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fighting ships of the world

SOVIET/RUSSIAN NAVY (USSR/RUSSIA)

MINE WARFARE SHIPS

BT-177 coastal minesweepers (project 1256) (1974)

Altayskiy Komsomolets 1990

Name No Yard No Builder Laid down Launched Comp Fate
БТ-177 [BT-177], 3.1975- Алтайский комсомолец [Altayskiy Komsomolets], 2.1992- БТ-177 [BT-177]   516 Sredne-Nevskiy SYd, Pontonnyy     1.12.1974 stricken 6.1993
БТ-137 [BT-137], 6.1975- Комсомолец Эстонии [Komsomolets Estonii], 2.1992- БТ-137 [BT-137]   517 Sredne-Nevskiy SYd, Pontonnyy     1.12.1974 stricken 6.1993

 

Displacement standard, t

386

Displacement full, t

473

Length, m

47.9

Breadth, m

8.70

Draught, m

2.36 hull 4.20 max

No of shafts

3

Machinery

2 M504A-3 diesels + 1 M-8NL gas turbine

Power, h. p.

9500 + 20000 = 29500

Max speed, kts

38

Fuel, t

diesel oil

Endurance, nm(kts)

500(15)

Armament

1 x 6 - 30/54 AK-306, 4 - 8 mines

Electronic equipment

Rym, Don-D radars, RTU-2V remote control equipment

Complement

20

Project history: These ships were conceived to escort larger ships through mined waters, dealing with mines with combination (pressure, acoustic, magnetic) fuzes. The unusually high power was intended to allow them to move at high speed to create a turbulent wake which would trigger pressure mines. In theory, the sweeper would first sweep for magnetic and acoustic mines, then escort ships in the hydrodynamic field of its own wake, manoeuvering to distort the pressure fields of the ships so as not to trigger the mines. Alternatively, the sweeper could create very strong fields of its own, to trigger mines beyond ranges at which they would be lethal. Hence the solenoid coils which were partly visible on the ship's side. Machinery noise could be amplified to trigger acoustic mines. Because there was always a change that a triggered mine would destroy the sweeper, remote-control gear was installed.

    They had plastic hulls, and large cable ducts running down both sides A prominent stack served a gas turbine generator, the propulsion diesels exhausting through the hull sides.

Modernizations: 1985, BT-177: diesels were replaced by 2 M504A-4 (9900hp)

Naval service: No significant events.

Komsomolets Estonii 1984

© Ivan Gogin, 2016