Kotor-class frigate

The Kotor-class frigate is a class of anti-submarine warfare frigate built by the SFR Yugoslavia. It was developed on the basis of the Soviet Koni-class frigate, but with significant modifications and improvements. The Kotor-class was built at the Tito Shipyard in Kraljevica and commissioned in the Yugoslav Navy until the Yugoslav Wars, when in 1992 they were passed to the successor state Serbia and Montenegro. The Kotor-class frigates were passed on to the Montenegrin Navy in 2006.

Design
The hull used sheet steel with a thickness of 3 to 15 mm, while the superstructure is made of aluminum alloy with a thickness of 2 to 10 mm. The superstructure was designed to reduce radar reflection.

The frigates are armed with four missiles, ship-to-ship P-21 or P-22 (NATO code SS-N-2 Styx). The weight of the missiles is 2607 kg, warhead weighing 480 kg, with a range from 8 to 80 km altitude flying at 25 or 50 meters, at a speed of Mach 0.9. They have infra-red self-guidance systems (P-22) or active radar guidance (P-21).

For air defense, the ships use OSA-M missile systems (NATO code SA-N-4 Gecko). It consists of the radio-controlled guided anti-aircraft missile RZ-13 mounted on the double ejector type missile rail ZIF-122, device management and shooting training operator. The RZ-13 missile can effectively destroy targets that fly at a height of 50-6,000 m at a distance to 15 km.

The ship has two quadruple launchers MTU-IV with four air Strela 2M missiles. Launchers are compatible with other, more modern MANPADS.

Two rocket twelve-barreled depth charge launchers RBU-6000 are intended for anti-submarine warfare. Their range is 350 to 5,500 m, with a maximum target depth of 400 m.

The frigates are also armed with artillery, consisting of a universal automatic AK-726 cannon caliber 2x76.2 mm and two AK-230 caliber 30 mm cannons.

The Kotor frigates are equipped with sensors to detect and track targets. To detect surface and air targets, the MR-302 Rubka (NATO codename Strut Curve) radar is used, which has an approximately 110 km range, while the RM 1226 Decca radar is intended for navigation. The MPZ-301 (NATO code Pop Group) radar system is used to fire Osa-M missiles, and for the management of artillery fire observation and sighting radar systems operation 9LV-200 MK-2 and sighting radar MR-104 Ris are used. The ships also have active sonar, radiological detectors, laser detectors and detector for radar irradiate. For the defense of anti-ship missiles frigate is equipped with infrared laser and Barricade type radar decoys.

The Kotor's are powered by CODAGE (combined), consisting of one M8G gas turbine, providing a maximum power of 14,720 kW and two Pielstick SEMT 12 PA 6V diesel engines, providing power of 280 kW by 3648. The ship has three propellers - two for diesel engines and one for the gas turbine. The main drive represents diesel engines and are used most of the time, while the gas turbine was designed to provide additional speed during the performance of combat tasks.

The other ship systems include a device for degaussing of the ship, two desalinization devices for the production of drinking water, devices for radio link, the device to receive data from hydro-acoustic buoys, devices for underwater connection, firefighting and drainage pumps, fuel pumps for the draft and oil, system air conditioning, fire system on the basis of halogen, equipment for the production of electricity and others.

Operators

 * Yugoslavia (SFRY and FRY) - 2 ships, Kotor (RF-33) and Pula (RF-34) (Novi Sad since 1992)
 * Montenegro - 2 ships, ex-Kotor (P-33) ex-Pula (P-34)