The ''Isuzu''-class destroyer escorts were four

destroyer escort Destroyer escort (DE) was the United States Navy mid-20th-century classification for a warship designed with the endurance necessary to escort mid-ocean convoys of merchant marine ships. Development of the destroyer escort was promoted by th ...

s (or

frigate A frigate () is a type of warship. In different eras, the roles and capabilities of ships classified as frigates have varied. The name frigate in the 17th to early 18th centuries was given to any full-rigged ship built for speed and maneuvera ...

s) built for the

Japan Maritime Self-Defense Force The , abbreviated , also simply known as the Japanese Navy, is the maritime warfare branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. The JMSDF was formed following the dissolution of the Imperial Japanese Navy ( ...

(JMSDF) in the early 1960s. The latter two (''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 Combined diesel and diesel (CODAD) is a propulsion system for ships using two diesel engines to power a single propeller shaft. System A gearbox and clutches enable either of the engines or both of them together to drive the shaft. Two advan ...

propulsion system of the ''Kitakami'' class became prototype of them of the latter DEs and DDKs such as and . The gun system was a scale-down version of the , four 3-inch/50-caliber Mark 22 guns with two Mark 33 dual mounts controlled by a Mark 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 warfare Anti-submarine warfare (ASW, or in the older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations ar ...

(ASW) 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 375 mm quadruple ASW rocket launcher. Later, the Weapon Alpha of the earlier batch was also replaced by a Type 71, Japanese version of the M/50.

Ships

References

* {{Combatant ship classes of the Japan Maritime Self-Defense Force Frigate classes Frigates of the Japan Maritime Self-Defense Force