In the 1930s, larger destroyers began joining the cruiser line ahead of the fleet to locate the enemy. Making contact first offered warning and a chance to deliver the opening salvos before the enemy could respond. Aircraft also offered a comparatively cheap way to attack a task group. Planners weighed the loss of pilots and aircrew against the loss of warships and contemplated attacks by hundreds of aircraft. Destroyers therefore needed dual-purpose weapons that could contribute substantial firepower to the fleet's anti-aircraft screen.
Notable Point · 42:50-44:42
Destroyer pickets extend reconnaissance and air defence
Larger destroyers join the cruiser reconnaissance line, while the prospect of mass air attack gives their dual-purpose guns a growing fleet-defence role.