Improved Kilo

Russia's diesel-electric Kalibr-capable attack submarine — the "Black Hole" of the Black Sea, a widely exported SSK and the platform behind the only documented submarine-launched cruise-missile strikes in combat.

Overview

The Improved Kilo (Project 636.3 "Varshavyanka") is the pinnacle of the Russian Kilo-class diesel-electric attack submarine (SSK) lineage, distinguished by its integration of the Kalibr family of cruise missiles and its reputation for extreme acoustic discretion — earning it the Western sobriquet "Black Hole." Built by Admiralty Shipyards in St. Petersburg, the first Project 636.3 boat entered service with the Black Sea Fleet in 2014, and the class has since become the workhorse of Russia's conventional submarine force and a global export bestseller, with more than seventy Kilo-family boats built and over sixty in service worldwide, according to USNI Proceedings. The Improved Kilo provides a layered capability — anti-surface and anti-submarine warfare from six 533 mm torpedo tubes, plus the ability to strike inland targets with Kalibr land-attack cruise missiles, a feature it has used in combat more than any other submarine class.

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