Richard H. Cummings
“Divided Cities and Contested Cities during the Cold War”
Gorizia, Italy
20-23 March 2025
From Conflict to Smokey Joe’s: Secret Tunnel Operations in Vienna
Operation Silver was a collective term for several individual tunnel projects. The British secret service MI6 completed three tunnels in Vienna from 1948/49. They were named Conflict, Lord, and Sugar. The purpose was to tap into the Soviet occupying power's military communication.
Conflict was the operational name for the first tunnel. In the summer or autumn of 1948, an Austrian telecommunications expert is said to have given British Intelligence an explosive tip: Under Aspangstraße in Vienna-Landstraße, a telephone cable handled a large part of Soviet military telephone traffic as well as the international lines to Prague, Budapest, Sofia, and Bucharest.
Three men worked around the clock in two or three-hour shifts in the tunnel nicknamed "Smokey Joe's" because of the unfiltered air mixture of cigarette smoke and cellar moisture. When a man heard a telephone call, he activated the recording device, the conversation was recorded on an Edison phone cylinder. The cylinders were then flown three times a week in special barrels from Vienna to London. There, the recordings of the MI6 department were listened to and transcribed. The team comprised of 50 to 60 Russian emigrants, Polish army officers in exile and language experts. The transcripts of summaries from this were incorporated into a regular bulletin about the order of battle of the Red Army in Austria.
. Lord, the longest and most elaborate of the three espionage tunnels, was created at the end of the Simmeringer Hauptstraße – just opposite the Soviet-occupied eastern bank of the Schwechat River The goal was also, in this case, an underground cable, which ran parallel to the road and the Hotel Imperial with the command of the Red Army. Access to the tunnel was via a villa where intelligence officer John Edward Wyke and his wife had previously moved in. Wyke was the right hand of MI6 head Peter Lunn, the driving force behind Operation Silver. The tunnel is said to have been just over 21 meters long. Previously, the house entrance had been renewed with a layer of concrete and dug from the cellar to the cable.
CIA Operation
Communications intelligence (COMINT) is information gathered from communications between individuals or groups of individuals, including telephone conversations, text messages, email conversations, radio calls, and online interactions. Specifically, COMINT refers to analyzing the signals containing speech or text generated by these interactions. The targets for the British and Americans were the same: the penetration of Soviet operations and Soviet order-of-battle intelligence. What went on in the Imperial Hotel in Vienna was, accordingly, a major intelligence target.
One time Director of CIA Richard Helms wrote in his memoirs: “By 1951 our research showed that the landlines followed the original conduits established for telephonic traffic before World War I in Austria and Germany. The proximity of these lines to areas in which we might work suggested a long-shot possibility of breaking into the mass of communications between Moscow and the Soviet occupation headquarters in Austria, Germany, and the Central Group of Forces in Hungary. However slight our chances, the potential product of a successful operation appeared to justify an all-out effort. Landlines can be intercepted only by tapping the telephone cables. Breaking into the lines—most of which were tucked underground—would be a considerable undertaking, but would have one advantage over radio monitoring.”
The CIA Vienna station had a blueprint of the underground cables and communications routes between the Soviet command in the hotel and Moscow. Using information from city plans and other sources, Carl Nelson, an officer in the CIA's Office of Communications, was able to put this blueprint together. Helms wrote, "We were well along with this research in Austria when our Vienna office earned that the British had independently come upon the same idea and had made considerable progress in tapping into the underground cables. The potential value of the intercept product in Austria and Germany meant there was too much at stake to risk any overlapping effort in such a narrow field. The British agreed, and we each cooperated to the hilt at all times."
According to one historian, "During its lifetime, the joint operation in Vienna kept a steady supply of firsthand information flowing to top decision-makers in London and Washington. The CIA recruited the first of a series of Soviet intelligence officers at the turn of the year 1952/1953. This invaluable source … contributed greatly to the West's requirements for reliable early warning of a Soviet offensive."
The deputy head of British Intelligence in London, Section Y, George Blake, had been a Soviet KGB since his imprisonment in the Korean War. In October of 1953, Blake was said to have handed over a folded piece of paper to his KGB contact in London. The folded piece of paper contained a list of all the SIS's telephone tapping operations in the Vienna tunnel operation, as well as information about microphones planted in Soviet and East Bloc embassies in Western Europe. In only their second or third meeting, in early December 1952, “Blake handed over a hugely damaging Minox film of a ninety-page report entitled 'Banner 54/1', which contained a compilation of the tapped calls between Austria and Hungary, obtained via the tunnels in Vienna.”
The CIA covered 75 percent of the cost of the joint tunnel operation, which ran until 1955 when Austria regained sovereignty. The CIA had been so impressed by Operation Silver's output that it copied it on a much larger scale: in 1954/55, a 450 meter-long tunnel was dug under the Soviet-occupied sector of Berlin: Operation Gold.

