An early Japanese 18-inch ship could prompt Britain to prioritize a fast response using new 15-inch/50 guns. A revived F3-style design, possibly enlarged to carry twelve guns, is one proposal. Existing 15-inch shell stocks around the world and the barrel repair, recasting, and sustainment industry would support it. Britain would need to retain older battleships until replacements arrived, so the proposed gun could also offer those ships an upgrade path. This scenario begins before the historical 14-inch program had matured, and the proposed 15-inch/50 response was not adopted historically.
Notable Point · 1:17:27-1:20:26
New 15-inch guns supported by a global ammunition system
Existing shells and barrel facilities could favor a new British 15-inch gun program for both new ships and upgrades to older battleships.