The Algol-class vehicle cargo ships, also known as Fast Sealift Ships (FSS) or SL-7s, are currently the fastest conventional steam powered cargo ships in the world that are still (intermittently) operating, capable of speeds in excess of 33 knots (61 km/h). Originally built in 1972 and 1973 as high-speed container ships known as SL-7s for SeaLand, the ships' high operating costs limited their profitability. All eight ships were acquired by the United States Navy in 1981 and 1982, with the last ship converted, delivered to and placed in service with Military Sealift Command in 1986. The conversion entailed the installation of four cranes, addition of roll on/roll off capability and a redesign of the cargo hold to better facilitate storage of vehicles. All ships are named after bright stars in the night sky.