Operation Gold
The Americans wanted to hear any warlike intentions being discussed by their military and were able to listen to telephone conversations for nearly a year, eventually recording roughly 90,000 communications.
This was primarily because the then-Director of Central Intelligence (DCI), Allen Dulles, had ordered "as little as possible" to be "reduced to writing" when the project was authorized.
2 Carlton Gardens, London, from which the West German government was excluded due to the "highly infiltrated nature" of their service.
The resulting agreement was that the US would supply most of the financing and construct the tunnel (as the closest access point was in their sector), while the British would use their expertise from Operation Silver to tap the cables and provide the required electronic communications equipment.
Blake apparently alerted the KGB immediately, as two of Gehlen's agents were caught trying to get a potential tapping wire across a Berlin canal.
The KGB decided to let Operation Gold proceed since, in order to attack the tunnel, the Soviets would have to compromise Blake, and they found it preferable to sacrifice some information rather than their valuable agent.
Although the British SIS suspected the opposite, the CIA report states that "the Soviet military continued to use the cables for communications of intelligence value.
"[7] In December 1953, the operation was placed under the direction of William King Harvey, a former U.S. Federal Bureau of Investigation (FBI) official who transferred to the CIA.
[10] Once complete, the tunnel ran into the Altglienicke area of Treptow borough, where British Army Captain Peter Lunn—a former Olympic alpine skier and the head of the SIS in Berlin supervised construction of the vertical shaft and the tapping of the three cables.Tunnelling was difficult with the need to avoid subsidence in the soft crumbly soil.
For the vertical shaft work an improvised device called the Mole was used by the British team from the Royal Engineers and the SIS plus staff from the BPO Research Station at Dollis Hill.
"[15] To protect Blake, the KGB was forced to keep the flow of information as normal as possible with the result that the tunnel was a bonanza of intelligence collection for the US and Britain in a world that had yet to witness the U-2 or satellite imagery.
According to Stephen Budiansky, "The KGB's own high-level communications went on a separate system of overhead lines that could not be tapped without its being obvious, and, concerned above all with protecting Blake as a valuable source inside SIS and unwilling to share its secrets with rival agencies, the KGB had simply left both the GRU and the Stasi in the dark about the tunnel's existence.
"[17] In the planning phase, the CIA and SIS had estimated that the Soviets would cover up any discovery of the tunnel, through embarrassment and any potential repercussions.
[citation needed] Operation Gold forms the background to the novels The Innocent by Ian McEwan, Voices Under Berlin: The Tale of a Monterey Mary by T.H.E.
