L9 destroyers and earlier adoption of the 4.5-inch gun

Which fictional or never-built warships stand out as favorites?

The unbuilt L9 destroyers, whose timely construction could have strengthened the early-war fleet and accelerated adoption of the 4.5-inch gun.

The unbuilt L9 destroyers are a personal favorite among designs that existed on paper. Henderson's proposed successors to the Tribals could, in this counterfactual, have been built in 1937-38 and launched in 1939-40. Their planned 4.5-inch guns are identified with those later fitted to the Battle class. Starting production while Britain still had spare industrial capacity could have established the manufacturing base and accelerated standardization of the weapon on destroyers. Two flotillas of large L9s alongside the Tribals are judged capable of making a substantial difference to the early-war force.