The operation was considered so secret that most of the Halibut’s crew were told their mission was to recover fragments from a P-500 “Sandbox” missile test for analysis. The supersonic anti-ship missile was rumored to use an advanced infrared-seeker. To reinforce the cover, after recording several hours of conversation, the Halibut sailed to the site of the test and her dovers did recover two million tiny P-500 missile fragment, which were reassembled jigsaw-like until it was discovered that Sandbox used only radar guidance!
The brief tape was brought back to Pearl Harbor and found to be highly promising. The Navy rapidly commissioned a new six-ton wiretap device from Bell Laboratories called ‘the Beast’ (photo here ) which used a nuclear power source and a massive tape recorder to records of weeks of conversation across multiple lines at the same time.
The Halibut returned and installed this new device, and the sub’s crew were soon listening in on Soviet telephone conversations, celebrating their success by feasting on a spider crab scooped up from the sea floor.
Thenceforth, the Halibut and other submarines began regular courier runs to install new tapes on the tap while bringing back the old tapes for analysis by the NSA in what was called Operation Ivy Bells. The Halibut herself was decommissioned in 1975, and the courier runs taken over by the USS Parche, Sea Wolf and Richard B. Russell.
The tapped cables provided a treasure trove of intelligence for the NSA: mixed in between personal calls to family and sweethearts were private conversations on sensitive political topics and detailed information on Soviet submarine operations. Much of the Soviet traffic was unencrypted because cables were considered a highly secure form of communication.
This candid, unfiltered portrait of the Soviet Navy’s state of mind vis-à-vis the United States reportedly influenced U.S. military leaders to deescalate activities which were threatening to panic Moscow, and also apparently informed the Washington’s negotiating posture for the SALT II treaty which limited the size of strategic nuclear weapons forces.
The cable-tap operation did have its risks. In Sherry Sontag’s book Blind Man’s Bluff , he describes how on a later tape-recovery mission, a sea storm bucked the Halibut to and fro until her anchors snapped, causing her to begin rising uncontrollably with divers trapped outside. The Halibut risked exposure in Soviet territorial waters, and her tethered divers risked death from rapid decompression. Captain John McNish decided to flood the Halibut until it smashed onto the seafloor and brought the divers back into their pressure habitat. But now the Halibut was dangerously mired.
After completing the planned data collection, the Halibut tried a dangerous emergency blow to free herself from seabed sediment, followed by an immediate dive to avoid breaching the surface. The submarine had only enough compressed air to try the maneuver once—and luckily, it worked.
In 1980 mishap also befell the USS Sea Wolf , which was uniquely equipped with a liquid metal-cooled nuclear reactor. On one tape-recovery mission, a storm caused her to crash into the seafloor and become stuck, with mud and mollusks gumming up her insides. Her captain considered scuttling the vessel before he managed to wriggle it free to surface in a noisy emergency blow out. After this incident, Soviet ships were observed heading towards the site of the cable tap.
However, it was human frailty, not sea storms or Soviet sonars, which brought an end to the intelligence bonanza. When the Parche went to pick up the latest tape, the tap was missing.
In July 1985 Soviet KGB defector Vitaly Yurchenko revealed that Ronald Pelton, a heavily indebted former analyst for the NSA, had walked into the Soviet embassy on January 14, 1980, and sold the secret of Ivy Bells for $5,000—with an additional $30,000 paid for later consultation. This led to the tap’s removal by Soviet divers, though it’s possible that the Soviets might have planted misleading information in the cable traffic before doing so.
Nonetheless, Ivy Bells proved one of the greatest coups by U.S. intelligence during the Cold War. The U.S. Navy maintained its undersea espionage capabilities today, particularly in the super-stealthy Sea Wolf-class submarine USS Jimmy Carter , which has a special chamber for splicing undersea cables.
And what came of the tapping device installed on the cable in Okhotsk? It can be seen today in the Great Patriotic War Museum in Moscow.
Sébastien Roblin holds a Master’s Degree in Conflict Resolution from Georgetown University and served as a university instructor for the Peace Corps in China. He has also worked in education, editing, and refugee resettlement in France and the United States. He currently writes on security and military history for War Is Boring.