![]() ![]() Barges or scows: Mechanical dredgers discharge the dredged material into barges or scows.Often, a project may use all three types of discharge pipeline. Sinker lines are used where floating lines would interfere with navigation or shore pipelines. Discharge pipelines may be floating or pontoon mounted, or they can be submerged (“sinker lines”). For long distances to the placement areas booster pumps may be required, spaced at intervals along the discharge line. Pipelines: Hydraulic suction and cutter suction dredgers use pipelines to transport dredged materials to the placement site.The method of transport is determined by the type of equipment being employed and the type of material, and the type of material in turn determines the suitable placement option. The transportation of dredged material is an integral part of the dredging process, both as a cost factor and an environmental factor. These dredgers, specifically designed for use in natural surroundings, are:Īuxiliary equipment for transporting dredged material The dredgers mentioned below are sometimes described as environmental dredgers. Some of the mechanical or hydraulic dredgers described above can be used in a hydrodynamic mode. Hydrodynamic dredgers loosen or dislodge material underwater and then use the bed slopes, natural water currents and density gradients at the dredging site to move the material to a different location. The dredgers that are representative of mechanical/hydraulic dredgers are: These dredgers are often employed on construction and maintenance projects. Mechanical/hydraulic dredgers are the reliable workhorses of the dredging industry. In some special cases, hydraulic dredgers pump into barges for subsequent transport to the placement site. They use hydraulic centrifugal pumps to provide the excavating force without mechanical cutters and hydraulic transport to carry solid/water slurries from the digging site through a pipeline to the surface and then to the discharge site. These dredgers use hydraulic means both for excavating and transporting material. These dredgers use mechanical means for the excavation of material and are generally speaking similar to equipment used for dry land excavation. All of these will influence the achievable production rates. Other factors to be considered are weather and sea state, shipping traffic at ports and in navigational channels, the depth and thickness of material being removed and seasonal/environmental windows. One key factor is the production rate of the dredger as rates vary widely depending on the circumstances, the material to be dredged and the transport and disposal methods employed. The selection of equipment is a crucial cost element in estimating the budget for a maritime infrastructure project. equipment that is self-propelled during the excavation phase or the transportation phase or both, and.Within these four categories, equipment can be further subdivided based on the means of propulsion: ![]() Mechanical/hydraulic dredgers (utilising both basic elements in some combination) – cutter suction dredgers.The four broad classifications used here are based on the method of excavation and operation: The above-mentioned dredgers can be categorised in several ways. environmental requirements and limitations.the availability of equipment or cost of mobilisation to deploy to a given area of the world,.the placement, relocation and reuse alternatives,.the quantities and types of material to be dredged,.No single type of dredger or system of employment will be suitable for all projects. When choosing equipment, contractors, clients and consultants must give careful consideration to the operation at hand. ![]()
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