Cemented in history as the submarine that nearly started World War III, the Foxtrot-class is one of the USSR’s most prolific and longest-lived submarine lines.

The Soviet Union’s first post-war attack submarines, belonging to the Zulu-class, were found to suffer from design and performance deficiencies so drastic that the Soviet military opted to cut their combat service short and set about procuring a new class of diesel-electric patrol submarines. The result of those efforts became the Project 641 class (NATO reporting name Foxtrot), with the first boat in a seventy-five strong series laid down in 1957.

Soviet submarine design is no stranger to extremes, replete with exotic component choices and eccentric engineering approaches. From the fastest submarine to the largest submarine, the USSR earned a reputation for naval projects centered on a wildly ambitious, if not always practical, idée fixe. But the Foxtrot class is, in a sense, unique in how technically unremarkable it is. The boat displaced roughly 2,000 tons when surfaced and featured an overall length of just under 300 feet. Designed prior to the widespread adoption of the teardrop hull construction for superior underwater performance, the Foxtrot-class was optimized for surface travel. Even then, the submarine was somewhat on the slower side at a modest surfaced top speed of sixteen knots. It did, however, offer a fairly competitive range of 20,000 nautical miles and underwater endurance of up to four to five days. The class was armed with ten standard 533 mm torpedo tubes.

The Foxtrot-class rose to global prominence—or rather, infamy—during the Cuban Missile Crisis, a tense political and military standoff in 1962 that saw Washington and Moscow come within a hair’s breadth of nuclear war.

Four Foxtrot submarines—the B-4, B-36, B-130, and B-59, each armed with a single nuclear-tipped T-5 torpedo—were dispatched to the Cuban harbor of Mariel to provide support to the Castro regime. The Soviet submarines were detected and pursued by surface vessels belonging to the U.S. Navy, which dropped practice depth charges to let the submarines know that they were spotted. Cut off from communications with Moscow, B-59 Captain Savitsky concluded that war had broken out and ordered the crew to fire the submarine's nuclear warhead at their pursuers. If not for the heroic efforts of second captain Vasily Arkhipov, whose refusal blocked the B-59's leadership from reaching the unanimous consent necessary to authorize the strike, Foxtrot would have earned the ignominious distinction of becoming the first submarine to initiate a nuclear war.

The Foxtrot line was much too long-lived for its own good, with the class drifting toward technical obsolescence by the time the last Foxtrot models were laid down in 1972. One of the last active-service Project 641 submarines, Zaporizhia, was seized by Russian forces during the 2014 annexation of Crimea. The Black Sea Fleet refused to accept the decrepit Zaporizhia, with the Russian military offering instead to return it to Ukraine.

The Foxtrot line was replaced in the Soviet Navy by the Tango-class of diesel-electric submarines from 1972 onward. The last Russian Foxtrot submarine was decommissioned in 1993.

Mark Episkopos is a national security reporter for the National Interest.

Image: Reuters