Second World War-era capital ships had three classes of artillery: the heavy main battery, intended to engage opposing battleships and cruisers (280 mm (11 inch) or greater); a secondary battery for use against enemy destroyers of 127 to 155 mm (5 to 6.1 in); heavy anti-aircraft guns of 76 to 127 mm (3 to 5 in), which could create barrages to knock out airplanes at a distance; finally, light rapid-fire anti-aircraft batteries (A/A) to track and bring down aircraft at close range. The light A/A was dispersed throughout the ship and included both automatic cannons (20–40 mm) and heavy machine guns.