What is a dredge? How does a dredge work?

A cutterhead hydraulic dredge is a machine designed to pump sediment from a body of water.  Hydraulic dredges are a barge designed to float with various means of propulsion including cables, walking spuds, and paddle wheels.  The dredge has an power source (diesel engine or sometimes an electric motor) that uses belts or hydraulics to turn a pump.  The suction side of the pump has an extension of pipe that extends down a ladder beneath the water’s surface.  The cutterhead turns to agitate the sediment or sludge so that it can be sucked into the pump.  The pump discharges the slurry through a pipeline to a dewatering or disposal area.