The 16-inch naval guns were heavy artillery pieces mounted on the deck of battleships used during World War II and the Korean War. The US Navy Iowa-class battleships were armed with nine 16″/50 Mark 7 guns, which were mounted in three triple-gun turrets; two on foredeck, and one on aftdeck. These powerful 410mm naval guns fired 2,700 lb (1,225 kg) shells to a maximum range of 24 miles.
The Japanese Nagato-class was equipped with eight 16″/45 (410mm) guns, which were fitted in four double-gun turrets; two fore and two aft. These 19-m-long gun barrels were slightly shorter than the Americans and had a maximum range of 22 miles.
Despite their destructive power, these 16″ naval guns were rarely used against enemy warships as they were mostly employed to provide fire support to landing troops, softening up the beaches of enemy-held islands, coastal bombardment.
US Navy’s 16-in guns in action in the Pacific (video)