A hybrid mount could make the 4.5-inch gun practical

Later Royal Navy Mark V 4.5-inch installations, exemplified by HMS Vampire, developed into a gun family used on British destroyers, frigates, and escorts for decades after the war. Those mature systems arrived too late for a treaty-era Tribal design. The proposed contemporary solution combines the Mark III 4.5-inch upper-deck mounting with the assisted movement and wider train of the Mark XIX 4.7-inch mount. The result would weigh roughly 30 tons and use two-piece ammunition to keep manual loading practical. The extra twenty tons across four mounts is manageable on an approximately 1,850-ton destroyer, although its position high in the ship still matters. Preserving the wider firing arc is important because losing 20 degrees of train can halve the number of guns bearing during a confused destroyer action such as Narvik.