Six 18-inch guns, twelve 15-inch guns, and the spare-turret evidence

Would Agincourt have carried six 18-inch guns, twelve 15-inch guns, or a new 16-inch battery?

Twin 18-inch mountings fit the proposed technological sequence, but the design remains an inference. A 16-inch step offered limited benefit, and the spare 15-inch turrets can be traced to other programmes.

An 18-inch battery in twin turrets would extend a familiar British mounting type, although fitting it on a Queen Elizabeth-like beam would be tight. Triple 18-inch turrets would require a wider ship and another technological development. A move from 15 to 16 inches offered little attraction before a treaty imposed that ceiling; 16.5 or 18 inches made more sense within this interpretation. Later appearances of 18-inch guns, small-tube boilers, and geared turbines provide indirect clues to Agincourt's possible design. The spare 15-inch twin turrets have a separate explanation: twelve mountings ordered for three Revenge-class ships could supply six for Renown and Repulse, four for Courageous and Glorious, and two for monitors. That accounting weakens the argument that those spare mountings reveal Agincourt's armament.