Suction dredger

A suction dredger lifts sediment hydraulically as a water slurry through a dredge pump, rather than mechanically with a bucket or grab. The two main families are the trailing suction hopper dredger, which trails a drag head along the bed while under way and stores material in its own hopper, and the cutter suction dredger, which holds station on spuds and breaks hard ground with a rotating cutter at the suction mouth before pumping the slurry ashore or to a barge. Plain suction and water-injection dredgers also fall in this class. Suction plant suits sand and soft to medium soils; the cutter type extends the range into stiff clay and weak rock.