In four years, the Nikolayev, Komsomol and Kaliningrad shipyards delivered 68 frigates of this type.
Unlike the later units of the Petya and Mirka classes, they were not specialized ASW units, but small, multi-purpose ships derived from the Kola, themselves inspired by the last German WWII torpedo-boats.
As a result, they had conventional weaponry consisting of three standard antiaircraft / mixed turrets complemented by dual 37mm DCA mounts, an anti-ship TLT bench (533mm), and two ASM MBU-200 rocket launchers completed by two grenade racks (12 in all), and 4 DTC launchers (12 in reserve) ASW.
The Riga, project 50, was defined in 1950 on Stalin’s injunction as mass production versions, very simplified, Kola. The smaller dimensions made it necessary to rethink propulsion, which became a system of turbines fed by boilers with overpressure in the same compartments.
These ships were also equipped with the new SFERA-50 firing system, similar to that of the Kotlin, but handicapped by excessive calculation time (more than 35 seconds).
However, their light hull was not exceptional at the level of holding at sea: From 28 knots in calm weather, the speed fell to 23 by force 6, the guns becoming inoperative because of the swell, and still they were limited use from the 16 knots reached.
In the years 65-75, these 68 units were modernized to the new ASM standards, yielding their MBU rocket launchers for RBU-2500, with 128 vectors in total, and obtaining in reinforcement 4 guns of 25 mm. Their fixed bow sonar became the Herkules, and an imposing solid ballast was added.
After Stalin’s death, Kushchev reduced orders for frigates of this type, and stopped the current programs.
China built four upgraded units, equipped with anti-ship missiles instead of torpedo tubes, and licensed the upgraded Kiangnan. Some “Riga”, cheap, were sold or transferred to friendly countries in the 1950s, to Bulgaria, the GDR, Finland, and Indonesia (16 in all). In 1960, the USSR thus lined up 61 vessels of this type, distributed among the four fleets.
Displacement: 1160, 1416t FL
Dimensions: 91 x 10.2 x 3.16 m.
Propulsion: 2 propellers, 2 turbines TV9, 21000 hp, 28 knots max.
Electronic: Radar Don-2, Slim Net, Sun Visor, sonar Pegas.
Armament: 3 x 100 mm AA (3×1), 4 x 37 mm AA, 2 x MBU 200 RLM, 2 grenade racks, 4 Grenade Launchers, 1×3 533 mm TT ASW