Anatomy of Yamato

10. Heavy Armor
The ship's steel armor weighed 23,000 tons—more than 30 percent of Yamato's total weight. The Imperial Navy developed new ways to harden steel and otherwise improve armor technology for the ship. Plates of armor 25 inches thick—the heaviest armor ever mounted on a warship—shielded the turrets of her main guns. The side of the ship could survive the impact of 3,000-pound armor-piercing projectiles like those shot from the ship's big guns. But Yamato's bow and stern were not as well protected. Most of the torpedoes that ultimately sank the ship struck there, below the waterline, where she was most vulnerable.