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

1 - 15 April 1940

PG30262

     
 
 
 
Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
  
 
 
   
 
K r i e g s t a g e b u c h      B. d. U.
 
  At sea:
 
a) In the area east to southeast of Shetlands:  U 38, 43, 52.
b) East of Pentland Firth:  U 22
c) Approaching the entrance to Scapa:  U 13, 58, 59.
d) Off Narvik:  U 46.  Off Trondheim U 51.
e) Possibly also U 44.  Position unknown, loss however, is probable.
   
  Intention:
          To recall U 38, 43 and 52 as soon as U 13, 58, 59 reach the Orkney area.  B.d.U. will be informed by telephone of the imminent sending of the keyword.  As the boats U 38, 43 and 52 at sea and fully armed, should be well prepared for the "Weser Exercise" it is high time that they were recalled.  In order to shorten their return route they have already been in the area east of the Shetlands for several days.  As long as their engine equipment is ready for action a supplementation of consumable stores is still possible up to the estimated beginning of the exercise.  In this connection, I have decided to order the return passage of these boats.  The keyword for the "Weser Exercise" will be received in the evening.  It is the 9th of April.
   
3. / 4.
          Put out to take up position:  U 7, 10, 19, 25, 30, 34, 47, 49.  Otherwise no events.
   
4. / 4.
          Put out to take up position:  U 9, 14, 48, 56, 57, 60, 62.  
   
              U 52 put in.  No successes as the boat was in a traffic-less area and was for the most part restricted to action.
   
5. / 4.
          Put out to take up position:  U 1, 2, 4, 5, 6.
   
6. / 4.
          Put out to take up position:  U 50 also U 64 escorting the auxiliary cruiser "Ship 36".  After executing her assignment (escorting the auxiliary cruiser until breakthrough into the Atlantic) this boat is at the disposal of B.d.U.
   
          At the moment therefore 2 U-boats are detailed for escort duties with outward bound auxiliary cruisers (U 37, U 64).  Their participation in the Weser operation is, it is true, intended, but does not appear certain.  It is not possible to foresee the course of the duties assigned to them so exactly that almost with any reserves of time, they may be further deployed.  Enemy action or adverse weather conditions could easily upset calculations and cause delay and surprise.  In view of the tireless concentration demanded by the coming task I have done everything to avoid splitting up.
   
          I consider the value of U-boat protection for surface craft negligible.  I see 2 possibilities in the execution:
 
1) Indirect protection: i.e.
  Occupation of potentially dangerous areas by U-boats.  Protection of these areas by U-boat attacks on patrol surface
 
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
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Air Pressure, Moonlight etc.
  
 
 
   
 
  craft in this area.  Warning auxiliary cruisers of enemy forces, which should be observed here.
   
  Stipulation:  large number of available U-boats.
  Advantage:  ship and U-boat are not dependent on one another they each operate in the way best suited to them.
  Disadvantage:  
  a) The protection of the ships is to take place in certain limited areas, not during the entire passage.  If the ship is not to dispense with protection it must pass through pre-arranged area of the U-boat and cannot therefore presume every U-boat to be encountered to be an enemy boat.
  b) Large number of U-boats required.
2) Direct protection by a permanent U-boat escort:
  Advantages:
  a) Permanent protection by the U-boat.
  b) Independence in choice of course, therefore, the possibility of adapting the course to the enemy situation without having to dispense with U-boat protection.
  c) Need of only one U-boat from time to time.
  Disadvantages:
  a) Dependence on maintenance of contact between ship and U-boat difficult, time-wasting and not always certain.
  b) Necessary mutual consideration of the tactical measures appropriate to the differing peculiarities of surface craft and U-boats in an encounter with the enemy and during passage - which would cause numerous restrictions on both sides.
        As we, at present, possess so very few U-boats the last possibility is to be given preference under all circumstances.  The simultaneous employment of U-boats in operation for merchant shipping warfare promises small success as the penetration route of an auxiliary cruiser must lead through the most far off and little used areas and these have long approaches.  If only 4 boats were used for this purpose, it would, in the present situation, mean an absence of 50% of all the large U-boats now in use against the enemy for the duration of the operations.  As not one, but several cruisers are involved, such an operation would considerably influence U-boat warfare.  (sinking figures of large U-boats for February over 200,000 tons, an amount unlikely to be exceeded by auxiliary cruisers).  
   
          U 38 and U 43 have put in.  While U 43 observed no traffic in her operations area west and north of England and was unable to sink anything, U 38 had more luck.  It sank: 5 steamers one in a convoy, of altogether 17 to 19,794 tons.  Both boats report strong and hindering U-boat patrol by fishing boats in the Shetland and Orkney area.  None of the three boats recently berthed are in a fit state to put out again in the next few days.  
   
  U 51 (Trondheim area patrol) has received orders to return to its original position in West Fjord, while the boats U 30 and 34, which have in the meantime arrived,
     
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
  
 
 
  are to take over the patrol of Trondheim.  U-boats at sea have received instructions to open the operational orders for the occupation of Norway.  The general political situation is coming to a head.  English operations against Norway again appear imminent.  This time a landing does not appear to be indicated by operations against German merchant shipping in territorial waters.  According to operational instructions transmitted before "Weser" day, the U-boats of the 1st U-boat Group off Westfjord are to patrol the fjord, if they are already there in place of delayed U 64 which put out with the auxiliary cruiser.  U 25 received orders to take up its position.  U 37 is intended as 4th boat of the group.  The boat should leave the auxiliary cruiser in good time, so that it will be able to take up this position before the 9th.  The fjord is to be patrolled for as long as possible.  The intermediate positions (to cut out changes) are only to be occupied shortly before the arrival of our destroyers (2000 on 8.4).
   
7. / 4.
        U 30 and U 34 must have reached their waiting position before tomorrow.
   
          As owing to the early intelligence of the Weser day the boats have already taken up position two days before zero hour in the harbor area, one boat (U 30) is to take over the patrol of the entrance.  U 37 reported leaving escort duties with ship 16.  The boat's position is so far west, that prompt occupation of the intended position near Narvik is no longer possible.  (Note:  I regret this very much as I considered the presence of tried and older commanders at this spot, where the greatest number of U-boats was deployed especially desirable.)
   
          U 52 has put out.
   
8. / 4.
          U 13 reports the presence of a heavy cruiser and 2 destroyers full speed ahead on a northeasterly course east of Pentland Firth.  Short signal received from U 64 according to which contact with the auxiliary cruiser was lost 24 hours ago.  Orders were given to proceed to Westfjord at high speed and to join 1st U-boat Group, while U 37, which would arrive too late in any case, is to be re-directed to a meeting point with the auxiliary cruisers.  The announcement of English declared areas on the Norwegian coast makes the appearance of English forces in the coastal waters appear probable.  The quickest possible closing of the entrances to our own landing ports is in this case particularly desirable.  Orders to draw in the end positions is therefore not only for the isolated groups but partly for the boats individually distributed. (F.T. No. 3)
   
          U 57 reports a heavy cruiser with destroyers on a southeasterly course east of Pentland Firth.  It presumes this to be a French unit.
   
          U 38 has put out.
   
          A German transport ship was torpedoed off the south coast of Norway.
   
9. / 4.
          Shortly before midnight Norwegian coastal lights were extinguished.  This apparently caused no delay to our surface craft putting into the rocky waters.  Reports are received according to plan.  The U-boats received orders to take in the end positions up to U 56 (inner position off Bergen) if this has not already been done as the occupation of these positions no longer appears necessary with the appearance of adequate patrols by other forces.  It remains for free disposal in the area west of Bergen.
                 
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
  
 
 
   
        a) Situation:
          "Scharnhorst" and "Gneisenau" contacted heavy enemy units at dawn about 60 sea miles west of Westfjord.  No further reports have been received today.  It is presumed that the battleships have managed to elude the enemy.
           
          U 51 reported 5 enemy destroyers on a southwesterly course in Westfjord at 2100.
           
        b) Waters of Shetland and Norway
          The evaluation of the enemy situation of 8.4 makes it appear certain that the enemy has strong forces at sea.  The enemy contact with our own battleships confirms this conjecture.  His heavy forces are far to the north.  In this case, the 5th U-boat Group's task - to intercept the enemy approaching to the northeast from English bases, pointless.  The enemy is already to the north in force.  Further, with the moving up of the Bergen boats to the area west of Bergen there is a gap which it would be desirable to fill.
                For this reason I have decided to transfer the group about 90 sea miles in the direction of 1200.
           
                U 37 is relieved of her escort duties, and receives orders to proceed at high speed to the area northeast of the Shetlands.  Together with U 38 and U 56 it joins the 5th U-boat Group.
           
                A W/T message was received from U 56 at 0920 reporting the sighting of 2 battleships on a southerly course in grid 8747 (northern east section of the Straits Shetland/Norway).  On account of radio intelligence reports the S.O. Home Fleet is presumed to be in this area, while a group of 2 battle cruisers are said to be in the north.  The enemy's southerly course - he is aware of German battleships to the north - shows that he has no intention of operating with the groupdirect.It must be presumed in this connection, that he will spread out in a cutting off position south of it with a group of heavy forces.  In order to deflect him on the way there, it is necessary to dispose as many U-boats as possible on his suspected course.  U 7's waiting position is to be transferred to the east.  The 3 U-boat training ships U 2, 5 and 6 are to be moved somewhat to the west, in order protect the flanks of our own sea route to Norway.  While, for the time being, there are no further U-boat reports, several a/c reports show that the enemy is actually moving forward in the area southwest of Norway.  Here, he is without question in an area that can no longer be occupied by U-boats.  It also lies within close range of our Air Force.  It is impossible to move U-boats there quickly enough.  At 1815 U 49 approaching from the north established contact.  The enemy, however, withdrew northwards.
           
 
1955
             U 49 reported again losing sight of him.  Apparently no other boats have come up.  Meanwhile - against my own judgment, by order of the Group - I have transferred the 4 U-boats disposed around Scapa, to the east.
           
                The group is of the opinion that the boats at present off Scapa where there are no more enemy forces, fulfill no useful purpose for the time being, while their presence east of the Shetlands could be of great value in the event of the enemy repeating his movements in the next few days.  U 10 and U 19 will in any case be
   
   
                                                           
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
  
 
 
     
  moved further to the east.  Such measures need more time for execution.  No noteworthy progress can be expected before the close of the coming night as in the operational area alone it will be necessary to submerge frequently owing to danger from a/c.  The withdrawal of the Scapa boats means as far as can be seen, that during the operations, they will be entirely lost to this position.  The area in which they were disposed provided every possibility of contact with the enemy, as sooner or later he must pass through it.
 
          The question as to which area is most important in view of the whole operation depends on an assessment of the war situation as a whole - a survey I am not in a position to make - in all operations with U-boats, however, one must not lose sight of the fact that the U-boat is a slow, unmaneuverable weapon which can only experience more than accidental success if given time to be effective in the ordered area.  In the case of transfer, it is especially to be remembered that they must be ordered in the evening and not in the morning, because in areas threatened by air activity U-boat practically only makes progress at night.
     
          A signal was received at 2145 that heavy enemy ships damaged in air attacks at 1730 were in grid AN 2338.  U 49, 50 and 52 received orders to proceed thither and to attack them.
     
  U 65 has put out for the operations area.
     
  2) Enemy reports:  See Appendix 2 to KTB of 9.4.
     
  3) Sketch of position and movements of U-boats with enemy reports in Appendix 3. (not attached)
     
  4) Collection of most important W/T messages to the U-boats, including boats disposition at 1000.  (in ink: see Appendix 1)
     
10. / 4.
          As they have not established contact, the operation was broken off as being no longer promising, so that the boats could take up their intended positions before dawn.
     
          U 49 was in contact with 2 large cruisers from 0159 to 0229.  They disappeared from sight at high speed on a southerly course.  U 50 and 52 were detailed to attack but did not sight them
     
  1) Situation:
    a) English destroyers attempted at dawn in mist weather and snow flurries to penetrate the Westfjord as far as Narvik.  They were detected with losses to both sides.  The U-boats disposed in the Westfjord could not, it seems, prevent the penetration.  The reason for this will be clear when the boats put in.  Without a doubt, their task is very tricky, especially opposed to destroyers which force their way through at high speed using depth charges, and twice as difficult in misty weather.  The operation shows though that one cannot be strong enough for such tasks.  In the course of the forenoon Naval War Staff ordered the dispatch of two boats to Trondheim and 4 to Narvik.  This order crossed with a relevant suggestion of mine to the Group.  There, the center point of the operation appears to have moved.This would be especially attractive to the English as an area for counter-attacks as it would be more difficult for us to be reinforced from home.  This situation is tricky for our own forces, as supplies have not arrived - the destroyers are for the most part unready to sail
         
      
      
                                 
 
 
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Date
Position, Wind, Weather
 
and
Sea State, Illumination,
Events
Time
Air Pressure, Moonlight etc.
  
 
 
 
      and their putting out is now questionable owing to the enemy - one small boat has been assigned to patrol the Kors Fjord
    b) A new distribution of boats in the northern North Sea is necessary as a result of this movement.  One has the impression that the English fleet has withdrawn in a northerly and southwesterly direction.  The Naval War Staff does not believe that a counter-landing on the southwest of Norway is imminent; in this connection they see no necessity for the enemy to operate near German bases from where apparently successful air attacks were carried out on 9.4.  In view of the considerable losses of surface craft and the return of units still lying in the landing ports, in the near future, they (SKL) consider the U-boat's main task to consist not so much in searching for targets as in the patrol of the recently occupied areas.  The new disposition shows here a concentration in the eastern section of the Shetland/Norway Straits.  The Narvik boats, to whom the very difficult and decisively important task at the moment calls - that of protecting these ports against every pursuing enemy - have received orders to penetrate still deeper into the fjord so that all boats are disposed in the narrowest possible positions, abandoning outer sections which are difficult to patrol.
       
11. / 4.
            Two destroyers of the Narvik Group attempted to put out of t