A technically possible design still has to survive a production decision. Reworking 4.7-inch mounts for high-angle fire would require altered mountings, production-line changes, and a rotation of old equipment through modification. Fitting an available four-inch high-angle mount could return ships to service sooner. Starting the work in 1938 might still create a stock of improved mounts for later Tribal-class refits. Henderson's repeated attempts to solve the dual-purpose-gun problem make the idea plausible even though the Royal Navy historically fielded several competing calibers.
Notable Point · 30:31-33:20
The production choice behind a dual-purpose 4.7-inch gun
Making the 4.7-inch mounting truly dual-purpose is technically plausible, but it competes with the faster wartime expedient of fitting separate four-inch high-angle guns.