Glossary Archive - Page 3 of 13 - Start Dredging

Glossary

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    • Coastal protection

      Coastal protection is an essential process to provide a defence against flooding and the erosion of land caused by waves, tides, currents and wind. Beach re-nourishment and dike construction are some examples of coastal protection works. Both require the recovery and transportation of large volumes of sand.

    • Critical velocity

      The critical velocity is the velocity below which the grains in the mixture start falling out of suspension and start forming a layer at the bottom of the pipeline.

    • Cutter suction dredger

      The cutter suction dredger (CSD) is a type of dredger that uses a rotating cutting tool to dislodge the soil in order for it to be drawn into a suction pipe. A CSD typically consists of a non-self-propelled pontoon with in a pivoting ladder that houses the cutter and suction pipe. The types of soil it can handle are sand, gravel, clay, sandstone and soft rocks. Cutter suction dredgers are widely used for land reclamation projects, the construction of dams, dikes and breakwaters, the excavation of new harbour basins and canals, the improvements of the course of a river, etc.

    • Cutterhead

      A cutterhead is a piece of dredging equipment used on cutter suction dredgers. The cutterhead dislodges the soil through a rotating motion, so that the slurry can be drawn into the suction pipe. Since the dredging process starts with excavation and slurry creation, a CSD’s performance is mainly defined by its cutterhead. Different soil types demand different forms of penetration. Therefore, there is a wide variety in cutterheads available.

    • Design/construct contract

      With a design/construct contract the customer will supply a concept with the main requirements of the project. Contractors have to include a detailed project design in the tender offers or pre-qualification documents.