Befehlshaber der Unterseeboote

   
Operationsabteilung   Wilhelmshaven, on 23.10.39

B.Nr. Gkdos 884

   
 
 
 
 

To the Oberkommando der Kriegsmarine, 1. Abt SKL

 
 
                 Concerns: Attack on convoy.
 
 

Attached you will find a report about an attack by three U-boats under tactical control of a flotilla commander on a heavily escorted convoy in the Atlantic.  It is the first attack of this type.  As far as we can ascertain at the time it was carried out essentially correct.  It shows how promising such a controlled operation of only three U-boats is.  Without doubt it would have been an even greater success if there would have been no torpedo failures.

 
 

The description does make no pretence of a gapless completeness.  It was compiled from received radio signals and radio messages from the U-boats and the B-Dienst reports.

 
 

Location: Atlantic Ocean in about 45°N and 12°30'W

 
  Time: 17. and 18. October 1939  
  Strength of convoy: 20 fast steamers  
  Strength of escort: 12 destroyers  
 

Results:

     
  a)  Sunk: 1.  steamer YORKSHIRE 10,183 grt
    2.  steamer CITY OF MANDALAY   7,028 grt
    3.  steamer SAGAING   7,968 grt
    4.  tanker, unknown name        ?
    Total, more than 25,179 grt
       
  b)  Losses: None  
 
     
 

Torpedo failures:

 
 
  Detonations after running the safety distance:
2
 
     
     
Click the flag to view the above page from the original German KTB
     

   
- 2 -
 
 
  Detonations at the end of its run:
2
  Surface runners:
_2_
  Total of torpedo failures:
6
 
  [Handwritten addition: U-48 additionally reported                      5 failures  
                                                                                             = 11]  
     
         
     
     
     
     
     
     
     
     
     
     

     

   
                                                                                  Attachment to BdU Gkdos 884.
 
 

               Sequence of combat operation.

 
                 (Extract from the war diary FdU SKL)  
     
 

17.10.39

 
00.55 Radio signal from U-46 reporting the sighting of a large cruiser, course north, 14 knots. It could not be gathered whether the boat was shadowing or trying to regain contact.
  U-46 reported at 08.51 convoy of 20 ships escorted by 12 destroyers, on a main course northeast. Boat was shadowing, lost contact for a while, regained it and shadowed until afternoon. Then English costal radio stations received reports of the torpedoing of 2 ships. At 20.00 hours, U-37 reported: "Convoy scattered, one ship sunk." She must therefore have reached the convoy. After the convoy had scattered, contact was lost. In order to regain it, U-37 ordered a reconnaissance line to be formed the following morning which is intended to pick up the convoy from the northeast.
   
18.10.39 At 00.29 hours, U-48 sighted the enemy again. She reported: "A straggler sunk. A second straggler steering a northerly course in BE 6789. Out of torpedoes."
  The boat shadowed this ship. At 05.00 hours, U-37 gave the order to act on U-48's report, thus canceling the order for a reconnaissance line. At first light U-48 again sighted the convoy, which had apparently reassembled meanwhile.  At 08.30 hours, a second U-boat was reported in sight of a ship. Therefore at least one more boat had reached the enemy on U-48's shadower's report. Towards midday aircraft appeared, contact was lost. U-37 ordered the boats which had been driven off to go to position "Black
 
     
     
                                                                                         
     
     
                                                             
     
     
     
     
     
     
     

                                       Attack of U-37 (tactical leader), U-46 and U-48

 
                                       on a convoy on 17. and 18. October 1939

in position 44°54'N/12°28'W

 

(times in MEZ)

 
     
  The U-boats U-37, U-42, U-45, U-46 and U-48 had patrolled in station "Yellow" of operational order #8 at a distance of 55 to 110 nm to each other until 16 October, where they carried out attacks on merchants individually. On 16 October, they were ordered to move south to station "Black". Very likely U-42 and U-45 had been lost to enemy action between 13 and 15 October.  
  Therefore only the following U-boats participated:  
 

    U-37 with the flotilla commander Korvettenkapitän Hartmann as commander, U-46 and U-48.

 
     
  According to the radio messages received, the sequence of the attack on the convoy:  
 
17.10      
1. 00.55 from U-46 Received 05.18
    Sighted enemy large cruiser  
    BE 9351  
    Course 0°, speed 14 knots  
2. 08.51 from U-46 Received 10.40
    Sighted enemy convoy  
    BE 9373  
    Course 40°  
3. 09.40 from U-46 Received 10.33
    Convoy consists of 20 ships  
    General course 0°  
4. 10.30 from U-46 Received 11.15
    Last observed position of the enemy in BE 9345  
    12 destroyers  
5. 09.50 from Quessant Received 09.55
    SSS IMPERIAL STAR gunned  
    44° 54'N/12° 28'W (10,018 grt)  
6. 11.46 from U-46 Received 12.50
    Enemy in sight in BE 9294  
    Course west, speed 14 knots  
 
                                                             
     
     
     

   
- 2 -
 
 
7. 14.45 from U-46 Received 15.16
    Enemy in sight in BE 9284  
8. 15.45 from U-46 Received 16.40
    Enemy in sight in BE 9276  
9. 17.00 from U-46 Received 17.40
    Enemy in sight in BE 9274  
10. 17.44 from Portishead Received 18.40
    SSS YORKSHIRE torpedoed  
    44° 52'N/14° 31'W  
  17.51 SSS unknown  
    44° 47'N/14° 48'W  
11. 19.32 from Home Fleet Received 18.32
    SSS CITY OF MANDALAY torpedoed  
    44° 55'N/14° 35'W  
12. 20.00 from U-37 Received 21.00
    Convoy scattered in BE 9272  
    Single steamers escaped to the north  
    Sunk one steamer  
13. 21.30 from U-37 Received 23.30
    U-45, U-48, U-42, U-37, U-46  
    Form patrol line from BE 6677 to BE 9334  
    06.00 hours, course 240°, speed 9 knots  
14. 21.52 from U-46 Received 00.02
    Sunk one tanker from convoy, during attack on second premature detonation of Eto after passing safety distance.  
 
     
     
     

   
- 3 -
 
 
18.10.39      
15. 00.29 from U-48 Received 02.40
    Sunk straggler in BE 9153  
    Second straggler in BE 6789 steering north  
    Out of torpedoes  
16. 02.32 from U-48 Received 03.25
    Straggler SAGAING in BE 6878  
    Course north, speed 13 knots  
17. 02.58 from Portishead Received 03.45
    SSS SAGAING chased by submarine  
    45° 37'N/14° 35'W at 00.51 hours  
18. 03.34 from U-48 Received 04.07
    Enemy steamer, main course 45°  
    BE 6885, speed 13 knots  
19. 04.29 from U-48 Received 04.34
    Enemy is steering northerly course  
    Speed 13 knots  
    My position in BE 6859  
    Enemy is astern  
20. 05.00 from U-37 Received 06.10
    Operate on the enemy reported by U-48.  
21. 05.02 from IYCG Received 05.55
    Picked up about 223 survivors from  
    YORKSHIRE, about 60 are missing  
   

Look out in 44° 47'N/14 °31'W

 
    Now heading to position SAGAING  
 
     
     
     

   
- 4 -
 
 
22. 07.26 from U-48 Received 08.38
    Enemy steamers are in BE 6944  
    Northeasterly course, speed 13 knots  
23. 07.41 from U-48 Received 07.52
    Enemy convoy in BE 6914  
    Northerly course, speed 13 knots  
24. 08.01 from U-48 Received 08.14
    Enemy convoy in BE 6917  
    Northeasterly course, speed 13 knots  
25. 08.25 from U-48 Received 09.36
    The reported enemy forces consist of six units.  Enemy is steering an easterly course, 4 spread out wide.  
26. 08.54 from Landsend Received 09.00
    SSS SAGAING (5,157 grt)  
    46° 17'N/13° 12'W at 06.53 hours  
    chased by submarine  
27. 08.15 from Landsend (repeated by Home Fleet) Received 09.17
    CITY OF GUILDFORD  
    46° 27'N/12 °52'W chased by submarine  
28. 08.30 from Landsend Received 09.17
    SSS SAGAING  
    Another U-boat appeared  
    46° 19'N/13° 00'W at 07.30 hours  
29. 09.44 from Portishead Received 10.10
    SSS GARTBRATTAN (1811 grt)  
    46° 30'N/12° 46'W chased by submarine  
30. 11.59 from Landsend Time received not specified
    SSS CITY OF GUILDFORD  
    46° 56'N/12° 09'W submarine  
 
     
     
     

   
- 5 -
 
 
31. 11.59 from U-46 Received 12.13
    Chased away by enemy aircraft  
32. 12.10   Received 12.45
    SSS IMPERIAL STAR  
    49° 54'N/07° 52'W submarine  
33.      
    SSS IMPERIAL STAR  
    49° 54'N/07° 52'W submarine  
34. 15.20 from U-37  
    Boats out of contact, go to station "black"  
35. 20.00    
    SSS CLAN MACBEAN  
    46° 21'N/09° 44'W submarine attacking  
       
19.10.39      
36. 08.35 from Quenant  
    SSS GARTBRATTAN submarine chasing  
    48° 45'N/09° 40'W  
 
     
          Afterwards it is quiet.  
 

        U-48 is returning to base as she is out of torpedoes.

 
          U-37 and U-46 are asked to report the fuel reserves available to operation on station "Black".  
 

        They report:  U-37 has 30 cbm

 
                               U-46 has 5 cbm  
 

        In consideration of the changed situation (low fuel reserves of U-46 and only two U-boats available), they receive new operational areas.