Here's What You Need to Know: The power of the November class’s reactors was bought at the price of safety and reliability.

The United States launched the first nuclear-powered submarine, the USS Nautilus, in 1954, revolutionizing undersea warfare. The Nautilus’s reactor allowed it operate underwater for months at a time, compared to the hours or days afforded conventional submarines. The following year, the Soviet Union began building its own nuclear submarine, the Project 627—known as the November class by NATO. The result was a boat with a few advantages compared to its American competition, but that also exhibited a disturbing tendency to catastrophic accidents that would prove characteristic of the burgeoning Soviet submarine fleet during the Cold War.

The original specifications drafted in 1952 for a Soviet nuclear submarine had conceived of employing them to launch enormous nuclear torpedoes at enemy harbors and coastal cities. At the time, the Soviet Union lacked the long-range missiles or bombers that could easily hit most of the continental United States. However, as these capabilities emerged in the mid-1950s, the Project 627 design was revised to reflect an antiship role, with eight torpedo tubes located in the bow and combat systems taken from Foxtrot-class diesel submarines.

The first Project 627 boat, the K-3 Leninsky Komsomol, launched in 1957 and made its first voyage under nuclear power in July 1958 under Capt. Leonid Osipenko, using a reactor design supervised by renowned scientist Anatoly Alexandrov. The large, torpedo-shaped vessel displaced more than four thousand tons submerged and was 107 meters long. Its double-hulled interior was divided into nine compartments, housing a crew of seventy-four seamen and thirty officers.

K-3 rapidly demonstrated the extraordinary endurance of nuclear submarines, embarking upon two-month long cruises while submerged. In 1962, it became the first Soviet vessel to travel to the North Pole, while a sister ship, K-133, was the first submarine to traverse the Drake Strait submerged in a twenty-one-thousand-mile cruise that lasted fifty-two days.

K-3 was soon joined by twelve additional November-class vessels of a revised design designated the Project 627A, distinguishable by a bulbous sonar dome under the bow, as well as a single Project 645 prototype powered by an experimental VT-1 liquid metal reactor with greater power efficiency. The fourteen November-class boats were deployed to the Third and Seventeenth Divisions of the Northern Fleet, though later four were transferred to the Pacific Fleet by transiting under Arctic ice.

The 627’s VM-A reactors were more powerful than their American contemporaries, speeding the Project 627s along up to thirty knots (34.5 miles per hour). However, the 627 lacked another quality generally expected of a nuclear submarine: the reactors were extremely noisy, making the Project 627 boats easy to detect despite the use of stealthy propellers and the first anti-sonar coating applied to a nuclear submarine. This lack of discretion, combined with its inferior sonar array, made the November class ill suited for hunting opposing submarines.

Nonetheless, the 627s still dealt the U.S. Navy a few surprises. In 1965, K-27 managed to sneak up on the antisubmarine carrier USS Randolph off of Sardinia and complete a mock torpedo run before being detected. In 1968, another November-class boat proved capable of matching pace with the carrier USS Enterprise while the latter moved at full power, causing a minor panic in the Navy leadership that led to the adoption of the speedy Los Angeles–class attack submarine, some of which remain in service today.

However, the power of the November class’s reactors was bought at the price of safety and reliability. A lack of radiation shielding resulted in frequent crew illness, and many of the boat suffered multiple reactor malfunctions over their lifetimes. This lack of reliability may explain why the Soviet Union dispatched conventional Foxtrot submarines instead of the November-class vessels during the Cuban Missile Crisis, despite the fact that the diesel boats needed to surface every few days, and for this reason were cornered and chased away by patrolling American ships.

In fact, the frequent, catastrophic disasters onboard the Project 627 boats seem almost like gruesome public service announcements for everything that could conceivably go wrong with nuclear submarines. Many of the accidents reflected not only technological flaws, but the weak safety culture of the Soviet Navy.

K-8 started the trend in October 13, 1960, when a ruptured steam turbine nearly led to a reactor meltdown due to loss of coolant. The crew was able to jury-rig an emergency water-cooling system, but not before radioactive gas contaminated the entire vessel, seriously irradiating several of the crew. K-14, which would distinguish itself in the medical evacuation of an Arctic expedition in 1963, also experienced a reactor breakdown in 1961, necessitating its replacement the following years.

In February 1965, radioactive steam blasted through K-11 on two separate occasions while it underwent refueling at base. The repair crews misdiagnosed the implications of the first event and followed incorrect procedures during the second, and were ultimately forced to evacuate the reactor room, leading to fires breaking out across the ship. The Soviet crew flooded the vessel with 250 tons of water to put out the flames, spreading radioactive water throughout the entire vessel. Seven men were badly irradiated, and the reactor required a complete replacement before it could be returned to active duty three years later.

K-3, the first Soviet submarine to sail on nuclear power, was on a Mediterranean patrol on September 8, 1967, when a hydraulic fire broke out in its torpedo tubes, with the resulting buildup of carbon monoxide killing thirty-nine sailors. The entire command crew passed out, save for a lone petty officer who managed to surface the ship, saving the vessel. A later investigation concluded the fire may have been caused by a sailor smoking in the torpedo compartment.

K-27, the lone Project 645 boat, experienced a breakdown in its port-side reactor on May 24, 1968, in the Barents Sea—despite the crew warning that the reactor had experienced a similar malfunction in 1967 and had yet to test that it was functioning properly. The entire crew of 124 was irradiated by radioactive gas, but Captain Leonov refused to take emergency measures until hours later due to his faith in the reactor. Shortly after the ship limped home on its starboard reactor, five of the crew died from radiation exposure within a month, with twenty-five more to follow in subsequent years. Repair of K-27 ultimately proved too expensive a proposition, so it was scuttled by ramming in Stepovoy Bay in waters only thirty-three meters deep—rather than the three to four thousand meters required by the IAEA.

In 1970, the ill-fated K-8 was participating in the Okean 70 war games off the Bay of Biscay when it suffered simultaneous short circuits in its command center and reactor control room, spreading a fire through the air conditioning system. The captain managed to surface the boat, and the crew nearly escaped with only moderate loss of life—except that the Soviet Navy ordered about half of the men back on board to conduct emergency repairs and pilot the ship home. An encounter with a sea squall led to the damaged boat sinking to the ocean floor, taking fifty-eight crew and four nuclear torpedoes with it.

The November-class boats finally began to enter retirement in the 1980s and early 1990s—but not before being subject to a final few accidents, not of their own making. In August 1985, K-42 was berthed next to the Echo-class submarine K-433 near Vladivostok when the latter suffered a nuclear refueling accident that killed ten and irradiated 239. K-42 was deemed so badly contaminated that it, too, had to be decommissioned.

As the Soviet Union was succeeded by an economically destitute Russia, many decommissioned nuclear submarines were left to rust with their nuclear fuel onboard, leading to safety concerns from abroad. International donors fronted $200 million to scrap the hulks in 2003. Flimsy pontoons were welded onto K-159 to enable its towing to a scrapping site, but on August 30 a sea squall ripped away one of the pontoons, causing the boat to begin foundering around midnight. The Russian Navy failed to react until hours later, by which the time submarine had sunk, taking eight hundred kilograms of spent nuclear fuel and nine of the ten seamen manning the pontoons with it. Plans to raise K-159 have foundered to this day due to lack of funding.

This is just an accounting of major accidents on the November-class boats—more occurred on Echo- and Hotel-class submarines equipped with the same nuclear reactors. Submarine operations are, of course, inherently risky; the U.S. Navy also lost two submarines during the 1960s, though it hasn’t lost any since.

The November-class submarines may not have been particularly silent hunters, but they nonetheless marked a breakthrough in providing the Soviet submarine fleet global reach while operating submerged. They also provided painful lessons, paid in human lives lost or irreparably injured, in the risks inherent to exploiting nuclear power, and in the high price to be paid for technical errors and lax safety procedures.