent from the outset, and so long as Halder could thrust responsibility onto Raeder, he did little to bring his own plans into line with practical possibilities. Intervention by the Fuehrer was necessary, but seems to have done little to improve the relations between the Services. In Germany the prestige of the Army was paramount and the military leaders regarded their naval colleagues with some condescension. It is impossible to resist the conclusion that the German Army was reluctant to place itself in the hands of its sister Service in a major operation. When questioned after the war about these plans, General Jodl impatiently remarked, “Our arrangements were much the same as those of Julius Caesar.” Here speaks the authentic German soldier in relation to the sea affair, having little conception of the problems involved in landing and deploying large military forces on a defended coast exposed to all the hazards of the sea.

In Britain, whatever our shortcomings, we understood the sea affair very thoroughly. For centuries it has been in our blood, and its traditions stir not only our sailors but the whole race. It was this above all things which enabled us to regard the menace of invasion with a steady gaze. The system of control of operations by the three Chiefs of Staff concerted under a Minister of Defence produced a standard of team-work, mutual understanding, and ready co-operation unrivalled in the past. When in course of time our opportunity came to undertake great invasions from the sea, it was upon a foundation of solid achievement in preparation for the task and with a full understanding of the technical needs of such vast and hazardous undertakings. Had the Germans possessed in 1940 well-trained amphibious forces equipped with all the apparatus of modern amphibious war their task would still have been a forlorn hope in the face of our sea and air power. In fact, they had neither the tools nor the training.

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We have seen how our many anxieties and self-questionings led to a steady increase in the confidence with which from the beginning we had viewed the invasion project. On the other hand, the more the German High Command and the Fuehrer looked at the venture, the less they liked it. We could not, of course, know each other’s moods and valuations; but with every week from the middle of July to the middle of September, the unknown identity of views upon the problem between the German and British Admiralties, between the German Supreme Command and the British Chiefs of Staff, and also between the Fuehrer and the author of this book, became more definitely pronounced. If we could have agreed equally well about other matters, there need have been no war. It was, of course, common ground between us that all depended upon the battle in the air. The question was how this would end between the combatants; and in addition the Germans wondered whether the British people would stand up to the air bombardment, the effect of which in these days was greatly exaggerated, or whether they would crumple and force His Majesty’s Government to capitulate. About this Reichsmarshal Goering had high hopes, and we had no fears.