The wartime S-class program was large, but orders were still reassessed as strategy and production needs changed. Seven of the twenty boats ordered in 1940 were never laid down, and four boats from the 1943 group were also canceled. Those decisions account for most of the difference between the number ordered and the number completed. The long sequence of proposed S-names also shows how the class expanded far beyond its compact prewar run.
Notable Point · 16:18-19:27
Large wartime orders did not make every S-class boat inevitable
Canceled boats in the 1940 and 1943 programs explain much of the gap between S-class orders and completed submarines.