The
heavy cruiser was a type of
cruiser, a naval
warship designed for long range and high speed, armed generally with naval guns of roughly 203mm calibre (8 inches in caliber) and
displacing approximately 10,000 tons. While the general mission of the heavy cruiser to act as a fast scout for a battle fleet and protect and hunt down commerce was largely unchanged from the days of sail, its design parameters were dictated by the
Washington Naval Treaty of 1922 and the
London Naval Treaty of 1930.