Page 240 - The Secret War in the Italian front in WWI (1915-1918)

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

In April 1917, for instance, the three-letter radio call-signs of the German submarines were
identified, of which the first two indicated the fleet they belonged to and the last the unit: “The
‘FQ’ two-letter group was the ‘submarine fleet call’. The names of the FQ fleet units heard in April
in the Mediterranean were as follows: FQC (9 April); FQWH (9 April), etc.” .
23
Goniometric triangulations, even triple or quadruple, were repeated several times to identify
the routes and activities of several units of the German and Austrian submarine fleet . Among
24
other results, the surveys supported the assumption concerning the presence of “submarines that
transported torpedoes and ammunition between Pula or Kotor and the Western Mediterranean
where they are believed to resupply the submarines that operate in the Atlantic” .
25
To this end, the Italian radiogoniometers followed the movements of the German submarine with
radio call-sign FBF that operated in the Atlantic but entered the Mediterranean to rendezvous near
the Balearic Islands with another submarine - supposed resupplying it - whose call-sign was PM
or LO. During its two one-month trips from Kotor to the Balearic Islands, the latter called other
subs, including the FBF, but neither sank nor tried to sink any allied ship.

11.3 Rendezvous between German U52 and U53 boots in the Mediterranean (© Creative Commons’)

Notizie e Proposte circa le Comunicazioni RT dei Sottomarini Nemici (Information an proposals on RT communications of
enemy submarines), to the Head of the 4 Division of the Navy Ministry.
th
23 ibidem.
24 The goniometric stations used for these detection activities also belonged to the Italian Navy - whose network extended to
the Adriatic, Ionian and Tyrrhenian seas - or to the Allies, such as the French stations in Thessaloniki and Florina.
25 Intelligence Service, Section R, Notizie Riassuntive, op. cit.

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