OVERVIEW: The RBU‑12000 “Udav‑1” is an unguided, ship‑launched, 300 mm anti‑submarine depth‑charge rocket system. It provides a hard‑kill defense against submarines and incoming torpedoes via salvo-fired depth-charge rockets.

DETAILS: RBU stands for Reaktivnaya Bombometnaya Ustanovka (“rocket depth-charge installation”). Developed by the USSR and entering service in 1986–87, the Udav‑1 employs the KT‑153 10-barrel launcher with automated below-deck reload. Among its rocket types, the 111SG is specifically a depth-charge rocket with a 80 kg warhead, and 300 mm caliber, detonating via contact or timed fuse.

FUNCTION: The 111SG depth-charge rockets are launched in salvo or single-shot modes to create a barrier of explosions aimed at neutralizing submerged threats. Fired in response to sonar detection, they sink rapidly and detonate under or near the target submarine.

NOTE:
IOC: 1986–87 (Udav‑1)
Operators: Soviet Union → Russia

SOURCE:
Weaponsystems.net: UDAV‑1 system overview; Wikipedia: RBU‑12000; Weaponsystems.net: 111SG rocket warhead data; de.wikipedia.org: RBU‑12000 technical specifications.