The Cold War saw numerous submarine accidents, especially on the Soviet side. For much of its existence, the USSR tried to maintain a world-beating military with a second-rate economy. Throughout the era, the Soviets struggled to maintain their magnificent weapons of war. In the effort to close this gap, the crews of Soviet submarines often paid with their lives.

But only one submarine had the poor luck to sink twice.

The Charlie class (Project 670) was the third class of cruise-missile submarines (SSG) deployed by the Soviet Union, and the second to use nuclear propulsion (SSGN). The Soviet Navy expected to use early SSGs and SSGNs to attack American land targets, primarily cities and naval bases, with conventional and nuclear warheads. The cruise missiles of the time lacked sophisticated guidance mechanisms, making attacks against the interior impossible. Over time, the improvement of radar-homing technology (as well as improvements in ballistic-missile technology) allowed the Soviets to reconceptualize the use of cruise missiles. The Echo II class, the immediate predecessor to the Charlies, were built with an anti-shipping role in mind. Antiship missiles appealed to the Soviets because of the noise of their submarines; the Soviet Navy did not expect that its boats could close within sufficient range to hit American capital ships with torpedoes.

Designed in the early 1960s, the first Charlie entered service in late 1967. Displacing 4900 tons and capable of twenty-four knots, the Project 670 submarines fired the P-70, a subsonic missile which could deliver a conventional warhead or a two-hundred-kiloton nuclear device up to thirty-five miles. This was not a particularly long distance, almost certainly within the anti-submarine warfare (ASW) reach of a carrier battle group or other major NATO asset, but development problems with a new missile forced the design choice. In any case, the ability of the Project 670 boats to fire while underwater gave NATO planners new headaches.

Tenth in its subclass, K-429 entered service in September of 1972. She joined the Pacific Fleet, homeported in Petropavlovsk. In early 1983, she entered port for an extensive refit, with her crew departing on leave. Nuclear-armed cruise missiles and torpedoes remained aboard the boat during refit.

In spring of 1983, tensions between the United States and the USSR ran as high as at any point in the Cold War. In addition to supporting anti-Soviet guerrillas in Afghanistan, the United States had begun aggressively testing Soviet air and sea defenses all along the USSR’s extensive border. In April, the U.S. Navy and several partners began Fleetex ‘83, a major exercise in the North Pacific. The exercise included the USS Midway and USS Coral Sea carrier battle groups, as well as numerous additional surface ships, aircraft, and submarines. At one point, U.S. aircraft overflew islands in dispute between the USSR and Japan.

Possibly in part because of the heightened tensions, the Soviet Pacific Fleet ordered K-429 back to duty before expected, and before the completion of her overhaul. Captain Nikolai Suvorov could not find his crew, and so went to sea (under protest) with an ad hoc crew assembled from several different submarines, including 120 men and two captains. Few of the men onboard K-429 had any direct familiarity with her systems.

The ensuing disaster was altogether predictable. Suvorov was unaware that the overhaul process had locked the ventilation system open. Instrumentation on the boat was not properly set up, and in any case the crew had little experience with the boat, or with each other. The captain ordered a test dive, which resulted in an extremely fast descent because of misunderstandings about the ballast tanks. At that point, one compartment of the boat began to flood quickly. Response procedures were slow because of crew inexperience, and fourteen sailors quickly died. Shortly afterward, the boat hit bottom, about 160’ below the sea.

The escape capsules and emergency buoys had, of course, been welded to the hull; losing a buoy was a serious offense. Captain Suvorov initially hoped that the descent of the submarine would be noted at the naval base, but after several hours grew concerned. It didn’t help that the temperature in parts of the submarine had reached 120 degrees, or that one of the boat’s main batteries had exploded. One of the captains asked for volunteers to swim to the surface, and report on the plight of the boat. Two sailors exited through the torpedo compartment, swam to land, and were promptly arrested under suspicion of spying. Several hours later a rescue contingent arrived; divers entered the boat, supplied the crew with sufficient numbers of diving apparati, and led the escape of most of the remainder of the men.

Three months later, Suvorov and one of his compartment chiefs were arrested, tried, and convicted for violation of fleet rules. Suvorov received a ten year sentence, of which he served three. Overall, sixteen men died. The Russian public only learned of the accident in the 1990s; the original crew of K-429 only found out when they arrived in port with their submarine nowhere to be found.

K-429 had not suffered irreparable damage; she was refloated, repaired, and returned to service. Her second life was brief, however; in September 1985, the boat sank at dockside with the loss of one crewmember. The causes of the second sinking remain hazy, but appear unrelated to the first incident. K-429 was again raised, but not returned to sea; for the rest of her career she served as a training hulk. She was scrapped, along with her sisters, in the 1990s.

The Cold War forced the USSR to compete with the United States, a state that enjoyed huge advantages in transportation and infrastructure, even setting aside the profound ideological edge of capitalism over state-socialism in producing innovative technology. Under these conditions the workers, soldiers, and sailors of the Soviet Union did as well as they could. But the immense pressure of the Cold War inevitably produced accidents, often in the cutting edge systems that the Soviets needed most. K-429 sank because the Soviet leadership grew paranoid about American military advantages, and then sank again because the Soviets lacked the resources to maintain basic port facilities.

Robert Farley, a frequent contributor to TNI, is author of The Battleship Book. He serves as a Senior Lecturer at the Patterson School of Diplomacy and International Commerce at the University of Kentucky. His work includes military doctrine, national security, and maritime affairs. He blogs at Lawyers, Guns and Money and Information Dissemination and The Diplomat.

Image: An aerial port quarter view of a Soviet Mike-class nuclear-powered attack submarine underway. Wikimedia Commons/U.S. Navy