In addition to the prison, labor camp “X,” and two departments
charged with instituting criminal proceedings, the restricted zone was
also the site of several other MfS units: the Operative Technical Sec-
tor, which produced eavesdropping systems, hidden cameras, and false
passports; the Armaments and Chemical Services Department, which
administered the weapons used by MfS personnel and coordinated
preparatory steps in the event of war; administrative elements of the
Behind the Lines Services, which oversaw MfS construction projects
and vehicles; and part of the Espionage Data Center of the Haupt-
verwaltung Aufklärung. The complex at Berlin-Hohenschönhausen
constituted the largest MfS deployment in East Berlin apart from the
main headquarters in Berlin-Lichtenberg. Ironically, MfS chief Erich
Mielke was briefly held in custody in Berlin-Hohenschönhausen prior
to his own trial. The Hohenschönhausen Memorial public trust founda-
tion now conducts public tours of the facilities.BERLIN TUNNEL. A joint British and American plan to tap Soviet
communication lines through an underground excavation, the Berlin
Tunnel was conceived over a three-year period and received approval
from the U.S. Central Intelligence Agency (CIA) on 20 January
- The British Secret Intelligence Service (which had mounted a
similar operation in Vienna between 1948 and 1955) dubbed the op-
eration stopwatch, while the CIA used the code name gold. As part
of their advance planning, the Americans recruited several agents in
the East Berlin post office, notably a woman called the “Nummer
Mädchen” (numbers girl), who conveyed essential information in
determining which lines to tap. Another source in the Ministry of
Post and Telecommunications of the German Democratic Republic
(GDR) supplied official maps indicating the location of the cables.
To disguise “the construction of a subterranean passage approxi-
mately 1,800 feet in length, one-half of which will be in Soviet terri-
tory”—as stipulated in the original plan—German contractors were
engaged to erect a large warehouse in Rudow near the East Berlin
border (a cupola was placed on top to give the appearance of a meteo-
rological installation). The U.S. Army Corps of Engineers completed
the six-foot-diameter tunnel in late February 1955, allowing British
telecommunications experts to make the actual tap in the lines that
ran along the Schönefelder Chaussee in the Soviet Zone.
BERLIN TUNNEL • 31