Which unbuilt 1920s Royal Navy capital-ship design would have been most useful in World War II?
Short answerF3 is preferred for its fast, heavily armed design and easier dockyard support, although G3's greater potential capability attracts a competing argument.
NotesF3's nine 15-inch guns and speed of roughly 29 knots would give the Royal Navy a useful fast capital ship for the Second World War. A competing preference for G3 rests on its larger platform and greater potential capability. F3's smaller size would make it easier to maintain across the available dockyards. K3 enters the comparison as another powerful possibility, but its design is described as less mature than F3's. Which proposal qualifies as an unbuilt ship also matters: a preliminary study is a different proposition from a design ready to go to a yard.