U-boat Archive - BDU KTB PG30251

F.d.U./B.d.U.'S War Log

1 - 15 November 1939

PG30251

Date	Position, Wind, Weather
and	Sea State, Illumination,	Events
Time	Air Pressure, Moonlight etc.

1.11

Group Headquarters West

Naval War Staff informed me that U 25 could not be supplied on the Spanish coast, as Spain had recently made political difficulties. Supply could only be arranged in Farrol in a case of extreme necessity. I have decided not to send the boat there, in order to have this possibility in hand for really urgent cases. I am not surprised at this development; I always regarded this matter as very uncertain.

2.11

U 49's operational readiness will be delayed a few days. U 47 also will not be ready until very late, not before the middle of November. There is a choice between letting the boats sail alone at long intervals or keeping the first ones back until they can all operate together. I have decided on the latter course, because I would like for once to have several boats out and off Gibraltar. So far such an operation has been planned, but never carried out, as events took a different turn. But the attack on the convoy by U 37, 46 and 48 opened up possibilities which I want to see used to the full. If this is successful there will be every justification for holding boats back.

U 26 reported that she had passed 45⁰ north. The other 2 boats of this wave (U 25 and U 53) will be kept in their operations areas for about another 3 days in order to give U 26 enough time in hand to carry out her operation.

3.11

Naval War Staff requested B.d.U to go into the question of attacking England's timber imports from north Russian ports. These imports are regarded as of great importance.

I had in any case planned to operate U 36 against those timber transports in the area east of North Cape. I think that chances of success are good in this area, but nevertheless I cannot decide further until I get information of the situation from this operation.

Naval War Staff also informed me at the same time that there was a chance of setting up a "Base North". I think everything possible should be done to get this matter cleared up.

The advantages of a base in the north are:

1)	The much better position for attacking the north Russia-England convoy routes.
2)	The safe approach route, loading well away from England through deep water.
The disadvantages are:
1)	A lengthening of the approach route by about 300 miles.
2)	Lack of suitable dock and repair facilities and the difficulty of supplying material overland.

As long as boats can pass through the North Sea without running too great a risk or losing too much time, a base in the north would only be important for attacking timber transports from

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Date	Position, Wind, Weather
and	Sea State, Illumination,	Events
Time	Air Pressure, Moonlight etc.


					the north Russian ports. But if at any time the disadvantage of the longer route should outweigh the increasing dangers of a passage through the North Sea, the Northern Base would assume very great importance.
					It cannot be foreseen how long the timber transports will continue, but it is justifiable to assume that they will either stop soon or else the political conditions for this base will become void.
					The base would also have to have reliable radio communication with the boats and with home. As a large-scale undertaking cannot be kept secret for long, there would have to be military protection from the first in order to prevent surprise coups by the enemy.
					A proposal has been worked out on these lines and sent to Naval War Staff.

		4.11			18th to 23rd November have been submitted to Naval War Staff as target dates for the first supply in the Northern base for U 36.

					U 25 reported that she was returning as the crosspiece of her forward torpedo hatch had broken. She might not be capable of diving if depth charged. The Commanding Officer has therefore acted correctly. His position is northwest of Cape Finisterre.

					Naval War Staff informed me that 10 German steamers would be ready to sail from Vigo about the middle of November and requested that they be given U-boat protection on their way home in as far as possible. This is a task for which the U-boat is imperfectly suited. If she is forced to dive, which is always the case if a/c appear, she cannot maintain the speed of the steamers. They will have to stop, or else contact will be lost. The U-boat is not very effective against destroyers as it is. Also on escort duty, starting from Vigo means that afterwards the boat or boats cannot be used elsewhere as their fuel stocks will be exhausted. While the value of the escort is doubtful the disadvantage for the U-boat war as a whole would be considerable. I must therefore advise against a close escort. Remote protection will be available if the steamers sail at such times as there are U-boats in the vicinity (position "ROT") in accordance with operations Plan No. 11. These times will be communicated to Naval War Staff for onward transmission to the steamers.

		5.11			U 25 reported a convoy, apparently making for the Channel on a northeast course. There were no further shadower's reports.

					U 53 was ordered to continue her passage south, as U 26 must be by now far enough ahead to carry out her minelaying operation. The "City of Flint", once taken in prize by the "Deutschland", has been detained in Bergen. The prize crew is said to have been interned there and the prize ship herself released. As the Naval War Staff attaches great importance to her recapture, U 34, U 37 and U 46 on their return passage, have been ordered to take such action as their fuel stocks permit. For further details see F.O. U/B West's War Log.

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Date	Position, Wind, Weather
and	Sea State, Illumination,	Events
Time	Air Pressure, Moonlight etc.

6.11

It is still not known what bases the British fleet is using at present. The ban on anchoring within certain limits in the Firth of Clyde make it likely that it is intended to base in these ports. Lough Swilly would be a good, well-protected berth. According to information available to B.d.U. it is a base used by the British fleet. Operations planned here some time ago however, were vetoed by Naval War Staff on the grounds that it stretched into Irish territory in parts and that Irish neutrality was not to be violated at any cost.

After renewed pressure Naval War Staff has promised to obtain information on the political aspect of this area via our Ambassador in Ireland. U 43 sailed for her operations area (Operations Plan No. 12).

7.11

U 46 grounded in the Little Belt, but got away again under her own power after several hours.

U 41 sailed for her operations area.

According to Naval War Staff it is again questionable whether U 36 can be supplied in the Northern Base in November, as requested.

U 46 entered Kiel. She sank one steamer of about 5,000 tons. The result is rather meager, but the C.O.'s verbal report tells quite another story of the patrol. The boat was in convoys 3 times. On one occasion the C.O. fired at a wall of several overlapping ships - failures. She had a stationary cruiser at inclination 90 off her bows. Again several failures, which finally warned the cruiser and she made off. 7 shots were quite definitely failures and not attributable to errors in drill. In spite of this, due to the C.O.'s determination, the boat still went on searching for the enemy and attacking. The boat could have sunk 30 or 40,000 tons; she actually sank 5,000. The crew are naturally somewhat depressed. Several patrols like this will turn keenness into indifference, if all efforts are to no purpose.

8.11

U 28 sailed for her operations area (Operations Order No. 10).

U 37 entered port. She sank:

1)	S.S. Vistula	1,018	tons	Swedish
2)	S.S. Asis	4,810	tons	Greek
3)	S.S. Vermont	5,186	tons	French
4)	S.S. Yorkshire	10,183	tons	English
5)	S.S. Menin Ridge	2,474	tons	"
6)	S.S. Ledbury	3,528	tons	"
7)	S.S. Tafna	4,413	tons	"
8)	S.S. Thrasyroulos	3,693	tons	Greek
	Total	35,305	tons.

Very good work. On her way out the boat encountered a battleship of the Royal Sovereign class and a cruiser of "C" or "D" class between the Orkneys and the Hebrides. She could not attack, as weather conditions did not permit keeping at attacking depth. This confirms the impression that this sea area is often used by the Home

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Date	Position, Wind, Weather
and	Sea State, Illumination,	Events
Time	Air Pressure, Moonlight etc.

Fleet. Information hitherto has been obtained from U 56's observation (see F.O. U/B West's War Log), from radio intelligence and odd agent's reports. All Atlantic boats have therefore been ordered to alter course so as to pass through this area, even if it means delay.

9.11

U 49 sailed for her operations area in accordance with Operations Order No. 11. U 36's operational readiness postponed for another 8 days.

10.11

U 38 will also be delayed for several days. Meanwhile U 26 must have decided whether or not she can carry out her operation off Gibraltar. There is no news from the boat and no reports of her being sighted by patrols.

Freight rates and risk premiums in the Mediterranean have been reduced, therefore presumably there is thought to be less danger from U-boats. The appearance of a U-boat there should cause great alarm. The next few days should show.

11.11

Analysis of information on the whereabouts of the British battle fleet shows that it is probably distributed over various places outside the North Sea. The possibilities if mining these places with TMB's must therefore be considered. The main difficulties will probably be navigational. It is hardly likely that all these places are under constant strong patrol, or that local defenses are very extensive. The first area to be considered is the Bay of Oban. The battleship Rodney was lying there some time ago.

Information received so far on the effects of the minefields laid by U-boats shows that not all the ships which ran into the fields were sunk. We must therefore try to lay the mines in shallow water and reduce their sensitivity so that they are only exploded by largish ships.

12.11

U 36 will not be ready for another week and operations against the timber transports will get more difficult as it gets darker, I have therefore decided to send U 38 up there. This boat was to have operated together with U 41, U 43 and U 49, but her sailing has been delayed so long that only a partial cooperation would be possible now. U 36 will then be the second boat to go north. Chances of success will be considerably improved if the boats are disposed in quarterline in the direction of the traffic, about 100-120 miles apart, as then there would always be at least one boat on the steamer route by day.

U 34 entered port. She sank:

1)	S.S. Gustav Adolf	935	tons	Swedish contraband
2)	British Sperrbrecher	1,200	tons	British
3)	S.S. Malabar	7,976	tons	British
4)	Steamer type Cairnona	4,666	tons	"

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Date	Position, Wind, Weather
and	Sea State, Illumination,	Events
Time	Air Pressure, Moonlight etc.

5)	S.S. Bronte	5,317	tons
6)	Tanker	6-7,000	tons
	Total	26,094	tons

She also brought in the Norwegian "Snar", 3,176, tons, timber, as prize.

13.11

U 40 declared missing today. There is definite news of a member of the crew being prisoner of war. It must now be assumed after all that she was lost in the Channel. Otherwise she would have reported that she had got through. Meanwhile further information has been received of the other missing boats, which give a different view of the circumstances of their loss.

Letters from prisoners, whose names have gradually been given out over the English wireless, show:

U 27:	C.O. and crew all prisoners. The boat was chased by destroyers, and finally could do no more. The Commanding Officer writes: It was only by a lucky chance that we were able to ge out of the sinking boat, after we managed to surface her with our last resources and a lot of luck." She must therefore have shipped so much water through damage to the pressure hull or through leaks in the stern-tube stuffing boxes or exhaust valves, that she could no longer be controlled, or her battery must have been empty. At all events she had to surface and surrender in the face of the enemy. The depth of water at this point was 1500 meters. It was therefore presumably west of the North Channel.
U 39:	C.O. and crew prisoners of war. This boat too was hunted with D/C's. She is said to have suffered much the same fate as U 27.

The original assumption that these boats were surprised on the surface is therefore incorrect.

Close attention must be paid to the problem of pressure-tightness. The stern-tubes will therefore be repacked after every patrol. The exhaust valves have been fitted with new packings.

As there are so few boats available for operations at one time it is particularly important that they should be able to remain a long time at great depths. The enemy is able to use a large proportion of his anti-S/M forces against each boat detected and thus cover a wide area, out of which the boats have to escape. The long nights will make it easer for them to get away from the pursuing formations, but the summer will mean more trouble. With regard to the loss of U 42, it is now known for certain that the C.O. and about half the crew (at least 16) are prisoners of war. She must therefore have faced differently than U 27 and U 39.

Nothing further is known of U 45.

U 25 entered port. The boat did not have much luck. The C.O.'s task was no easy one. There were torpedo failures, the guns failed at a decisive moment and this boat, parts of which are still rather antiquated, is not easy to handle. She scored one hit on

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Date	Position, Wind, Weather
and	Sea State, Illumination,	Events
Time	Air Pressure, Moonlight etc.

each of 2 ships, but did not observe the results owing to anti-S/M activity. As the ships were of medium size, it can be assumed that they were so damaged that they could not be brought in to a port. They can therefore be assumed sunk.

14.11

U 38 and U 29 sailed for their operations areas. Attacks on English timber traffic and minelaying off Milford Haven. (Operations Orders No. 10 and 12). Professor Cornelius visited B.d.U. He was nominated "Torpedo Dictator" some days ago, with wide powers, which give him a great deal of scope to reorganize and develop torpedoes. His duties are of major importance for the U-boat Arm. It is to be hoped that he will be completely successful. His duties cover 3 main fields:

1)	to eliminate the faults in the pistols
2)	to ensure that the torpedoes will keep perfect depth
3)	to ensure adequate production.

While at present the torpedo can in no way be regarded as a front-line weapon of any use, the TMB has proven a very effective weapon for U-boats. It has nevertheless been found:

1)	that large ships are not sunk for certain at depths of about 30 meters
2)	that the mines are fired by smaller ships than intended.

This has led me to go into the question of the use of mines again with a specialist. The following are the results of a conference with Commander Lucht:

1)	The TMB can only be expected to be fatal up to about 25 meters.
2)	The firing of the mines by too small ships can be avoided at all depths by a coarser setting of the mine. New tables will have to be brought out accordingly.
3)	The effect of the mine can probably be increased by increasing the charge, without any great difficulty.
The following steps must therefore be taken at once:
1)	New conversion tables must be brought out for coarser settings.
2)	The practical possibilities of increasing the weight of the charge must be examined. The aim would be to construct a mine which would:
	a) fill half the tube
	b) fill the whole tube.

The latter would only be for special, rare undertakings, if water depths would make the others unlikely to be effective or where the mines were intended against the largest ships. Practical conclusions to be drawn are:

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Date	Position, Wind, Weather
and	Sea State, Illumination,	Events
Time	Air Pressure, Moonlight etc.

1)	TMB's may only be laid at depths not exceeding 25 meters.
2)	Even shallower depths should be aimed at. For shallower water, the mines must be set according to the type of ship against which they are primarily intended to react.

15.11

U 43 reported from the area southwest of Ireland that the weather was so bad that she could take no offensive action. According to metrological observations it is not likely to improve in the near future and conditions are much quieter on the Portuguese coast; U 41, 43 and 49 have therefore been ordered to proceed on to position "ROT".

U 53 reported a convoy west of Gibraltar. During the last few days Radio Intelligence Service has provided some very useful reports on convoys, no action could be taken as there were no boats in the areas concerned. Today several more reports were received on which the boats may in fact be able to act. Reports of enemy surface forces have also now reached such a degree of accuracy that they are of practical value, which was only seldom the case to begin with. It is however, desirable that they be confined to hard facts, without any inferences from individual radio stations; those inferences make it more difficult to sift the material. Reports can only be evaluated by a unit which is adequately informed on the whole situation and can take all factors into account. It would be much easer for the operational units to make use of the material if it were sifted by a central department and passed on by them to units concerned. It would be necessary of course to work very quickly; comprehensive and connected situation reports are of less value than a collection of connected reports and dependent operations.

A radio message from U 45, intercepted by another boat on 14th October, has now reached B.d.U. It was not received here.

	"B.d.U. from U 45: 3 large darkened steamers, 15 knots, sunk. Am chasing a 4th steamer 3366 to 3355 BRT."
This is the last news of this boat. At any rate the enemy paid dearly for her loss.

Radio intelligence reports have provided the following information on the whereabouts of the British battlefleet:

1)	the fast battleships and battlecruisers and several a/c carriers are not in home waters, but on special operations (chasing pocket battleships or escorting particularly valuable convoys from Canada).
2)	The major part of the remaining battleships apparently use mainly the Firth of Clyde as anchorage.
The question of a U-boat action here against the English fleet has been considered and the following conclusions:
a)	U-boats cannot attack the anchorages themselves. The ships are laying in a long, fairly narrow strip of water, the only access to which is closed by a boom.

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Date	Position, Wind, Weather
and	Sea State, Illumination,	Events
Time	Air Pressure, Moonlight etc.

b)	It would be quite possible for U-boats to penetrate into the wider part of the Firth, as far as the boom. There is a shallow position here, exactly on the main route, where mines could be laid.

This operation must be carried out as soon as possible. There is a good chance of catching large warships. It will however, be necessary to use mines of greater explosive effect than the TMB, as these cannot be guaranteed to sink if laid at this depth. Then setting must be sufficiently coarse for them not to be exploded by the many merchant vessels which ply in these waters. The operation cannot be carried out until the mines have been manufactured.

If the fleet sails north from the Clyde, it will be bound by navigational considerations. U-boats might operate with success along their route.The only question is: when will the fleet sail? As long as it has nothing to do off the entrance to the North Sea, this is entirely uncertain. It must therefore be forced to go to sea at a certain time. This can only be effected by operations by our own battleships.

The operation of a lot of U-boats against the Home Fleet in the Firth of Clyde therefore only promises to be worthwhile if it is carried out in cooperation with our own surface forces.

Group Command informs that Naval War Staff have agreed to operations of battleships beyond the line Shetlands-Norway, as long as the British Fleet is in the Clyde and that such an operation is being planned for the next days. It appears however, that it is impossible to postponed this even for a few days, which would be necessary to prepare the U-boats and get them to their positions. If it could only have been postponed for 4 days a total of 11 U-boats would have been available. On the date fixed on the other hand only 3-4 boats can be sent.

A similar operation will therefore have to be planned for a later date. If it is planned long enough in advance, the rest of the U-boat war will not suffer to any extent.

The date must be chosen to fit in with the sailing times of the U-boats, so that they will only have to be kept back for a few days and at the worst if the operation falls through, they can go on to their operations areas for the war against merchant shipping.

(signed): Donitz

Rear Admiral and B.d.U.

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