U-boat Archive - BDU KTB PG30249

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

1 - 15 October 1939

PG30249

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

1.10

Group Command Headquarters West.

The following boats will be ready for operations during the first half of October:

U 42	on	2.10	U 45	on	8.10
37	on	5.10	40	on	16.10 doubtful
46	on	4.10	25	on	15.10
47	on	4.10	34	on	11.10
48	on	4.10

I intend to operate them against merchant shipping in the Atlantic. They are almost all boats of large radius of action. I regard the enemy situation as follows:

a)	Convoy system has been widely introduced. Ports for incoming convoys are: Weymouth for the channel area, Barry for the Bristol Channel - Irish Sea. Ports for outward bound convoys are:
	Plymouth for the Channel area
	Milford Haven for the Bristol Channel - Irish Sea
	Gibraltar is used by convoys bound in all directions and as port of control for ships bound for northern Europe.
	Ramsgate or the Downs are ports of control for east bound traffic coming from the Channel.
b)	The strength of convoys varies between 4 and 20 ships, their speed between 7 and 18 knots. Very fast convoys have only been observed in the Mediterranean.
c)	Convoy escort:
	Close escort by 4-6 destroyers, sometimes also cruisers, a/c accompany the convoys off the coast.
	Remote protection:
	Strong air activity all around England.
	Stationary a/c carriers:
	In the Scapa area, west of Iceland, southwest of Iceland, in the Channel area, in the gibraltar area. Protection in coastal areas by patrol vessels and other light forces. French submarines operate along the sea routes in the Atlantic, always 2 at a time. Occasionally remote cover by heavy units.
d)	Boats which were stationed immediately off the coast, off the English Channel, in the Bristol Channel and adjacent sea areas were less successful than those in remote sea areas. Apparently they are too much hindered by patrol.
e)	The best area has been southwest of Ireland.
f)	There is a great accumulation of traffic off Gibraltar. There is a lot of reliable information on convoys here. The outstanding feature of our own situation is the small number of available boats. In view of the enemy's concentration of shipping into convoys, I do not think it wise to scatter them individually over a very wide area.

- 31 -

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

	Our aim must be to intercept convoys and to concentrate on sinking them with our few available boats. It is difficult to find convoys at sea. The boats must be operated in areas where there is likely to be traffic, as is the case for instance southwest of England and in the Gibraltar area.
	The England position has the advantage of a shorter outward passage, but patrol is strong in the coastal area and is made from many bases. Bad weather must be expected here at this time of year.
	Gibraltar has the disadvantage of a long outward passage, but as the outward route cuts across merchant shipping routes, successes may be expected here, also there is a great concentration of shipping around Gibraltar. Weather conditions may be expected to be more favorable than in the north. There is little information on patrol, mostly to the effect that it is concentrated in the Straits; it can only be sent out from Gibraltar or Casablanca.
	I have decided to operate the boats against Gibraltar traffic.
	Execution: Success will depend on the boats making a surprise appearance together. They will be ready on different dates. They will therefore sail on different days and will occupy an operations area southwest of Ireland, which sinking figures so far have shown to be the best area. When all the boats have arrived there, they will receive orders to proceed on from F.O. U/B; he will order them to leave sooner or later according to the situation. Lieut Commander Hartmann will be in U 37 as S.O. of this Atlantic group and he will, if necessary, take over control in convoy operations. If he finds things are not promising off Gibraltar he will be authorized to order a new disposition, rather further from the enemy bases, along the west coast of Spain and Portugal. Only north-south bound merchant ships would be picked up here, of course.

2.10

Naval War Staff has authorized an area around England in which darkened ships may be sunk without warning. This will be a great relief to U-boats. Nevertheless the area is very narrow, so the practical results will probably be few. It has become known in Germany that English merchant ships have repeatedly attacked U-boats which had stopped them in accordance with prize law. It was announced that if such cases were repeated German U-boats would have to take steps accordingly. In reply, the Admiralty announced an instruction to all English merchant ships to heave to and ram any German U-boats sighted.

U 31 entered port. She sank:

S.S. "Hazelside" 4,646 tons.

She also attacked 2 ships in the convoy she reported at the time and sank one for certain.

This boat gives the impression of being particularly smart and cheerful.

- 32 -

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

In Most Secret 9212 of 30.9 Naval War Staff has ordered that the U-boat war against merchant shipping in the North Sea and Baltic be stopped.

A further order from Naval War Staff states:

Ships which, in the view of the C.O., are equipped to carry more than 120 passengers, are to be regarded as passenger ships. M.D.V. 87 (T.N.: German Naval official publication) explains this further. The main points to note are the number of boats - 4 or more each side of the ship, length and number of promenade decks, bull's eyes.

Boats were instructed on these orders.

The term "passenger ship" is a very wide one, and its final definition left to the C.O.'s impressions. It must be realized that in practice this order is open to very wide interpretation, especially as the submerged boat's powers of observation are limited.

3.10

Several radio intelligence reports indicate that the Greek S.S. "Diamantis" has been sunk at the western entrance to the Channel. They are confirmed by a radio message from U 35, reporting that the entire crew of the ship sunk are on board unharmed. Presumably the C.O. made the signal because he thought he ought to contradict contrary reports.

4.10

The following orders on the conduct of the war against merchant shipping were received from Naval War Staff:

1)	The area within which darkened ships may be attacked without restriction is extended westwards to 15⁰ west.
2)	U boats may attack immediately without restriction any enemy merchant ships which are unmistakably seen to be armed or which Naval War Staff announce as being armed, on the basis of unmistakable evidence available to them. Steps are to be taken to save the crew if circumstances permit, this without endangering the U-boat. Passenger ships are still not to be attacked provided they are not troop transports, even if they are armed.
	Both these orders mean a good step forward for the conduct of the war. They are better suited to the nature of a U-boat attack and increase chances of success.

U 46 and U 48 sailed for their operations area. U 46 had to turn back in the evening because of engine trouble and was ordered to put into Wilhelmshaven. U 35 reported that she was starting on her return passage. The radio message also mentioned that:
1)	Again there had been 2 spontaneous explosions of G7a pistols.
2)	She had to land the crew of the Greek ship on the Irish coast.

- 33 -

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

5.10

U 37 sailed for her operations area.

Late in the evening U 45 sailed from Kiel through the Kaiser Wilhelm Canal. The boat was ready sooner than expected. All the boats of this way will sail via the Bight. I consider the route through the Baltic approaches less safe at present. Experience has confirmed that there are too many opportunities here for enemy S/M's to lie in wait for U-boats. Our own defenses have not been able to master this danger. In order to lessen it U-boats have been ordered to proceed submerged by day when using the Baltic approaches between Äbelö and Skagen. This stretch cannot be covered in one night surfaced and therefore this route takes a lot of time. Conditions are more favorable in the North Sea. There are 3 routes which are less restricted from a navigational viewpoint. They are far apart and each can be covered in one night. Defense forces can concentrate on the area off river mouths and is not restricted by natural territorial waters.

6.10

The English S.S. "Lockgoil", 9,462 tons, ran into the minefield laid by U 32 in the Bristol Channel.

Sinking not certain.

On the orders of Naval War Staff U-boats are in future to report:

1)	Cases of ships guilty of incorrect behavior, contrary to neutrality and international law, when stopped.
2)	Cases of armed merchant ships.
3)	Incidents with neutral a/c and warships.
4)	Own violation of neutral territorial waters.
5)	Illegal action on the part of neutrals.

Statements from witnesses are to be obtained in writing and signed by them. If possible the witnesses are to be brought in person.

Reports are to be made as soon as possible, so that they may be exploited for political and propaganda purposes in good time. They are not however, to be made if this entails operational disadvantage for the boat.

7.10

U 46 sailed, her engines having been repaired.

U 47, which should have sailed for the Atlantic on 4.10, has been given a special operation and will not take part in this Atlantic patrol. (For special operation see F.O. U/B West's War Log).

8.10

The period during which U 39 might have returned, or news have been received of her, has expired. The boat can no longer be expected to return. The crew are to be regarded as "missing".

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

Enquiries about members of the crew, who may have been taken prisoner are to be conducted in such a way that the enemy cannot discover that the boat has been lost if he does not already know this from other sources.

U 15, a North Sea boat, entered port from the Channel and brought valuable reconnaissance results. The following is of importance for Atlantic boats:

1)	Channel patrol, including the line Dover-Calais, was only slight, the weather being bad on an average. Patrol vessels' listening gear was little effective and inaccurate. Other forms of location were not observed. There are only a few uncertain reports of echo ranging from U 17 (Downs) and U 14 (Orkneys).
2)	Accurate navigational orientation was possible everywhere. There were a number of lights showing, if only in restricted sectors in some areas. There were a number of sea marks.
3)	No barrages were observed, but several buoys appeared to be in connection with barrage defenses.

U 15's statements agree with U 31's, though the latter only passed through the Channel and was not stationed there for observation as U 15. U 35's experiences show that conditions can be different on occasions. Nevertheless it is clear that, for the present at least, it is possible to proceed through the channel.

This means a considerable shortening of the approach route for the Atlantic boats. It remains to be decided whether the added risk is justified by the success to be expected if U-boats use the Channel route and can therefore remain longer in their operations area.

The following order was received from Naval War Staff: As so far the English have not seized German exports in neutral ships, enemy exports in neutral ships bound for neutral ports are not to be seized by us either.

9.10

The following are expected to be ready, as the next wave of Atlantic boats:

U 25	on	17.10	U 26	on	20 or 22.10
31	on	19.10	53	on	21.10
32	on	19.10

3 boats with large and 2 with small radius of action. I intend to use the large boats in the Mediterranean, approximately between Gibraltar and Oran. There are so many reports of convoys there that it should be worthwhile to send them in spite of the long approach route and the consequent short period in the operations area. I think there will be very little opportunity for warfare according to prize law, but the chances of attacking without warning should be many. Also the long narrow sea areas makes a certain amount of cooperation possible between boats, even with so few. There is also the point that it is policy, especially now with so few boats available, to worry the enemy in as many and as remote places as possible. He is then forces to provide for anti-S/M action everywhere and to maintain patrols. This means a weakening

- 35 -

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

of local defenses. The more forces the enemy is able to use in anti-S/M operations the more necessary it becomes for us to change the operations areas frequently and thus avoid the expected concentrated attack.

Boats of the 2nd U-Flotilla can only be used in the sea area around England. There are several minelaying operations which have been shown to be worthwhile, and I intend to carry them out now as follows:

1)	Fouling of Loch Ewe. It is to be expected with certainty that this place will be in due course used as an anchorage by heavy English forces, especially when Scapa is attacked by air, which is not yet permitted.
2)	Fouling of English convoy and control ports, first of all Milford Haven, then the Bristol Channel and off Liverpool.
3)	Fouling of the steamer routes in the Channel.
Fouling of Loch Ewe and Milford are of first importance. The operations in the Channel can be done as well by the small boats and are therefore not to be considered for Atlantic boats.
The following are reasons for paying more attention to minelaying as a whole at the present moment:
1)	The long nights and the bad weather to be expected at this time of year reduce the chances of a torpedo-carrying U-boat, but are just the right conditions for minelaying operations.
2)	There is now sufficient information on the routes of English merchant shipping to enable us to pick out the most valuable positions.
3)	It is very probable that the enemy has no means of detecting and sweeping ground mines. This fact must be exploited.

10.10

U 40 sailed for her operations area. She has been ordered to try and break through the Channel, but to take the route around the north of England if strong opposition is encountered. I decided to give this order because, as long as it is not definitely known that the Channel is impossible, we cannot let pass the advantage of this much shorter approach route, which offers many more opportunities of success even on the way out. So far it is not definitely known that the English Channel is impassable. There are only warnings, which are countered by the fact that U 31 and U 15 got through almost unhindered. I would not really have been necessary for U 35 to turn back. The C.O. was too much influenced by a few observations, as he himself now agrees. My decision was also influenced by the fact that the disposition planned off Gibraltar can only lead to the expected success if there are enough boats there. U 40 was not ready for operations until much later than the others and the only way to compensate for this delay is to shorten her outward passage.

11.10

The question of creating bases comes to mind again and again when considering the boat's long approach routes to their operations areas during which they are in constant danger, but have

- 36 -

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

little opportunity of taking action themselves. There are 2 possibilities:

1)	Fixed bases in friendly neutral countries.
2)	Floating bases.
	To 1.	Supplying to a limited extent has been agreed to in remote northwest Spanish bays. Several rendezvous with supply ships have been fixed. The actual feasibility of the scheme can only be tested in practice.
	To 2.	S.S. Ammerland is being converted into a supply ship. It is intended to station her in a suitable bay in Iceland, camouflaged as a ship with engine trouble.

12.10

	U 35 entered port. She sank:
	1)	English trawler "Arlita"	325	tons
	2)	" " "Lord Minto"	285	tons
	3)	a freighter from a convoy	9,000	tons
	4)	the Belgian S.S. "Suzen"	2,239	tons
	5)	the Greek S.S. "Diamantis"	4,990	tons
			16,839	tons
She also scored a hit on a tanker of 17,000 tons, the sinking of which was not observed as the boat had to dive.
She also encountered the "Aquitania", darkened in the Channel. She did not attack, as permission to attack darkened ships did not arrive until 48 hours later.
This has been a particularly successful patrol. The crew gave a very good impression on return.

13.10

The first sign of the activity of the boats which have put to sea has been a sudden large number of radio intelligence reports of sightings of and actions with U-boats in the Atlantic. U 37 reported the first sinking.

14.10

Radio intelligence reports of U-boats continue to increase. They give the impression of a very promising surprise in the area planned for the operation.

U 40 which sailed on the 10th, has not yet reported on her passage through the Channel. She had verbal orders to do this. She is not yet through therefore and must have been delayed.

15.10

Radio intelligence reports from the Atlantic have abated almost entirely. Only S.S. "Stonepool" in contact with a U-boat. U 48 reported her sinkings, 4 ships totaling 29,000 tons,

- 37 -

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


					and made a short situation report. She reports good weather (she was even able to reload upper deck torpedoes), while on information here it had been assumed that weather conditions in the operations area were very bad. It becomes clear how valuable such situation reports are for operations control. As the weather was believed to be definitely bad, the flotilla S.O. was advised on the 13th to leave position "GELB" and go to position "SCHWARZE" (Ops. order No. 7).
					Towards evening reports were received showing that apparently there has been a large-scale S/M hunt in area "GELB".





					(signed) Dönitz
					Rear Admiral and B.d.U.

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