Kilo class

   The Project 877 or Vashavyanka diesel-electric submarine, better known in the West as the Kilo class, was designed in the early 1970s for the anti-submarine and anti-ship defense of Soviet naval bases, coastal installations and sea lanes, and also for the patrol and surveillance tasks. First delivered from the shipyard at Komsomolsk in eastern Siberia, but then built in the western USSR at Nizhny Novgorod ant the Admiralty Yard in Leningrad (now St Petersburg), the boat is of the medium-endurance type and the first example was launched in 1979 for completion in 1982.

   Some 24 Kilos were built for the Soviet navy, and by the first part of the 21st century the Russian navy had deleted 15 of these, leaving it with nine boats with the Northern and Pacific Fleets (three and four respectively), and single boats with the Baltic and Black Sea Fleets, the latter's boat having been modified with pumpjet propulsion.

   In design the Kilo class is a development of the Tango class with an improved hull form. Even so, the boat can be considered only basic by comparison with contemporary Western submarines.

   The Kilo class has achieved respectable export sales. These boats have been exported to Algeria (two), China (12), India (10), Iran (three), Poland (one) and Romania (one), some of them Type 636 submarines with improved propulsion and fire-control systems.

Variants

   Project 877K, with improved fire control;

   Project 877M, with provision for wire-guided torpedoes from two tubes;

   Project 4B, with uprated diesels. It is slightly longer and fitted with an automated data system to provide fire-control data for two simultaneous interceptions. It's electric motor is turning more slowly for less noise.

   Lada class, improved version of the Kilo, fitted with air-independent propulsion system and new combat systems.