The CIA's Secret Deep-Sea Heist of a Soviet Submarine
In 1974, the CIA orchestrated one of the most audacious covert salvage missions in history: Project Azorian. To retrieve a sunken Soviet nuclear submarine resting three miles beneath the Pacific Ocean, the agency partnered with billionaire Howard Hughes to invent an elaborate cover story about deep-sea mining. Hughes built a 618-foot vessel equipped with a colossal mechanical claw to hoist the 1,750-ton submarine section unseen from the ocean floor.
The Disappearance of K-129
In March 1968, a Soviet Golf II-class ballistic missile submarine designated K-129 slipped beneath the surface of the North Pacific Ocean on routine patrol and vanished. Armed with three nuclear-armed ballistic missiles and two nuclear torpedoes, the diesel-electric vessel suffered an unexplained catastrophic event that sent it plunging to the ocean floor. When the submarine missed scheduled radio check-ins, the Soviet Navy mounted an enormous naval search involving dozens of ships and aircraft. For over two months, Soviet search vessels swept the Pacific, but they focused on the wrong waters and ultimately abandoned the effort without finding any trace of the lost crew or hull.
The United States Navy, however, had been quietly listening. Using the Sound Surveillance System (SOSUS)—an underwater global network of hydrophones designed to track Soviet submarines—American acoustic analysts identified anomalous sonic pulses recorded in early March. By analyzing the timing of the signals recorded across multiple hydrophone arrays, naval intelligence triangulated the submarine's final position. Later that summer, the specialized American surveillance submarine USS Halibut was dispatched to the area. Equipped with robotic cameras and sonar arrays towed on long cables, Halibut located the wreck resting upright more than 16,000 feet beneath the surface, approximately 1,560 nautical miles northwest of Hawaii, and captured thousands of detailed photographs of the shattered hull.
An Audacious Intelligence Prize
To the United States intelligence community, the wreckage of K-129 represented an unprecedented intelligence windfall. The Cold War was defined by a delicate nuclear balance, and gaining access to Soviet military hardware could reveal vital cryptographic systems, codebooks, radio manuals, radar technology, and the precise design and telemetry of Soviet nuclear warheads. If the United States could salvage the submarine intact, it could evaluate the true capabilities and limitations of the Soviet naval deterrent.
The technical obstacle was formidable: no salvage operation in history had ever attempted to lift an object weighing thousands of tons from a depth of over three miles. Deep-sea recovery at the time was limited to small submersibles and lightweight wreckage. Military planners recognized that standard naval salvage vessels lacked the lifting capacity and could not operate in the open Pacific without drawing immediate Soviet suspicion. The mission was handed to the Central Intelligence Agency, which organized the effort under the code name Project Azorian, approved at the highest levels of the United States government by President Richard Nixon and National Security Advisor Henry Kissinger.
The Hughes Mining Cover Story
To mask the purpose of the operation from Soviet surveillance and the American public, the CIA devised one of the most intricate cover stories in espionage history. The agency partnered with eccentric billionaire industrialist Howard Hughes, whose sprawling corporate empire frequently engaged in classified defense contracting. Hughes agreed to act as the public face of a supposed commercial enterprise: an experimental deep-sea mining venture aimed at harvesting manganese nodules from the abyssal plains of the ocean.
Under the auspices of Hughes's Summa Corporation, the agency funded the design and construction of the Hughes Glomar Explorer, a colossal, 618-foot commercial-looking vessel with a 200-foot-tall central derrick. The ship was outfitted with an enormous internal well, known as a 'moon pool,' whose bottom doors could open beneath the waterline to bring large objects inside away from the gaze of satellites or passing ships. To keep the heavy recovery machinery concealed during transit, a specialized covered submersible barge, the Hughes Mining Barge (HMB-1), was built. The barge was submerged off the West Coast to transfer the massive mechanical capture vehicle into the belly of the Glomar Explorer away from prying eyes.
Engineering the Abyssal Claws
The mechanical heart of Project Azorian was the capture vehicle, nicknamed 'Clementine.' Clementine was an enormous steel framework equipped with hydraulically actuated grasping tines designed to wrap entirely around the submarine's hull. Lowering Clementine three miles to the seabed required stringing together hundreds of thirty-foot sections of high-strength steel pipe, creating a heavy pipe string that had to support its own immense weight along with the thousands of tons of the captured submarine.
Operating at such depths presented extreme engineering challenges. The pipe string was subject to deep-ocean currents, harmonic vibrations, and catastrophic bending stresses. The Glomar Explorer relied on an advanced dynamic positioning system, using computers, satellite navigation, and hull thrusters to maintain a fixed position above the wreck despite ocean swells. Specialized heave compensators buffered the ship's vertical movement, preventing wave swells at the surface from snapping the rigid pipe string thousands of feet below.
The Operation at Sea
On July 4, 1974, the Hughes Glomar Explorer arrived at the recovery site in the central North Pacific. The crew began the painstaking process of threading miles of pipe downward into the darkness. As the salvage effort progressed, Soviet interest was piqued. Two Soviet naval vessels, including an ocean-going tug and an intelligence-gathering ship, circled the Glomar Explorer for nearly two weeks, watching the derrick operate and photographing the ship at close range.
The American crew maintained their commercial mining cover under intense scrutiny. Technicians staged routine deck operations, and ship officers traded friendly hand signals with the Soviet crews to defuse suspicion. Even when a Soviet helicopter flew close to inspect the deck machinery, the crew kept the moon pool doors closed and the capture machinery hidden below the waterline. Convinced that the vessel was merely conducting deep-sea mineral testing, the Soviet ships eventually departed the area, allowing the salvage attempt to proceed.
Failure and Partial Recovery
After Clementine successfully locked its mechanical arms around the submarine hull, the lifting phase began. For several days, the crew hoisted the pipe string back to the surface, joint by joint. However, approximately a third of the way up the water column, disaster struck. Several tines on the capture vehicle fractured under the immense stress, causing the bulk of K-129 to break apart. A major section of the submarine slipped from the claw and plummeted back to the seafloor, carrying with it the sail, the missile compartments, and the intelligence prize the CIA had sought.
Only the forward section of the submarine, measuring approximately thirty-eight feet in length, remained lodged within the claw. This section was hoisted into the Glomar Explorer's moon pool, where it was drained and examined by specialized intelligence teams. Inside the recovered wreckage, the team discovered two nuclear-armed torpedoes, various pieces of naval equipment, and the remains of six Soviet submariners. Despite falling short of its goal to retrieve the ballistic missiles and cryptographic systems, the salvage of a heavy multi-ton structure from three miles down marked an unprecedented engineering achievement.
Exposure and the Glomar Legacy
The bodies of the six recovered Soviet crew members were treated with military dignity. CIA personnel prepared an official naval burial ceremony, draping the remains in the Soviet naval ensign and reciting prayers in both English and Russian as the sailors were committed to the sea with full honors. The entire ceremony was recorded on film. In October 1992, following the dissolution of the Soviet Union, CIA Director Robert Gates presented the film and the ship's bell of K-129 to Russian President Boris Yeltsin in Moscow.
A planned follow-up mission to recover the remaining wreckage was aborted after the operation's cover collapsed. In June 1974, burglars broke into the Los Angeles offices of Howard Hughes's Summa Corporation, stealing classified documents that linked the Glomar Explorer to the CIA. By early 1975, journalists, led by Seymour Hersh and Jack Anderson, pieced the story together and published accounts of the secret mission. When reporters subsequently submitted Freedom of Information Act requests seeking agency files on the operation, the CIA crafted a novel legal formula, stating it could 'neither confirm nor deny' the existence of the records. This response, upheld by federal courts, entered American jurisprudence and the global lexicon as the 'Glomar response.'
Key takeaways
•Project Azorian was a covert 1974 CIA operation that attempted to raise the sunken Soviet submarine K-129 from a depth of over 16,000 feet in the Pacific Ocean.
•The agency partnered with Howard Hughes to create an elaborate public cover story claiming the ship, the Hughes Glomar Explorer, was designed for commercial deep-sea manganese mining.
•Structural failure in the mechanical claw caused the majority of the submarine to break away and sink back to the ocean floor, though a forward section containing two nuclear torpedoes was retrieved.
•The legal response the CIA developed to evade press inquiries about the ship gave rise to the enduring 'Glomar response' ('neither confirm nor deny').