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53-500: Dredging took place from 2006 through 2009, costing $ 18 million and removing 2,000,000 cubic feet (57,000 m) of muck from the bottom of the St. Sebastian River. The muck consisted of silt, clay, sand, shell and organic material, which consumed oxygen and threatened the life of aquatic species. 27°51′17″N 80°29′26″W  /  27.8547468°N 80.4906081°W  / 27.8547468; -80.4906081 This article about

106-500: A crankshaft , anticipating Al-Jazari 's invention by several centuries and its first appearance in Europe by over five centuries. However, the automatic crank described by the Banu Musa would not have allowed a full rotation, but only a small modification was required to convert it to a crankshaft. A mechanism developed by the Banu Musa, of particular importance for future developments, was

159-402: A dragline . This technique is often used in excavation of bay mud . Most of these dredges are crane barges with spuds , steel piles that can be lowered and raised to position the dredge. A backhoe/dipper dredger has a backhoe like on some excavators . A crude but usable backhoe dredger can be made by mounting a land-type backhoe excavator on a pontoon . The six largest backhoe dredgers in

212-482: A capacity of 6,000 cubic metres per hour (59,000 cu ft/ks). An even larger dredger, retired in 1980, was the U.S. Army Corps of Engineers Essayons , which was 525.17 feet (160.07 m) long. The Mallard II , a clamshell dredger that maintains levees in San Francisco Bay , has operated continuously since being built in 1936. Dredgers are often equipped with dredge monitoring software to help

265-403: A dispenser for hot and cold water, where the two outlets alternate, one discharging cold water and the other hot, then vice versa repeatedly. It also describes a vessel with a basin by its side where, when cold water is poured into the top of the vessel, it discharges from the mouth of a figure into the basin; when hot water or another liquid is poured into the basin, the same quantity of cold water

318-439: A few different types of dredge hoses that differ in terms of working pressure, float-ability, armored or not etc. Suction hoses, discharge armored hoses and self-floating hoses are some of the popular types engineered for transporting and discharging dredge materials. Some even had the pipes or hoses customised to exact dredging needs etc. Other times, it is pumped into barges (also called scows ), which deposit it elsewhere while

371-567: A few situations the excavation is undertaken by a specialist floating plant , known as a dredger. Usually the main objectives of dredging is to recover material of value, or to create a greater depth of water. Dredging systems can either be shore-based, brought to a location based on barges , or built into purpose-built vessels. Dredging can have environmental impacts: it can disturb marine sediments , leading to both short- and long-term water pollution , damage or destroy seabed ecosystems , and can release legacy human-sourced toxins captured in

424-422: A fountain with variable discharge. The book also describes fountains that change shapes at intervals. The Banu Musa invented an early mechanical musical instrument , in this case a hydropowered organ which played interchangeable cylinders automatically. According to Charles B. Fowler, this "cylinder with raised pins on the surface remained the basic device to produce and reproduce music mechanically until

477-464: A large quantity, no further extractions are possible. In modern terms, one would call the method used to achieve this result a fail-safe system. The non-manual crank appears in several of the hydraulic devices described by the Banū Mūsā brothers in their Book of Ingenious Devices . These automatically operated cranks appear in several devices, two of which contain an action which approximates to that of

530-740: A location in Indian River County , Florida is a stub . You can help Misplaced Pages by expanding it . This article related to a river in Florida is a stub . You can help Misplaced Pages by expanding it . Dredging Dredging is the excavation of material from a water environment. Possible reasons for 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

583-478: A long tube like some vacuum cleaners but on a larger scale. A plain suction dredger has no tool at the end of the suction pipe to disturb the material. A trailing suction hopper dredger (TSHD) trails its suction pipe when working. The pipe, which is fitted with a dredge drag head , loads the dredge spoil into one or more hoppers in the vessel. When the hoppers are full, the TSHD sails to a disposal area and either dumps

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636-496: A process known as dewatering. Current dewatering techniques employ either centrifuges, geotube containers, large textile based filters or polymer flocculant /congealant based apparatus. In many projects, slurry dewatering is performed in large inland settling pits, although this is becoming less and less common as mechanical dewatering techniques continue to improve. Similarly, many groups (most notable in east Asia) are performing research towards utilizing dewatered sediments for

689-409: A sheet of water concave downwards , or a spray ." Another fountain "discharges a shield or a single jet," while a variation of this features double-action alternation, i.e. has two fountainheads, with one discharging a single jet and the other a shield, and the two alternating repeatedly. Another variation features one main fountainhead and two or more subsidiary ones, such that when the main one ejects

742-411: A shipping channel through coral reefs . A bucket dredger is equipped with a bucket dredge, which is a device that picks up sediment by mechanical means, often with many circulating buckets attached to a wheel or chain . A grab dredger picks up seabed material with a clam shell bucket , which hangs from an onboard crane or a crane barge , or is carried by a hydraulic arm, or is mounted like on

795-417: A single jet, the subsidiaries eject shields, with the two alternating. The Banu Musa brothers also described the earliest known wind-powered fountain, which is described as, "operated by wind or water, it discharges a single jet or a lily-of-the-valley." A variation of this fountain incorporates a worm -and- pinion gear , while another variation features double-action alternation. The book also describes

848-515: Is a bar or blade which is pulled over the seabed behind any suitable ship or boat. It has an effect similar to that of a bulldozer on land. The chain-operated steam dredger Bertha , built in 1844 to a design by Brunel and as of 2009 was the oldest operational steam vessel in Britain, was of this type. This is an early type of dredger which was formerly used in shallow water in the Netherlands. It

901-617: Is a large illustrated work on mechanical devices , including automata , published in 850 by the three brothers of Persian descent, the Banū Mūsā brothers (Ahmad, Muhammad and Hasan ibn Musa ibn Shakir) working at the House of Wisdom ( Bayt al-Hikma ) in Baghdad , Iraq , under the Abbasid Caliphate . The book described about one hundred devices and how to use them. The book was commissioned by

954-909: Is forbidden unless authorized by a permit issued by the Army Corps of Engineers . Due to potential environmental impacts, dredging is often restricted to licensed areas, with vessel activity monitored closely using automatic GPS systems. According to a Rabobank outlook report in 2013, the largest dredging companies in the world are in order of size, based on dredging sales in 2012 Notable dredging companies in North America Notable dredging companies in South Asia Book of Ingenious Devices The Book of Ingenious Devices ( Arabic : كتاب الحيل , romanized :  Kitāb al-Ḥiyāl , Persian : كتاب ترفندها , romanized :  Ketâb tarfandhâ , lit.   'Book of Tricks')

1007-424: Is mainly used in harbours and other shallow water. Excavator dredge attachments The excavator dredge attachment uses the characteristics of cutter-suction dredgers, consisting of cutter heads and a suction pump for transferring material. These hydraulic attachments mount onto the boom arm of an excavator allowing an operator to maneuver the attachment along the shoreline and in shallow water for dredging. This

1060-410: Is usually sucked up by a wear-resistant centrifugal pump and discharged either through a pipe line or to a barge. Cutter-suction dredgers are most often used in geological areas consisting of hard surface materials (for example gravel deposits or surface bedrock) where a standard suction dredger would be ineffective. They can, if sufficiently powerful, be used instead of underwater blasting. As of 2024,

1113-692: The Book of Knowledge of Ingenious Mechanical Devices in 1206. Given that the Book of Ingenious Devices was widely circulated across the Muslim world , some of its ideas may have also reached Europe through al-Andalus , such as the use of automatic controls in later European machines or the use of conical valves in the work of Leonardo da Vinci . The Banu Musa brothers described a number of early automatic controls . Two-step level controls for fluids, an early form of discontinuous variable structure controls , were developed by

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1166-479: The Leiv Eriksson are: 46,000 cubic metre hopper and a design dredging depth of 155 m. Next largest is HAM 318 ( Van Oord ) with its 37,293 cubic metre hopper and a maximum dredging depth of 101 m. A cutter-suction dredger's (CSD) suction tube has a cutting mechanism at the suction inlet. The cutting mechanism loosens the bed material and transports it to the suction mouth. The dredged material

1219-553: The Abbasid Caliph of Baghdad , Al-Ma'mun (786–833), who instructed the Banū Mūsā brothers to acquire all of the Hellenistic texts that had been preserved by monasteries and by scholars during the decline and fall of Roman civilization. The Banū Mūsā brothers invented a number of automata (automatic machines ) and mechanical devices, and they described a hundred such devices in their Book of Ingenious Devices . Some of

1272-477: 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

1325-473: The Banu Musa brothers that does not appear in any earlier Greek works. The grab they described was used to extract objects from underwater, and recover objects from the beds of streams. The Banu Musa also described bellows that could remove foul air from wells. They explained that these instruments allow a worker to "descend into any well he wishes for a while and he will not fear it, nor will it harm him, if God wills may he be exalted." The book describes

1378-478: The Banu Musa brothers. Some of the other mechanisms they described include a float chamber and an early differential pressure sensor . The book describes the construction of various automatic fountains , an aspect that was largely neglected in earlier Greek treatises on technology. In one of these fountains, the "water issues from the fountainhead in the shape of a shield , or like a lily-of-the-valley ," i.e. "the shapes are discharged alternately—either

1431-423: The Banu Musa brothers. They also described an early feedback controller . Donald Routledge Hill wrote the following on the automatic controls underlying the mechanical trick devices described in the book: The trick vessels have a variety of different effects. For example, a single outlet pipe in a vessel might pour out first wine, then water and finally a mixture of the two. Although it cannot be claimed that

1484-427: The Banu Musa's "use of self-operating valves , timing devices, delay systems and other concepts of great ingenuity." Many of their innovations involved subtle combinations of pneumatics and aerostatics . The closest modern parallel to their work lies in control engineering and pneumatic instrumentation. In turn, the Banū Mūsā brothers' work was later cited as an influence on the work of al-Jazari , who produced

1537-520: The beds of streams. 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. These operate by sucking through

1590-600: The bottom of the harbour during the first and second centuries AD. The Banu Musa brothers during the Muslim Golden Age in while working at the Bayt-Al-Hikmah (house of wisdom) in Baghdad, designed an original invention in their book named ‘ Book of Ingenious Devices ’, a grab machine that does not appear in any earlier Greek works. The grab they described was used to extract objects from underwater, and recover objects from

1643-459: The conical valve , which was used in a variety of different applications. This includes using conical valves as "in-line" components in flow systems, which was the first known use of conical valves as automatic controllers. Some of the other valves they described include: The double-concentric siphon and the funnel with bent end for pouring in different liquids, neither of which appear in any earlier Greek works, were also original inventions by

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1696-605: The construction industry. Dredging is a four-part process: loosening the material, bringing the material to the surface (together extraction), transportation and disposal. The extract can be disposed of locally or transported by barge or in a liquid suspension in pipelines. Disposal can be to infill sites, or the material can be used constructively to replenish eroded sand that has been lost to coastal erosion , or constructively create sea-walls, building land or whole new landforms such as viable islands in coral atolls . Ancient authors refer to harbour dredging. The seven arms of

1749-538: The devices described in the Book of Ingenious Devices were inspired by the works of Hero of Alexandria and Philo of Byzantium , as well as ancient Persian , Chinese and Indian engineering . Many of the other devices described in the book, however, were original inventions by the Banū Mūsā brothers. While they took Greek works as a starting point, the Banu Musa went "well beyond anything achieved by Hero or Philo." Their preoccupation with automatic controls distinguishes them from their Greek predecessors, including

1802-492: The dredge continues its work. A number of vessels, notably in the UK and NW Europe de-water the hopper to dry the cargo to enable it to be discharged onto a quayside 'dry'. This is achieved principally using self discharge bucket wheel, drag scraper or excavator via conveyor systems. When contaminated (toxic) sediments are to be removed, or large volume inland disposal sites are unavailable, dredge slurries are reduced to dry solids via

1855-482: The dredge operator position the dredger and monitor the current dredge level. The monitoring software often uses Real Time Kinematic satellite navigation to accurately record where the machine has been operating and to what depth the machine has dredged to. In a "hopper dredger", the dredged materials end up in a large onboard hold called a "hopper." A suction hopper dredger is usually used for maintenance dredging. A hopper dredge usually has doors in its bottom to empty

1908-425: The dredged materials, but some dredges empty their hoppers by splitting the two-halves of their hulls on large hydraulic hinges. Either way, as the vessel dredges, excess water in the dredged materials is spilled off as the heavier solids settle to the bottom of the hopper. This excess water is returned to the sea to reduce weight and increase the amount of solid material (or slurry) that can be carried in one load. When

1961-543: The environment, including the following: The nature of dredging operations and possible environmental impacts requires that the activity often be closely regulated and requires comprehensive regional environmental impact assessments alongside continuous monitoring. For example, in the U.S., the Clean Water Act requires that any discharge of dredged or fill materials into "waters of the United States," including wetlands,

2014-519: The form of a scoop made of chain mesh, and are towed by a fishing boat . Clam-specific dredges can utilize hydraulic injection to target deeper into the sand. Dredging can be destructive to the seabed and some scallop dredging has been replaced by collecting via scuba diving . As of June 2018, the largest dredger in Asia is MV  Tian Kun Hao , a 140-metre (460 ft) long dredger constructed in China, with

2067-447: The hopper is filled with slurry , the dredger stops dredging and goes to a dump site and empties its hopper. Some hopper dredges are designed so they can also be emptied from above using pumps if dump sites are unavailable or if the dredge material is contaminated. Sometimes the slurry of dredgings and water is pumped straight into pipes which deposit it on nearby land. These pipes are also commonly known as dredge hoses , too. There are

2120-469: The material could well suit the building industry, or could be used for beach nourishment. Dredging can disturb aquatic ecosystems , often with adverse impacts. In addition, dredge spoils may contain toxic chemicals that may have an adverse effect on the disposal area; furthermore, the process of dredging often dislodges chemicals residing in benthic substrates and injects them into the water column . Dredging can have numerous significant impacts on

2173-460: The material through doors in the hull or pumps the material out of the hoppers. Some dredges also self-offload using drag buckets and conveyors. As of 2008 the largest trailing suction hopper dredgers in the world were Jan De Nul 's Cristobal Colon (launched 4 July 2008 ) and her sister ship Leiv Eriksson (launched 4 September 2009 ). Main design specifications for the Cristobal Colon and

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2226-462: The most powerful cutter-suction dredger in the world is DEME 's Spartacus , which entered service in 2021. The auger dredge system functions like a cutter suction dredger, but the cutting tool is a rotating Archimedean screw set at right angles to the suction pipe. Mud Cat invented the auger dredge in the 1970s. These use the Venturi effect of a concentrated high-speed stream of water to pull

2279-426: The nearby water, together with bed material, into a pipe. An airlift is a type of small suction dredge. It is sometimes used like other dredges. At other times, an airlift is handheld underwater by a diver . It works by blowing air into the pipe, and that air, being lighter than water, rises inside the pipe, dragging water with it. Some bucket dredgers and grab dredgers are powerful enough to rip out coral to make

2332-667: The production of concretes and construction block, although the high organic content (in many cases) of this material is a hindrance toward such ends. The proper management of contaminated sediments is a modern-day issue of significant concern. Because of a variety of maintenance activities, thousands of tonnes of contaminated sediment are dredged worldwide from commercial ports and other aquatic areas at high level of industrialization. Dredged material can be reused after appropriate decontamination. A variety of processes has been proposed and tested at different scales of application ( technologies for environmental remediation ). Once decontaminated,

2385-587: The results are important, the means by which they were obtained are of great significance for the history of engineering. The Banu Musa were masters in the exploitation of small variations in aerostatic and hydrostatic pressures and in using conical valves as "in-line" components in flow systems, the first known use of conical valves as automatic controllers. The Banu Musa also developed an early fail-safe system for use in their trick devices, as described by Hill: In several of these vessels, one can withdraw small quantities of liquid repeatedly, but if one withdraws

2438-476: The seabed to bring the sediment in suspension, which then becomes a turbidity current , which flows away down slope, is moved by a second burst of water from the WID or is carried away in natural currents. Water injection results in a lot of sediment in the water which makes measurement with most hydrographic equipment (for instance: singlebeam echosounders) difficult. These dredgers use a chamber with inlets, out of which

2491-461: The seabed with its hull out of the water. Some forms can go on land. Some of these are land-type backhoe excavators whose wheels are on long hinged legs so it can drive into shallow water and keep its cab out of water. Some of these may not have a floatable hull and, if so, cannot work in deep water. Oliver Evans (1755–1819) in 1804 invented the Oruktor Amphibolos, an amphibious dredger which

2544-405: The second half of the nineteenth century." The Banu Musa also invented an automatic flute player which may have been the first programmable machine . The flute sounds were produced through hot steam and the user could adjust the device to various patterns so that they could get various sounds from it. The mechanical grab , specifically the clamshell grab , is an original invention by

2597-628: The sediment. These environmental impacts can reduce marine wildlife populations in some cases, contaminate sources of drinking water and interrupt economic activities such as fishing. Dredging is excavation carried out underwater or partially underwater, in shallow waters or ocean waters . It keeps waterways and ports navigable, and assists coastal protection, land reclamation and coastal redevelopment, by gathering up bottom sediments and transporting it elsewhere. Dredging can be done to recover materials of commercial value; these may be high value minerals or sediments such as sand and gravel that are used by

2650-427: The water is pumped with the inlets closed. It is usually suspended from a crane on land or from a small pontoon or barge. Its effectiveness depends on depth pressure. A snagboat is designed to remove big debris such as dead trees and parts of trees from North America waterways. Some of these are any of the above types of dredger, which can operate normally, or by extending legs, also known as spuds, so it stands on

2703-681: The world are currently the Vitruvius, the Mimar Sinan, Postnik Yakovlev (Jan De Nul), the Samson (DEME), the Simson and the Goliath (Van Oord). They featured barge -mounted excavators. Small backhoe dredgers can be track-mounted and work from the bank of ditches. A backhoe dredger is equipped with a half-open shell. The shell is filled moving towards the machine. Usually dredged material is loaded in barges. This machine

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2756-446: Was America's first steam-powered road vehicle. These are usually used to recover useful materials from the seabed. Many of them travel on continuous track . A unique variant is intended to walk on legs on the seabed. Fishing dredges are used to collect various species of clams , scallops , oysters or mussels from the seabed. Some dredges are also designed to catch crabs, sea urchins, sea cucumbers, and conch. These dredges have

2809-464: Was a flat-bottomed boat with spikes sticking out of its bottom. As tide current pulled the boat, the spikes scraped seabed material loose, and the tide current washed the material away, hopefully to deeper water. Krabbelaar is the Dutch word for "scratcher". A water injection dredger uses a small jet to inject water under low pressure (to prevent the sediment from exploding into the surrounding waters) into

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