Why secret drawings cannot preserve a battleship industry

Could Germany secretly continue designing battleships during the interwar period even if it built none?

It could preserve some paper design, but would still lose generations of practical designers and shipyard expertise.

Germany could continue drawing battleships on paper, but designers could retire or move abroad for work when construction stopped. The exact balance between government and commercial design teams is recalled tentatively, with German shipyards thought to have had a larger role than their British counterparts. Paper iteration can compound an untested mistake across several designs because no completed ship exposes the original problem. Even the way drawings are formatted affects whether a design can be built reliably. Foreign contracts could preserve some experience, but a hypothetical Dutch colonial battlecruiser would answer different requirements from a German battle-line ship. Such work could help with stability and arrangements for aircraft or anti-aircraft weapons without providing equivalent experience of battleship protection.