“Constructing a quarter-mile tunnel into enemy territory and tapping into Soviet lines would be a major feat of engineering beyond the capabilities of either the CIA or SIS.”

By Steve Vogel

THE BERLIN TUNNEL, the joint Cold War operation by the Central Intelligence Agency and the British Secret Intelligence Service to physically tap into Soviet military communication cables, has earned a place in intelligence lore as one of the most audacious espionage operations of the era. Its exposure by the notorious British spy George Blake is likewise remembered as one of its most infamous betrayals. Less known is the critical role the U.S. Army Corps of Engineers played in the operation

The tunnel was conceived during the Korean War – a time of maximum anxiety and vulnerability in the West. The Soviet Union, newly armed with nuclear weapons, maintained an enormous Red Army force on a permanent war footing in Eastern Europe. Access to Soviet radio communications had been cut off by Moscow’s move to landlines. Similarly, the West had had little success in planting agents behind the Iron Curtain, while the overhead surveillance that the U-2 spy plane or satellites would later provide, was still years away from completion. Western intelligence was effectively blind. Yet President Harry Truman and his successor, Dwight Eisenhower, lived in dread of a nuclear Pearl Harbor and were desperate for better intelligence.

The solution proposed by the CIA and SIS was to dig a tunnel in the divided city of Berlin from the American sector into the Soviet sector to reach three trunk cables carrying vital Red Army communications. But constructing a quarter-mile tunnel into enemy territory and tapping into Soviet lines would be a major feat of engineering beyond the capabilities of either the CIA or SIS. For that, they would need the help the Corps of Engineers.

[pullquote]“They said they had a job for me. They wouldn’t tell me what it was or where it was,” recalled Williamson. “I said, ‘I’ll take it.’”[/pullquote]

While researching my book about the tunnel, Betrayal in Berlin,  I interviewed two U.S. Army officers who would oversee the project. Captain Keith Comstock, who had been awarded two Bronze Stars for his service in Korea, and Captain Robert G. Williamson, a West Point graduate who had done military intelligence work in Germany. Each had received a mysterious call from superiors prior to joining the project. “They said they had a job for me. They wouldn’t tell me what it was or where it was,” recalled Williamson. “I said, ‘I’ll take it.’”

Williamson was given the task of recruiting a crew of about 20 enlisted men with secret clearances. He was told to get people with the variety of skills required to dig a long tunnel.

“Where or why wasn’t known,” Williamson said.

In spring 1954, the team reported to the Pentagon for a briefing. A CIA officer gave a redacted rundown on their mission to dig a tunnel. There was no mention of Berlin or tapping Soviet lines, but it was clear this would be no ordinary dig. It needed to be carried out in secret, as silently as possible, which meant by hand. The shaft would run a quarter-mile through soil prone to collapse and stretch beneath a major highway that carried tanks and heavy vehicles. A special shield to protect against collapse was being built.

In a few weeks, the recruits would travel to Sandia Base in New Mexico to test and train with the equipment. Then they would move to Virginia to pack everything up and ship out to their ultimate, unknown destination.

Comstock stared straight ahead as the briefing continued, doing mental calculations about the task at hand, including the amount of soil that would have to be removed.

“I was shocked, like all the other guys who were there,” he said. “I was so surprised at what we were going to do. I was overwhelmed.”

After finishing the training in New Mexico and packing the equipment at Fort Lee, Virginia for shipment, the team finally learned their destination: Berlin.

In August 1954, Comstock arrived at the West German port of Bremerhaven to meet the ship carrying the cargo. The 200 tons of gear was loaded onto a train that would take it through Soviet-controlled East Germany.

“I was scared spitless because we had all these phony shipping documents, and I could just see it if the Russians decided they were going to look in one of those packages,” Comstock recalled. “I just thought, ‘Oh God, there goes me to the gulag.’”

But the material made it safely to Berlin. From there it was trucked to an U.S. Army installation in Rudow in the far southeast of the American sector, where it was hidden inside a warehouse built specifically to hide the tunnel construction and provide a place to store the excavated earth.

With no pomp and little circumstance, the engineers broke ground on Sept. 2, 1954, jackhammering through the warehouse’s concrete floor. The team had only dug a few feet when disaster struck: They hit water. The water table was supposed to be 32 feet deep, but they found it at half that depth. The work came to a halt. The moisture would not only greatly complicate the construction of any tunnel, it would pose a serious threat to the tapping equipment.

“There was much head-scratching and concern about how to handle it,” said Williamson. The verdict was there was little choice but to dig the tunnel above the water table, bringing the construction closer to the surface and increasing the chances of Soviet detection or a tunnel collapse.

[pullquote]“You’d have two people digging side by side, one digging, one holding the sandbag, so those tools were perfect.”[/pullquote]

The engineers set up three six-man crews, each under the command of a captain. Digging continued around the clock in eight-hour shifts. The teams used ordinary entrenching tools – short-handled shovels normally used for digging foxholes and the like – which were easy to handle in the tight, six-foot diameter space at the face of the tunnel.

“You’d have two people digging side by side, one digging, one holding the sandbag, so those tools were perfect,” Comstock explained

For half a year, the engineers dug nonstop, save for a week’s leave each crew was given at a U.S. Army resort in Garmisch in the Bavarian Alps, where the men mostly drank and slept. After the early problems with water, and later sewage, progress on the tunnel had continued unabated.

On Feb. 28, 1955, the engineers reached the point that they calculated was directly below the targeted cables underneath Schönefelder Chaussee. The 1,476 feet they had tunneled was 20 feet longer than the Empire State Building was tall. It stretched from the American zone eastwards into Soviet territory.

The end was abrupt. There was no ceremony or elaborate farewell, or even a chance to take leave in Europe. Still, said Williamson, the engineers departed with “a pretty solid sense of satisfaction.” The Corps of Engineers had done “what can only be described as a magnificent job in all respects,” a CIA report concluded.

Much work remained to be done, and the story would take many twists, as related in my book, Betrayal in Berlin. Over the next month, a team of Royal Engineers dug a vertical shaft to reach the cables. On May 11, British postal technicians working with enormous delicacy inches below the pavement, successfully placed the taps on the first cable. Almost immediately, teams of translators, transcribers and analysts in Berlin, London and Washington were swamped with intercepted communications, which would soon reach the level of over 1,000 a day. The KGB, alerted to the tunnel by Blake, was uncertain what to do. Doing anything to block the tunnel’s output would almost certainly expose Blake as a spy. But doing nothing would allow secrets to flow to the West. It seemed an unsolvable dilemma.

Journalist and author Steve Vogel reported for the Washington Post for more than 20 years, writing frequently about defense issues. His latest book, BETRAYAL IN BERLIN: The True Story of the Cold War’s Most Audacious Espionage Operation, was published Sept. 24 by Custom House. His previous books include THROUGH THE PERILOUS FIGHT and THE PENTAGON: A History, both published by Random House.