44 • BERLIN TUNNEL
to be head of station in Lima. In 1966 Benton served as SIS head of
station in Rio de Janeiro, his final assignment.
Benton’s retirement from the clandestine world took place two
years later, and his talent for writing spy thrillers manifested itself in
the publication the next year ofThe Twenty-Fourth Level,a spy thril-
ler with secret agent Peter Craig as its hero, set in a Brazilian gold-
mine. Numerous other thrillers followed, including two murder
mysteries,A Time for MurderandGreek Fire, written under the pen
name James Kirton.BERLIN TUNNEL.Codenamedstopwatchby theCentral Intelli-
gence Agency(CIA) andgoldby theSecret Intelligence Service
(SIS), this was a joint project involving the construction of a tunnel
almost half a mile long, extending under the border at Rudlow into
the Soviet zone of Berlin, to intercept a cable duct beside the Scho ̈n-
felder Chaussee that carried traffic between the Soviet military head-
quarters in Zossen-Wunsdorf and Karlshorst to Moscow. The tunnel
was dug undetected, the target cables were tapped unnoticed, and the
product was recorded, processed, translated, and distributed without
a leak. This very expensive undertaking was massive in size and
technically very challenging, but it promised to supply the West with
a trip wire that would virtually guarantee that the Soviets could not
mount a surprise attack on the Allies. Monitoring and analysis of the
intercepts would remove the continuing anxiety about Soviet inten-
tions in Germany and act as a window into the daily activities of the
Red Army’s Central Group of Forces permanently based in East Ger-
many.
Elaborate precautions were taken to isolate the CIA’s Berlin base,
located in the Clayalee, and the local Secret Intelligence Service
station in the compound beside the Olympic Stadium, from the plan-
ning of the tunnel. The initial planning meeting took place over three
days in London in December 1953, attended byGeorge Youngas
SIS’s director of requirements; Tom Gimson, who headed the Y Sec-
tion that had masterminded the Vienna tap; the project manager,
Stewart Mackenzie, a future SIS controller of operations; and John
Taylor, a technical expert from the Post Office Research Establish-
ment atDollis Hill. Having agreed the general principles, another
meeting was held early in 1954 at the Y Section’s office at 2 Carlton