A single faulty weld triggered an explosion felt as far as Alaska

Countries & Cities · Published 12 October 2026 Swipe more like this →

In short: The K-141 Kursk was designed to sink aircraft carriers, a pinnacle of Soviet engineering. Yet, its destruction in 2000 was caused by a microscopic failure: high-test peroxide seeping through a faulty weld, creating a chain reaction that turned a training exercise into a maritime catastrophe.

Constructed as a nuclear-powered cruise missile submarine of Oscar II-class, the Kursk represented the second biggest vessel ever produced in that category. Designed to defeat entire U.S. Navy carrier strike groups, it featured a high-nickel stainless steel hull for corrosion resistance and a magnetic signature low enough to evade detection systems. Despite its formidable capabilities—including 24 supersonic Granit missiles and torpedoes capable of carrying nuclear warheads—the vessel was plagued by the systemic decay of the post-Soviet era.

In August 2000, while participating in the 'Summer-X' naval exercise, the Kursk prepared to fire dummy torpedoes. A failure occurred when high-test peroxide (HTP), a highly concentrated propellant, leaked through a faulty weld in a Type 65 torpedo casing. Upon contact with a catalyst, the HTP expanded by a factor of 5000, generating massive amounts of steam and oxygen. This pressure ruptured the kerosene fuel tank, causing an initial explosion equivalent to 100–250 kilograms of TNT.

The disaster escalated rapidly. The heat from the first blast reached over 2,700 °C, detonating five to seven additional torpedoes. This secondary explosion was equivalent to 3–7 tons of TNT and registered a magnitude 4.2 on seismographs across Europe, detectable as far away as Alaska. While some personnel survived the initial blast by plunging under water, a subsequent chemical reaction in oxygen generators caused a flash fire that consumed all remaining breathable air.

The tragedy highlighted deep institutional failures. Vice-admiral Valery Ryazantsev noted that the crew had received no specific training for HTP torpedoes and were provided with incorrect safety manuals. Furthermore, the Russian Northern Fleet had suffered severe funding cuts throughout the 1990s, leaving many vessels—including search and rescue equipment—in a state of neglect.

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