The "Nimitz"-class aircraft carriers were ordered to supplement the aircraft carriers of the and es, maintaining the strength and capability of the U.S. Navy after the older carriers were decommissioned. The ships were designed to be improvements on previous U.S. aircraft carriers, in particular the "Enterprise" and supercarriers, although the arrangement of the ships is relatively similar to that of the "Kitty Hawk" class. Among other design improvements, the two reactors on "Nimitz"-class carriers take up less space than the eight reactors used on "Enterprise". Along with a more generally improved design, this means that "Nimitz"-class carriers can carry 90% more aviation fuel and 50% more ordnance when compared to the "Forrestal" class.