Tango-class submarine

A Tango-class submarine in the North Atlantic.
Class overview
Name:	Tango class (Project 641B)
Builders:	Gorky
Operators:	Soviet Navy
Preceded by:	Foxtrot class
Succeeded by:	Kilo class
Completed:	18
Active:	1
Retired:	14
Preserved:	3
General characteristics
Type:	Submarine
Displacement:	3,100 tons surfaced 3,800 tons submerged
Length:	91 m (298 ft 7 in)
Beam:	9.1 m (29 ft 10 in)
Draught:	7.2 m (23 ft 7 in)
Propulsion:	3 diesel engines 4.6 MW (6,200 shp) 3 electric motors 3 shafts.
Speed:	13 knots (24 km/h; 15 mph) surfaced 16 knots (30 km/h; 18 mph) submerged
Complement:	62 men (12 officers)
Armament:	6 x 533 mm (21.0 in) bow torpedo tubes 24 x 533 mm (21 in) anti-submarine and anti-ship torpedoes or equivalent load of mines

The Tango class was the NATO reporting name of a class of diesel-electric submarines that were built in the Soviet Union to replace the Foxtrot-class submarines assigned to the Black Sea and Northern Fleets. The Soviet designation of this class was Project 641B and it was also known as the Som (Catfish) class. The first of the class was completed in 1972 at Gorky. A total of 18 were built in two slightly different versions. The later type was several metres longer than the first, possibly because of the installation of ASW missile equipment.

The bow sonar installations appear to be similar to those fitted to Soviet nuclear attack submarines. The propulsion plant was the same as the last subgroup of the Foxtrot class. The Tango class had far more battery capacity, far higher than any previous conventional submarine class in the Soviet Navy; as a result, pressure hull volume increased. This allowed an underwater endurance in excess of a week before snorkeling was required.

Coupled with new armament and sensor fit, the Tango class were ideal for ambush operations against Western nuclear submarines at natural chokepoints.

Because of its all-hull rubber coating, the sub class was nicknamed "rezinka" [rubber]

Construction of this class has now stopped. One unit remains in the Black Sea Fleet but it may have been decommissioned since 2010.

Schematic of the Tango class

B-307, Togliatti

B-396, Moscow

B-515, Hamburg

Tango B-396 torpedo room

Three 641B-class submarines operate as museum ships:

The conning towers of stricken B-319' and B-474 are on display in Polyarny and Ryazan.