High Quality Content by WIKIPEDIA articles! The Kirov-class battlecruiser is a class of nuclear-powered military ships of the Russian Navy, the largest and heaviest surface combatant warships (i.e., not an aircraft carrier, amphibious assault ship, or submarine) currently in active operation in the world. Among modern warships, they are second in size only to large aircraft carriers, and of similar size to a World War I-era battleship. The official designation of the ship-type is heavy nuclear-powered guided missile cruiser, but because of their size and general appearance, the ships are sometimes referred to as battlecruisers in western media.