How early triple turrets could transform Orion

If the St Vincent class adopted triple centreline turrets, when would the Royal Navy move to all-triple battleship batteries?

Probably with the Orion class, producing an all-centreline battery of fifteen 13.5-inch guns.

The proposed St Vincent arrangement mixes triple centreline turrets with twin wing turrets. Once the Royal Navy moved to an all-centreline layout, the answer expects the triples to remain. That would make Orion the transition point to a battery of fifteen 13.5-inch guns. The exchange shows how one turret-layout decision can cascade into the next generation of dreadnought design.