The programme involved 21 yards and 19 organisations. Nihon Kokan, Mitsubishi Heavy Industries and Hitachi Zosen accounted for 44, 43 and 23 ships respectively, together about 59 percent of construction. Total output was about 187 vessels, making kaibōkan Japan's largest wartime shipbuilding category by number in this comparison. The British Empire built 338 corvettes, 205 frigates and 29 sloops during the same period. Japan's smaller industrial base and resource supply complicate the inference that fewer completions meant less effort.
Notable Point · 3:23-4:56
Escort output against Japan's industrial capacity
Japan's roughly 187 escorts need to be weighed against its industrial capacity when comparing the programme with British Empire output.