-25-
 
    Page 249 of original
     
Top Secret.
Copy No. 171
                                       74
Current Order No. 43 of June 1944 U-boat  "U 249"
    Recd.     18.7.44.
Use of Tunis Installation (Fliege and Miicke) Reg No.  Top Secret 75
    Encl.      ----
 
     
 
A. Enemy apparatus.
    The enemy locates at present mainly with apparatus in a centimetre range.
     
  1) For this purpose focal point lies, at the moment, in a range of 10cm.  Dynamo apparatus is used with rotating, fixed or turning aerials, with continuous radiation and short range location (Radar gear economizer).  Aircraft sets, up to now, intercepted as having only rotating beam, rotating at about 1 to 4 times per second.  (At a height of 1000m. the range of an aircraft against U-boats must be calculated at about 50 km. to 100 km.)-deleted.  In normal locating conditions, surfaced U-boats intercepted between 20-50 km. in very favorable conditions, the range of interception can increase considerably.  (Insertion to page).
     
  2) Further, the use of enemy apparatus also in the 3 cm. band must be reckoned with.
     
  Locating activity outside this range has been intercepted only over land, since for interception at sea so far, none of our own interception gear has been used.  Information about ranges, continuous radiation, short range location etc. are not yet available.
     
B. Own Installations.
     
Tunis:  Installation consists of combination of "Fliege and Miicke".
     
"Fliege":  Reflecting aerial (developed from Naxos-finger) with rough bearing.  Receiving section about 90°.  At heights of 1000m. warning range between 60-70 km.  "Fliege" is in use at present as independent apparatus.
     
"Miicke":  Cavity aerial (shaped like a small megaphone) with D/F possibilities.  Receiving about 15.  (At present still no discoveries re range)-deleted Range as for "Fleige" (inserted in page).  At present used in combination with "Fleige".
(Specification:  Tunis)
     
Both aerials are mounted in a frame.  Flying cable through conning tower hatch with 2 amplifiers.  "Tunis" can be put into the D/F frames or used mounted on a pole.
     
C. Directions for hand manipulation.
     
        "Tunis" installation works with detectors, and is free of beams.
     
        For the interception of enemy apparatus a continuous search over 360° is necessary.
     
        "Tunis" must be turned 360 at least 6-8 times per minute, since otherwise the interception of the slowly moving 3 cm. apparatus cannot be relied upon.
     
        Penetration of the 10 cm. apparatus of the enemy into the range of the Miicke" has not so far been established even at the shortest distance.  Careful overhauling of both aerials with "Puck" before use is necessary, and hourly when in use.
     
        When own Fu MO beam is in action, take in "Fliege" and "Tunis".  Detectors are endangered.  (According to latest experiments, both can be worked simultaneously up to 30 mins. without being damaged.  -(Insertion))  A clear-cut image of the intercepted and located enemy, reduces the comprehensive range of the enemy apparatus considerably.
 
 
 
 
 

 


 

Click the icons to view the associated records

Return to the B.d.U. KTB/War Standing Orders page