Chikugo-class destroyer escort

The Chikugo-class destroyer escort (or frigate) was a class of destroyer escorts built by the Japanese Maritime Self-Defense Force as the successor of the Isuzu-class destroyer escort, with the same ASW mission. This class was followed by JDS Ishikari. This is the first Japanese destroyer escort class to carry ASROC anti-submarine missiles.

The class entered service with Chikugo in 1971. Eleven ships were constructed and saw service until the mid-1990s and early 2000s. All vessels in the class were retired with Noshiro being the last to decommission in 2003.

Design
This class was designed as the modified variant of the Isuzu-class destroyer escort, the preceding destroyer escort class. The main anti-submarine weapon was changed from the M/50 375 mm ASW rocket launcher to the ASROC Anti-submarine missile. The octuple launcher for ASROC was stationed at the mid-deck, and the entire ship design was prescribed by this stationing. To exploit the range of ASROC, this class was equipped with the long-range low-frequency (5 kHz) bow sonar, OQS-3A (Japanese version of the AN/SQS-23), and in addition, the latter batch had SQS-35(J) Variable Depth Sonar system. These anti-submarine sensors and weapons could be compare with those of destroyers in the main fleet of this age, such as Minegumo-class destroyer and Yamagumo-class destroyer.

In contrast to their anti-submarine capability, the anti-aircraft fire power was weakened compared to the preceding class. The foredeck gun was a Type 68 3"/50 caliber twin cannon controlled by a FCS-1B Gun Fire Control System, which was standard anti-air weapon system in the JMSDF of this age. But the afterdeck gun was the old-fashioned Bofors 40 mm L/60 twin cannon, lacking the anti-ship missile defense (ASMD) capability. The final batch of this class was planned to equipped with the new Oerlikon 35 mm twin cannon, but this plan was frustrated because of the budgetary consideration.