TSHD

Trailing suction hopper dredge (TSHD) is a self-propelled dredging vessel that excavates sediment from seabeds, harbors, and coastlines. It uses a long flexible suction pipe, known as a drag head, which is towed along the seabed by the vessel to draw sediment into the onboard hopper through a dredge pump. The hopper stores dredged material and can discharge it at a disposal site or at land reclamation sites by gravity through bottom doors or by pumping through a pipeline.

Construction and equipment: The hull features a large, bottom-hinged hopper for cargo; a trailing suction pipe with a drag head; a dredge pump and pipes; ballast tanks to adjust trim and stability; discharge arrangements including bottom doors and pump-out systems. Cutter heads may be fitted to loosen cohesive sediments, but many TSHDs dredge non-cohesive sand and mud without cutting.

Operation: The vessel moves slowly while dredging, with the drag head sweeping the seabed. Dredged material is pumped into the hopper; the ballast system allows for control of trim; crew monitor navigation and environmental constraints. When the hopper is full, the vessel returns to an unloading area; material is discharged through bottom doors or pumped to shore.

Applications and environment: TSHDs are widely used for harbor maintenance, fairway deepening, beach nourishment, and land reclamation. Dredging can increase turbidity and disturb benthic habitats; operations follow regulatory requirements and environmental management plans.

Owners and operators: The leading global dredging contractors—Boskalis, Van Oord, DEME Group, and Jan De Nul Group—operate large fleets of TSHDs.