Page 270 - The Secret War in the Italian front in WWI (1915-1918)

THE SECRET WAR ON THE ITALIAN FRONT IN WWI (1915 – 1918)

The Commission of enquiry on the Battle of Caporetto stated categorically in its report that “even
the smaller (enemy) units down to Regiment were equipped with radiotelegraphic devices”. The
gross mistake probably derived from the belief that the Austrian units were equipped like the
German ones, showing the superficiality of the Commission’ analysis on radiocommunications .
25

radIo InTellIgence before The aTTack
In October, unlike the previous months, some Austro-Hungarian radio stations started transmission
activity, but very sparingly. The larger number of radio messages detected by the Italian interception
stations on the Isonzo front, from about the middle of the month, together with the presence of
several German field radios, was interpreted as the sign of the planned attack .
26
The goniometric stations in Codroipo and Padua pinpointed the enemy transmitting stations
“along a line from the sea to the region of Trieste up to northern Langefeld; some more were
localised around Tolmino” with a clear distinction between “stations having Austrian or German
call signs” . Even if the operating sectors of these stations overlapped slightly, they were in fact
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part of two separate networks. Over the same period, traffic also increased between coastal radio
stations and Austro-Hungarian ships.
Therefore, in mid-October, the Italian listening and radio goniometric stations had already identified
three networks, namely the German field network, and the Austrian field and naval networks.
These maintained their own distinctive characteristics during the following operational phases,
also when the enemy field radio stations began moving. A clear distinction also existed between
German and Austro-Hungarian traffic, with a strong predominance of the former, notwithstanding
the 1:10 ratio between the two Armies on the Italian fronts.
The cryptograms intercepted by the Italian listening stations were promptly routed to the R Section
of the Intelligence Service in Rome, where the only Army Cryptography centre was on duty. On
25 October, the Chief of the Intelligence Service submitted to the Assistant Chief of the General
Staff, General Porro, a note with the results obtained by the Cryptographic Unit and the praises
for its chief, Major Sacco, recently promoted .
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The Austro-Germans tried to spread disinformation between 15 October and 8 November by setting
up 13 German transmitting stations in the Tyrol area as a diversion. They attempted to ‘rebalance’
the number of German radio stations along the Isonzo River to let the Italians believe the attack
would come from two directions . Ronge believed the transmissions in Tyrol would contribute to
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spreading fear among the Italian Headquarters of an Austro-German offensive in Trentino at the
same time as the attack along the Isonzo, leading Cadorna to strengthen the Italian formations in

25 Caporetto Commission report, op. cit., p. 227.
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26 3 Telegraph Engineers Regiment, 1 Radio-goniometric Section, Stazioni RT campali austro - tedesche (Austro German
RT field stations), Bullettin 4, 3 January 1918, ISCAG, Coll. 249. This 21-page typewritten report was signed by Lieutenant
Magni, an officer directly involved in the events. The same Section issued the Relazione sull’operato della 1 Sezione Radio
a
Goniometrica nella presente guerra, (Report on the activity of 1 Radio Goniomtric Station in the present war), November
st
1918, p. 3, ISCAG, Coll. 242, where Lieutenant Giuseppe Dotto wrote, “Before the offensive in October 1917, the goniometric
office could pinpoint a concentration of enemy field stations, especially around Tolmino, and follow their movements”.
27 3 Telegraph Engineers Regiment, 1 Radio-goniometric Section, Relazione sull’operato, op. cit., p. 1.
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28 Section R logs, 26 October 1917, AUSSME, Series B1, 101S, Vol. 303d. One can reasonably assume these congratulations
addressed the whole activity of the Cryptographic Unit to that date, in addition to some specific successes it had eventually
obtained in the days that preceded the Austro-German attack. Sacco had been promoted to the rank of Major in April 1917.
29 M. Ronge, Der Radiohorch, op cit., p. 23; O.J. Horak, Oberst a. D, Andreas Figl, op. cit., p. 149.
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