dead night tonight. assume you fuckers have something better to do than entertain me on a friday night.
Yes. Specifically, I am boring you on a Friday night instead.
Dredging
Dredging is an excavation activity or operation usually carried out at least partly underwater, in shallow seas or fresh water areas with the purpose of gathering up bottom sediments and disposing of them at a different location.
This technique is often used to keep waterways navigable. It is also used as a way to replenish sand on some public beaches, where too much sand has been lost because of coastal erosion. Dredging is also used as a technique for fishing for certain species of edible clams and crabs, see fishing dredge.
A dredge is a device for scraping or sucking the seabed, used for dredging. A dredger is a ship or boat equipped with a dredge (though in American usage, there is no added letter).
The process of dredging creates spoils (excess material), which are conveyed to a location different from the dredged area. Dredging can produce materials for land reclamation or other purposes (usually construction-related), and has also historically played a significant role in gold mining. Dredging can create disturbance in aquatic ecosystems, often with adverse impacts.
[edit] Uses
* Capital: dredging carried out to create a new harbour, berth or waterway, or to deepen existing facilities in order to allow larger ships access. Because capital works usually involve hard material or high-volume works, the work is usually done using a cutter suction dredge or large trailing suction hopper dredge, but for rock works drilling and blasting along with mechanical excavation may be used.
* Preparatory: work and excavation for future bridges, piers or docks/wharves, often connected with foundation work.
* Maintenance: dredging to deepen or maintain navigable waterways or channels which are threatened to become silted with the passage of time, due to sedimented sand and mud, possibly making them too shallow for navigation. This is often carried out with a trailing suction hopper dredge. Most dredging is for this purpose, and it may also be done to maintain the holding capacity of reservoirs or lakes.
* Land reclamation: dredging to mine sand, clay or rock from the seabed and using it to construct new land elsewhere. This is typically performed by a cutter-suction dredge or trailing suction hopper dredge. The material may also be used for flood or erosion control.
* Beach nourishment: mining sand offshore and placing on a beach to replace sand eroded by storms or wave action. This is done to enhance the recreational and protective function of the beaches, which can be eroded by human activity or by storms. This is typically performed by a cutter-suction dredge or trailing suction hopper dredge.
* Harvesting materials: dredging sediment for elements like gold or other valuable trace substances.
* Seabed mining: a possible future use, recovering natural metal ore nodules from the sea's abyssal plains.
* Construction materials: dredging sand and gravels from offshore licensed areas for use in construction industry, pricipally for use in concrete. Very specialist industry focused in NW Europe using specialized trailing suction hopper dredgers self discharging dry cargo ashore.
* Anti-eutrophication: Dredging is an expensive option for the remediation of eutrophied (or de-oxygenated) water bodies. However, as artificially elevated phosphorus levels in the sediment aggravate the eutrophication process, controlled sediment removal is occasionally the only option for the reclamation of still waters.
* Contaminant remediation: to reclaim areas affected by chemical spills, storm water surges (with urban runoff), and other soil contaminations. Disposal becomes a proportionally large factor in these operations.
* Removing trash and debris: often done in combination with maintenance dredging, this process removes non-natural matter from the bottoms of rivers and canals and harbors.
[edit] Relevance
Without the many and almost non-stop dredging operations world wide, much of the world's commerce would be impaired, often within a few months, since much of world's goods travel by ship, and need to access harbours or seas via channels. Recreational boating also would be constrained to the smallest vessels. The majority of marine dredging operations (and the disposal of the dredged material) will require that appropriate licences are obtained from the relevant regulatory authorities, and dredging is usually carried out by (or for) harbour companies or corresponding government agencies.
[edit] Types of dredging vessels
[edit] Suction
For suction-type excavation out of water, see Suction excavator.
These operate by sucking through a long tube, like some vacuum cleaners but on a big scale.
A plain suction dredger has no tool at the end of the suction pipe to disturb the material. This is often the most commonly used form of dredging.[citation needed]
[edit] Trailing suction
A trailing suction hopper dredger (TSHD) trails its suction pipe when working, and 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 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. The largest trailing suction hopper dredger in the world is currently Jan de Nul's Cristobal Colon (launched July 4, 2008 [1]); its sister ship Leiv Eriksson is under construction as of the end of 2008 (keel laid August 27, 2008, expected launch July 2009[2]). Main design specs for the Cristobal Colon and the Leiv Eriksson are: 46,000 cubic meter hopper and a design dredging depth of 155 m.[3] Next largest is HAM 318 (Van Oord) with its 37,293 cubic meter hopper and a maximum dredging depth of 101 m.
[edit] Cutter suction
A cutter-suction dredger's (CSD) suction tube has a cutter head at the suction inlet, to loosen the earth and transport it to the suction mouth. The cutter can also be used for hard surface materials like gravel or rock. The dredged soil is usually sucked up by a wear-resistant centrifugal pump and discharged through a pipe line or to a barge. In recent years, dredgers with more powerful cutters have been built in order to excavate harder rock without blasting.
The, at this moment, two largest cutter suction dredgers in the world are Deme's D'Artagnan (28,200 kW total installed power)[4] and Jan De Nul's J.F.J. DeNul (27,240 kW).[5]. Jan de Nul has by far the most heavy cutters in the market.
[edit] Auger suction
This process functions like a cutter suction dredger, but the cutting tool is a rotating Archimedean screw set at right angles to the suction pipe. The first widely used auger dredges were designed by Mud Cat Dredges[6] in the 1980s.
[edit] Jet-lift
These use the Venturi effect of a concentrated high-speed stream of water to pull the nearby water, together with bed material, into a pipe.
[edit] Air-lift
An airlift is a type of small suction dredge. It is sometimes used like other dredges. At other times, an airlift is used, 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.
[edit] Bucket
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. Some bucket dredgers and grab dredgers are powerful enough to rip out coral to make a shipping channel through coral reefs.
[edit] Grab
A grab dredger picks up seabed material with a clam shell grab, which hangs from an onboard crane or a crane ship, or is carried by a hydraulic arm, or is mounted like on a dragline. This technique is often used in excavation of bay mud. Most of these dredges are crane barges with spuds.
[edit] Backhoe/dipper
This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (July 2008)
A backhoe/dipper dredge 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 three largest backhoe dredgers in the world were Tauracavor (Great Lakes), New York (Great Lakes) and Il Principe (Jan De Nul).[citation needed] 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 dredges material is loaded in barges. This machine is mainly used in harbors and other shallow water.
[edit] Water injection
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 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.
[edit] Pneumatic
These dredgers use a chamber with inlets, out of which 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.
[edit] Bed leveler
This 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.
[edit] Krabbelaar
This is an early type of dredger which was formerly used in shallow water in the Netherlands. It 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 Dutch for "scratcher".
[edit] Snagboat
Main article: Snagboat
A snagboat is designed to remove big debris such as dead trees and parts of trees from rivers and canals.
[edit] Amphibious
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 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 an amphibious dredger which was America's first steam-powered road vehicle.
[edit] Submersible
These are usually used to recover useful materials from the seabed. Many of them travel on caterpillar tracks. A unique variant[7] is intended to walk on legs on the seabed.[8]
[edit] Fishing
Fishing dredges are used to collect various species of clams scallops, oysters or crabs from the seabed. These dredges have the form of a scoop made of chain mesh, and are towed by a fishing boat. Careless dredging can be destructive to the seabed. Nowadays some scallop dredging is replaced by collecting via scuba diving.
[edit] Police drag
In some police departments a small dredge (sometimes called a drag) is used to find and recover objects and bodies from underwater. The bodies may be murder victims, or people who committed suicide by drowning, or victims of accidents. It is sometimes pulled by men walking on the bank.
[edit] Images
The 'business end' (excavator) of a Yukon dredge.
Profile view of this Yukon dredge tied up to a quay, note the size. The dredge conveys the spoils to the rear (left side) into a receiving vessel such as a barge.
The Geopotes 14 lifting its boom on a canal in The Netherlands. (gēopotēs is Greek for "that which drinks earth")
Example of a trailing suction dredger: the Orisant in the port of IJmuiden, Netherlands
Example of the grab dredging process in Port Canaveral, Florida
Grab dredging in Victoria Harbor, Hong Kong
Bucket dredging
Stuyvesant
Essayons
Alexander von Humboldt of the Jan de Nul fleet
Sand mining
April Hamer at Lakes Entrance, Victoria
[edit] Disposal of materials
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 the dredged materials, but some dredges empty their hoppers by splitting the two halves of their hulls on giant 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 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. Other times, it is pumped into barges (also called scows), which deposit it elsewhere while the dredge continues its work.
When contaminated (toxic) sediments are to be removed, or large volume inland disposal sites are unavailable, dredge slurries are reduced to dry solids via a process known as dewatering. Current dewatering techniques employ either centrifuges, 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 the production of concretes and construction block, although the high organic content (in many cases) of this material is a hindrance toward such ends.
[edit] Environmental impacts
Dredging can create disturbance to 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.
The activity of dredging can create the following principal impacts to the environment:
* Release of toxic chemicals (including heavy metals and PCB) from bottom sediments into the water column.
* Short term increases in turbidity, which can affect aquatic species metabolism and interfere with spawning.
* Secondary effects from water column contamination of uptake of heavy metals, DDT and other persistent organic toxins, via food chain uptake and subsequent concentrations of these toxins in higher organisms including humans.
* Secondary impacts to marsh productivity from sedimentation
* Tertiary impacts to avifauna which may prey upon contaminated aquatic organisms
* Secondary impacts to aquatic and benthic organisms' metabolism and mortality
* Possible contamination of dredge spoils sites
[edit] Major dredging companies
* Ellicott Dredges [1] (United States)
* Royal Boskalis Westminster (Netherlands)
* Jan De Nul [2] (Belgium)
* DEME [3] (Belgium)
* Van Oord Dredging and Marine Contractors [4] (Netherlands)
[edit] Dredging in nature
Some animals have evolved adaptations to find their food by dredging:
* Ducks
* Grey whales: they filter seabed sand with their baleen
As everyone was quietly expecting, I am chickening out of my grand plans of having everyone in the AC in a fancy hat in my challenge entry and will be submitting a rehash of this girl right here:
I don't use swear words, much less in English.... but I'm curious about the word asshole & mother fucker. It seems that every time I hear someone in a movie use them its directed towards a man. Can a girl be an asshole/mother fucker too?
MT: Really anyone can be called mother fucker or asshole, male or female. But, I think it's just more used with men because... we're more likely to be mother fuckers (see Metal) or assholes (see Metal). Really they're both just a harsh way of saying, "Not cool dude" or "that was not very nice at all sir" and likewise, "please go fuck yourself when you get a chance".
Thanks Prosp! This always happens to me, I learned my English from school books and cable TV, I have very little interaction with gringos outside this forum. So when ever I speak to an English speaker, it's like "Oh, is that how you say it?" It also happens when I speak Japanese with my girl, shes like "Yeaaaaah, don't be so formal"
I don't use swear words, much less in English.... but I'm curious about the word asshole & mother fucker. It seems that every time I hear someone in a movie use them its directed towards a man. Can a girl be an asshole/mother fucker too?
Due to divorce rates rising in the United States, more and more men are becoming motherfuckers do to the increasing number of single mothers. So the word has lost a bit of it's impact.
It's not like the 1950s anymore where being a motherfucker would be a truly bad thing.
There's about a half dozen Korean ESL students that use me for their introduction into casual English.
It's rewarding when I greet one of them, and they stick out their palm and say "slap me some skin, dog."
...more of Mr. Manon's English You Shouldn't Use Around Your Mother after the break!
I don't use swear words, much less in English.... but I'm curious about the word asshole & mother fucker. It seems that every time I hear someone in a movie use them its directed towards a man. Can a girl be an asshole/mother fucker too?
Due to divorce rates rising in the United States, more and more men are becoming motherfuckers do to the increasing number of single mothers. So the word has lost a bit of it's impact.
It's not like the 1950s anymore where being a motherfucker would be a truly bad thing.
I'm pretty sure it's a reference to someone fucking their own mother which is still fairly taboo, even today.
I don't use swear words, much less in English.... but I'm curious about the word asshole & mother fucker. It seems that every time I hear someone in a movie use them its directed towards a man. Can a girl be an asshole/mother fucker too?
Due to divorce rates rising in the United States, more and more men are becoming motherfuckers do to the increasing number of single mothers. So the word has lost a bit of it's impact.
It's not like the 1950s anymore where being a motherfucker would be a truly bad thing.
I'm pretty sure it's a reference to someone fucking their own mother which is still fairly taboo, even today.
I really doubt that.
I've always though of it as a person who fucks any mother, instead of a nice young single woman.
Obs on
0
NappuccinoSurveyor of Things and StuffRegistered Userregular
edited June 2009
Well, there is one way to solve that. Google the origin of "mother fucker" and I'm sure you'll find the answer.
Now, can we discuss something that's actually discuss-able...
I don't use swear words, much less in English.... but I'm curious about the word asshole & mother fucker. It seems that every time I hear someone in a movie use them its directed towards a man. Can a girl be an asshole/mother fucker too?
Due to divorce rates rising in the United States, more and more men are becoming motherfuckers do to the increasing number of single mothers. So the word has lost a bit of it's impact.
It's not like the 1950s anymore where being a motherfucker would be a truly bad thing.
I'm pretty sure it's a reference to someone fucking their own mother which is still fairly taboo, even today.
I really doubt that.
I've always though of it as a person who fucks any mother, instead of a nice young single woman.
Posts
Yes. Specifically, I am boring you on a Friday night instead.
Dredging is an excavation activity or operation usually carried out at least partly underwater, in shallow seas or fresh water areas with the purpose of gathering up bottom sediments and disposing of them at a different location.
This technique is often used to keep waterways navigable. It is also used as a way to replenish sand on some public beaches, where too much sand has been lost because of coastal erosion. Dredging is also used as a technique for fishing for certain species of edible clams and crabs, see fishing dredge.
A dredge is a device for scraping or sucking the seabed, used for dredging. A dredger is a ship or boat equipped with a dredge (though in American usage, there is no added letter).
The process of dredging creates spoils (excess material), which are conveyed to a location different from the dredged area. Dredging can produce materials for land reclamation or other purposes (usually construction-related), and has also historically played a significant role in gold mining. Dredging can create disturbance in aquatic ecosystems, often with adverse impacts.
[edit] Uses
* Capital: dredging carried out to create a new harbour, berth or waterway, or to deepen existing facilities in order to allow larger ships access. Because capital works usually involve hard material or high-volume works, the work is usually done using a cutter suction dredge or large trailing suction hopper dredge, but for rock works drilling and blasting along with mechanical excavation may be used.
* Preparatory: work and excavation for future bridges, piers or docks/wharves, often connected with foundation work.
* Maintenance: dredging to deepen or maintain navigable waterways or channels which are threatened to become silted with the passage of time, due to sedimented sand and mud, possibly making them too shallow for navigation. This is often carried out with a trailing suction hopper dredge. Most dredging is for this purpose, and it may also be done to maintain the holding capacity of reservoirs or lakes.
* Land reclamation: dredging to mine sand, clay or rock from the seabed and using it to construct new land elsewhere. This is typically performed by a cutter-suction dredge or trailing suction hopper dredge. The material may also be used for flood or erosion control.
* Beach nourishment: mining sand offshore and placing on a beach to replace sand eroded by storms or wave action. This is done to enhance the recreational and protective function of the beaches, which can be eroded by human activity or by storms. This is typically performed by a cutter-suction dredge or trailing suction hopper dredge.
* Harvesting materials: dredging sediment for elements like gold or other valuable trace substances.
* Seabed mining: a possible future use, recovering natural metal ore nodules from the sea's abyssal plains.
* Construction materials: dredging sand and gravels from offshore licensed areas for use in construction industry, pricipally for use in concrete. Very specialist industry focused in NW Europe using specialized trailing suction hopper dredgers self discharging dry cargo ashore.
* Anti-eutrophication: Dredging is an expensive option for the remediation of eutrophied (or de-oxygenated) water bodies. However, as artificially elevated phosphorus levels in the sediment aggravate the eutrophication process, controlled sediment removal is occasionally the only option for the reclamation of still waters.
* Contaminant remediation: to reclaim areas affected by chemical spills, storm water surges (with urban runoff), and other soil contaminations. Disposal becomes a proportionally large factor in these operations.
* Removing trash and debris: often done in combination with maintenance dredging, this process removes non-natural matter from the bottoms of rivers and canals and harbors.
[edit] Relevance
Without the many and almost non-stop dredging operations world wide, much of the world's commerce would be impaired, often within a few months, since much of world's goods travel by ship, and need to access harbours or seas via channels. Recreational boating also would be constrained to the smallest vessels. The majority of marine dredging operations (and the disposal of the dredged material) will require that appropriate licences are obtained from the relevant regulatory authorities, and dredging is usually carried out by (or for) harbour companies or corresponding government agencies.
[edit] Types of dredging vessels
[edit] Suction
For suction-type excavation out of water, see Suction excavator.
These operate by sucking through a long tube, like some vacuum cleaners but on a big scale.
A plain suction dredger has no tool at the end of the suction pipe to disturb the material. This is often the most commonly used form of dredging.[citation needed]
[edit] Trailing suction
A trailing suction hopper dredger (TSHD) trails its suction pipe when working, and 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 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. The largest trailing suction hopper dredger in the world is currently Jan de Nul's Cristobal Colon (launched July 4, 2008 [1]); its sister ship Leiv Eriksson is under construction as of the end of 2008 (keel laid August 27, 2008, expected launch July 2009[2]). Main design specs for the Cristobal Colon and the Leiv Eriksson are: 46,000 cubic meter hopper and a design dredging depth of 155 m.[3] Next largest is HAM 318 (Van Oord) with its 37,293 cubic meter hopper and a maximum dredging depth of 101 m.
[edit] Cutter suction
A cutter-suction dredger's (CSD) suction tube has a cutter head at the suction inlet, to loosen the earth and transport it to the suction mouth. The cutter can also be used for hard surface materials like gravel or rock. The dredged soil is usually sucked up by a wear-resistant centrifugal pump and discharged through a pipe line or to a barge. In recent years, dredgers with more powerful cutters have been built in order to excavate harder rock without blasting.
The, at this moment, two largest cutter suction dredgers in the world are Deme's D'Artagnan (28,200 kW total installed power)[4] and Jan De Nul's J.F.J. DeNul (27,240 kW).[5]. Jan de Nul has by far the most heavy cutters in the market.
[edit] Auger suction
This process functions like a cutter suction dredger, but the cutting tool is a rotating Archimedean screw set at right angles to the suction pipe. The first widely used auger dredges were designed by Mud Cat Dredges[6] in the 1980s.
[edit] Jet-lift
These use the Venturi effect of a concentrated high-speed stream of water to pull the nearby water, together with bed material, into a pipe.
[edit] Air-lift
An airlift is a type of small suction dredge. It is sometimes used like other dredges. At other times, an airlift is used, 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.
[edit] Bucket
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. Some bucket dredgers and grab dredgers are powerful enough to rip out coral to make a shipping channel through coral reefs.
[edit] Grab
A grab dredger picks up seabed material with a clam shell grab, which hangs from an onboard crane or a crane ship, or is carried by a hydraulic arm, or is mounted like on a dragline. This technique is often used in excavation of bay mud. Most of these dredges are crane barges with spuds.
[edit] Backhoe/dipper
This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed. (July 2008)
A backhoe/dipper dredge 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 three largest backhoe dredgers in the world were Tauracavor (Great Lakes), New York (Great Lakes) and Il Principe (Jan De Nul).[citation needed] 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 dredges material is loaded in barges. This machine is mainly used in harbors and other shallow water.
[edit] Water injection
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 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.
[edit] Pneumatic
These dredgers use a chamber with inlets, out of which 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.
[edit] Bed leveler
This 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.
[edit] Krabbelaar
This is an early type of dredger which was formerly used in shallow water in the Netherlands. It 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 Dutch for "scratcher".
[edit] Snagboat
Main article: Snagboat
A snagboat is designed to remove big debris such as dead trees and parts of trees from rivers and canals.
[edit] Amphibious
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 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 an amphibious dredger which was America's first steam-powered road vehicle.
[edit] Submersible
These are usually used to recover useful materials from the seabed. Many of them travel on caterpillar tracks. A unique variant[7] is intended to walk on legs on the seabed.[8]
[edit] Fishing
Fishing dredges are used to collect various species of clams scallops, oysters or crabs from the seabed. These dredges have the form of a scoop made of chain mesh, and are towed by a fishing boat. Careless dredging can be destructive to the seabed. Nowadays some scallop dredging is replaced by collecting via scuba diving.
[edit] Police drag
In some police departments a small dredge (sometimes called a drag) is used to find and recover objects and bodies from underwater. The bodies may be murder victims, or people who committed suicide by drowning, or victims of accidents. It is sometimes pulled by men walking on the bank.
[edit] Images
The 'business end' (excavator) of a Yukon dredge.
Profile view of this Yukon dredge tied up to a quay, note the size. The dredge conveys the spoils to the rear (left side) into a receiving vessel such as a barge.
The Geopotes 14 lifting its boom on a canal in The Netherlands. (gēopotēs is Greek for "that which drinks earth")
Example of a trailing suction dredger: the Orisant in the port of IJmuiden, Netherlands
Example of the grab dredging process in Port Canaveral, Florida
Grab dredging in Victoria Harbor, Hong Kong
Bucket dredging
Stuyvesant
Essayons
Alexander von Humboldt of the Jan de Nul fleet
Sand mining
April Hamer at Lakes Entrance, Victoria
[edit] Disposal of materials
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 the dredged materials, but some dredges empty their hoppers by splitting the two halves of their hulls on giant 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 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. Other times, it is pumped into barges (also called scows), which deposit it elsewhere while the dredge continues its work.
When contaminated (toxic) sediments are to be removed, or large volume inland disposal sites are unavailable, dredge slurries are reduced to dry solids via a process known as dewatering. Current dewatering techniques employ either centrifuges, 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 the production of concretes and construction block, although the high organic content (in many cases) of this material is a hindrance toward such ends.
[edit] Environmental impacts
Dredging can create disturbance to 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.
The activity of dredging can create the following principal impacts to the environment:
* Release of toxic chemicals (including heavy metals and PCB) from bottom sediments into the water column.
* Short term increases in turbidity, which can affect aquatic species metabolism and interfere with spawning.
* Secondary effects from water column contamination of uptake of heavy metals, DDT and other persistent organic toxins, via food chain uptake and subsequent concentrations of these toxins in higher organisms including humans.
* Secondary impacts to marsh productivity from sedimentation
* Tertiary impacts to avifauna which may prey upon contaminated aquatic organisms
* Secondary impacts to aquatic and benthic organisms' metabolism and mortality
* Possible contamination of dredge spoils sites
[edit] Major dredging companies
* Ellicott Dredges [1] (United States)
* Royal Boskalis Westminster (Netherlands)
* Jan De Nul [2] (Belgium)
* DEME [3] (Belgium)
* Van Oord Dredging and Marine Contractors [4] (Netherlands)
[edit] Dredging in nature
Some animals have evolved adaptations to find their food by dredging:
* Ducks
* Grey whales: they filter seabed sand with their baleen
Source: Wikipedia
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I am too busy painting an exceptionally fancy hat to bury all these silly fuckers in the challenge thread with.
One hat to rule them all.
One hat to find them.
but yours must be pretty damned fancy to beat the top hat with separate monocle.
Loom had a turban.
I need 10 different 200x200 sprites, and each of them has animation, I've estimated there will be about 134 frames of art.
artistjeffc.tumblr.com http://www.etsy.com/shop/artistjeffc
MT: Really anyone can be called mother fucker or asshole, male or female. But, I think it's just more used with men because... we're more likely to be mother fuckers (see Metal) or assholes (see Metal). Really they're both just a harsh way of saying, "Not cool dude" or "that was not very nice at all sir" and likewise, "please go fuck yourself when you get a chance".
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Due to divorce rates rising in the United States, more and more men are becoming motherfuckers do to the increasing number of single mothers. So the word has lost a bit of it's impact.
It's not like the 1950s anymore where being a motherfucker would be a truly bad thing.
bitches, cunts, sluts, whores, etc. for broads.
There's about a half dozen Korean ESL students that use me for their introduction into casual English.
It's rewarding when I greet one of them, and they stick out their palm and say "slap me some skin, dog."
...more of Mr. Manon's English You Shouldn't Use Around Your Mother after the break!
I'm pretty sure it's a reference to someone fucking their own mother which is still fairly taboo, even today.
I really doubt that.
I've always though of it as a person who fucks any mother, instead of a nice young single woman.
Now, can we discuss something that's actually discuss-able...
like rainbows?
Hey I heard that.
Like a father?