The RBU-6000 Smerch-2 (Реактивно-Бомбовая Установка, Reaktivno-Bombovaja Ustanovka; reaction engine-bomb installation & Смерч; waterspout) is a 213 mm caliber Soviet anti-submarine rocket launcher. It is similar in principle to the Royal Navy Hedgehog system used during the Second World War. The system entered service in 1960–1961 and is fitted to a wide range of Russian surface vessels. It consists of a horseshoe-shaped arrangement of twelve launch barrels, that are remotely directed by the Burya fire control system (that can also control the shorter ranged RBU-1000). It fires RGB-60 unguided depth charges. The rockets are normally fired in salvos of 1, 2, 4, 8 or 12 rounds. Reloading is automatic, with individual rounds being fed into the launcher by the 60UP loading system from a below