The lack of an ASW emphasis in the Shimushu class can be evidenced from the limited depth charge stowage (12, increased to 24 since May 1942 and 60 since Autumn 1943) and the lack of sonar until Autumn 1942, coastal defense ships became genuine, purpose-built, convoy escorts only with the Mikura class, that was fitted with sonar since the beginning and carried 120 depth charges, albeit the minesweeping gear was dropped from the plans only with the Ukuru class. Mass production wasn't attempted until the Ukuru class and the Type C&D, which extensively employed welding and pre-fabrication. | The lack of an ASW emphasis in the Shimushu class can be evidenced from the limited depth charge stowage (12, increased to 24 since May 1942 and 60 since Autumn 1943) and the lack of sonar until Autumn 1942, coastal defense ships became genuine, purpose-built, convoy escorts only with the Mikura class, that was fitted with sonar since the beginning and carried 120 depth charges, albeit the minesweeping gear was dropped from the plans only with the Ukuru class. Mass production wasn't attempted until the Ukuru class and the Type C&D, which extensively employed welding and pre-fabrication. |