https://cdn.earthdata.nasa.gov/conduit/upload/5182/KeywordsCommunityGuide_Baseline_v1_SIGNED_FINAL.pdf 23.6 2026-03-19T10:41:57.720Z https://gcmd.earthdata.nasa.gov/KeywordViewer/scheme/instruments/96471be4-6078-477d-8e66-c02b92f594d4 DREDGING DEVICES Date=2021-08-05 User Id=sritz Entity=AltLabel Operation=INSERT System Note=insert AltLabel New Value=id: null category: primary text: DREDGING DEVICES language code: en Dredging is the removal of earthen materials, including rock orcoral, from under water. It increases the size of the waterwayand provides construction materials for land-based projects. Italso improves logistics. The wider, deeper shipping channelprovides easier passage of vessels with deep draft. The deeperthe draft of a vessel, the more tonnage it can carry. If fewships are available for logistics, then dredging can make theseships more efficient.Material removed during dredging is often a naturally-occurringconstruction material. In military operations, natural materialsmake up for scarce resources. Typically, sand is available alongthe coast and in most rivers. Care must be taken to avoid clayor fine-grained sediments.Two primary types of dredging occur: mechanical and hydraulic.Mechanical equipment dredges easily with a clam shell, shovel,backhoe, or other device that scoops the material up. A simpletype of mechanical dredge is a land crane, equipped with asuitable bucket mounted on a barge. This dredge needs barges orscows to move the material from the dredging site to thedisposal site.The hydraulic dredge uses water to remove and transport thematerial. This system has a pump for moving the water. The pumpcreates a vacuum or a pressure head, which moves water rapidlythrough the pipe. This system always has at least threecomponents: dredging device, pump, and discharge system. Thereare many common hydraulic dredging systems--hopper dredges,sidecast dredges, cutterhead dredges, and dustpan dredges.[Summary provided by the Globe Security Organization] 2021-08-05 11:32:20.0