C-class cruisers became anti-aircraft ships because the 5.25-inch turret was too large and the 4.5-inch gun was not ready, leaving the available high-angle four-inch weapon. Four or five twin 4.7-inch mounts would give them the same calibre as a Tribal destroyer, with enough surface power to make a raider or opposing destroyer take them seriously. They would still serve as escorts and fleet support instead of first-line cruisers. Their greater flexibility could matter when a convoy temporarily relied on one C-class cruiser while its destroyers pursued another threat. Once the same mount entered mass production, destroyers could receive it during refits as the dive-bomber threat became clearer.
Chapter · 21:41-26:54
C-class anti-aircraft cruisers keep a surface punch
Twin high-angle 4.7-inch mounts would let C-class anti-aircraft cruiser conversions engage aircraft while retaining more useful surface firepower than their historical four-inch batteries.