Twenty-inch guns: loading cycles and range

Peacetime encounters with Japanese ships would make their unusually large guns harder to conceal and could provoke a calibre race. Britain and the United States could answer six 20-inch weapons with twelve 16-inch guns and more chances to hit. An illustrative loading cycle of 70 to 80 seconds may be optimistic: moving very heavy shells at sea, handling damage, and returning the guns to loading elevation could push practical firing intervals toward two minutes. Smaller 16- or 16.5-inch weapons might then fire several salvos for each Japanese salvo, making ranging easier. A 20-inch gun only 35 or 40 calibres long could also have less range than a smaller weapon with a longer barrel. These are estimates of possible performance, raising the question of whether heavier shells would compensate for slower fire.