Isuzu-class Destroyer Escort

The Isuzu-class Destroyer Escort was a destroyer escort (or frigate) class built for the Japan Maritime Self-Defense Force (JMSDF) in the early 1960s. The latter batch (Kitakami and Ōi) were quite different from the earlier two vessels in their propulsion and weaponry, so sometimes they were classified as the "Kitakami-class".

This class was the first JMSDF surface combatant adopted shelter-deck design. Propulsion systems varied in each vessels because the JMSDF tried to find the best way in the propulsion systems of future DEs. The design concept of this class and the CODAD propulsion system of the Kitakami-class became prototype of them of the latter DEs and DDKs such as Chikugo-class and Yamagumo-class.

The gun system was a scale-down version of the Ayanami-class, four 3"/50 caliber Mk.22 guns with two Mk.33 dual mounts controlled by a Mk.63 GFCS. Main air-search radar was a OPS-2, Japanese variant of the American AN/SPS-12.

In the earlier batch, the main Anti-submarine armament was a Mk.108 Weapon Alpha. The JMSDF desired this American brand-new ASW rocket launcher earnestly, but then, it became clear that it was not as good as it was supposed to be. So in the latter batch, it was changed with a M/50, Swedish 375mm quadruple ASW rocket launcher. And later, Weapon Alpha of the earlier batch was also replaced by a Type 71, Japanese version of the M/50.

Specifications

 * Type: Destroyer Escort
 * Service Period: 1961-1993
 * Characteristics:
 * Length: 308 feet 4.8 inches (94 meters)
 * Beam: 33 feet 5.56 inches (10.2 meters)
 * Depth: 22 feet 11.64 inches (7 meters)
 * Draft: 11 feet 5.8 inches (3.5 meters)
 * Displacement: 1,670 tons (Standard); 1,904 tons (Full Load)
 * Crew: 185
 * Propulsion (Isuzu and Mogami): 4 x diesel engines (4,000 hp each), 2 x shafts
 * Propulsion (Kitakami and Ōi): CODAD, 4 x diesel engines (4,250 hp each), 2 x shafts
 * Range:
 * Speed: 25 knots (46.3 km/h)
 * Sensor Suite:
 * OPS-2 Air Search Radar
 * OPS-16 Surface Search Radar
 * OQA-1 Variable Depth Sonar
 * OQS-12 Search Sonar
 * OQY-2 Attack Sonar
 * Mk.63 Gun Fire Director
 * Mk.105 ASW Command System
 * Countermeasures:
 * NOLR-1 Electronic Support Measures
 * Armament (Isuzu and Mogami):
 * 4 x 3"/50 caliber Mk.22 guns (Type 57)
 * 1 x Mk.108 ASW Rocket Launcher
 * 2 x Mk.2 ASW torpedo racks
 * 1 x Y-gun depth charge throwers
 * 1 x depth charge rack
 * 4 x 533mm torpedo tubes
 * Armament (Kitakami and Ooi)
 * 4 x 3"/50 caliber Mk.22 guns (Type 57)
 * 1 x M/50 375mm ASW rocket launcher
 * 2 x Type 68 12.75" triple torpedo tubes
 * 1 x Y-gun depth charge throwers
 * 1 x depth charge rack
 * 4 x 533mm torpedo tubes