Kapitan Patimura Class Indonesian Corvette

The Parchim-class corvette (Soviet designation Project 1331M) was developed for the East German Navy in the late 1970s, and built by the Wolgast Peene-Werft. The ships were designed for coastal anti-submarine warfare. In case of an all-out NATO-Warsaw Pact war in Europe their prime targets would have been the small U-206 coastal submarines of the West German navy. The first ship, Wismar (now the Indonesian KRI Sutanto), was launched on 9 April 1981 in Rostock, and subsequently another 15 ships were built until 1986. To make production more economical, the Soviet Union agreed to purchase another 12 ships from Wolgaster Peenewerft built between 1986 and 1990, thereby effectively subsidising the East German shipbuilding industry. The ships of the Soviet Navy were named Parchim II by NATO. Though useful as a coastal ASW platform, the Soviet production of the similar but far more powerful Grisha class made this purchase even more illogical for the Soviet Navy. After German re-unification the former East German ships were sold to the TNI-AL (Indonesian Navy) in 1993. The Indonesian Navy extensively refurbished their Parchims, to the point where the refurbishing exceeded the cost of purchase. They are still in service, both in the Indonesian Navy and in the Russian Baltic Fleet. For air defence, the ships were equipped with one double-barrel AK-230 30 mm gun and one double-barrel AK-725 57 mm gun. The Ak-725 double 57 mm AA gun, designed in 1959, was directed by the ESP-72 fire control system, which received ranging and target bearing information from an MR 103 (NATO codename 'MUFF COB') radar. The MR 103 had a 1.30 m (4.3 ft) parabolic radar dish, with an optical camera system slaved to it, as a backup system in case of failure or heavy EW environment. The barrels of the gun were water-cooled and belt-fed, with each belt containing 550 rounds, but the first round had to be manually chambered. In an emergency, the turret could be manually operated with an optical fire control system. The MR 103 radar system, already outdated when the Parchims were developed, used 1950s-style electromechanical systems, built around vacuum tubes. As a result, it wasn't considered to be an effective anti-missile system, or CIWS (Close-in weapon system), as was evidenced by a Soviet training accident in 1987 when a test missile drone accidentally locked in on a small Soviet Navy training vessel. Although the ship's AK-725 system kept firing until the moment of impact, no hits were scored and the ship was destroyed by the resulting fire, allegedly killing 39 crew members. The AK-230 gun was a fully automatic, stabilized, NN-30 double-barrel, water-cooled, four-chamber revolver cannon. The guns had a 1,000 round per minute (rpm) rate of fire and were fed by independent 500 round ammunition belts. The regular associated radar system was the (NATO codename) DRUM TILT radar, which was not used in the Parchim class. According to some sources the AK-230 could not only be linked with the DRUM TILT but also with the MUFF COB radar system, but this is disputed by old East German naval sources. According to these East German sources, the AK-230 gun on the Parchim-class corvette was optically guided, thereby leaving the Parchim class without an effective CIWS, and therefore unable to counter anti-shipping missiles. There were also two SA-N-5 (Naval SA-7 or Strela II) MANPAD positions aboard the Parchims. But without an effective, radar guided SAM missile system, the Parchims were left completely vulnerable to enemy precision guided anti-shipping weapons. This was a major restriction and confined the Parchims to brown water coastal operations, close to the protective air force and air defence umbrella. The air search radar was the ubiquitous (NATO codename) STRUT CURVE radar. This radar had a 4 m (13 ft) parabolic radar dish, worked in the F-band frequency, and had a respectable 60 nautical miles (110 km) radar range against aircraft flying at 5,000 m (16,000 ft) height, and a less respectable 20 nautical miles (40 km) radar range against surface shipping or low flying aircraft. The electronic defense suite was very basic, and consisted of an IFF (Identification Friend or Foe) receiver and transmitter, and an 'ELOKA' multiband passive RWR antenna slaved to a double 16-cell chaff dispenser. All in all, air defence - or the lack of one - was a very restrictive factor in the tactical usefulness of the Parchim design.