Diesel propulsion initially looks like a questionable choice for an anti-submarine destroyer because machinery noise can interfere with hunting submarines. The Mitsui and Mitsubishi diesels in the Yamagumo class were quiet enough to be an exception to that rule of thumb. ASROC, a 375 mm ASW rocket launcher, and lightweight torpedoes gave the ships a serious hunter-escort fit. Japan gained useful fleet numbers and presence vessels while continuing investment in the yards that would build later classes.
Notable Point · 34:28-36:12
Yamagumo makes quiet diesel propulsion serve ASW mass
The Yamagumo class complicates the assumption that diesel propulsion is too noisy for submarine hunting by pairing unusually quiet Japanese machinery with a heavily ASW-oriented fit.