The main armored belt was thick, while the main armored deck was up to thick. The main battery gun turrets had thick faces, and they were mounted atop barbettes that were protected with the same thickness of steel. The conning tower had thick sides. The ship's armor layout had been designed with opponents equipped with 14-inch guns in mind, but since the treaty system broke down just before construction began, her design could not be revised to improve the scale of protection to defend against heavier guns. Despite this shortcoming, the "North Carolina" class proved to be more successful battleships than the better-armored but very cramped .