The BL 15-inch Mark I succeeded the BL 13.5-inch Mk V naval gun. It was the first British 15-inch (380 mm) gun design and the most widely used and longest
Boalsburg, Pennsylvania. 14-inch/50-caliber gun – later 14-inch gun (American) BL 14-inch Mk VII naval gun – for British RoyalNavy King George V-class battleships