A modern 18-inch weapon could not be recreated by simply scaling up an existing gun. Recreating one would take years of technological reinvention, and construction at this scale would still be an art as much as a science. That distinction points to manufacturing judgement accumulated through repeated design and production, not engineering equations alone. Continued heavy-gun development matters to the counterfactual because it preserves a capability that would be slow to recover after decades of disuse.
Notable Point · 23:13-24:20
Why an 18-inch gun cannot simply be restarted
Building an 18-inch naval gun today would require years of technological reinvention because weapons of that size depend on practical craft as well as formal science.