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Dredging

technology Maturity 9-11

Big boats clean the water.

Dredge (PSF).png
Dredge (PSF).png
They scoop up sand and mud from the bottom. This helps big ships move safely. It can also make new land.
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
It is like a giant vacuum for the sea. Do you like the beach?

50 words

Big boats clean the water.

Dredge (PSF).png
Dredge (PSF).png
They scoop up sand and mud from the bottom. This helps big ships move safely. It can also make new land.
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg

Some boats act like giant vacuums. They suck up mud through a long tube. Other boats use big buckets to grab things. They can even find gold in the water.

This work can change the sea. It can make the water deeper. It can also help fix a beach. People use the sand to build new places.

Moving all that mud is a big job. Boats can carry it away. They can also use long pipes. This moves the mud to a new spot.

Cleaning the water is very important. It keeps the ocean healthy for fish. It helps people use the water, too.

140 words

Dredging is a way to move material from the bottom of water.

Dredge (PSF).png
Dredge (PSF).png
People do this to make water deeper. This helps big ships move through ports and rivers.
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Dredging also helps make new land. Workers can take sand from the sea to build beaches.

There are many ways to do this work. Some machines act like giant vacuums. These are called suction dredgers. They suck up mud through a long tube. Other machines use big buckets to scoop up sand.

Dredging technique schematic.png
Dredging technique schematic.png
Some boats even use a cutter. A cutter-suction dredger has a tool to break up hard ground.

Dredging can change the environment. It can stir up mud from the bottom. This can make the water dirty for a short time. It can also hurt the homes of sea animals. But dredging can also help. It can remove old trash or bad chemicals from the water.

178 words

Dredging is the way people move material from the bottom of water.

Dredge (PSF).png
Dredge (PSF).png
This work can happen in shallow rivers or deep ocean waters. It is a very important job for many reasons. People dredge to make waterways deeper so large ships can pass through. It also helps build new land or protect coasts from erosion. Sometimes, people dredge to find valuable things like gold or diamonds.
Dedge haul including live clams and empty shells.jpg
Dedge haul including live clams and empty shells.jpg

The way dredging works usually follows four main steps. First, a machine must loosen the material on the floor. Second, that material is brought up to the surface. This part is called extraction. Third, the material is moved from the machine to a new spot. Finally, the material is disposed of in a new place.

Dredging technique schematic.png
Dredging technique schematic.png
It might be dumped in a new area or sent through a long pipeline.

People have been dredging for a very long time. Ancient writers wrote about dredging in harbors. In the 3rd millennium BC, people worked on the Nile. In the first century AD, people were dredging at Marseille.

Draga cavafango Leonardo - Museo scienza e tecnologia Milano.jpg
Draga cavafango Leonardo - Museo scienza e tecnologia Milano.jpg
Later, the Banu Musa brothers designed a grab machine in Baghdad. During the Renaissance, Leonardo da Vinci drew a design for a drag dredger.
Draga cavafango Leonardo 2 - Museo scienza e tecnologia Milano.jpg
Draga cavafango Leonardo 2 - Museo scienza e tecnologia Milano.jpg
Even the famous Panama Canal used dredging to finish in 1914.

There are many different types of machines used for this work. Suction dredgers work like giant vacuum cleaners. They suck up mud through a long tube.

Pogłębiarka „Sawa”, głowica, Wisła, Saska Kępa, Warszawa 3.jpg
Pogłębiarka „Sawa”, głowica, Wisła, Saska Kępa, Warszawa 3.jpg
A cutter-suction dredger has a tool to break up hard ground. Some machines use big buckets on a chain to scoop things up.
ErfgoedLeiden LEI001016474 Baggervaartuig Hollandsch Diep 4..jpg
ErfgoedLeiden LEI001016474 Baggervaartuig Hollandsch Diep 4..jpg
Large ships like the Cristobal Colon can hold 46,000 cubic meters of material.

Dredging can change the world around it in many ways. It can help by removing trash or bad chemicals from the water. This is called contaminant remediation. However, it can also cause problems for nature. It can stir up mud and create plumes of dirty water.

Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
This can hurt the homes of sea animals on the seabed. It can even affect the water that people drink. We must be careful to balance these needs.

408 words

Dredging is the process of excavating material from underwater environments.

Dredge (PSF).png
Dredge (PSF).png
This work occurs in various settings, ranging from shallow rivers to deep ocean waters. It is a vital engineering practice used to manage water features and landforms. People dredge to improve navigability by deepening channels for ships. It also assists in coastal protection, land reclamation, and the recovery of valuable resources.
Dedge haul including live clams and empty shells.jpg
Dedge haul including live clams and empty shells.jpg
By gathering bottom sediments and transporting them elsewhere, dredging reshapes our world.

The dredging process follows a specific four-part sequence. First, the machine must loosen the material on the bed. Second, the material is brought to the surface through a step called extraction. Third, the extracted material is moved via transportation. Finally, the material reaches its destination during disposal.

Dredging technique schematic.png
Dredging technique schematic.png
The material can be moved by barge or through pipelines as a liquid suspension. Once moved, it may be used to create new landforms, such as islands in coral atolls, or to replenish sand lost to coastal erosion.

There are several distinct categories of dredging based on the machine's design. Suction dredgers function like large-scale vacuum cleaners, pulling material through a long tube. A trailing suction hopper dredger (TSHD) pulls its suction pipe while moving. It loads material into hoppers and then sails to a disposal area to dump the load. Cutter-suction dredgers (CSD) are different because they use a cutting mechanism to loosen hard surfaces like gravel or bedrock. Other mechanical dredgers use physical tools. Bucket dredgers use a wheel of circulating buckets, while grab dredgers use a clam shell bucket attached to a crane.

Dredge (PSF).png
Dredge (PSF).png

Humanity has practiced dredging for thousands of years. Ancient authors recorded dredging in harbors during the 3rd millennium BC near the Nile. In the first century AD, dredging was active in Marseille, where remains of three dredging boats were found. During the Muslim Golden Age, the Banu Musa brothers designed an original grab machine in Baghdad.

Draga cavafango Leonardo - Museo scienza e tecnologia Milano.jpg
Draga cavafango Leonardo - Museo scienza e tecnologia Milano.jpg
Later, Leonardo da Vinci drew designs for a drag dredger during the Renaissance.
Draga cavafango Leonardo 2 - Museo scienza e tecnologia Milano.jpg
Draga cavafango Leonardo 2 - Museo scienza e tecnologia Milano.jpg
In the 20th century, dredging was essential for the construction of the Panama Canal, completed in 1914.

Modern dredging involves massive scales of operation and highly specialized vessels. The largest trailing suction hopper dredgers are incredibly powerful. For example, the Cristobal Colon and Leiv Eriksson can hold 46,000 cubic meters of material in their hoppers. These ships can reach a design dredging depth of 155 meters.

Daniel Laval (2018).jpg
Daniel Laval (2018).jpg
Another large vessel, the HAM 318, has a hopper capacity of 37,372 cubic meters. These numbers show how much sediment must be moved to reshape coastlines or build new harbors.

Specific purposes for dredging range from industrial use to environmental cleanup. Capital dredging is used to create entirely new harbors or deepen existing ones for larger ships. Maintenance dredging keeps channels from becoming too shallow due to silt and mud.

Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Some dredging is used for harvesting, such as catching edible clams, crabs, or oysters. It is also used for contaminant remediation, which means cleaning up areas affected by chemical spills or sewage sludge. Even law enforcement agencies use a "drag" to recover evidence from the bottom of water bodies.

While dredging is useful, it has significant environmental impacts that must be managed. The process can disturb marine sediments and create dredge plumes. These plumes can cause short-term or long-term water pollution.

Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Such disturbances can damage seabed ecosystems and release toxins that were trapped in the sediment. This can lead to the reduction of marine wildlife populations and the contamination of drinking water. Balancing the need for navigation and construction with the health of the ocean is a major challenge for modern engineering.

666 words
🖼️ Images & Media (16)
File:Dredge (PSF).png
Dredge (PSF).png
File:Excavator dredger in Neeme harbour, Estonia (2023 April).jpg
Excavator dredger in Neeme harbour,...
File:Draga cavafango Leonardo - Museo scienza e tecnologia Milano.jpg
Draga cavafango Leonardo - Museo scienza...
File:Draga cavafango Leonardo 2 - Museo scienza e tecnologia Milano.jpg
Draga cavafango Leonardo 2 - Museo...
File:Pogłębiarka „Sawa”, głowica, Wisła, Saska Kępa, Warszawa 3.jpg
Pogłębiarka „Sawa”, głowica, Wisła, Saska...
File:Sudging dredger Tuk87-47-10.jpg
Sudging dredger Tuk87-47-10.jpg
File:2022-10-06 01 Dredger PROVINCIA DE EL ORO NO I, III & IV.jpg
2022-10-06 01 Dredger PROVINCIA DE EL ORO...
File:Geopotes 14.jpg
Geopotes 14.jpg
File:Berky Dredge King Typ 6780.jpg
Berky Dredge King Typ 6780.jpg
File:Dredging technique schematic.png
Dredging technique schematic.png
File:ErfgoedLeiden LEI001016474 Baggervaartuig Hollandsch Diep 4..jpg
ErfgoedLeiden LEI001016474 Baggervaartuig...
Dredging the Gowanus Canal (05880).webm

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