If T21 comes a year or so earlier then Speer isn't armaments minister and there's probably no modular construction plan, at least not initially. With T7/9 still having some value, the process probably isn't so rushed. Skipping a prototype was supposed to save 6 months but in reality cost time. It was about a year between completion of the first boat and the first and only T21 operational mission.Terry Duncan wrote: ↑31 Aug 2020 02:37Unless they can be fixed there will never be even close to as many Type XXI's at sea as there were Type VII's and Type IX's. Bringing forward a failed production process will hardly be an advantage. Might as well abandon the entire modular construction idea and just let experienced yards build them.
With a longer time horizon and - depending on ATL - greater security in the Baltic and Med, the Germans would have the option of using more slipway space instead of using modular construction. Leningrad, for example, had a lot of slipway space and was safe from any bombing. Likewise Italy. Or they could have started with normal construction and, once the kinks were worked out, ramped up modular. In any ATL in which Germany beats SU, they can probably do both more shipyard space as well as later modular construction.