 The light A/A was dispersed throughout the ship and included both automatic cannons (20 mm to 40 mm) and heavy machine guns (12.7 mm to 14.5 mm).During World War II, the US Navy, Royal Navy, the French Navy and the Imperial Japanese Navy combined the secondary battery with the heavy anti-aircraft guns, creating a dual-purpose secondary battery.They discarded the dedicated, anti-ship secondary batteries altogether, because a battle-line fleet would be screened against cruisers and destroyers most of the time.