scraper dredge
Quick Summary
A scraper dredge, also known as a dragline, is a type of floating excavation device used for underwater work. It handles material using a scoop suspended from a swinging boom. The scoop is pulled forward by a line attached to its front, while a second line at the rear controls its angle to slice into the earth as the dredge moves.1
Dredges, in general, are employed for several purposes: maintaining or increasing water depths in canals, rivers, and harbors; creating new land by excavating fill; constructing dams and dikes; and recovering valuable underwater deposits or marine life. They are categorized as either mechanical or hydraulic, with many specialized designs and combinations of the two. The scraper dredge, specifically, is one type of mechanical dredge, distinct from grab (clamshell) dredges or ladder dredges that use a continuous chain of buckets.1
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dredgeThe scraper dredge, also called a dragline, handles material with a scoop suspended from a swinging boom. The scoop is drawn forward by a line attached to the front, while a second line attached to the rear holds the scoop at the proper angle to slice…
Read MoreThe scraper dredge, also called a dragline, handles material with a scoop suspended from a swinging boom. The scoop is drawn forward by a line attached to the front, while a second line attached to the rear holds the scoop at the proper angle to slice…
Read More
power shovelThe dragline excavator has a long boom of lattice design that extends from the cab at an angle of about 35° with the ground. From its end is suspended a hoist cable, at the end of which is the digging bucket. The dragline runs from the…
Read MoreThe dragline excavator has a long boom of lattice design that extends from the cab at an angle of about 35° with the ground. From its end is suspended a hoist cable, at the end of which is the digging bucket. The dragline runs from the…
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miningDragline or backhoeIn certain cases placer material is most economically excavated with a shore-mounted dragline or backhoe and a floating (barge-mounted) concentrating plant. (The digging equipment may also be mounted on a separate barge or on the same barge as the plant.) Material is…
Read MoreIn certain cases placer material is most economically excavated with a shore-mounted dragline or backhoe and a floating (barge-mounted) concentrating plant. (The digging equipment may also be mounted on a separate barge or on the same barge as the plant.) Material is…
Read More- miningMarine beaches and continental shelves
Draglines are commonly used, since they can work in the surf zone as well. Offshore beach and placer deposits are mined by wire line or dredge. In wire line methods the digging tools or buckets are suspended on a steel cable and lowered to the…
Read MoreDraglines are commonly used, since they can work in the surf zone as well. Offshore beach and placer deposits are mined by wire line or dredge. In wire line methods the digging tools or buckets are suspended on a steel cable and lowered to the…
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