Wash Plate in Ship (Forepeak) any of several plates fitted in a ship’s bottom to prevent surging of bilge water when the ship is rolling or pitching. plates may be used in different structural designs as the un-stiffened panels, plane or corrugated, intact or perforated, including the wash plates that are constructed to minimise the impact of sloshing in closed tank spaces. sloshing, in partially filled cargo and ballast tanks, causes severe damage to ship structures. with ships being built with larger tanks less internal structure and free surface area, the number of failures atributted to sloshing effect is significant for wash plating, the minimum requirements for plate thickness may be based on the reaction forces imposed on the neighbour structures. the existence of a wash plate depends on the tank configurations, for example, the peak tanks shall have a centre line wash bulkhead when the breadth of the tank is greater than 2/3 of the moulded breadth of the ship. (DN