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

1 - 15 May 1940

PG30264

     
 
 
 
Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
 
 
 
 
1.5.
 
        Nothing to report.
2.5.
 
        U 13, 17, 23, 58 entered port and UA put into Trondheim.  U 17 and U 23 have nothing special to report off Bergen and near the Shetlands.  Reports from U 13 and U 58 show:
 
        East of the Orkneys and Shetlands and east of Pentland Firth very infrequent shipping but very strong patrol and numerous destroyers.  Operation during the summer (short nights) promises little success and losses may be incurred.
 
        West of Pentland Firth rather more shipping, including independently-routed, unescorted ships.  U 13 succeeded in sinking 2 steamers there, including the 7,000 ton tanker "Scottish American".  It would appear possible for small boats to operate in this area even at this time of year, if they are able to move away from the coast to rest the crews and charge their batteries.
 
        U 13 very probably sank a Tribal class destroyer north of the Shetlands.
 
 
        UA put into Trondheim after a record patrol.  U 44 must be declared missing and with her one of the best commanding officers, Lieut.(s.g.) MATTHES, who sank 36,000 tons on his first patrol.  This boat was off the Norwegian coast and west of the Shetlands before the Norway operation.  There is no clue as to her fate.
 
3.5.
 
        U 24 and U 57 started on their return passage, U 58 entered port.
 
        U 58's observations confirm the view that operation east of the Shetlands is possible.  U 7 and U 9, training boats, will have to be prepared for operations for case "GELB", in spite of my concern for the effect on their training.  Other U-boats are not yet able to proceed after the Norway operation.
 
 
        Of the transport boats, U 32 and U 101 (both still at sea) will be withdrawn.  These boats have the least petrol carrying capacity.  UA, U 26, U 122 and later U 123 are also intended for transport duties.
 
4.5.
 
        U 59 started on her return passage.
 
 
        U 29 and U 30 entered port, U 101 entered Trondheim.  U 29 took material to Bergen and Trondheim, was heavily depth-charged in FROHAVET off Trondheim and on her way back made an attack which failed.  U 30 was heavily bombarded by "Hipper" and "Eckholdt" in the approach to Trondheim, fortunately without results.  She was then to operate off the Romsdal Fjord, but did not succeed in entering the fjord as there was strong anti-S/M activity and she frequently touched ground in badly charted waters.  West of the
 
 
 
 
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
 
 
 
 
 
Shetlands the boat found little patrol, but also no shipping.  On her way there she had to abandon the attack on a convoy as, when she hauled ahead, the Shetlands were between her and the convoy.
 
        U 32, about whom considerable concern had been felt, reported her position.  A few days ago she reported petrol gas in the boat, which proves that there is danger in transporting petrol, even in outer fuel tanks.
 
5.5.
 
        U 25 and U 65, the only boats west of the Shetlands, have been given freedom of action in the whole area.
 
 
        U 32 entered Trondheim, U 14 Kiel.  Her experience off Bergen and NW of the Shetlands do not differ from those of other boats.
 
 
        UA and U 101 have been ordered to return direct from Trondheim.Now that the English have retreated from the whole of southern Norway, an operation against the supply routes to Narvik doesn't promise success.
 
 
        According to radio intelligence reports, 2 steamers, one a 6,000 tonner, have run into the minefield laid by U 9 in the Firth of Moray.  This is further proof of the fact that such minefields, laid with the mines far apart, are successful in the long run.
 
 
        "Gneisenau" struck an a/c mine between the Elbe and the Jade.  It is thus necessary for boats to proceed only with mine escort until they reach the 25 meter line.  This will mean delays, with the few forces we have at present which are suitable as escort against contact mines.
 
 
        U 24, 57, 59, 61 were first ordered to Wilhelmshaven instead of to the Elbe, as it was thought that the mine hit had occurred in the Elbe, Gneisenau having given a wrong position.
 
6.5.
 
        U 9 sailed for case "GELB", UA and U 101 for Trondheim.
 
 
        U 25, 24, 57, 59, 61 entered Wilhelmshaven, U 25 unexpectedly.  She had trouble with her transmitter during the last few days and could not report.  She made the same observations as the other boats in the Westfjord, but the Commanding Officer knew how to make clever use of the positive aspects of disposition in the fjords.  He is probably responsible for the sinking of a destroyer off Narvik.  U 24 had no opportunities to attack off Bergen and NE of the Shetlands.
 
              U 61 was operating first off Trondheim (Gripshoelm) and then off the Minch.  Her experiences agree with those of U 13 (see 2.5).  Off the Minch she sighted the "Warspite" at 12,000 meters and later had to start on her return passage as one diesel was out of action.
       
              U 57 and U 59 confirm the impression that it is now hardly possible to operate east of the Orkneys and Shetlands.  U 57 was heavily depth-charged.  She had 2 unmistakable gyro failures and so lost her chances of success.
       
              Since 16.1 U 57 has been at sea for 82 days out of 111 (-74%).  With this, the limits of the possible have been reached.
       
 
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
 
 
 
 
 
there are similar cases with other boats.  Many boats will require a long period of rest after these weeks of utmost strain.
7.5.
 
        Narvik requested U-boats as defense against enemy landings.  Naval War Staff refused.  A request from Sea Defense Commandant Trondheim to use U 32 as wing protection for Army troops proceeding north also had to be refused.With the few U-boats available, it is already difficult to do without the transport boats.  It is essential to avoid wasting boats for other subsidiary tasks, especially if these do not promise any success.
 
8.5.
 
        U 65 has been recalled.  She is alone NW of the ORkneys and it is no longer possible for her to proceed to another more favorable operations area, as she has used up most of her supplies.  It is therefore better not to keep this boat at sea any longer, but to make her ready at time for operation in the Atlantic, now that it is finally clear that operation west of the Orkneys is very difficult for large boats.
 
9.5.
 
        U 101 and UA entered Heligoland and in the afternoon both proceeded up the Elbe to Kiel, attached to an escort unit.  These boats have carried supplies to Trondheim.  The transport of petrol was unpleasant, but presented no major difficulties.  No attacks were made.
 
10.5.
 
        C-in-C Navy in the plotting room, head of Operations Department reported to him.
 
 
        The transport boats are being redistributed:  U 25, a boat which is not very suitable for use in the Atlantic, will be converted for transport.  U 122 will make one transport trip and then be available for use in the Atlantic.
 
 
        UA, U 26 and U 123 will remain detached for transport, U 123 after she has commissioned.  The smaller Type VII boats, which have only a small carrying capacity for a/c petrol, will thus be released from transport duties.
 
11.5.
 
        Nothing to report.
 
12.5.
 
        U 32 requested to enter port along Route II, without giving a reason.  It was assumed that she had encountered strong anti-S/M forces on the W boundary of the declared area and this was later confirmed by the Commanding Officer.
 
13.5.
 
        U 43 sailed for Trondheim with supplies for "Theodor Riedel" and will later proceed into the Atlantic.  U 65 entered port via Heligoland.  She was operating in the Vaagsfjord and in the area Faroes-Shetlands-Minch.  She scored no successes.
 
 
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
 
 
 
 
14.5.
 
        Recently war logs and verbal reports have shown that the mainly good hydrophone results obtained have often misled the C.O.'s into diving, even in the open sea area, without there being any great enemy activity and thus certainly missing some good opportunities to attack.  Instructions covering this have therefore been given to the Flotillas for the boats (B.d.U. Most Secret 834 of 18.5 1940).  Contents:  Hydrophones should only be used as auxiliaries and the commanding officer must control their activity.  The human eye is always a better means of obtaining data as a basis for tactical procedure.
15.5.
 
        Naval War Staff has now decided that no more petrol is to be transported to Norway.  UA and U 26 will therefore be reconverted to their normal state and U 25's conversion for petrol transport has been cancelled.  U 122, which is ready to sail at Kiel, will put to sea with the petrol she has on board, otherwise her sailing would have been delayed for about 6 days.  A part of her remaining cargo of supplies would also have had to have been unloaded, as the light specific weight of petrol raises buoyancy and permits the boat to take a greater load.
 
 
        U 37 sailed for the Atlantic.
 
 
        Experiments at the Torpedo Trials Department proved that the "AZ" unit of the pistol is liable to a high percentage of failures:  premature release of the firing pin.  Detonation of the priming.
 
        My suspicions of October and November and later that even the "AZ" does not always work, have thus been proved correct.
 
        The facts are worse than could ever have been suspected.  I have been informed that the correct functioning of the "AZ" was considered to be proved in peacetime after only two shots and even these were not perfect.  A method of working such as this can only be regarded as criminal.
 
        The numerous defects of the torpedoes were only suspected bit by bit by B.d.U. on the basis of practical operational experiences and show up; premature detonations, failure of the impact firing unit, failure of the torpedo to fire, faulty depth keeping.  In all cases the torpedo technicians either denied the possibility of a failure or else attributed it now to one cause, now to another.  In all cases a basic defect was actually finally discovered.
 
        The results is staggering.  After 20 years' peacetime work one might have expected a torpedo better than the one used in the last war, a torpedo, for instance, capable of sinking a battleship with one shot (shot at Barham 28.12.39).
 
        It is true that splashless discharge has been developed - but otherwise there is nothing right with our torpedoes.
 
        I do not believe that ever in the history of war men have been sent against the enemy with such a useless weapon.
 
 
 
 
 
 
 
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
 
 
 
 
 
        Many past shots which were taken as misses will now have to be regarded in a new light on the basis of this fresh information.  In many cases the Commanding Officers have reported that they heard an impact for certain and no explosion followed.  There is also the case of the shot by U 56 at "Nelson" on 30.10.39 (Churchill on board).  It will never be known how many other shots hit without the torpedo exploding.
        Past analysis of failures and hits are more or less valueless now.
 
        I hope now for a pistol of the simplest type, in which the striker will transfer the blow immediately aft and not, as in ours, work from aft forward after a complicated transmission of the striking force.   I have therefore demanded, as set out in a T/P to the Torpedo Inspectorate, that the English pistol be copied as quickly as possible.  A faultless functioning of this pistol may be expected by reason of its simple construction.  We will then abandon magnetic firing which is in any case becoming mythical with the enemy's increased use of magnetic gear.  When depth-keeping and impact firing are working properly, we can wait for the development of an effective non-contact firing unit without any questions.
 
 
 
 
                                        (signed):  Dönitz
 
                                    Rear Admiral and B.d.U.
 
 
 
 
 
 
 
 
 
 
 
 
       
       
       
       
       
       
       
       
       
       
 
 
 
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