Why Birmingham changed the forward gun layout

The earlier layout could theoretically put three guns ahead, but blast from the wing guns damaged or disrupted the bridge, control positions, and spotting process. Firing the weapons in sequence rather than as a clean salvo also made fall-of-shot observation harder. The Birmingham subclass replaced that awkward arrangement with two forward six-inch guns, a pattern later carried into Adelaide. The change traded a paper advantage for a forward battery that could be controlled and spotted more effectively.