Abstract: A hopper vessel has a series of discharge valve members in the bottom, which valve members can swing about a transverse axis from a horizontal postion, in which they close the bottom openings of the hold of the vessel, into a vertical position, in which they fully open said bottom openings, which valve members also can be placed in an inclined intermediate position in which they still close the bottom openings, said valve members being provided with channels which are in line with channels in the intermediate parts of the bottom and with a conduit connected to a pump, and the bottom openings, at the level of the valve members, having openings in the side walls connecting to water supply which openings are closed in the horizontal position of the valve members by said valve members and opened in the intermediate position whereby water entering through the openings assists in the discharge of material through the conduit with at least one valve member in said intermediate position.

Abstract: A barge for receiving dredged materials and water comprising a hull defining a hold and overflow apparatus for discharging excess water from the hold; the overflow apparatus comprises a separate discharge passage having a discharge outlet below the water line of the barge, a port defining an overflow opening communicating the hull and the discharge passage at a fixed position above the predetermined level to which solids are to be collected in the hold and below the predetermined levels of water in the hold and in the discharge passage, and a control valve in the discharge outlet for regulating the water level in the discharge passage. The method of dredging comprises maintaining the water level as aforesaid to prevent aeration of overflowing water.