A trailing suction hopper dredger dredges loose material and soft soils such as sand, gravel, sludge or clay. One or two suction pipes are lowered on the seabed and the drag head is trailed over the bottom. A pump system sucks up a mixture of soil and water and discharges it in the ‘hopper’ or hold of the ship.
The fully loaded vessel sails to the unloading site, where the material is deposited on the seabed through bottom doors or reclaimed by using the rainbowing technique. The material can also be pumped ashore through a pipeline, where it can be used for reclaiming land.