An all-big-gun ship built for salvo fire

Earlier pre-dreadnoughts commonly carried only four heavy guns. These weapons could make occasional long-range shots or deliver close-range blows, but the small battery was poorly suited to sustained, accurate salvo fire. Dreadnought's ten 12-inch guns provided a much larger heavy-gun broadside. With more than four heavy guns in action, a ship could fire a meaningful salvo, observe the fall of shot, and correct the next one. Coordinating enough comparable shells for effective long-range gunnery mattered as much as the calibre itself.