Lighter machinery could preserve the original Tribal dual-purpose turret

The original dual-purpose 4.7-inch turret was considered too heavy for the Tribal design. Gas-turbine machinery savings could allow four of those turrets without the weight reductions that later compromised the mount developed for the L class. Its design lost roughly 20 percent of its weight before regaining about 10 percent as problems emerged. A true dual-purpose main armament would give destroyers better protection against aircraft. Exercises had encouraged confidence in low-angle guns because attacking aircraft concentrated on carriers and capital ships, an assumption that left destroyers vulnerable when they became targets.