Researching the Luftwaffe through Prisoner Interrogations

[Dan O'Connell]

Amazing.

[Nick Beale]

Originally Posted by Dan O'Connell

Amazing.

Agreed, would people like a dedicated "Researching the Luftwaffe through Prisoner Interrogations" thread?

Other thoughts: (1) Bruce has done me a great service, at least — my microfilm print-out of No. 160/1944 is almost impossible to read, now I finally know what it says!

(2) If you're interested in the last flight of Z6+FH, on what was a busy night over Holland and Belgium, there's this http://www.ghostbombers.com/kf4/West/zeisig1.html and this
http://www.ghostbombers.com/Olga/map23jan.html

[SES]

[quote=Nick Beale;259922]Agreed, would people like a dedicated "Researching the Luftwaffe through Prisoner Interrogations" thread?
QUOTE]

Hi Nick,
Yes what a wonderful idea.
bregds
SES

[Marcel van Heijkop]

Originally Posted by Nick Beale

Agreed, would people like a dedicated "Researching the Luftwaffe through Prisoner Interrogations" thread?

(2) If you're interested in the last flight of Z6+FH, on what was a busy night over Holland and Belgium, there's this http://www.ghostbombers.com/kf4/West/zeisig1.html and this
http://www.ghostbombers.com/Olga/map23jan.html

Absolutely! Count me in, Nick!

PS: Is your website down at the moment? I tried to read the info from the links you provided, but couldn't get on your site.

Best regards,

Marcel

[Nick Beale]

Originally Posted by Marcel van Heijkop

Absolutely! Count me in, Nick!

PS: Is your website down at the moment? I tried to read the info from the links you provided, but couldn't get on your site.

Best regards,

Marcel

Hi Marcel,
My website is still alive (I just checked) and both those links work for me.

Another site with a selection of transcribed ADI(K) reports is: http://www.cdvandt.org/felkin_reports.htm. The emphasis there is on radar and communications systems.

[Bruce Dennis]

"SECRET A. D. I. (K) Report No. 125/1945
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W
AS THE STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO
MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY
INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.

G.A.F.NIGHT FIGHTERS.
RECENT DEVELOPMENTS IN GERMAN NIGHT FIGHTING.
1. Between the opening of the Rundstedt offensive on 17
December 1944 and the night of 1st January 1945, fifty-nine
German night fighter aircrew captured on the Western Front
were brought to England for interrogation by A.D.I.(K). Of
these prisoners, ten were selected as being suitable for
special interrogation with the object of investigating current
German tactics, and the extent of their deviation from methods
employed up to the end of November and reported in A.D.I.(K)
508, 599, 620 and 700/1944.
2. The present report is based on the interrogation of these
ten prisoners, who came from III/N.J.G.1, II and III/N.J.G.2
and II, III and IV/N.J.G.3, and of whom one had recently spent
some time at the G.A.F. radar experimental station at
Werneuchen. In addition, there was one prisoner who had spent
one year as a ground radar mechanic with I/N.J.G.4 and had
then transferred to the Schulstaffel of the same unit to train
as a radar operator. The Schulstaffel had been dissolved at
the end of October 1944 and its personnel posted to the
infantry; this P/W fell into Allied hands as an unwilling
member of the Waffen SS.
3. From interrogation of previous night fighter prisoners -
captured between September and the end of November 1944 - it
has been amply proved that the German night fighter force has
been at a loss to overcome the successful Bomber Command
spoofery and radio countermeasures and as yet has made no
progress in its efforts to overcome this disadvantage.
4. From the present interrogations there are signs that the
Germans, not content to let the matter rest as it is, are
striving to gain the upper hand over Bomber Command by the
introduction of at least two new measures. One of these,
discussed in the following paragraphs, is the employment of
Bernhardine beacons for the dual purpose commentary and
navigation, and the other - as yet in its early stages - the
probable introduction of a new type of search equipment, the
SN 3. Details of the latter are at present lacking, but
evidence suggests that it may be of the nature of centimetre
A.I.

BERNHARDINE – FuGe.120.
Earlier Vicissitudes.
5. As far as G.A.F. prisoners are concerned, Bernhardine is
no innovation, as early as May 1942 hazy allusions to this
form of navigational aid were made by prisoners, but the first
mention of Bernhardine by name was made by an officer of
1(F)/121 captured in October 1943 (A.D.I.(K) 498/1943;
thereafter nothing further was heard until K.G.66 opened its
pathfinder operations over England early in 1944.
6. A prisoner from 5/K.G.66 captured in England on 25th March
1944 gave an account of Bernhardine which, in the light of the
present interrogation proves to have been remarkably accurate
(A.D.I.(K) 187/1944, paras.19 – 24)
7. In October 1943, 5/K.G.66 had had 1 Do.217-M equipped with
Bernhardine, but after some experiments the experts had come
to the conclusion that the apparatus was not sufficiently
accurate for pathfinder operations; the P/W concerned had
heard later that work on the ground installations had ceased.
8. In spite of continued interrogation of subsequent
prisoners, nothing more was heard of Bernhardine until late in
December 1944. The capture of a prisoner from III/N.J.G.1 on
17th December 1944 and other prisoners from II and III/N.J.G.3
later in the same month has now revealed that Bernhardine is
being seriously considered - if not already used - not only as
an aid to night fighter navigation but as a source of the
commentaries.
Introduction of Bernhardine to Night Fighting.
9. Some time in October 1944, crews of 8/N.J.G.1 were given a
preliminary lecture on Bernhardine in which its principles
were explained, they were told that it was no new discovery
but would shortly be introduced to night fighting. In
III/N.J.G.3 crews had also been given frequent lectures and by
November some of the aircraft of that Gruppe already had the
necessary apparatus installed.
10. According to prisoners who attended these lectures, the
transmissions from the ground station take the form of a
conventional twin lobe polar diagram with an equisignal area
and with a very small amount of rearward radiation. A signal
transmitted from the ground station once every minute is
translated by the airborne apparatus into a teleprint message
on a paper tape giving the QTE (true bearing) of the aircraft
from the ground transmitter followed by a further image in
figures and letters which is a Divisional commentary of the
type at present broadcast by the high powered W/T beacons.
11. It was explained that the Bernhardine transmitters would
operate on 32 frequencies between 30.0 and 33.1 mc/s, and that
the signal would be received through the normal E.Bl.3 in the
aircraft. Thus the first 32 of the 34 spot frequencies of the
E.Bl.3 would be used for Bernhardine whilst the remaining two,
33.2 and 33.3 mc/s, would be retained for blind landing
purposes.
12. It is claimed by P/W that Bernhardine signals are
unjammable and that transmissions have a range of 400 - 500
kilometres.
13. A captured night fighter map, recovered from a recent
crash in Belgium and issued by the signals officer of N.J.G.3,
was marked with Bernhardine transmitters at approximately the
following pinpoints;-
N° 0(?) Berlin 52°13'N;13°6'E
N° 8 Alkmaar, Holland. 52°42'N;4°38'E
N° 9(?) Leck 54°41'N;9° 2'E
N° 10 Thisted, Denmark. 56°42'N;8°33’E
N° 11 Breslau 51°25'N;17°5’E
N° 12 Pilsen 49°45'N;13°15’E
14. A further indication that Bernhardine may already be in
operational use was found in a file of signals orders from an
aircraft of II/N.J.G.1 shot down on December 31st. On the same
page as the usual numbering of the Y-line frequencies was
another column headed "Kanäle" (= channels); the channels were
numbered from 1 to 32 and to each number was appended a
frequency, commencing with 30.0 at No.1 and rising by .1 mc.
to 33.1 mc/s at No.32.
15. Both of the above documents have been forwarded to
A.I.4(b).

Airborne Apparatus.
16. The Bernhardine apparatus in the aircraft is contained in
a box measuring some 60 cm in width, 30 cm in height and 20 cm
in depth, placed in the JU.88 in some cases to the right of
the W/T operator on the lower port wall of the fuselage and in
others to the left of the W/T operator or in the forward
instrument panel.
17. The front of the box has a wide glass-covered slot about
40 cm. in length and 12 cm. in depth along which the paper
tape travels from right to left after the necessary data have
been printed upon it by a teleprinter contained in the box.
The on-off switch for the apparatus, marked FuGe.120, is
placed on the R/T operator's switch panel, and is used in
conjunction with the click-stop frequency selector for the
E.Bl.3.
18. From evidence supplied by the present P/W it is possible
to give a description of the Bernhardine display and of the
exact data which it supplies. An impression of the Bernhardine
display is given below; it will be seen that the printed tape
is divided into three horizontal sections, on the uppermost of
which appears a series of close vertical lines shortening at
intervals to a "V", on the central section a reading in
degrees, and on the lower a coded image which is the
commentary. One simultaneous printing of these sections takes
place during ten seconds of every minute, the tape remaining
stationary for the remaining fifty seconds, after which the
process is repeated.
19. In the lectures on Bernhardine it was stated that the
ground transmitter makes one full revolution of 360° in sixty
seconds; a section of the pattern of the ground transmission
is repeated on the tape in the form of the series of vertical
lines, the equisignal zone being represented by the apex of
the "V".
20. In each printing lasting ten seconds a sector of 60°
appears on the tape and in every case it contains a repetition
of the equisignal zone. The reading in degrees appears in the
central section of the tape in numbers representing 10's of
degrees, and the point opposite to which the apex of the "V"
is printed represents the bearing in degrees of the aircraft
from the transmitter. Accuracy of bearings was stated to be
within 0.5°.
21. A recognition letter is allotted to each transmitter and
is repeated on the tape at every 20° on the scale; in the
sketch the letter X - the recognition for the Leck transmitter
is shown.
22. The commentary in the lowest section appears in each 10-
second printing as a group of a maximum of ten letters and
numerals, inclusive of two crosses denoting the beginning and
end of a message. Should a message be of more than ten
characters it wi11 be continued in the succeeding printing, a
cross appearing at the end of the message.
23. Thus, the commentary message shown in the sketch, + 40 KA
27 100, just falls within the ten-character limit if the final
+ denoting the end of the message is omitted. The latter is
therefore carried forward and appears at the commencement of
the next printing; it denotes simultaneously the end of the
one message and the beginning of the next. It was stated that
a single message could be continued over three or four
printings.
24. The commentary always appears in a standard order;
analysis of the typical message shown in the sketch is as
follows:-
25. It will be noted that the form of this commentary is
exactly the same as that at present put out by the Divisions
on the high powered W/T beacons (see A.D.I.(K) 599/1944 para.
57).
26. The present P/W had been told that, in addition to the
Divisional commentary, instructions to individual formations
of night fighters would be transmitted by the Bernhardine and
printed on the lowest section of the tape. How, in such a
case, the aircraft would be tracked or how the orders by the
subordinate units would be coded, they did not know.

Operational Use.
27. The aircraft set is switched on soon after take-off, so
that the bearing transmitter can be constantly watched. If the
+ = beginning of message
40 = height of head of bomber stream in 100’s of metres
KA = fighter-grid position of head of stream
27 = course of formation in tens of degrees
100 = estimated number of aircraft
W/T operator wants the fix, he switches over to the
transmission of a second Bernhardine station for a gross
bearing; it was stated, however, that quicker and more
favoured method was to obtain a simultaneous cross bearing
from a high powered beacon through the PeilGe 6.
28. As far as these prisoners knew, only the Bernhardine
stations at Berlin and Leck are so far capable of transmitting
a commentary and flying instructions; the latter station was
only modified in this way at the beginning of November 1944
and aircraft of 9/N.J.G.3 made several test flights, usually
taking off from Uetersen at about 0230 hours and remaining
airborne for some four hours.
29. The present P/W of 9/N.J.G.3 had not taken part in these
flights, but after the tests he had seen the tape, which he
described as being printed on white paper in red letter,
4 - 6 mm. high as clearly as with a typewriter. He was told
that there was sufficient tape to allow of continuous
operation for 4 hours 20 minutes.

SIGNALS TRAFFIC.
German Spoof Signals.
30. An aircraft of 7/N.J.G.3 shot down in Belgium on January
1st carried a signal order on which appeared the word
"Orgelpfeife" (= organ pipe). Interrogation of all the present
P/W elicited the fact that Orgelpfeife is the codeword for
spoof R/T and W/T traffic passed between small numbers of
aircraft and the ground with the object of simulating large
numbers of night fighters in operation.
31. According to a P/W of 9/N.J.G.2 Orgelpfeife was
introduced in that unit, in mid-November; one crew in the
Staffel had received special briefing and usually operated the
spoof traffic. In operating R/T spoof, this crew’s duty was to
imitate a large number of night fighters operating by the
simple expedient of all four members of the crew taking turns
to speak, each using different callsigns.
32. It was said that the pilot of the crew in question,
Oberfeldwebel GELLNER was something of an actor and was able
to imitate various German dialects and different voices; P/W
claimed that the single Aircraft could simulate as many as
twelve night fighters.
33. The Orgelpfeife aircraft operated under Y control, since
such importance was attached to its position in relation to
the raiding force; the spoof aircraft patrolled an area near
the estimated target and as the raiding force was approaching
the target, the simulation of night fighters operating
commenced.
34. According to P/W the spoof aircraft carried large
quantities of Düppel (Window).
35. It seems that only one aircraft in a Staffel operates
Orgelpfeife; this was certainly the case in III/N.J.G.2, and
another P/W of III/N.J.G.3 stated that similar conditions
prevailed in that Gruppe.
36. None of the present P/W could give any useful information
on the method of coding the Orgelpfeife traffic, but it was
stated that the briefing usually gave two codewords or groups,
according to whether the spoof was R/T or W/T, and the crew
was to ignore all orders from the ground except those preceded
by the operative Orgelpfeife codewords or group.
37. In the captured briefing sheet mentioned above, the
codewords for 7/N.J.G.3 on the night of December 31st were
"Elfenbein" for the aircraft and "Hallore" for the ground.
38. A P/W of 9/N.J.G.3 stated that early in December R/T
silence had been enforced amongst the normally operating night
fighters of that Staffel.

Defence of the Ruhr by N.J.G.1.
39. The four Gruppen of N.J.G.1 have been allotted the
special task of defending the Ruhr in night attacks by R.A.F.
Bomber Command, and to achieve this aim all the Gruppen are
based strategically at airfields in that area.
40. In operations over the Ruhr the Gruppen are not
controlled separately as would normally be the case, but
operate under the central control of a special Geschwader
commentary put out on a M/F and an alternative V.H.F.
frequency; the latter, however, is almost invariably jammed.
41. This commentary consists of tactical instructions to the
aircraft as well as reports on the general situation;
according to P/W, the latter are not based on a Divisional
picture of events, but on data supplied by the Ruhr Flak
defences.
42. When a Mosquito force is reported over the Ruhr area, and
providing that flying conditions are suitable, all aircraft of
N.J.G.1 are put up and ordered to orbit any of the beacons
Börse, Bruno, Achmed, Gemse, Heide, Schnake, Paule, Ratte and
Drossel to await further events.
43. In case of jamming of both channels of Geschwader
control, two of these beacons, Achmed and Paule, are set aside
for transmission of the Geschwader commentary. P/W also heard
that a further alternative H.F commentary is to be put out on
a 20 kW transmitter whose signals will be superimposed on a
Cologne broadcast programme.
44. The aircraft of N.J.G.1 usually orbit the beacons for
about an hour, and if by then no attack by four-engined
bombers has materialised they are recalled; upon returning to
base, the aircraft are immediately refuelled so that should a
further attack be made a fresh sortie can be initiated
immediately.
45. In the middle of December some 50% of the aircraft in
N.J.G.1 were equipped with two white LC.50 flares carried
externally under the outer rings, and in the event of a major
bombing attack on a Ruhr objective these aircraft were to make
for the target and lay the flares at the operative height of
the bombers, so that the remainder of the night fighters could
quickly close in the area for visual attack.
46. The flare-carrying aircraft were to be given an X-time
for arrival over the target to coincide with the arrival of
the bomber stream; at this time the Flak would have orders to
cease fire, the flares would be laid and the night fighters
would go in to attack.
47. Importance was attached to the flare-carrying aircraft
arriving exactly at X-time, since a previous arrival would put
them and the remainder of the night fighters in danger of
being shot down by the Flak, and a late arrival would
jeopardise the operation.
48. In such a case where the aircraft of N.J.G.1 had been put
up against a spoof attack of Mosquitos and a four-engined
attack developed against targets outside the Ruhr, the
Geschwader commentary would transmit the codeword "Diogenes",
at which the aircraft would revert to their respective Gruppe
commentaries and would operate against the new attack in the
normal manner.
49. Crews of the flare-carrying aircraft were instructed that
in defending targets outside the Ruhr they could use their
flares, but only if they were certain of the true target.
Jamming of Commentaries.
50. Prisoners of II and III/N.J.G.3 stated that the Gruppe
commentaries were not seriously jammed in the Hamburg area;
although R/T could occasionally be heard, however, crews
relied mostly on the morse commentaries.
51. They stated that intensity of jamming varied considerably
from night to night. They could not understand the reason for
this since they had been officially told that the jamming had
been D/F’d and traced to the London area.
Verbandsführer (Formation Leader).
52. From the present P/W there are again conflicting reports
on the success or failure of the system of flying in formation
with a leader aircraft (A.D.I.(K) 700/1944, paras.34 – 49).
53. Whilst one P/W of N.J.G.3 stated that the system had been
working well in that Gruppe up to mid-December and that leader
aircraft operated under Y control, another prisoner, of
8/N.J.G.1, stated that in his unit the system had proved
unworkable and had been dropped in October. He gave as one
reason the dislike by the more experienced crews who flew as
formation leaders of acting as flying beacons, with the
attendant danger of being homed on by Mosquitoes.

I.F.F.
54. Much has already been said about the FuGe.25a in recent
A.D.I.(K) reports but nevertheless interrogation has continued
as to the conditions under which the apparatus is or is not
switched on during operations. One P/W of 8/N.J.G.1, based at
Düsseldorf, stated that if no intruders were reported at the
time the night fighters were ordered up for an operation, he
would switch on the FuGe.25a at take-off and keep it operating
until well clear of the airfield.
55. During operations he would have the instrument turned
off, but on returning to base would again switch it on shortly
before reaching the airfield - provided no warning of
intruders was in force.
56. A P/W of 9/N.J.G.3 knew of the British air-to-air I.F.F.
and knew that R.A.F. A.I. included a button which, upon being
pressed, identified the friendly aircraft on the A.I. picture.
57. Crews in this Staffel were told that a German air-to-air
I.F.F. was shortly coming into operation, but no further
details were given.
58. A prisoner of 11/N.J.G.3 remembered having seen a note in
a G.A.F. intelligence summary stating that the R.A.F. was
using infra red air-to-air recognition.

Hermine Beacons.
59. One of the present P/W had first heard of Hermine V.H.F.
beacons in March 1944, and at the time had learned that these
were radio beacons of new type from which pilots of singleengined
aircraft could obtain bearings.
60. He stated that the beacon, which has an effective range
of 200 – 300 kilometres, rotates through 360° in about three
minutes. The beacon transmits a continuous tone over about
359° with a silence zone of 1° which sweeps through 360° as
the beacon rotates; additionally a "speaking clock" counts
continuously from 1 to 360 and the continuous tone is
superimposed over this speech.
61. The pilot in the aircraft hears the continuous tone and
the counting on the FuGe.16Z, but hears the bearing spoken
clearly when in a line with the silence zone; he thus hears
his bearing to the beacon.
62. It will be remembered that prisoners of the Wilde Sau
single-engined night fighter unit I/J.G.301, captured in July
1944, had made mention of these radio beacons, albeit not by
name. The Kommodore of a single-engined day fighter Geschwader
had suggested that "Hermine" is derived from Oberst HERMANN,
founder of Wilde Sau night fighting.

INTERCEPTION EQUIPMENT.
Spot frequencies of SN.2.
63. The word "Streuwelle" in conjunction with SN 2 has been
mentioned for the first time by the present batch of
prisoners. Although none was able to define the word
Streuwelle or its origins, one suggested an alternative word
"Frequenz"; A.D.I.(Sc.) has supplied an agreed translation of
"Streuwelle" in the term "Spot frequency".
64. It has already been reported that in I/N.J.G.2 an attempt
had been made to reduce the effects of electrical jamming by
mounting the SN 2 aerial arrays diagonally instead of
vertically. These prisoners confirmed that this had also been
the case in other units, but the present interrogations have
established that this arrangement of aerials has no connection
with the spot frequency of the SN 2. In many cases prisoners
have known the differing aerial arrangements to exist in
several aircraft all equipped with SN 2's of the same spot
frequency.
65. These prisoners knew of three Streuwellen at present in
operational use, namely 4, 5 and 6; in two units, 8/N.J.G.1
and IV/N.J.G.3 some of the aircraft carried No.6, and other
prisoners stated that aircraft of their units were equipped
with 4 or 5 or a mixture of both. In 5/N.J.G.3, for example,
Streuwelle 5 had superseded 4, whilst 8/N.J.G.1 was equipped
with a mixture of 4 and 6, the latter having been delivered in
October.
66. It is worth noting that aircraft equipped with
Streuwellen 5 or 6 are forbidden to fly over enemy territory
unless the boxes have previously been removed; no such
security measures, however, exist with Streuwelle 4.
67. One prisoner had heard that a JU.88 equipped with SN 2
and Flensburg had landed at an airfield in East Anglia last
summer and that the British were therefore in possession of an
SN 2. He naturally assumed that the latter apparatus was of
Streuwelle 4. Upon being asked how it was known that a German
night fighter had landed in England he replied that the
information had been given by British prisoners in Germany.
68. Not one of the present P/W could supply the respective
frequencies of Streuwellen 4, 5 and 6, but the radar servicing
mechanic P/W, who had been with N.J.G.4 up to the end of
October, was able to give a few details of 4 and 5; up the
time when he left the unit he had not encountered No.6.
69. He was certain that the frequency of 5 was slightly
higher than that of 4; No.5 has one more induction coil and
has a range exceeding No.4 by 5 kilometres, being provided
with an extra switch giving two range pictures, one at 5 km.
and one at 10 km.
70. He and other prisoners stated that no matter which
Streuwelle, 4, 5 or 6, is installed in an aircraft, the aerial
array remains unchanged and in all cases the same CRT's and
the same electrical length of connecting cables are employed.
71. The ground radar mechanic stated that outwardly there is
little difference between the three Streuwellen, and to avoid
confusion by the ground staff all boxes have the appropriate
number painted on the back; the boxes of different Streuwellen
are not interchangeable.
72. An example of the effects of jamming on the differing
Streuwellen was given by one of the present prisoners. In May
1944 all aircraft of his unit were equipped with Streuwelle 4
with provision for the alternative frequency. In July 1944,
however, Window jamming made the set useless.
73. In October 1944 Streuwelle 5 and then 6 were delivered,
both with the alternative frequency; these, however, were
seriously jammed by the so-called Rauschsender (electrical
jammer). It was found, however, that the remaining SN 2's of
Streuwelle 4 were not so seriously upset by electrical
jamming, and the result was that many crews asked for No.4
back again and their wish was granted.
74. According to the radar mechanic, the C.R.T's used in the
SN 2 are manufactured by both Lorenz and Siemens Nürnberg; the
latter are the more satisfactory in service.
75. One P/W had spent six months up to May 1944 installing
SN 2's in Me.110’s at Werl; he stated that installation work
for Ju.88’s was carried out at Gütersloh.
Serviceability of SN 2.
76. Considerable trouble in the servicing of the SN 2 was
experienced in misty or wet weather; the chief source of
trouble was rain water percolating into the pulse distributor
at the base of the antennae and was the cause of squints and
the blowing of valves.
77. In units recently examined, night flying tests are no
longer made; in the experience of one P/W of II/N.J.G.1 some
30% of the SN 2's were found to be u/s if the unit had been
stood down for more than three or four days.
78. Should radar equipment be found to be u/s after an
aircraft has taken off on an operation, the order is that the
sortie must be completed. This is a state of affairs which
rattles the crews, particularly if the SN 2 is not working and
they are robbed of backward cover.

SN 3.
79. As compared with prisoners captured up to the end of
November 1944, the present P/W gave the impression that
developments in the SN 3 have reached a further stage.
80. No prisoner has yet been encountered who has seen an
SN 3, but several had heard some scraps of information. It was
stated that the aerial array for this set is carried inside
the aircraft, and that Major SCHMAUFER, Kommodore of N.J.G.4,
is already flying an aircraft with this new search equipment.
81. There is no doubt that the Germans are in possession of
details of British centimetre A.I. and it has recently been
freely discussed by G.A.F. aircrew under the name "Grille"
(= grid).

TAIL WARNING.
SN 2 Tail Warning.
82. The present P/W were able to add considerably to
information obtained on night fighter tail warning equipment
and set out in A.D.I.(K) 700, paras.13-16. The present
interrogations, leave no doubt that the tail warners now
extensively fitted to German night fighter aircraft are a part
of the SN 2 equipment and that the picture appears on the SN 2
azimuth tube.
83. No height or bearing, but only a range reading can be
obtained from the backward aerial; forward and backward
displays do not appear simultaneously on the SN 2 tube, but
the set is provided with a switch which can select one or the
other. The method employed by the radar operator is therefore
to search for contacts with the forward aerials whilst
occasionally switching over to rearward aerial to see if an
enemy night fighter is following.
84. A tail warning tactic recommended to crews of III/N.J.G.1
is one of not taking immediate action when a rearward contact
is picked up, but of waiting until the range begins to close
in. When this occurs, the pilot increases speed and if the
blip closes in to 600 metres the pilot then takes evasive
action.
85. In the above-mentioned unit evasive action has been
ordered to take the form of a 180° hard turn to port or
starboard. If the pursuing aircraft has been seen by the crew,
the turn will be made according to its position; when the
pursuer is to port, the pilot of the night fighter will turn
in to port, or vice versa.
86. Previously, the tactics of the night fighter in those
circumstances was to peel off towards the pursuing aircraft,
but this resulted in losing 1500 to 2000 metres in height
which took about ten minutes to regain.
87. The newer tactic described above was ordered in
III/N.J.G.1 late in November to obviate this loss of height
and time and in that unit at least, the tactic of peeling off
is now forbidden except in extreme urgency.
88. A number of P/W knew the SN 2 tail warning as the D (or
Dora) Zusatzgerät (= the Dora attachment).
Fu.Bl.2 as Warning Device.
89. Yet another piece of German Airborne radio equipment, the
Fu.Bl.2 has been added to the list of sets that are capable of
giving a warning of approach of an aircraft.
90. Three P/W had heard that if the Fu.Bl.2 is switched on,
the red marker beacon warning lamp lights up when a radarequipped
aircraft is in the immediate vicinity.

Naxos as Tail Warning.
91. Crews of 8/N.J.G.2 had recently been told officially that
Naxos is capable of acting as a warning of the presence of
enemy A.I.–equipped aircraft. No such information had been
given to any of the other units examined during the present
interrogations, and none of the other prisoners knew that
Naxos had such capabilities.
92. It was pointed out by the one P/W concerned that Naxos
can do no more than give warning of A.I. radiation on a given
bearing, and range of the source of the radiation cannot be
measured; a bearing reading would, however, at least indicate
the probability of an enemy night fighter in pursuit.
HOMING EQUIPMENT.
The Naxos as an A.I. Instrument.
93. Since the first mention of Naxos by a prisoner in July
1944 (A.D.I.(K) 407/1944) and in the subsequent fuller account
of other aspects of Naxos and its tactical use (A.D.I.(K) 508
and 620/1944) it has frequently been reported how some night
fighter pilots have claimed to have used Naxos as an A.I.
instrument. There have been frequent claims usually by
lecturers at Werneuchen, that night fighter crews have shot
down four-engined bombers with their upward armament without
having used SN 2 at any time during the pursuit, but no
prisoner has been encountered with first-hand knowledge of
this fact.
94. Amongst the present P/W was a crew of 4/N.J.G.2 who had
six victories, each with the help of Naxos to a greater or
lesser extent. On five occasions they had located the bomber
stream with Naxos and had made the final approach with SN 2.
On the sixth occasion, however, they had shot down a fourengined
bomber with upward armament after an approach with the
sole use of Naxos.
95. In an attack on Berlin in March or April 1944, this crew
took off from Twente and flew towards the Baltic coast. At
about 54° 30' N; 11° 30' E some eight H2S contacts were
obtained from a height of 4,500 metres; one of these was
selected by manipulation of the Naxos brilliancy knob and
followed to about 13° E and then southward over Berlin.
96. The contact was held and followed from Berlin towards
Leipzig whilst the night fighter gradually approached its
target by making contact with the edge of the H2S cone,
throttling back to avoid penetrating too far and being
detected, then climbing and again making contact with the cone
in horizontal flight; a visual of the R.A.F. bomber was
obtained near Frankfurt-am-Main when the night fighter was at
a height of 7,800 metres.
97. The pilot closed in to make the attack but missed the
bomber; after a second unsuccessful attempt, the rear gunner
of the bomber fired a burst but missed. On the third attempt
by the night fighter the bomber was hit and was claimed as a
victory by this crew.
98. Early in October H2S contacts in the Naxos began to be
fewer, and such contacts as were made invariably disappeared
abruptly. The pilot who, incidentally, had a very high opinion
of his own capabilities, put this down to his radar operator
and blamed him for inefficiency; the result was that the crew
was continually quarrelling and was engaged in heated argument
when shot down.

The Naxos Aerial.
99. The radar mechanic had been with I/N.J.G.4 had attended a
Naxos course at Werneuchen in May 1944 and subsequently had
had some experience in servicing the apparatus. The
interrogation of this P/W on the subject of Naxos was carried
out with the co-operation A.I.2(g), with the result that he
was able to add some useful details to the substance of
A.I.2(g) Report No.1734.
100. In August 1944, Naxos began to be delivered to
1/N.J.G.4. The Naxos-equipped Ju.88’s first delivered to the
unit had the aerials installed on the after part of the
fuselage, but in later deliveries, the plexiglass dome
containing the aerials was fitted to the jettisonable hood of
the cabin – a position known as "Ausführung A". It was feared,
however, that the hood would be difficult to jettison and in
some aircraft the original position of the aerials was again
adopted.
101. When this P/W left I/N.J.G.4 in October 1944 the display
unit in use was the Naxos-Post, but he did not know which type
of aerial array was associated with this display, and he knew
of no further designation of any part of the equipment.
102. When Naxos was first introduced to the unit, the aerials
consisted of two plastic rods, of a material known as
Trollitul, of square cross-section with rounded ends and
measuring some 40 cm. in length and 5/6 cm in thickness. This
type of rod was, however later superseded by one of circular
cross-section with a diameter of 3-4 cm. and of the same
length.
103. These aerials were fixed parallel to one another and
about 3 - 4 cm, apart, being held in position at their central
points by a bakelite clamp made in two halves. Rotation of the
aerials was in a clockwise direction about an axis which was
vertical when the aircraft was in flying position, the aerials
cleared the aircraft skin by about 5 cm. Speed of rotation was
estimated by P/W at about 3000 r.p.m.
104. The aerials were mounted on a vertical axle running in a
ball Bearing flush with the aircraft skin and driven directly
from an electric motor which P/W recognised as being similar
to that illustrated in A.I.2(g)1734.
105. A copper lead came away from each plastic aerial rod and
joined the axle on which the aerial rotated; between the ball
bearing and the electric motor, a right-angle plug led the
signals received by aerial out of the axle and through a length
of single 1 mm. copper high tension wire to the Abgleichkasten
(cable matching box). P/W had also heard the term "Hochpass
Einrichtung" in connection with this box.
106. The cable matching box was shaped in cross-section like
a half ellipse and measured about 25 x 8 x 8 cm. The screws
securing the lids were sealed, and if any fault developed, the
box had to be sent away to the Gruppe repair and servicing
depot; the Staffel servicing staff were forbidden to break the
seals.
107. This P/W had seen a box open at the Gruppe at the
servicing depot and remembered that it contained a special
type of coil and detector of a type similar to that shown in
the A.I.2(g) Report. He was under the impression that there
were six such detectors.

Daily Inspection of Naxos.
108. The daily inspection of Naxos consisted of running up
the aerial array on ground batteries and using an ordinary
buzzer working from a torch battery as the transmitter. The
oblong box containing the buzzer had to be held so that one of
its ends, called the Strahlenseite (radiating end) pointed
towards the aerial and was in their plane of rotation. A
lightening of the appropriate part of the Naxos trace showed
that Naxos was in order.

AIRBORNE PLOTTING TABLE.
109. In the autumn of 1942 one at the present P/W had taken
part in some flying trials of a television device which was
being tried out at Werneuchen. For the purpose of the trials a
television receiver which was to repeat an 18 cm. square
picture of the Seeburg Tisch of a night fighter box, was
installed in a He.111.
110. In the trials reception was remarkably good and a clear
definition was obtained, the two spots of light representing
the friendly and enemy aircraft could be seen, but the only
means of distinguishing between the two was by the insertion
of a cardboard arrow on the Seeburg Tisch. In a similar way
cards bearing written vector instructions were placed on the
plotting table in view of the camera.
111. At that time the Germans were experiencing no
difficulties with box-control of night fighters and since
continual troubles were experienced with the television
transmitter the trials were discontinued toward the end of
1942.

GERMAN H2S - THE BERLIN GERÄT.
112. The same prisoner had heard of a German version of the
H2S called "Berlin" which he understood, was an improvement on
the British apparatus.

GERMAN KNOWLEDGE OF 100 GROUP R.A.F.
Activities.
113. In lectures on night fighting given to 8/N.J.G.1,
7/N.J.G.2 and 9/N.J.G.3 in October and November 1944, crews
had been given some details of the activities by 100 Group
R.A.F. which gave them the impression that the German Higher
Command has the greatest respect for the efficiency of those
responsible for planning that unit's activities. Some details
of these lecturers which prisoners from the above units could
remember show that the Germans are now accumulating
considerable knowledge of the equipment and tactics of 100
Group.
114. At recent briefings to 8/N.J.G.1 great importance had
been attached to the part played by 100 Group, and the many
occasions when warning of an impending attack had been given
and the aircraft had been airborne only to find the advertised
raid melt away, were now ascribed to the wizardry of that same
unit.
115. It was stated that the Group is equipped with Mosquitoes
and Lancasters - amongst whose crews were some expert bombers
- and that both these aircraft types carry the jamming
equipment which together with ground jammers upset the
commentaries and the SN 2. Long range intruders were also
ascribed to the same unit.
116. In a lecture on 100 Group given to 7/N.J.G.2 early in
November 1944, crews were told of so-called 'D' aircraft which
has the duty of putting out spoof R/T and W/T instructions to
German night fighters; one instance was related in which a
whole night fighter Gruppe had returned to base as a result of
spoof orders by one of these D aircraft. The W/T operators at
the 1ecture were advised that if they paid sharp attention to
their R/T and W/T signals they would be able to distinguish
between the false and genuine instructions.
117. It is now widely known by G.A.F. night fighter aircrew
that Mosquitos are equipped with a search equipment, the
Grille (= grid), that has a range of 15 kilometres (about 10
miles) and is said to work on a frequency of 3 cm. An
interesting extra piece of information given in these lectures
was that Grille was capable of homing on SN 2 transmissions, a
point that was noted by crews with some consternation.
A.D.I.(K) and S.D. Felkin
U.S. Air Interrogation. Wing Commander
27th January 1945"

[Bruce Dennis]

"SECRET A.D.I.(K) Report No.151/1944
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W
AS THE STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO
MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY
INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.

UNDERGROUND FACTORIES - NIEDERSACHSWERFEN AREA
(July 1944)
1. The following information on underground factories in the
Niedersachswerfen area was obtained from the Dutchman, who was
the subject of A.P/W.I.U. (2nd T.A.F.) 3/1945. Representatives
of A.I.2(a) and A.C.I.U. were present at the interrogation and
due thanks are rendered for their co-operation.
2. According to informant's story he began to work for the
Germans in January 1942, when he was employed as a labourer by
the 0.T. in connection with the electrical installations on
Lorient airfield. Thanks to diligent work, spare-time study,
judicious bribery and his self-assertive nature, he claims to
have risen rapidly in the world and to have acquired something
of a reputation both as an electrical engineer and as a reliable
satellite of the Germans.
3. After working as a foreman electrician on the Dutch coastal
defence works between Flushing and Den Helder, he was given the
task of supervising the installation of electrical equipment at
the Vught concentration camp. Finally, he asserts that at the
beginning of 1944 he obtained employment on the staff of S.S.
Gruppenführer und Generalleutnant der Waffen S.S. Dr. Ing
Kammler (see A.D.I.(K) 522/1944), who was entrusted with the
task of constructing important secret underground aircraft and
armament factories.
4. According to informant's account, Kammler placed him in
charge of the Abteilung Energieversorgung of Amt C.III of his
staff, which was charged with supervising the provision of
electric power to underground factories in course of
construction under the aegis of the S.S.
5. In this capacity, informant stated that in June 1944 he was
sent to Niedersachswerfen to arrange for the provision of
electric current to a number of underground sites which the S.S.
proposed to construct in the area, but at the end of six weeks
he was called away to undertake similar work at other projects
at Litomerice (Leitmeritz), Czechoslovakia, which will be dealt
with in a separate report.
6. It was apparently intended that he should return to Niedersachswerfen
on 1st December 1944 but before that date he had
decided, for motives best known to himself, to desert the S.S.,
and in due course he arrived inside the Allied lines.
7. As the well-known underground factory at Niedersachswerfen
itself was already working at the time of informant's visit, it
did not fall within his province and he only entered it on one
occasion. His information on this factory was therefore
disappointingly meagre, but he was able to make some general
remarks on the Niedersachswerfen complex as a whole which,
although based on impressions gathered during a short stay,
sound reasonably plausible.
8. As regards the function of the already native
Niedersachswerfen plant informant could not enlarge upon
existing knowledge. He was aware that Junkers were installed and
thought they were making "the turbine for the V.1 and V.2".
General.
9. According to informant, no less than seven underground
factories were projected by the S.S. in the Niedersachswerfen
area, and the project as a whole was known as Bauvorhaben X.
10. These sites comprised the already active factory at
Niedersachswerfen, the Woffleben site which was numbered B.3.
and on which construction work had already started by Ju1y 1944,
another site some 800 yards to the North West of the Woffleben
one to which the code name "Nie" had been allotted, and four
other projected sites numbered B.8, 3.9, B.11 and B.12 of which
informant pinpointed two.
11. It was pointed out that the letter 'B' stood for
Bauvorhaben and that in theory the number indicated the original
order of priority in which it was intended that construction
work should be undertaken.
12. Informant stated that all seven sites in the area were
destined to be occupied by Junkers and that all the plans were
drawn up by Ing. Spott, the chief construction engineer of the
parent Junkers works at Dessau. The factories, however, formed
independent units in that there were no underground connections
between the various sites.
13. The scheme was carried out under the supervision of S.S.
Sonderinspektion II, who were responsible for the provision of
labour and materials and, of course, security precautions, but
the actual construction work was in charge of the "Wifo"
organisation, a fact which may explain rumours which have
connected the Niedersachswerfen project with P.O.L. storage and
or production.
14. The S.S., however, provided technicians to assist in the
construction cork and they also installed their own agents, such
as informant, in order to exercise a general supervision and to
keep an eye on developments. There was said to be continual
friction between Junkers, who desired the best possible
standards of accommodation, and the S.S., who insisted that the
utmost economy must be exercised in every respect.
15. According to the planned schedule, the six new factories
were to be ready for occupation by February 1945 but in
informant's opinion they would not be able commence work before
July at the earliest, chiefly owing to the difficulty of
obtaining transformers.
16. In July 1944 the original Niedersachswerfen factory was of
course in operation, and construction work had started at
Woffleben, where informant thought that work had begun on two
tunnels, and possibly also at the site 800 yards to the North
West of Woffleben.
17. In August 1944 the underground sites at Litomerice were
given priority over the projects of the Niedersachswerfen area,
but informant did not know whether this was on account of the
urgency of the activity to be accommodated at Litomerice or
because of the greater rapidity with which these latter
projects, which largely occupied existing workings, could be
pushed forward.
Niedersachswerfen.
18. As P/W had only been inside the Niedersachswerfen complex
on one occasion he could only give a very general and not
particularly reliable impression of its internal layout. He
confirmed a previous informant's statement that the workings
consisted of two main tunnels serving a number of workshops, but
thought that the workings, though quite level, were not
straight, and that the standard gauge railway line did not run
into the tunnels.
19. He had noted that the entrances were strengthened with
concrete reinforced by railway metals, and that inside the
galleries weak places were also reinforced with concrete for
distances of up to 100 metres in some cases. He could make no
statement on overburden.
20. Informant believed that in the floor of the galleries there
were a drainage channel one metre wide and another channel 75
cm. wide for the piping of the air conditioning system. Some of
the power cables were installed in third channel in the floor
and others, together with the wires for the lighting and the
telephone cables, were carried on iron supports along the walls
of the galleries.
21. Informant believed that a power supply of 600 kW was
required to run the air conditioning plant and that the capacity
of the Niedersachswerfen stand-by plant was insufficient for
this. He therefore believed that, if normal supplies could be
cut off, the air conditioning system would necessarily cease to
function and that the galleries would start to drip, with
disastrous results to the virtually irreplaceable machine tools.
Woffleben. (B.3).
22. In July 1944 the Woffleben site enjoyed the highest
priority of the six new projects envisaged in the Niedersachswerfen
area. At this date two entrances giving access to two
parallel main tunnels running roughly N.W. - S.E. through the
hill were said to have been started, and several subsidiary
galleries running off the main tunnels had also been commenced.
It was believed that considerable difficulty was being met with
on this project owing to underground springs and streams
encountered in the course of the excavations.
23. It was believed that when construction work was completed
the site would be taken over by Junkers for the manufacture of
aero-engines.

Woffleben West ("Nie").
24 The project 800 yards North West of the Woffleben workings
and designated by the code name "Nie" was the last of the
Niedersachswerfen sites on the official priority list but,
strangely enough in July 1944 it was the only site besides
Woffleben on which construction activity appeared likely to
begin in the immediate future.
25. One entrance only was planned, and this was to be located
at the south-western corner of the hill. This entrance was to
give access to the main tunnels running the length of the hill,
and these tunnels were to be connected by a network of some 40
or 50 cross-galleries. A servicing gallery was to run round the
whole site in order to facilitate transport; the workshops were
to be arranged to give a production flow running northwards from
the entrance, the finished articles being collected at the
northern end of the site and brought round to the entrance by
the servicing gallery.
26. This factory also was earmarked for Junkers, but informant
had no reliable information as to the purpose for which it would
be utilised. In July 1944 instructions were given to extend the
existing power cables as far as this site, so that construction
work could be commenced.

Ilfeld.
27. Besides the above-mentioned sites, another underground
Junkers factory was planned in the hills a short distance to the
West of the village of Ilfeld some two miles North of
Niedersachswerfen. The entrance was to be in the vicinity of
110360 GSGS 4416 Sheet Q5, and this was to serve a complex of
galleries arranged on the conventional grid pattern. In July
1944 construction work had not begun but a small group of
contractors' huts had been put up near the proposed entrance.

Appenrode.
28. Although informant knew that a total of seven underground
factories was envisaged, the only other projected site which he
was able to identify was in a hill between the villages of
Appenrode and Ilfeld and to the North of the road connecting the
two. It was understood that the entrance would be located in the
neighbourhood of 087361.
29. In July 1944 two contractors' huts had been put up on the
site but at that date construction work had not been started and
power cables had not been brought up to the area.

Power Supplies.
30. Informant alleged that in July 1944 all power supplies both
for the already active Niedersachswerfen factory and for
construction work at the other sites was supplied exclusively by
the 110 kV line from the Bleicherode power station. At the new
sites the 110 kV line was to be led directly into the tunnels
and the transformers intended to serve the factory machinery
were to be installed inside the workings, and informant
understood that this system was already obtained at the

Niedersachswerfen factory.
31. It was intended that when other sites came into operation,
power would also be supplied by a new 110 kV line running from a
power station at Frose in the Magdeburg area to Woffleben, where
it would join the grid serving the underground factories in the
Niedersachswerfen district. As in the case of the existing line
from Bleicherode, the power was to be stepped down in the
Niedersachswerfen complexes to 20 kV and 6 kV in the first
instance.
32. According to informant's story, the power stations at
Bleicherode and Frose would therefore be the sole sources of
electricity supplies for the underground plants around
Niedersachswerfen. He explained that it was not intended to draw
on other sources partly on account of the load already carried
by other power stations and partly because of the acute shortage
of materials needed for the construction of transmission lines
which made it necessary to rely on generating stations located
reasonably near the factories.
33. The new line from Frose was said to be intended to run
South-West across country from Frose for about one third of its
length and thence almost due West to Woffleben. The most direct
route was chosen in order to effect the greatest possible
economies in cables and pylon.
34. In July 1944 the holes for the pylons had been excavated
and sufficient pylons were on hand at the Frose and for
completing about one quarter of the proposed line. In the
following month, however, some of those pylons were
requisitioned for the Litomerice projects, which in the meantime
had been given a higher priority, and some of the new pylons on
order were also later diverted to Litomerice.
35. The contract for supplying the pylons was held by the firm
of Seidl of Falkenstein (Vogland) who were said to be able to
deliver three daily.

Emergency Power Supplies.
36. Unfortunately informant did not claim to be conversant with
the emergency power supply system in the Niedersachswerfen
complex. He stated, however, that he understood that it
conformed to the general instructions on the subject issued by
Generalleutnant Kammler on 1st August 1944, and he had the
foresight to bring with him a photostat copy of the document in
question.
37. In his instructions Kammler draws the attention of his
Sonderinspektionen and S.S. Führungsstäbe to the fact that the
emergency power plants proposed by these bodies are of
excessively high capacity. He adds that as a measure of fuel
economy emergency plants are only to serve such appliances as
necessary for the safety of the personnel, i.e. lighting, water
supplies end air conditioning.
38. The two last-named systems are to be confined to the
absolutely necessary minimum and Kammler formally forbids the
connection of any normal equipment to emergency generators.
39. Future demands for emergency sets are to show the capacity
of the act divided into the requirements for lightening, water
supplies and air conditioning. The projected requirements for
lightning are to be cut down to the necessary minimum since, if
the normal supplies of power fail, normal activity will cease
ipso facto. For the same reason, good grounds are to be shown
for the maintenance of air conditioning and water supplies
during the period when normal power is cut off.

Railway Services.
40. The plans for the Niedersachswerfen complex of underground
factories provided for a now ring railway connecting E11rich,
Ilfeld and Nordhausen and serving the whole of the sites. For
the convenience of workers proceeding between their quarters and
their place of work as well as between the various factories, a
train was to be run every three minutes on this line.
41. In addition, a large marshalling yard was envisaged on both
sides of the village of Woffleben and on both sides of the
existing Nordhausen - Ellrich line.

Personnel.
42. Appendix I contains a list of some of the principal personalities
connected with the Niedersachswerfen complex of sites.
Construction work at Woffleben was being carried out by inmates
of the Buchenwald concentration camp under the supervision of
"Wifo" personnel.
43. When all the factories were in operation it was expected
that they would employ a total staff of some 45,000 workers. In
July 1944 some personnel was already billeted in Ellrich and
Nordhausen and it was rumoured that when the various sites came
into production these towns and the area surrounding them would
be evacuated to provide accommodation, especially for married
employees and their families.
A.D.I(K) and S.D. Felkin
U.S. Air Interrogation. Wing Commander
5th February, 1945.

APPENDIX. SECRET.
PERSONALITIES CONNECTED WITH UNDERGROUND ACTIVITY IN THE
NIEDERSACHSWERFEN AREA
S.S. Gruppenführer und Generalleutnant der Waffen S.S. Dr. Ing.
H. Kammler.
Entrusted by Himmler, in his capacity as the head of the
S.S. Wirtschaftsverwaltungs Hauptamt, with the execution of
the Deutsches Geheimbauprogramm, which comprised important
secret underground factories.
Head of the so-called Stab Kammler which was created for
this purpose (see A.D.I.(K) 522/1944).
S.S. Hauptsturmführer Dipl. Ing. Geissen.
Head of S.S. Sonderinspektion II, which was charged with
the supervision of construction work on the sites in the
Niedersachswerfen area.
S.S. Sturmbannführer Fleto.
Head of Amt C.III (Technische Fachgebiete) of the Stab
Kammler and in this capacity in charge of the technical
side of construction work.
Sturmbannführer Skowronneck.
Head of the Abteilung Maschinen of Amt C.III of the Stab
Kammler. A subordinate of Flote and responsible for the
provision of the necessary machinery.
Major Regierungsbaurat Dr. Dr. Ing. Trautvetter.
In charge of the section of the S.S. Wirtschaftsverwaltungs
Hauptamt responsible for the provision of materials.
Dr. Neu.
"Wifo" representative in charge of construction work in the
Niedersachswerfen district.
Ing. Schwatz.
Chief "Wifo" engineer at Niedersachswerfen.
Ing. Reinzhagen.
"Wifo" engineer in charge of the electric,
gas, heating and air conditioning equipment.
at Niedersachswerfen.
Ing. Spott.
Chief Junkers constructional engineer. Responsible for the
plans for all the Niedersachswerfen sites.
Dipl. Ing. Pönitsch.
Junkers constructional engineer responsible for
electricity, gas and similar supplies."

[Bruce Dennis]

"SECRET A.D.I.(K) Report No.157/1945
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W
AS THE STATEMENTS HAVE NOT AS YET BEEN VERIFIED, NO
MENTION OF THEM SHOULD BE MADE IN INTELLIGENCE
SUMMARIES OF COMMANDS OR LOWER FORMATIONS, NOR SHOULD
THEY BE ACCEPTED UNTIL COMMENTED ON AIR MINISTRY
INTELLIGENCE SUMMARIES OR SPECIAL COMMUNICATIONS.


LUFTWAFFE MORALE.
(August to December 1944)
1. This report is an endeavour to assess and analyse
Luftwaffe aircrew morale in the period of five months from
17th August 1944, on which date a similar assessment was made
in A.D.I.(K) 473/1944. The number of aircrew prisoners
interrogated for the present review, amounting to 246,
comprises the largest sample since 1940.
2. The majority of these prisoners have been tough and well
drilled in security; at no point did the proportion with high
morale fall lower than 51% and, as may be expected, the period
when it reached this lowest ebb was during the German
withdrawal in August. Since then, the proportion of high
morale amongst all aircrew has risen steadily until, in
December, it was found to stand at 64%, with day fighters even
higher at 74%.
3. It should be noted that the present report deals
throughout solely with aircrew morale and that ground
personnel are not taken into account. The morale of the ground
personnel, judging from recent samples, is just the same as it
has been for a long time – bad.


THE BASIS OF MORALE.
4. The basis of G.A.F. morale remains very much the same as
before, and can be said to consist of a mixture of the
following factors: the natural discipline of nearly all
Germans, youth, love of flying, patriotism and a general
ignorance of the real facts of the war. It is true that
aircrew have very few amusements and almost no time off, but
they continue to live fairly well; in fact, better than any
other section of the population. They experience no hardship
comparable to that of the front-line soldier, and they receive
on the whole less bombing than either the army or the
civilians.
5. Expectations and promises for the future play a large part
in maintaining morale and still continue to be believed. As
one fighter-pilot said: "In the autumn we were guaranteed
2,000 new fighters. They have turned up, and this makes me
prepared to believe that the other new weapons and aircraft
promised will also turn up". However small the "come back" of
the Luftwaffe might seem to the Allies, it has helped the
ordinary German pilot to believe that the inventors and
technicians still have the situation in hand. The promise of
large numbers of jet aircraft for the spring has had the same
effect.
6. Many, though a decreasing number, of the younger P/W still
profess belief in ultimate German victory, a belief which is
quite unconnected with any logical process of thought
whatever, but depends on what can only be termed as mystic
belief in German invincibility. This faith is no doubt
fostered by the good fight they are putting up in spite of the
enormous difficulties caused by bombing and the shortage of so
many necessities inside Germany.
7. It cannot be said there is much desperation in their
courage. Rather is it a quiet resignation to the fact that
they have no alternative to fighting on. Certainly the impetus
derived from fighting on German soil against unconditional
surrender helps to counteract strain and war weariness; but
although attempts have been wade by German propaganda to
instil a kind of "Battle of Britain" spirit, it is doubtful
whether it has succeeded.
8. One of the smaller props to morale has gradually been
upset. When the Luftwaffe was in its prime, outstanding aces
were carefully built up as heroic types, an example to others.
This hero-worship, to which the Germans are so addicted, was
encouraged to what we would consider an inordinate degree. But
by now most of the aces have been killed and others, like G
GALLAND and PELZ, no longer fly on operations and are even
accused of becoming out of touch with the operational
personnel. At the same time the camaraderie between officers
and men has become less.
9. The new appeal is based more on staple patriotism and fear
of the consequences of defeat. A frequent propaganda theme is:
"Life will not be worth living after the war". The horrific
picture of a conquered Germany, easily concocted by GOEBBELS
from unofficial Allied pronouncements, is well calculated to
make men fight to the bitter end.
10. Much greater than fear of defeat at the hands of Britain
and America is dread of Russia. "Sieg oder Sibirien" - Victory
or slavery in Siberia, is a slogan which has a considerable
effect, an effect not unconnected with a sense of guilt for
what Germany has done above all to the populations in the
East. Manly realise that such wrongs avenge themselves, but
nevertheless justify their conduct by persuading themselves
that they are upholding a higher civilisation.
11. Among aircrew less resentment of our bombing policy is
felt than might be expected. The destruction of so much of
both private and public property and fine cities, however, not
to mention the casualties involved, helps to foster a certain
feeling of futility about the future, and even a wish to
escape it. Thus in some ways continued resistance is a
putting-off of an evil day - with the small, but to them
worthwhile chance that the Allies might quarrel, the German
technicians produce a trump, and defeat might be avoided in a
triumph of defensive warfare.


A STATISTICAL ANALYSIS OF MORALE.
12. The three tables presented below show morale at time of
capture; the assessments are those made by the original
interrogators on the Continent, and differ slightly - almost
always for the better - from the assessments given at the end
of A.D.I.(K) reports in which allowance is not always made for
the weaknesses which develop under prolonged interrogation and
in the isolation of theme from the sustaining effect of his
group.
(a) Period August – November 1944.
August Morale.
Type of Unit. No. of P/W High. Fair. Low.
Bomber 22 12=55% 6=27% 4=18%
Day Fighter 14 6=42% 6=42% 2=16%
Others 7 4 -
Total 43 22=51% 15=35% 6=14%
Average age - 23.3 years.
September - November Morale.
Type of Unit. No. of P/W High. Fair. Low.
Bomber and
transport 18
+
11=61% 2=11% 5=28%
Day Fighter 10 7=70% 2=20% 1=10%
Night Fighter
and N.S.G. 15 8=54% 2=13% 5=33%
Others 2 2 - -
Total 45 28=62% 6=13.5% 11=24.5%
Average age - 23.3 years.
+ This figure includes the only bomber crew captured
between 16th August and 18th December; this crew comprised
the three survivors of a V-1 launching He.111 which
ditched in the North Sea on 6th October.
Notes on the above Tables.
(1) Even in the catastrophic days of August, 51% of the
Luftwaffe aircrew captured showed good morale, and of the
rest 35% could be said to have fair morale.
2) Although the sample is too small to be satisfactory,
it is perhaps significant that the morale of the crews of
heavy aircraft retrained steadier than that of the fighter
pilots which, however, recovered more quickly.
(3) The absence of any marked defeatism in the Luftwaffe
directly after the attempted Putsch of 20th July and the
catastrophe in France indicates the extent to which its
personnel are imbued not only with a sound fighting spirit
but with esprit de corps. Though of an age which has only
known a Nazi upbringing, flying personnel of the G.A.F. are
not very politically minded. Loyalty to the regime which has
done them personally no apparent harm, and which has often
benefited them, is strong, as there is no substantial
alternative.
(4) The fact that there was a virtual debacle in the air
at the same time certainly had a depressing effect, but
there was always the excuse of overwhelming superiority on
the Allied side. Furthermore, promises were made that a
great new fighter force would be formed and a new training,
programme was put in motion. It was believed by many that
the new jet-propelled aircraft would enable the Luftwaffe to
make a startling come-back with qualitative superiority. In
fact the 0.K.L. reacted to the new situation with vigour
which gave a new hope to a depressed but eager-body of young
airmen; whose mental horizon is as limited by flying as it
is by propaganda and education.
(b) Period December 1st 1944 - January 1st 1945.
14. By the end of November 1944 it seems that the German Air
Staff considered that the Luftwaffe had been sufficiently
nursed back to health to be employed on a large scale in
tactical support of the Army. At the same time, in the absence
of an adequate bombing force, night-fighters were sent in
considerable numbers in an attempt to cause dislocation over
the Allied lines at night. The result has been the largest
batch of aircrew prisoners, since the Battle of Britain.
15. The morale of the 158 P/W, assessed as before at time of
capture, is analysed as follows:-
State of morale
Type of unit N° of
P/W
High Fair Low Average
Age
Day Fighter 80 59=74,5% 14=17% 7=9% 22.9yrs
Night Fighter 54 28=52% 19=35% 7=13%
Others, incl.
Bombers,transport
and recce crews
24 14=58% 8=33.5% 2=8.5% 23.2yrs
Total 158 101=64.6% 41=26.5% 16=10% 23.0yrs
Notes on the above Table
(1) The over-all improvement in morale seems very slight
against the previous three months. This steadiness is in
contrast to the fluctuation noticed in 1943 during the same
period, i.e. between the low point reached with the
landings in Italy and the defection of BADOGLIO, and the
recovery connected with the bogging-down in Italy and the
beginning of reprisal raids on England. Unfortunately the
method of assessment was not identical with the present one
and the samples much smaller but it is interesting to note
that in the period September to mid-November 1943 the
percentages of high, fair and low morale were found to be
61% 31% and 5%, while in the period mid-November to January
1944 they were 83%, 17% and nil.
(2) The only marked improvement is among day fighter
pilots, whose morale has jumped from 42% high in August to
74% high in December. This has been due (a) to careful
husbanding of strength for a big effort. (b) the
maintenance of the fighter aircraft industry in spite of
Allied bombing and (c) the successful defence of the
frontiers of the Reich.
(3) While these three factors also apply to the whole of
the Reich defence force, the morale of one branch, the
night-fighters, has noticeably declined although they are
better trained and more strictly selected, and not long ago
were the most steadily successful part of the Luftwaffe,
they show an inferior spirit to the day-fighters. One
reason for this is that they have an increasing sense of
frustration, caused by jarring of signals channels and
interception equipment and frequent failure owing to
"spoofery" to contact bombers at all. They also show a high
level of intelligence, which does not help morale. They may
fly blind, but they think less blindly about the war.
(4) The majority of these P/W were captured during the
RUNDSTEDT offensive and before they were plainly aware of
its failure. That it could be launched at all gave, a
certain fillip to morale.
(5) The fighter unit showing the most consistently good
morale is J.G.4, with J.G.2 coming second.
(6) It would be wrong to consider all those with morale
assessed as fair to be only fair fighting material. In a
unit with a high spirit - which applies to most - they
would be carried along with the majority, and would hardly
be aware themselves of the chinks in their armour.
(7) Fewer P/W are found to have listened to Allied
broadcast propaganda than at any time during the last 18
months. This is partly due to the fact that most are
fighter pilots, as opposed to bomber crews as in the past,
and live in less permanent quarters, and partly because
morale itself is higher.


THE EVENTUAL UNDERMINING OF MORALE.
16. Interrogators on the Continent who see P/W in the first
days after their capture have found them extremely tough
almost without exception. In so far as the time taken to break
down a man's security is an indication of his fighting spirit
and not of improved security instruction, morale is higher
than it has been for some time. It is, however, not so deeply
ingrained. P/W to-day are not only slightly younger than in
the past, but each time they come from a later age-group. This
means they are more unformed. Fewer are intelligent and more
are bone-headed, and the eventual undermining of security, and
later of morale, is made easier by this fact. With them
security is often merely an induced state with automatic
reactions rather than intelligent attempt to continue fighting
although a prisoner or war. Once it breaks they tend to talk
freely. This applies chiefly to N.C.O.'s and other ranks.
17. With most younger officers the basis of the high morale is
somewhat different. They attempt to explain their professed
faith in victory, which for them amounts to avoiding defeat,
on the score of superior fighting ability, V-weapons etc. But
they also tend to be less fact-proof and easier to reach with
argument, though only with much time and trouble. Older or
senior officers, who know more facts, are nearly always
prepared to admit that Germany has lost the war, but their
discipline and sense of responsibility clearly keeps them from
showing any defeatist spirit to the men under their command.
18. It is nevertheless startling to find how different is the
attitude of most P/W after a week or so of being moved from
place to place and being interrogated. During this time they
learn with their own eyes or from the people they meet a great
many unlightening facts and some truths; they have time to
reflect on the tremendous material superiority of the Allies
which they see behind our lines; if they happen to pass
through London, this especially brings home to them the
swindle of their own propaganda.
19. The young generation in Germany has so long been denied
the possibility of finding out the other man’s point of view
that when he gets the chance of doing so he frequently
discovers he cannot answer it. This is a weakness of which
interrogators have learnt to take advantage. If a patient and
serious attempt is made to open a P/W's eyes to the facts he
has been denied, for him the GOEBBELS machine begins to
operate in reverse.
20. This very susceptibility of Germans to propaganda might
suggest that their re-education after the war may not be so
difficult, but it should be remembered that the interrogators
achieve little more than a rather static "deconditioning and
with the assistance of depressing circumstances. Any eventual
"reconditioning" must depend on a new dynamic of ideals, and
social and political loyalties, which are at present all too
painfully absent.


CONCLUSION.
21. It would seem that since morale is not built on reason,
but on blind faith, loyalty and patriotism, it will only break
down when facts or a conflict of ideas, successfully undermine
the original basis. In so far as these destructive influences
operate at all in the field, the whole of German propaganda is
working, not unsuccessfully, to exclude them. As a result
aircrew on capture continue to show good fighting spirit.
22. Morale did not slump seriously during the disastrous days
of the summer, and does not become unduly depressed by failure
or heavy losses, or even as a result of land reverses. This
suggests the conclusion that taking flying personnel in the
Luftwaffe as a whole, morale will not break as long as they
have aircraft and petrol, the army continues to resist, and
they themselves are told to go on fighting.
A.D.I.(K)&
U.S. Air Interrogation. S.D. Felkin,
8th February 1945 Wing Commander"

[Bruce Dennis]

Originally Posted by Nick Beale

Agreed, would people like a dedicated "Researching the Luftwaffe through Prisoner Interrogations" thread?

Nick, I look forward to following whatever course you decide on.

For the record, within these P/W reports are references to 'captured documents': I hope everyone recognizes that this meant ULTRA or another sensitive source that could not be named at the time, hence my choice of the 'Using ULTRA...' thread for posting.

Bruce

[Bruce Dennis]

"SECRET A. D. I. (K) Report No. 357/1945.
THE FOLLOWING INFORMATION HAS BEEN OBTAINED FROM P/W. AS THE
STATEMENTS MADE HAVE NOT AS YET BEEN VERIFIED, NO MENTION OF THEM.
SHOULD BE MADE IN INTELLIGENCE SUMMARIES OF COMMANDS OR LOWER
FORMATIONS, NOR SHOULD THEY BE ACCEPTED AS FACTS UNTIL COMMENTED
ON IN AIR MINISTRY INTELLIGENCE SUMMARIES OR SPECIAL
COMMUNICATIONS.
RADIO AND RADAR EQUIPMENT IN THE LUFTWAFFE - II
Navigational Aids.
1. This report is the second of the series dealing with radio and radar equipment in the
Luftwaffe.
2. As in the case of the first of the series (A.D.I.(K) 343/1945) dealing with Blind Landing
and Airborne Communications Equipment, it is based on interrogation of General
Nachrichtenführer MARTINI, Director General of G.A.F. Signals, and a few important
members of his staff, and has been supported by a file of current papers which were in the
possession of the General’s Chief of Staff.
3. An index of the numerical designations of the navigational equipment mentioned in this
report appears in Appendix I.
4. For convenient reference, a translation of the document entitled "Funkausrüstung der
Flugzeugmuster, Notprogramm" (signal Equipment in the G.A.F. - Emergency Program) - item
45/99 ff in A.D.I.(K) Documents List 45/9 - which has also appeared as an Appendix to
A.D.I.(K) 343/1945, is reproduced as Appendix II to the present report but the list of equipment
contained in that document has been omitted as Appendix I gives a fuller list.
TRENDS OF DEVELOPMENT.
5. Throughout the course of the war, the general standard of German navigational training was
undoubtedly inferior to that of the Allies. A simple form of navigation was taught but
navigators track plotted only and relied on W/T aids and in particular positioning by means of
loop fixes as the main basis for their navigation.
6. During the early part of the war extensive use was made of Knickebein and other beam
systems, but later this form of navigational aid gave way to the "Y" control system (better
known by the Allied codeword Benito) and "Egon".
7. Sonne was universally accepted as an outstanding success and from the time of its inception
in 1942 research was continuously directed towards overcoming its imperfection, in particular
the range limitation. Komet was a typical example, of attempted improvement on these lines
8. The Germans were patently backward in the field of pulse systems and the majority - if not
all - of their navigational aids of this type were copied from Allied methods.
9. The fear of the Allied countermeasures was much to the fore during the last two years and
considerable research and efforts was devoted to offsetting such interference and to perfecting
systems which would reduce and if possible preclude the danger of jamming. Another factor
always present in the minds of those responsible for tactical navigational requirements was that
the apparatus must be as light and small as possible because of the limited space available in
German aircraft.
10. During the last stages of the war, and as a natural consequence of German air policy, being
forced to concentrate on the defensive, thereby involving almost exclusive use of fighter power,
a great deal of attention was devoted to the development of simple navigational aids suitable
for single-engine aircraft of which Rübezahl was a typical example.
D/F LOOP EQUIPMENT.
PeGe (Peil Gerät) 6.
11. PeGe 6 was the successor of PeGe 5, the standard loop D/F, set in use at the beginning of
the war, and. operated on 150 - 1200 kc/s (2000-250 meters). It provided automatic D/F
facilities, the W/T operator merely having to tune to the signal and the "answer" being produced
on a course indicator.
12. In the opinion of P/W, who was responsible for operational requirements in the
navigational field and who had had fairly extensive navigational experience with K.G.40,
PeGe 6 was less reliable than the manually-operated PeGe 5 as the automatic D/F facilities
could not distinguish between the true signal and jamming and were apt to record bearing midway
between the two if they were near together. The human ear was much more acute and
could distinguish the minimum of the real signal from that of the "phoney” one. It had the
further disadvantage that it was a heavier piece of equipment than the manually operated set.
FuGe 141
13. The FuGe 141 operating on a frequency band of 58.0 - 59.2 mc/s was a receiver with a D/F
loop fitted to Air Rescue aircraft used for homing on to the NS 4 emergency radio set carried on
the chest by pilots.
14. The NS 4 had a flexible steel tape aerial and batteries which gave it an endurance of 2 to
2,5 hours.
FuGe 142.
15. The FuGe 142 using the 2000 - 250 metre band was a small D/F battery set for use in
emergency in the event of failure of the aircraft' s electricity supply.
16. The FuGe 142 had a manually-operated loop and its accuracy was only 10° to 15°.
17. When the P/W who, in October 1944, took over the navigational tactical requirements first
made its acquaintance, he discovered that the designer of the emergency set, while having the
laudable object of assisting a crew in dire emergency when they where probably well and truly
lost, had omitted to include any sensing arrangement. The set was, therefore, quickly scrapped
as being as much of a danger as an aid.
FuGe 145
18. The FuGe 145 was a simple type of D/F set in development for use in single-seater aircraft.
It was for use with M/F beacons and was designed for use by coastal reconnaissance aircraft, as
for example the Do.335, so that they could obtain a bearing when flying at low level.
19. It was much lighter than the PeGe 6 and had no automatic facilities, but was very easy to
operate. P/W had thought that it might ultimately supersede the PeGe 6 for other types of
aircraft.
Suggested loop for fighter aircraft
20. The research centre at Rechlin had been asked to examine a rough type of loop for singleseater
fighter aircraft, which would consist of a loop built into the pilot' s helmet. It was thought
that this would enable the pilot to establish the general direction of a beacon by movements of
his head and without recourse to the use of a compass.
21. This idea was tried out and seemed promising, but was never fully developed.
HOMING BEACONS.
Schwanboje.
22. The Schwanboje was a waterborne V.H.F. beacon dropped by parachute and originally
used by K.G.40 for marking convoys or submarines. In the autumn of 1944 a 1ine of Schwan
buoys was used to aid the He.111's when launching V-1’s from the North Sea against this
country.
23. The beacon consisted of a frame aerial and transmitted on a wavelength which could be
homed on by the FuGe 17, the standard equipment of K.G.40 in 1942 when the Schwanboje
came into use.
24. The set was powered by accumulators and had a live of five hours; by the means of a
clockwork device it could be pre-set before release so that it ran for a testing period
immediately on release and later started up again after a prescribed interval governed by the
expected time of arrival of the homing aircraft. The buoy was fitted with a self-destroying
charge operated automatically.
25. A later type of Schwanboje operated on the 38 - 42 mc/s waveband so that aircraft
equipped with the FuGe 162 could also use the system.
Biene
26. Biene is the code word for a responder beacon. The idea of responder beacons for homing
purposes had only been hit on in 1944 and Bienen to respond to the different airborne radar sets
were still under development in 1945. The FuGe 243 - Hohentwiel Biene – had been used by
coastal units in Norway, in February or March 1945.
27. Responder beacons were also being developed for use in the Baldur method of navigation
(see paragraphs 79, 82 of this report).
BEAM SYSTEMS.
Zyklop.
28. This was the latest form of the well-known Knickebein working on 30 - 33,3 mc/s and
received by E.B.L.3 in the aircraft. It was a mobile station which could be fully erected into
operation within a week.
29. A still more mobile unit known as the Bock-Zyklop had been introduced. This could be set
up in three days and could be adapted for use on the FuGe 16 frequency although as yet,
according to documents, no visual indicator for the FuGe 16 had been developed.
30. The 120 W ground transmitter was called the ???? which gave a beam 0.5° wide and a
range of 300 km. at a height of 5,000 meters. The Zyklop systems had been made use of on the
Russian front up to the end of the hostilities.
Sonne.
31. The Sonne beacon system which worked on a frequency of 270 - 480 kc/s was received in
the aircraft on the FuGe 10. It was considered an extremely effective daylight system but the
range limitation was a disadvantage. Fixes could be obtained from ranges up to 1,000 - 1,200
km. Sonne 6 at Quimper which was the most efficient of the Sonne beacons, had been used on
an occasion at a distance of 1,400 km.
32. The sectors served by Sonne covered, an angle of 120 – 150°. The beacon was very reliable
over the centre sector of 100°, but the error increased progressively towards the edges of the
beam in conformity with the sine law.
33. At night errors up to 4° were liable to occur even in the centre of the sector of the beacon
and no real use could be made of it.
Mond.
34. To improve the Sonne beacons both in range, and accuracy, an experimental system
working on the same principle, but on 3000/6000 kc/s was tried out in 1942. The shorter wave
transmission did not prove very reliable and was given up about the end of 1943.
Stern.
35. Finally a beacon of the Sonne type under the name "Stern" was designed for use on a V.H.
frequency. It, not unnaturally, only gave optical range and was, therefore, of no practical value
and was not developed.
Dora.
36. One P/W had seen documentary mention of Dora which he believed was a navigational aid
system and a precursor of Komet. He did not know whether it worked on the same principle but
the Komet experimental site at Kolby was on the former Dora site.
Komet.
37. In 1942 the question of navigation over the Atlantic stood in the limelight . As the He 177
was supposed to be coming into service shortly to enable K.G.40 to reach further West, the
need for navigational equipment of longer range became acute.
38. A year or so earlier Professor von HANDEL had categorically stated in a lecture that a
long-range navigational system based on pulse would inevitably be extremely inaccurate.
In view of Professor von HANDEL's views on pulse systems, an improved form of Sonne
which would give much greater ranges and be less susceptible to night effect was given high
priority.
39. The system evolved was called "Komet" and experimental stations were erected at
Bordeaux and Kolby (see A.D.I.(K) 364/1944). The ground station called for an array of no less
than 127 masts and 19 control huts in order to cover a 90° sector. It worked admirably provided
a 10° sector only was covered, but as soon as the planned 90° sector was put into operation,
mutual interference between the masts arose and the various lobes radiated were no longer of
symmetrical pattern, with the result that large errors crept in.
40. Research on this delayed the project considerably. After the invasion when long distance
reconnaissance in the Atlantic was no longer practical politics, the Komet system was given up
without ever having been effectively used. The development people were the more pleased to
dispense with it since it left the German radio research and industry free to deal with other more
urgent matters.
41. The beacon was to operate on frequencies of 5000, 9000 or 12,000 kc/s received on the
FuGe 10K, and it was estimated that ranges up to 3000 km would be obtained. The system
employed was to be similar to that used in the Sonne but instead of obtaining one reading per
minute, oscillation of the beam was to be speeded up to give 100 readings par minute.
42. The true bearing of the aircraft was automatically recorded by the FuGe 124 which was
known as the Kometschreiber. The recording took the form of a series of vertical lines, one for
each reading, printed on a strip of paper. At the same time as the lines were printed the
Kometschreiber recorded the section of the swept area in which the aircraft was flying, thus
giving what amounted to a rough position.
43. The fine reading was obtained from the length of the recorded lines. Any inaccuracies due
to night effect could be easily eliminated by averaging the length of the lines, as recorded, on
the paper strip, by eye.
Erika.
44. Erika was a navigation system (see A.D.I.(K) 364 and 409/1944.) which had already
reached the development stage in 1942 but its operational employment was of brief duration
and it was soon discarded in favour of Bernhard.
45. Erika was based on the principle of a V.H.F. (30 - 33 mc/s) beam oscillating rapidly over a
segment of about 60 – 90°. The beam was phased, a different phase being picked up in different
sections of the segment and read off in relation to a standard phase producer in the aircraft. In
order to obtain a fix, two such Erika stations had to be received and to receive each station no
less than two E.B.L.3's were necessary making a total of four receivers.
46. The range presentation unit in the aircraft, FuGe 121, took the form of a clock-face with a
needle indicator and calibrated, P/W thought, from 0 -100. A specially prepared map was
required to establish bearing.
47. A disadvantage of Erika was the vulnerability to jamming, interference signals modifying
the phase and thereby giving inaccurate readings. The great weight, carried and the bulk of the
four receivers, which were particularly cumbersome in the relatively small aircraft in use in the
G.A.F. made its widespread use impracticable.
Bernhardine.
48. This system was first introduced in 1942 for use by bomber aircraft, but was later dropped
in favour of the Benito and Egon control systems. With the increasing British jamming during
night raids it was reintroduced for use in night fighter commentary (see A.D.I.(K) 125/1945,
paras.5 to 29), which it was thought could only be jammed with great difficulty.
49. The term “Bernhard” was used for the ground stations whilst the airborne recording
equipment was called Bernhardine or FuGe 120. The latter made use of the E.B.L.3. receiver as
the transmissions lay in the 30-33 mc/s band.
50. At the time of the German capitulation, the following three transmitting stations were in
operation, the first two, of which could transmit commentary.-
-Thisted, on N.W. coast of Denmark.
-Bretstedt, N. of Husum, Germany.
-Trebbin, S.E. of Berlin.
51. A further station near Breslau had been almost completed when it had to be dismantled on
account of the Russian advance. Additional stations were in the course of construction near
Kassel, Munich, Pilsen and Vienna.
52. The Bernhardine system was looked upon as a considerable improvement on Erika. It gave
360° coverage as compared to 60/90° with Erika and, whereas from the jamming aspect stray
signals could disturb the phase of Erika causing false indication, in the case of Bernhardine,
interference merely resulted in no reading being possible, and furthermore to attain this through
360° a very powerful jamming transmitter flying near the ground station would be needed.
53. The Bernhardine system was not regarded as unjammable but it was thought that use of
high power and aerial gain would render jamming by airborne means impracticable.
54. In addition to the E.B.L.3 receiver, the airborne Hellschreiber FuGe 120, also called the
Bernhardine, which gave both bearing and commentary was employed. According to P/W the
FuGe 120 was large and weighty and the first improvement aimed at was to reduce the weight
and provide a set which occupied less space in the aircraft. To this end an attempt was made to
eliminate the use of paper strip for the Hellschreiber and a rotating "Folienschreiber" a
cellophane paper moving over a sticky carbon surface which constituted a self-eraser - was
employed. This projected recording method proved a failure and the use of paper strip had to
be reverted to. According to documents the type using paper strip was known as FuGe 120a,
and the self-erasing recorder FuGe 120b.
55. A smaller model, the FuGe 120k, to operate on the paper strip principle which constituted
the latest improvement, was still in the development stage at the conclusion of hostilities.
Previously the ground transmitter broadcast simultaneously from the upper and lower aerial
arrays on two frequencies close enough to one another for them both to be received on one
channel of the E.B.L.3. One lobe was used for coarse D/F, the other for fine. The two
frequencies were then separated by a filter before being fed into the Hellschreiber. The FuGe
120k was designed for use with a ground transmitter operating only on the coarse D/F
frequency. The filter could therefore be dispensed with and considerable weight saved in the
airborne set at the expense of some accuracy in D/F.
56. With the loss of D/F accuracy the sharp “V” in the vertical printing indicating the reading
(see diagram A.D.I.(K) 125/1945 para.18) became a gap about 4° wide. To facilitate the
reading of the centre of the gap by eye, and to reduce the size and weight of the apparatus, the
vertical lines referred to above were superimposed on the scale which could then only be read
in the gap. This allowed the paper strip to be considerably narrower.
57. The FuGe 120k was designed primarily for use in single seat jet aircraft but was also to be
embodied in the Ju.88 where space was at a premium, as soon as sufficient numbers of this set
were available.
Hermine.
58. The Hermine system was originally developed, in response to a tactical requirement
formulated during the second part of 1942, as a navigational aid for the purpose of giving an
approximate bearing to single-engine night fighters engaged on “Wilde Sau” operations.
59. By the time the initial difficulties in development had been overcome Wilde Sau night
fighting had almost ceased; it was found however that Hermine could be used to advantage by
day fighters, and it came into operational use.
60. An accuracy of ±5° was assumed, but it was found in practice that this could be improved
upon to ±3° by experienced pilots.
61. Thirteen or fourteen ground stations were in operation by Easter 1945 which, P/W claimed,
gave complete coverage of the Reich. It was intended to fit two Schlechtwetter (bad weather)
Fighter Geschwader with the necessary airborne equipment, and this program had been onethird
completed by May 1945. One P/W had heard that ten to fifteen Me.262's of K.G.51 were
amongst the aircraft so equipped.
62. The following may be added in modification of the description of the Hermine system
given in A.D.I.(K) 125/1945, paras.59 to 62. The Hermine rotating beacon transmits a
continuous tone on which is superimposed a speaking clock which counts from 1 to 35, each
figure representing tens of degree. Over an angle of about 15° the continuous tone falls to a
minimum and rises again. During this period the voice appears to become more audible and the
pilot can estimate where the minimum of continuous tone occurs, and so obtain his bearing
from the beacon.
63. The beacon recognition is given by means of a self-evident code name for example,
"Berolina” for Berlin – which is spoken by the voice in place of 000°.
64. The airborne equipment is the FuGe 125 consisting of the E.B.L.3 with the Tzg
(Telephoniezusatzgerät) which enables the 30.0 - 33.3 mc/s transmission picked up on the
E.B.L.3 receiver to be heard in the pilot's headphones. Though the Hermine beacons were fully
operational there was a scarcity of FuGe 125 sets, as a result of which practical experience of
this system was too limited to judge of its efficiency or to lead to further improved tactical
requirements been formulated.
PULSE SYSTEM.
Ingolstadt
65. All the P/W had heard reference to Ingolstadt and agreed that it was a long-range
navigational system.
66. One P/W thought that Ingolstadt was the cover name for a pulse navigation system using
hyperbolic curves and similar to British Gee; it was originated by Telefunken in 1938 but was
then turned down by the R.L.M. In his recollection the original Telefunken idea derived from
theoretical discussions at an international conference before the war.
67. As mentioned earlier under the heading of Komet, Professor von HANDEL maintained that
owing to the incidence of mutual interference between direct and reflected waves the system
was impracticable at long range. In consequence of von HANDEL’s view the system was
dropped.
68. Much consternation and annoyance was occasioned in 1944, when it was found that the
Allies were successfully operating a similar system.
69. Truhe is the cover name used to describe navigational aid system, using ground stations,
similar to those of British Gee. In effect the British Gee stations were also used, the airborne
sets being almost identical with the British Gee boxes.
Truhe.
70. There is no very distinct difference between "Truhe" and "Hyperbel". The latter term was
originally coined to denote our Gee. It was also used when German aircraft equipped with
British Gee sets made use of British ground stations.
71. The British Gee chain was used successfully but it was realised that so soon as the
Germans lost an aircraft, over England, a change would be made. The German "Y" service
monitored the British ground stations to follow any change in Gee phasing and passed advice of
such change to their aircraft by W/T.
72. Truhe referred to the German system which was ultimately to cover the 20 to 100 mc/s
band and employed various types of ground transmitters including Feuerhilfe, Feuerstein,
Feuerzange and Feuerland. All these transmitters could also be used to jam our own Gee,
further details of which will appear in a subsequent report on German Radio Countermeasures.
The original 46 to 50 mc/s system was known as Truhe I and the new 30 to 60 mc/s system as
Truhe II.
73. A chain of Truhe stations was built around Berlin, primarily for training purposes and there
were in addition groups of ground stations in the Schwarzwald and in Pomerania. The last
named was intended for operations against Russia and it is not known if the stations were
destroyed before their capture.
74. The airborne sets which were known as FuGe 122 covering 46-50 mc/s and FuGe 123
covering 25-75 mc/s were replicas of the British Gee boxes and according to P/W were
equivalent to British R.1324 and R.1355. These German sets were slightly smaller and more
compact than the British sets.
75. Truhe was used by F.A.G.2 and K.G.66, but up to the time of capitulation only a few
FuGe 122 and FuGe 123 sets had been produced and only one R.F. box for the latter set.
Baldur.
76. The Baldur range-measuring system is comparable to the British G.H. and appears to have
been imitated from it. It was referred to by P/W as “Egon in reverse" and was the only
navigational system developed by the German by means of which an aircraft could measure
distance from a known source as opposed to fixing itself by a position line. As the G.A.F. staff
were still thinking in terms of a grandiose bomber policy as late as June 1944, it was intended
for use by bomber aircraft for pinpointing targets and for accurate blind bombing.
77. The wavelength employed was in the neighbourhood of 2-4 meters and fell in the SN 2
band.
78. Only two experimental transmitters, both located in Lower Silesia, were erected and one
P/W maintained that this system never progressed beyond experimental trials by the
manufacturers. It was eventually relegated to low priority owing to the virtual cessation of
German bomber operations and the pressure of more urgent demands on radio research and the
radio industry.
79. The airborne equipment was known as the FuGe 126 which was made up of a transmitter to
interrogate a ground responder beacon, a receiver and a presentation unit. The receiver and
transmitter were SN 2 units, though P/W thought they might have been slightly modified for
use with Baldur.
80. From documents, the presentation unit appears to have been a modification of the
Würzburg range measurement tube, and the accuracy is given as ± 100 meters at all ranges, but
this was thought to be purely theoretical and P/W doubted whether it would have been possible
to achieve this accuracy in actual practice.
81. A smaller airborne set, the FuGe 126k (k = klein = small) was built for use by single-seat
aircraft. In reducing the size and weight of the set, and making it pilot-operated, accuracy had
to be sacrificed. P/W, who was responsible for putting up the tactical requirements, considered
a clock-face presentation to be the ideal solution. It was expected that the accuracy of the
FuGe 126k would then be of the order of 500 meters independent of range.
Baldur - Truhe
82. It was planned to experiment on a combination of Baldur and Truhe (Gee) for use by
bombers. The intention was to use a hyperbolic grid line of Truhe for the target approach. This
could be pre-set, and the pilot could fly along it by keeping the blip centralised, and could
ascertain his exact position along the line by measuring his distance from a Baldur beacon. This
system was considered simpler particularly for a single-seater aircraft, than the method of using
two hyperbolic grid lines or two distances from Baldur beacons. The first experimental sets
were to be ready in the autumn of this year.
Baldur - Bernhardine
83. A further project was a combination of Baldur and Bernhardine to give simultaneous
bearing and range. The range indication was to be obtained by the pilot pressing a knob when
the range would appear in kilometres on a dial. This system was suggested for use by both day
fighters and bombers.
GROUND CONTROL SYSTEMS,
Benito.
84. The Benito system of control using FuGe 16, known to the Germans as "Y", is too well
known to warrant description. The following paragraphs deal with recent developments.
85. When operating the bomber Benito procedure with the narrow beam. (0.3°) essential for
azimuth accuracy, it was easy for the bomber pilot to get on to one of the side lobes in error
since these were only about 3° from the main beam.
86. In order to minimise the possibility of mistake and to relieve the pilot of the strain of flying
on a beam, an automatic device, the FuGe 28a, was in use which was the improved and final
form of the old Y-Gerät of 1941. Documents dated about June 1944 show that it was used in
conjunction with FuGe 17, but P/W thought that it had been modified for use with FuGe 16ZY
as well.
87. The procedure was that the bomber pilot flew on instructions conveyed over the FuGe 17
until it had been established by ground D/F stations that he was on the true beam, when the
code word "Bako" would be given whereupon the pilot would switch on the FuGe 28a which
took over control of the automatic pilot and kept him on the beam.
88. P/W gave the accuracy of range measurement with the Bomber Benito procedure as only
± 1 km. at maximum range.
Egon.
89. The original Egon procedure which involved the use of two Freyas, the one for rough
positioning and the other for fine positioning - later became known as "Egon Einstand" (One
location) to differentiate from an improved system termed “Egon Zweistand”
90. Egon Zweistand was evolved to offset the inaccuracies in azimuth D/F, and cash in on the
range accuracy of radar. With Zweistand a third Freya was introduced, placed some
considerable distance from the other two Freyas in order to give a distance cut. It was intended
for use by bomber aircraft operating over England or on long range sea missions.
91. The original Zweistand system, which was first tried out in Italy by a Schlacht unit, was
somewhat primitive in that the readings from the extra Freya were telephoned through to the
plotting centre and worked out before being plotted on the Seeburg table.
92. To eliminate the delay thereby involved a landline connection was introduced to feed the
Freya pulse to the C.R.T., which then had two blips showing ranges from the two Freya sites.
The vulnerability of landline to disturbance and destruction later led to the development of a
W/T transmitter and this method was employed successfully in operations.
93. Since the Freya pulse was not strong enough to trigger off the FuGe 25A at ranges
exceeding 250 kilometres, it was planned to supplant the Freya by extra powerful
Wassermanns, and thereby increase the effective range of Egon Zweistand to 350 kilometres.
94. A further line of development was the provision of a new type of control table giving the
exactitude of plotting necessary for pinpoint bombing. This control table, which was under
development at Rechlin, made use of complicated mechanical apparatus for accurate projection
of the position of the bomber. One of these tables was destroyed in the course of a daylight air
attack on Rechlin in February 1945; two other tables were in existence at the time of the
capitulation, and were located somewhere in Western Germany.
95. Egon when first introduced was received with some scepticism by the crews, as it was felt
that it was too vulnerable to jamming. After it had been used operationally without being
jammed in the attacks on London in March 1944, the procedure was adopted with greater
confidence, and it gained a good reputation. As recounted in A.D.I.(K) 343/1945, Egon was
always favoured by the R.L.M. technical development section in preference to Benito control.
96. A drawback of the system was its restricted range at low altitude, which according to P/W
was the reason why it was not used in conjunction with V.1 operations.
Nachtlicht
97. The Nachtlicht system was the first method of control not using R/T speech to be
improvised by the Germans, and had been tried out during the raids on London in the spring of
1944.
98. It had been observed that the red signal lamp of the FuGe 25A was illuminated when the
aircraft was being swept by a Freya, and it was suggested that use could be made of this as a
means of transmitting morse signals from the ground. A Freya operating on a special
wavelength, which P/W thought was 2.55 meters, was set up on the Channel coast and was used
to send simple instructions to the aircraft attacking London by means of visual morse
indications on the lamp of the FuGe 25A.
99. The primitive method of giving distant control indications was the forerunner of
"Nachtfee", "Barbara" and "Barbarossa".
100. Luftkurier was the first development of the Nachtlicht idea. It was primitive device
intended to give visual indication to the pilot by means of a pointer which was started and
stopped by the reception of pulses.
101. P/W thought that Luftkurier was first tried out by K.G.66 on the Freya band, but it was so
easy to jam by the addition of extra pulses that it was never developed.
Nachtfee
102. Nachtfee was the term used to describe a system for the transmission of control
instructions to a pilot in the beam of the controlling Freya through the medium of a C.R.T.
indicator similar to the Lichtenstein range tube. The airborne equipment used was known as
FuGe 136 and weighed 12 kg.
103. The original purpose of Nachtfee was, to provide a solution to the jamming of R/T control
systems, and it had been used operationally by the Pathfinders of K.G.66 for mines in the
Scheldt estuary. It was to be adapted for use by night fighters to overcome our jamming of the
night fighter commentary.
104. Nachtfee was a system using the FuGe 25A as receiver.
105. The presentation screen in the aircraft was inscribed with various commands both on the
inside and outside of a circular time trace. There was a stationary zero blip in the 12 o'clock
position, and when an instruction was radiated the pulses received caused a second blip to
emerge from the first and travel round the C.R. tube in a clock-wise direction, presumably by a
slight change in p.r.f. This blip came to a stop and the command corresponding to its position
could be read off on the inside of the time trace where a total of about eight different
instructions were inscribed. It took from one to two second, for the blip to travel round the
tube.
106. It was thought that the further eight commands inscribed on the outside of the time trace
were denoted by the blip making a complete circle starting round a second time before coming
to rest at any one of the eight sectors. In this way a total of sixteen different orders could be
given. For night fighters such instructions as "turn left/right", "climb", "dive”, etc. appeared on
the inner side and figures for transmitting bearing on the outer side of the trace.
107. This system was used operationally, but it was found that, apart from the susceptibility to
jamming, other pulse transmissions could interfere by unlocking the system and thereby cause
wrong positioning of the indicator blip.
108. Another pronounced objection to the Nachtfee lay in the fact that it was necessary for a
member of the crew to watch the C.R.T. indicator uninterruptedly for missing one blip
indication might give the message a false value. It was not therefore possible to use it in singleseater
aircraft.
Barbara
109. This apparatus, also called FuGe 138, consisted of an attachment to the FuGe 25A
receiver and only weighed 2 kg. This unit contained an audio filter which allowed the pilot to
hear morse signals superimposed on the Freya interrogator transmission if they were emitted on
a suitable audio frequency usually about 800 cycles. By keying other morse signals on different
audio frequencies and equipping aircraft with suitable filters, more than one aircraft could be
controlled by a single Freya.
110. Barbara was to be used for Egon control of ground-strafing aircraft and bombers but not
for night fighters.
111. In the Germans' opinion there were three disadvantages, namely that the Allies could
intercept and make use of signals so transmitted, that the aircraft had to be in the beam of the
Freya if it were to receive, and so an aircraft "lost" by the Freya owing to jamming could not be
communicated with and finally that, though intended for single-engined aircraft, fighter pilots
rarely had sufficient command of morse to be able to use this type of control.
Barbarossa
112. Barbarossa was a set designed to meet the same requirements as Barbara but to remedy
two of the drawback mentioned in the last paragraph.
113. The instructions to the aircraft were to be transmitted by code pulse modulations which
were passed through a "pulse filter" in the airborne set and a written indication obtained on a
Hellschreiber. The pulse filter and Hellschreiber unit were attachments to the FuGe 25A and
were known as the FuGe 139. This apparatus was in development at Rechlin under the
supervision of Stabs.Ing. von HAUTEVILLE.
114. With this arrangement pulse modulations could not be read by the Allies, and for spoof
purposes in order to produce a wrong indication we would have had to know the exact type of
modulation accepted by it. Visual indication was also quicker and did not depend on knowledge
of morse.
115. This scheme was only in a very early stage of development and P/W were unable to give
details. It was hoped that in due course it would be possible to develop matters a stage further
and find a means of transmitting scrambled speech instead of morse, but P/W understood that
the question of pulse modulation for speech transmission had not been solved.
Rübezahl
116. Consideration had been given in 1945 to the introduction of a crude system of navigation
which could be only used within the boundaries of the Reich. This was to go under the code
name of Rübezahl, and the fact that it was seriously considered and actively supported by the
P/W responsible for Navigational Aids on the G.A.F. signals staff is an interesting reflection of
the depths to which a combination of Allied jamming under-trained fighter had forced German
technique.
117. It was expected that in the course of the summer of 1945 thousands of 162 Volksjäger
would be available for the protection of the Fatherland. They were to be equipped with
FuGe 24, which was to become the standard G.A.F. R/T set as described in A.D.I.(K)
343/1945. This set did not for the present give Benito control facilities and indeed as they were
short-range, high speed, fair-weather aircraft it was not certain that Benito control would be
essentially needed.
118. It was essential that their relatively inexperienced pilots should have a simple means by
which they could locate their approximate position without any additional navigation
equipment having either to be manufactured or carried in the aircraft. It was therefore decided
to develop a system which could be used with FuGe 24.
119. In order to direct the Volksjäger pilots to their target, recourse was to be had to the night
fighter system of broadcasting a commentary, and this commentary was to be combined with
the primitive navigation system Rübezahl.
120. It was therefore planned to set up ground transmitters over Germany at 30 km intervals.
The transmitters were to be beamed upwards, so that at 6,000 meters the polar diagram was
about 40 km in diameter and lobes from neighbouring transmitters just overlapped, thus
covering the whole area. Each transmitter emitted a plain language recognition signal in the
form of the name of its district, e.g. Halle, Magdeburg, etc.
121. All transmitters were to be operated on the same frequency so that to locate himself the
pilot merely tuned his FuGe 24 to the frequency for the day. The ground transmitters were to be
adapted from the FuGe 15 transmitters which had been manufactured in quantity as described
in paras. 23-39 of A.D.I.(K) 343/1945 before it was found that the FuGe 15 was unsuitable as
an airborne R/T set. They were renamed Bs.15 (Bodensender).
122. Later it was believed that the night fighters which were also to carry FuGe 24 (see
appendix 1) would also use the Rübezahl commentary as yet another alternative source for
vectoring themselves to the bomber stream."