page_title: Dredging
section_title: History
hierarchical_section_title: Dredging / History
caption_attribution_description: Italiano: Draga cavafango di Leonardo da Vinci. Esposta presso il Museo nazionale della scienza e della tecnologia "L. Da Vinci" di Milano.
context_page_description: Dredging is the operation of excavating material from a water environment. Possible purposes of dredging include: improving existing water features; reshaping land and water features to alter drainage, navigability, and commercial use; constructing dams, dikes, and other controls for streams and shorelines; and recovering valuable mineral deposits or marine life having commercial value. In all but a few situations the excavation is undertaken by a specialist floating plant, known as a dredger. Dredging is carried out in many different locations and for many different purposes, but the main objectives are usually to recover material of value or use, or to create a greater depth of water. Dredges have been classified as suction or mechanical.
context_section_description: Ancient authors refer to harbour dredging. The seven arms of the Nile were channelled and wharfs built at the time of the pyramids (4000 BC), there was extensive harbour building in the eastern Mediterranean from 1000 BC and the disturbed sediment layers gives evidence of dredging. At Marseille, dredging phases are recorded from the third century BC onwards, the most extensive during the first century AD. The remains of three dredging boats have been unearthed; they were abandoned at the bottom of the harbour during the first and second centuries AD.
  During the renaissance Leonardo da Vinci drew a design for a drag dredger.
  Dredging machines have been used during the construction of the Suez Canal from the late 1800s to present day expansions and maintenance. The completion of the Panama Canal in 1914, the most expensive U.S. engineering project at the time, relied extensively on dredging.
caption: Reconstruction of the mud-drag by Leonardo da Vinci (Manuscript E, folio 75 v.)
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