The most extensive microphoning operation Winterborn and I ever undertook was in Lancaster House, the ornate building which hosted the Colonial Conferences of the 1950s and 1960s. As soon as Macmillan became Prime Minister the pace of change in Colonial Affairs became more marked. MI5, which was responsible for security and intelligence-gathering in all Crown Territory, including the Empire, came under increasing pressure to provide intelligence assessments during negotiations toward the various independence settlements. Lancaster House was almost impossible to cover effectively in a piecemeal way. We could never be sure which rooms were going to be used, and this seriously impaired our intelligence-gathering. Winterborn and I proposed that MI5 install a comprehensive microphone system throughout the building which could be used whenever and wherever it was required. The Colonial Office agreed enthusiastically to our request, and Lancaster House was closed for "renovations" for a fortnight while an A2 team moved in. Hugh and I had already studied the room plans with great care and drawn up a circuit diagram specifying the locations of each microphone. We supervised the installation, and throughout the rest of the 1960s and the 1970s the system was used whenever high-level diplomatic negotiations took place in London.
But bugging the CPGB headquarters and covering Third World delegations were, in the end, interruptions of the main task, which was to confront the Soviet Union and her allies. The first A2 operation I undertook against the Russians was Operation CHOIR. It actually began some months before I joined MI5, when Hugh Winterborn mounted an operation to bug the Russian Consulate on the Bayswater Road. The opportunity arose when the building next door was refurbished in preparation for new occupants. MI5 went in under cover as decorators and Winterborn fitted a new device called the probe microphone, which had been developed by John Taylor in the Dollis Hill Laboratory.
The probe microphone was a large, high-sensitivity microphone, which was used to gain covert access through a party wall. The device was lodged inside the wall about eighteen inches from the target side. The eighteen inches between the probe microphone and the target room were drilled out by hand at a quarter-inch diameter in steps of half an inch. Half an inch from the target side the quarter-inch-diameter hole ended and a small pinhole was drilled, again by hand, using a No 60-size bit, so that the intrusion into the target side was almost invisible to the naked eye. The eighteen-inch bore hole was then lined -with a smooth perspex tube which was acoustically matched into the microphone. The microphone fed out into the street and back along telephone wires to Leconfield House, where amplifiers boosted the captured sound into intelligible speech.
Six months after Winterborn installed the CHOIR microphone it suddenly went dead. MI5 had, at the time, an agent who worked as an occasional decorator and odd-job man for the Russians. His name was Nutkin, which earned him the inevitable nickname of "Squirrel." Nutkin told us that the target room had been repainted. Although it seemed most likely that the pinhole had been covered with paint, we were still puzzled. Before the installation was made, Winterborn had obtained detailed measurements of the target wall from Nutkin. Using these he had planned the microphone pinhole to emerge behind a plaster leaf of the elaborate cornicework fourteen feet above the floor. It seemed unlikely that anyone would paint so carefully as to actually seal the hole. Still, Winterborn and I decided to drill it out again.
The new operation involved considerable planning. The renovation work in the building next door to the Consulate had finished. It was now a busy office with a constant stream of visitors, some of whom we knew to be Russians checking on security. We had to work at night and in total silence. We needed scaffolding to work fourteen feet up as well as plaster and paint to repair any damage. Winterborn arranged for a prefabricated scaffolding system and quick-drying decorating materials, specially developed for MI5 by the Building Research Station, to be delivered to the office in small packages so as not to alert the ever-vigilant Consulate.
A week later Jagger and I took a taxi to the top of Bayswater Road. It was winter and the streets were dark and crowded with returning commuters. We walked briskly down toward the Consulate and let ourselves into the building next door using one of Jagger's famous keys. We unpacked our attache cases, which contained our tools and a small radio receiver. The observation post opposite the Consulate was under instructions to monitor the building for any signs of movement. We monitored the broadcasts on our receiver without acknowledgment, so that we could cease work if anyone came into the target room.
Every microphone MI5 installs is recorded in the A Branch Index, which logs technical specifications, a history of its operation, and, most important of all, its precise location. While Jagger erected the scaffolding in total silence, I studied the wall plan, which we had brought with us from the A Branch Index, and made the triangular measurements. We began scraping away the plaster. It was tense work.
Each piece of plaster had to be removed by hand before it fell to the floor, and could then be placed in a bag for removal. After an hour we unearthed the microphone, carefully sealed inside the wall in a layer of plasticine. I disconnected the cables and slid out the perspex acoustic tube which led into the target room.
The No. 60 drill bit had a special stop on it ensuring the bit turned so slowly that a flake of plaster or paint could not be pushed out into the target room. I inserted the drill bit and held the body steady while Jagger delicately turned the handle. After two turns there was still resistance. Whatever was blocking the hole, it was obviously not a thin layer of paint. In the light of passing car headlights we exchanged puzzled glances. The drill turned again. And again. Still resistance. Then suddenly the bit ran free and almost immediately encountered another obstacle. I gently pulled the drill back to our side of the wall and Jagger packed the bit into a small box for examination in Leconfield House. Listening down the hole with an acoustic tube, I could hear the ticking of a clock in the target room, so without doubt the drill had entered the target room as originally designed, behind the rear side of a plaster leaf in the cornice.
We swiftly packed the microphone back into the wall, reconnected the cables, and replastered the hole. We had three hours to kill, waiting for the plaster to set before we could repaint the damage. We sat smoking, our receiver crackling intermittently. Even at the dead of night both sides were still dancing the Cold War waltz, as Watcher cars chased Russian diplomats through the darkened streets of London. But the Consulate remained silent.
The next day on the seventh floor Winterborn and I listened to the CHOIR microphone. It was muffled, but clearly working. The only problem was that nobody was saying anything in the target room. All I could hear was the steady clacking of a solitary typewriter. We went down to the basement to examine the No. 60 drill bit under a microscope. It was covered to a depth of three-eighths of an inch with plaster dust.
Whoever the Russian decorator was, he had been mighty conscientious.
"That's no bloody redecoration," said Winterborn, squinting down the microscope. "You can't trowel plaster three-eighths of an inch down a pinhole. That's been done with a bloody syringe!"
A month or so later, "Squirrel" Nutkin was able to catch a sight of the target room. It had been completely remodeled with a soundproofed partition across the party wall. Behind the partition a single secretary worked with a typewriter. The Russians obviously knew, as we did, that party walls were vulnerable to attack. But, as far as we could tell, they did not know about the probe microphone. And yet it seemed probable that they had detected the pinhole and stopped it.
In July 1955 I tackled the Soviets once again, this time in Canada. MI5 received a request for technical assistance in an operation the Royal Canadian Mounted Police (RCMP) were planning to install microphones in the Russian Embassy in Ottawa. The old three-story Embassy building overlooking the Rideau River had recently burned down. The RCMP planned to install eavesdropping equipment during the rebuilding work, but needed access to the latest equipment, so they contacted MI5.
I was met at the airport by Terry Guernsey, the head of the RCMP's Counterespionage Department, B Branch. With him was his assistant, a Welshman named James Bennett. Guernsey was a lanky Canadian whose outwardly unflappable manner was constantly betrayed by the nervous, explosive energy underneath. Guernsey was trained in Britain by both MI5 and MI6 and returned to Canada in the early 1950s convinced that the RCMP was unsuited, as a uniformed police force, to the delicate work of counterespionage. Guernsey began to recruit civilian intelligence officers and single-handedly built up B Branch into one of the most modern and aggressive counterespionage units in the West. Many of the ideas which later played a major role in British and American thinking, such as computerized logging of the movements of Russian diplomats in the West, began as Guernsey initiatives. But he constantly ran up against the oppressive restrictions of the Mountie tradition, which believed that the uniformed RCMP officer was inherently superior to his civilian counterpart. This was a struggle which ran deeply, not just through Canadian Intelligence, but also in the FBI. Guernsey believed that the British were correct in drawing a distinction between criminal detective work and the entirely different skills of intelligence-gathering, and he fought many battles to ensure that B Branch remained independent of the mainstream of the RCMP. But the effort virtually cost him his career. The Mountie senior officers never forgave him, and he was eventually banished to the UK, where he acted as RCMP liaison with MI5 and MI6, before ill-health finally drove him into retirement.
But in 1956, when I made my first trip to Canada to help plan Operation DEW WORM, Guernsey was still very much in charge. Over dinner that first night he described where the operation stood. The RCMP had successfully recruited the contractor who was rebuilding the Russian Embassy, and had installed RCMP officers under cover as workmen on the site. With the help of Igor Gouzenko, a Russian who had worked inside the old Embassy as a cipher clerk until he defected to the Canadians in 1945, Guernsey had been able to pinpoint the area in the northeast corner of the building where the KGB and GRU (Soviet Military Intelligence) secret sections, and the cipher rooms, were located.
After studying the plans I decided that a SATYR operation, using a cavity microphone activated from outside by microwaves, was not technically feasible. The distance from the device to safe ground was too great to be assured of success. It had to be a wired operation.
Wired operations have one major advantage. If they are skillfully installed, they are almost impossible to detect. The best plan of attack was to conceal the microphones inside the aluminum sash windows on the target side of the building. Guernsey obtained a sample frame from the contractor. They were friction windows with no sash weight, perfect for concealing a device. There was an air path into the sash where the two pieces locked together, ensuring a good sound quality.
The metal window frames would effectively dampen the electromagnetic field emitted by the microphones, making them impervious to sweeper detection.
But the main problem was how to conceal the cables leading to the microphones. The walls of the new Embassy building were planned to be nearly two feet thick, with a fourteen-inch concrete block inner leaf, a two-inch air gap in the middle, and then four-inch-thick stone facing on the outside of the wall. I checked with MI6 for details of Russian electronic sweeper operations. They told me that the Russians never swept the outsides of their buildings, only the insides. The Russians apparently considered it demeaning to be seen to be sweeping their premises. I told Guernsey that the best plan was to lead the cables up through the air gaps, where they would be virtually assured of nondetection through fourteen inches of concrete, especially as MI5 had developed a new thin cable which gave off far less electromagnetic emission.
Once the building work got under way we had to find a way of concealing the cables from the Russian security teams who regularly visited the site to check on the Canadian contractors. We buried large coils beneath each of the eight-foot concrete footings, and cut them into the bitumen coverings. Every night, as each course of masonry was installed, RCMP workmen went onto the site and lifted a length of cable from the coil into the air gap. There were eight cables. Each was labeled at random from one to twenty to mislead the Russians in the event they were ever discovered. It was a nice touch; the sort of joke the Russians would appreciate after they had finished tearing down the Embassy searching for the phantom cables.
The most difficult part of the whole operation was connecting the wires to the microphones. The windows in the northeast section of the building had been successfully fitted, supervised by an RCMP officer to ensure the frames went into the right places. The cables had been painstakingly raised inside the air gaps over months of construction work. But connecting the two together was impossible to conceal. It could be done only by an engineer working outside, four floors up on the scaffolding. The job was given to one of Guernsey's technical men, a young engineer who handled the operation brilliantly. He was a big man, but he scaled the building in pitch dark in a temperature approaching minus forty degrees centigrade, carrying his soldering tools in a shoulder bag. Taking each of the eight microphones in turn, he carefully joined the cables and ensured the connections were solid.
As soon as the connections were made, RCMP technicians began to dig a twenty-yard tunnel from an RCMP safe house next door to the Embassy, through to the coils buried under the footings. The coils were led back ten feet underground to the safe house and the tunnel backfilled with three feet of concrete. The eight cables connected to head amplifiers concealed in the garage of the safe house, with power fed to them over output leads from RCMP headquarters. When the microphones were tested, each one worked perfectly.