Finnish Riga class Hämeenmaa
Class overview
Name	Riga class
Operators	Soviet Navy Bulgarian Navy  Volksmarine  Finnish Navy  Indonesian Navy  People's Liberation Army Navy
Preceded by	Kola class
Succeeded by	Petya class Krivak class
Completed	69
General characteristics
Class and type	Frigate
Displacement	1,160 tons (standard) 1,416 tons (full load)
Length	91 m (299 ft)
Beam	10.2 m (33 ft)
Draught	3.16 m (10.4 ft)
Propulsion	2 × shaft steam turbines, 2 × boilers; 21,000 hp (16,000 kW)
Speed	28 knots (52 km/h; 32 mph)
Range	1,950 nmi (3,610 km; 2,240 mi) at 14 kn (26 km/h; 16 mph)
Complement	175
Armament	3 × 100 mm guns/56 (B-34) (3×1) 4 × 37 mm guns (2×2) 4 × 25 mm guns (2×2) - Some ships MBU-600 anti-submarine rocket launchers (replaced by two RBU-2500) 2 or 3 × 533 mm torpedo tubes (1×2 or 1×3)

The Riga class was the NATO reporting name for class of frigates built for the Soviet Navy in the 1950s. The Soviet designation for these ships was Storozhevoi Korabl (escort ship) Project 50 Gornostay (Ermine stoat). The Riga class was analogous to World War II era destroyer escorts.

Design

These ships were a smaller and simpler version of the Kola class. According to Conway's, this simpler group of ships were ordered by Joseph Stalin who was concerned about the cost of large ships. The class introduced high pressure steam turbines and new radars into Soviet service. The bridge, gun turrets, and magazines were covered in 8 mm (0.31 in)-thick armour. The main armament comprised three single dual-purpose 100 mm (3.9 in) guns with remote power control and a single Yakor type fire control director. The machinery comprised two TV-9 steam turbines with two boilers and had initial problems with reliability.

The Project 50 Riga class was a rather simplistic and straight forward design. With their basic capabilities, moderate size and ease of operation, they made perfect export vessels for smaller navies where such ships could easily fill the multi-purpose role, taking the place of large minesweepers and actual destroyers.

There was a modernisation programme designated Project 50 A in the late 1950s early 1960s. This included fitting anti-submarine rocket launchers (RBU-2500) new radar and adding permanent ballast for improved stability.

Ships

A total of 68 ships were built by Nikolayev yards (20 ships), Komsomolsk-on-Amur (7 ships) and Kaliningrad (the lead yard 41 ships). Most ships were decommissioned by 1980, however some were sold to China. The programme was cut short by Nikita Khrushchev in 1956 as the ships were becoming obsolete and the last ship was completed in 1959.

Export operators

 Bulgaria

Bulgarian Navy : 3 ships (Druzki, Smeli and Bodri) operated 1957-1990, decommissioned 1990^[2][3]

 People's Republic of China

4 ships were built in kits for the People's Liberation Army Navy to be licence assembled in China as Chengdu class (Type 6601/01) frigate. After that, PRC built 5 ships with a different gun arrangements as Jiangnan class (Type 065) frigate, reverse-engineered copies from type 6601.

 Finland

Finnish Navy : 2 ships (Uusimaa and Hämeenmaa) acquired 1964, decommissioned 1979 and 1985 (source Conway's)

 East Germany

East German Navy : 4 ships (Ernst Thälmann, Karl Marx, Karl Liebknecht, Friedrich Engels)

 Indonesia

Indonesian Navy: 8 ships (Jos Sudarso, Slamet Rijadi, Ngurah Rai, Monginsidi, Lambung Mangkurat, Hang Tuah, Kakiali, Nuku) transferred 1962-1964, decommissioned 1971-1986 (Source Conway's)