The speed and protection trade-off

Lexington suited peacetime presence, economic warfare, and scouting, where speed and offensive power carried much of the burden. Direct combat with enemy capital ships exposed the cost of her lighter protection. The stated scheme included a five-to-seven-inch belt, five-to-nine-inch barbettes, eleven-inch turret faces, six-inch turret sides, a twelve-inch conning tower, and a deck between one and a half and two and a quarter inches. Hood provides the immediate comparison: her belt reached twelve inches, turret armour ranged from eleven to fifteen inches, and barbettes from five to twelve inches, although some deck areas were thinner than Lexington's. The comparison shows why a design suited to presence and reconnaissance became vulnerable once it was expected to fight enemy capital ships.