What would the Royal Navy do if the US Navy acquired Tillman battleships in 1916?
Short answerIt would likely answer with enlarged G3/N3-style ships and a move toward 18-inch armament.
NotesTillman III is the most plausible version of the scenario: roughly 63,000 tons, 30 knots, and twelve 16-inch guns. That makes her about 16,000 tons heavier than Hood and large enough to provoke a major British response. The Royal Navy would probably scale up the G3 and N3 concepts toward a similar 60,000- to 65,000-ton range. British work on 18-inch weapons makes that calibre the logical reply, with an enlarged N3 potentially carrying four triple turrets and the G3 taking either 18-inch guns or a larger 16-inch battery. The result is a new capital-ship race rather than a British attempt to answer the Tillmans within the historical treaty designs.