Ballast System

a system of pipes and pumps that serves to take in and expel the liquid ballast of a ship. Ballast is usually taken on in ballast tanks (sections of double hull, deep tanks, on-board and below-decks tanks, and the forepeak and afterpeak); in some instances it is taken into the fuel tanks, and on tankers into the cargo tanks. The productivity of the ballast-system pumps in a freighter is generally calculated to expel all ballast in four to ten hours. 12–1725–51