An auger suction dredger functions like a cutter suction dredger, but the cutting tool is a rotating Archimedean screw set at right angles to the suction pipe and resting horizontally on the seabed. This auger head agitates and loosens material from the seabed and pushes it toward the centre to the mouth of the suction pipe. There the mixture is transferred through a pipeline to its destination. Augers were originally stationary, but the introduction of self-propelled versions of the auger dredger allow the dredger to propel itself without the use of anchors or cables.
Auger dredgers were primarily used for sludge removal applications from waste water treatment plants and clean-up projects in lakes. Today, auger dredges are used for a wider variety of applications including for river maintenance and sand mining. They are often used for environmental dredging because their low turbidity and minimal resuspension is less disruptive of marine life. Augers are also effective for dredging contaminated sediments as they are designed for the removal of thin layers.
