The Soviet submarine that nearly launched a nuclear torpedo in 1962 was B-59. The incident occurred on October 27 during the Cuban Missile Crisis, when B-59 was operating near Cuba and being pursued by US Navy forces.
B-59 was a diesel-electric Foxtrot-class submarine carrying a nuclear-tipped torpedo. Its batteries were running low, its air-conditioning system had failed, and its crew had been out of contact with Moscow. US ships dropped practice depth charges intended to signal the submarine to surface, but the exhausted crew could not initially know whether a war had begun.
Captain Valentin Savitsky reportedly considered launching the nuclear torpedo against the American fleet. Vasili Arkhipov, the submarine's flotilla chief of staff who was aboard B-59, refused to support the launch. The submarine eventually surfaced and withdrew, avoiding a potentially catastrophic escalation.
B-59 is sometimes confused with the other Soviet submarines sent toward Cuba, including B-4, B-36, and B-130. The episode is also simplified in popular accounts: the US forces did not know the submarine carried a nuclear torpedo, and the exact launch discussions were reconstructed from later testimony and records.