Abstract: Nodule dredge comprising one or more of the following: convergent wall device, e.g., "horn member", for accelerating liquid flow through the apparatus; comb or grid-like collecting or lifting device that can lift nodules into accelerated flow without necessarily lifting an entire layer of silt, especially where silt is relatively loose; inclined surface to receive and raise nodules driven down stream by accelerated flow, while silt is removed; and collection chamber below nodule path defined by inclined surface, to receive nodules from inclined surface.

Abstract: A dragged or self-propelled unit has drag shoes or other means to dislodge nodules from the sea bed into a duct which may be associated with nozzles to project fluid against the nodules. The duct increases substantially in cross-section, thereby slowing the velocity of a stream formed by the nodules, accompanying silt and water. The slowed nodules and silt are caused to follow divergent separate paths within the unit, the nodule path being relatively below the silt path, and the nodules are removed from the duct upstream of the final outlet by which silt and water depart the unit.