Commander in Chief of the Kriegsmarine

Minutes of the Conference of the Commander in Chief, Navy, with the Führer on 31 May 1943 at the Berghof.

Present:

Generalfeldmarschall Keitel Generalleutnant Warlimont Kapitän zur See von Puttkamer

A The Commander in Chief, Navy, reports as follows: The substantial increase of the enemy Air Force is the cause of the present crisis in submarine warfare. By means of sound detection it has been determined that as many planes now pass through the narrows between Iceland and the Faroe Islands in one day, as only recently appeared in the course of a week. In addition, aircraft carriers are being used in conjunction with North Atlantic convoys, so that all convoy routes are now under enemy air protection. However, the submarine crisis would not have come about solely as a result of an increase in enemy aircraft. The determining factor is a new location device evidently also used by surface vessels, by means of which planes are in a position to locate submarines. When the ceiling is low, visibility poor, or at night, they can carry out surprise attacks. Without this device the planes would be unable to locate the submarine at night or in a heavy sea. This is shown too by our losses, the great majority of which were caused by planes. Surface vessels have not been very successful although a relatively large number of U-boats, 5 to be exact, were surprised by destroyers during a heavy fog which suddenly set in while a convoy was being attacked on 8 May. Without this location device it would have been impossible to surprise the submarines in a fog.

Accordingly, approximately 65% of the losses occur while the submarines are en route or lying in wait; only about 35% occur near the convoys themselves. That is to be expected, for a submarine spends most of the 6 to 8 weeks of an operation en route or lying in wait. During this time the danger of sudden attacks from the air, when it is dark or when visibility is poor, by an enemy who cannot be detected beforehand, is very great. Our losses have increased during the last month from approximately 14 submarines, or 13% of the submarines at sea, to 36 or even 37 or approximately 30% of all submarines at sea. These losses are too high. We must conserve our strength, otherwise we will play into the hands of the enemy. The following measures have been initiated:

1. I have withdrawn from the North Atlantic to the area West of the Azores in the hope of encountering less air reconnaissance there. I am lying in wait there for a convoy headed for Gibraltar. It is very difficult, however, to locate this convoy in so large an area. With new submarines now becoming available I shall proceed to more distant areas in the hope that the planes there are not yet as fully equipped with the modern location devices. I intend, however, to resume attacks on convoys in the North Atlantic at the time of the new moon, provided that the submarines will have additional weapons at their disposal by that time.

2. The following equipment is required:

a. An efficient radar interception set, that is, an apparatus which will show the frequency used by the radar-equipped plane and will warn the submarine of an impending attack. We do not have such a set. We don't even know on what wave length the enemy locates us. Neither do we know whether high frequency or other location devices are being employed. Everything possible is being done to find out what it is. Until such a warning device is made available, I have ordered that our submarines shall operate at night only on one electric motor. Elimination of the noise of the Diesel engines will facilitate detection of the plane by sound. This seems to me the only means of warning submarines of an air attack. An investigation is being made whether it is possible to install a sound detection apparatus on the submarine conning tower that will stand up under diving and other conditions at sea.

b. A second possibility is that of jamming or dispersing the enemy radar waves. We do not have facilities for jamming the enemy's reception, since the range of a jammer on a submarine is too limited. Furthermore, a jammer which does not automatically adjust itself to the wave length of the enemy beacon, can very easily be evaded by changing to a different wave length. Such an automatic device is being experimented with under Minister Ohnesorge, but is still far from being ready for submarine use.

Only in regard to dispersion of the enemy radio waves do we have anything positive to offer. Beginning this June we are going to equip our submarines with the so-called "Aphrodite". This device produces the same kind of reflective effect as a conning tower, and can be released by the submarines in order to confuse the enemy. Furthermore, in June large buoys will be planted in the Bay of Biscay, which also produce a reflective effect like the conning tower of a submarine, and are meant to mislead enemy planes. Since we are here dealing with a new weapon, I request permission to introduce it. The Führer gives permission hereto.

c. So far no satisfactory solution has been found which would enable the submarine to detect the searching plane by means of its own radar set. The difficulty lies in the fact that the submarine's location beam is very narrow - comparable to a narrow beam search light - and therefore it takes much too long to search the sky with it.

d. Experimental measures to protect submarine conning towers against radar detection have shown that it is possible to reduce the reflections of the conning tower to 30%. In other words, an enemy who was formerly able to detect the submarine from a distance of 9,000 meters can now do so only from a distance of 3,000 meters. Actual use alone will tell whether this device is effective on all wave lengths. We are still a long ways from putting it into actual use.

e. Four-barreled machine guns will be installed in increasing numbers beginning this coming July and the conning towers rebuilt accordingly.

f. It will not do the submarines much good to fight off the planes with the four-barreled machine gun unless they have the anti-destroyer torpedo at the same time. Otherwise the destroyer called to the scene by the plane can still force the submarine to submerge. By October we are definitely going to get the so-called "Falke", an acoustic torpedo which can be used effectively against an enemy not making over 12 knots. This limitation is a great drawback. Therefore everything possible must be done to put the so-called "Zaunkönig" into use at the front by fall. This torpedo is effective against an enemy making up to 18 knots. I shall discuss with Minister Speer what steps will be necessary to make "Zaunkönig" available to the front by fall. I ask your support in this, since I consider it absolutely necessary that the submarines be supplied with the anti-destroyer torpedo before the favorable winter fighting season. The Führer agrees that everything possible must be done to make "Zaunkönig" available.

g. It is necessary to concentrate aerial attacks on the Bay of Biscay, where enemy planes are attacking our submarines on departure and return without interference. Support from our Air Force is completely inadequate there at the present time. The Junker 88 can fly only in formation, since otherwise it would in turn become the victim. Only when flying in formation are the Junkers 88 occasionally able to shoot down an enemy plane. In my opinion it is essential that the Messerschmitts 410 be brought to the Bay of Biscay as soon as possible. In this I concur with the request of the 3rd Air Fleet and the Commanding Officer, Naval Air, Atlantic.

The Commander in Chief, Navy, is of the opinion that the construction of suitable planes for naval warfare should have been undertaken at the latest the moment we began to build a large submarine fleet. The Führer agrees with this. Our submarines undoubtedly could have sunk more shipping during the past year if we had had naval planes. These can further submarine warfare by scouting, as well as by affording protection against enemy planes. Many of the planes in the Atlantic area are inferior to our planes. Furthermore, the Air Force would find many targets in the Atlantic and in that way could increase the tonnage sunk by us. Even now it is not too late to give our naval forces an Air Force. The Führer agrees fully with these views.

The Commander in Chief, Navy, states that it will be necessary in that case to begin the training of the plane crews in time and to allow for an adequate training period, otherwise we shall have to use untrained and inexperienced personnel who know nothing about naval warfare. Therefore a school for naval flyers must be started at once at Gotenhafen in direct conjunction with the convoy training flotillas directed by the submarine branch, for the naval flyers must be trained just as systematically for 4 to 5 months as the submarine personnel. The naval flyers must learn navigation at sea, celestial navigation, drift computation, how to keep contact with a convoy, cooperation with the submarines by means of direction-finder signals, how to be guided to the convoy by other planes, and the necessary communications. In short, they must receive their training in the Baltic Sea together with the submarine personnel so that they will speak the same language and can subsequently fight together. A situation must not arise where cooperation in the Atlantic between submarines and the Air Force breaks down because certain mistakes are made which actually have nothing to do with the fundamentally sound principle of cooperation. Such errors might lead to the false generalization that cooperation is useless. The Führer agrees fully with the views expressed and stresses once more the tasks, prospects, and possibilities which our own Air Force would have in the Atlantic. He then closes with the words: "It seems that long-range bombers should be sent into the Atlantic area."

The Commander in Chief, Navy, has the following to say about the future prospects of submarine warfare: At the present time our efforts are being frustrated by a technical device against which countermeasures will be found. It is impossible, however, to foretell to what extent submarine warfare will again, become effective. The enemy's anti-submarine defense on water and from the air will be improved. That entails many uncertainties and unknown factors. In 1940 a submarine was able to sink an average of 1,000 tons per day at sea; toward the end of 1942, approximately 200 tons. This shows clearly the growing effectiveness of anti-submarine defense, and the diminishing effectiveness of submarines. Nevertheless, I am convinced that submarine warfare must be carried on, even if great successes are no longer possible. The forces tied up through submarine warfare were considerable even during the [First] World War.

The Führer interrupts at this point with the following remark: "There can be no talk of a let-up in submarine warfare. The Atlantic is my first line of defense in the West, and even if I have to fight a defensive battle there, that is preferable to waiting to defend myself on the coast of Europe. The enemy forces tied up by our submarine warfare are tremendous, even though the actual losses inflicted by us are no longer great. I cannot afford to release these forces by discontinuing submarine warfare."

The Commander in Chief, Navy, continues: "I therefore believe that we must continue the present effort to increase submarine production. As a matter of fact I don't believe that 30 submarines are sufficient. Even in what amounts to purely defensive submarine warfare in the Atlantic we will need great numbers of submarines. In my opinion we should strive for 40 submarines. In agreement with Minister Speer, I have already arranged for the construction of 30 submarines and for building auxiliary vessels as previously mentioned. I now request that this annexed order be signed by the Führer."
The Führer agrees, changes the number of submarines from 30 to 40 per month, and signs.

B. The Commander in Chief, Navy, proposes destruction of lines of communications along the North African coast by means of submarine assault troops, so that the enemy will be forced to use considerable resources of materiel and personnel for coastal defense, and will not have the forces landed in Africa available for offensive operations alone. The Führer believes, however, that the British in that case would use the French for such defense operations and therefore would not suffer any curtailment of their own forces. Field Marshal Keitel calls attention to the fact that the "Brandenburg" Battalion is already engaged in similar operations. The Commander in Chief, Navy, says that he will nevertheless make corresponding suggestions to the OKW, Operations Staff (OKW/Führungsstab) since he believes that these operations should be carried out in strictly military fashion.

C. The Commander in Chief, Navy, proposes a surprise attack on Gibraltar with the new weapon of the Luftwaffe [Fritz X and Hs 293 guided anti-ship glide bombs], as soon as these have been stockpiled in sufficient numbers; in other words, about the end of June. He thinks that this is preferable to letting the British naval forces get out of Gibraltar and then hunt them down and attack them individually when they have considerable fighter escorts. Gibraltar could readily be reached from the Marseilles area. The Führer is of the opinion that he will then run the risk that some of the new weapons might fall on land at Gibraltar, and that the British will find out what they are. Furthermore, he is doubtful about reaching Gibraltar, particularly since it is becoming increasingly difficult from a political point of view, to fly over Spain. The Commander in Chief, Navy, stresses once more that it is necessary to concentrate these weapons. The Führer remarks that he had intended to make up for the falling-off in submarine warfare, which must be expected during the next few months, by means of some such attacks.

D. The Commander in Chief, Navy, advocates the mining of Port Said and Alexandria in order to interfere with British movements through the Mediterranean. The Führer says that it would be possible to do this by operating from Rhodes, but that planes are not available.

In conclusion the Führer states that means must be found to offset the enemy's present advantage over us in regard to technical anti-submarine devices. The Commander in Chief, Navy assures him that any aid, no matter how insignificant, would be welcome, for a number of such measures together might in the end enable the submarines to resume the offensive. The Führer is worried that the new detection device might involve principles with which we are not familiar. The crisis must be overcome by all possible means.