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 a routine necessity in waterways around the world because sedimentation, the natural process of sand and silt washing downstream, gradually fills channels and harbors.
Dredging is also used as a technique for fishing for certain species of edible clams and crabs.
Dredger is a Vessel\Ship which is used to excavate and remove material from the bottom of a body of water.
Dredging is also used as a technique for fishing for certain species of edible clams and crabs.
Dredger is a Vessel\Ship which is used to excavate and remove material from the bottom of a body of water.
Types of Dredging Vessels :
1. Suction: This is the most commonly used form of Dredging, These operate by sucking through 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.
Please refer, below PDF file for all the info regarding this Vessel.
1. Suction: This is the most commonly used form of Dredging, These operate by sucking through 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.
Please refer, below PDF file for all the info regarding this Vessel.
the-cutter-suction-dredger.pdf |
2. Trailing Suction:
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 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 dredgers in the world are currently Jan De Nul's Cristobal Colon (launched 4 July 2008[2]) and its sister ship Leiv Eriksson (launched 4 September 2009). Main design specs for the Cristobal Colon and 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.
Have a look at the video of one of the Leading Companies in Dredging, "Jan De Nul Group".
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 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 dredgers in the world are currently Jan De Nul's Cristobal Colon (launched 4 July 2008[2]) and its sister ship Leiv Eriksson (launched 4 September 2009). Main design specs for the Cristobal Colon and 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.
Have a look at the video of one of the Leading Companies in Dredging, "Jan De Nul Group".
3. Clamshell Dredger:
A Camshell/grab dredger is a dredger which 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 a dragline. This technique is often used in excavation of bay mud. Most of these dredges are crane barges with spuds.The clamshell dredger uses a crane with a clam mounted on a barge, and the dredged material is loaded on to independently operating lighters.
These are also commonly used all over world, mostly for mining and heavy duty projects.
We are attaching below the PDF's for reference of the reader:
A Camshell/grab dredger is a dredger which 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 a dragline. This technique is often used in excavation of bay mud. Most of these dredges are crane barges with spuds.The clamshell dredger uses a crane with a clam mounted on a barge, and the dredged material is loaded on to independently operating lighters.
These are also commonly used all over world, mostly for mining and heavy duty projects.
We are attaching below the PDF's for reference of the reader:
ceda_2006_clamshell.pdf |
-the-grab-or-clamshell-dredger.pdf |
4. Bedleveler:
Seabed levelling is a modern day dredging technique used in many ports and harbours. A plough is towed behind a tug along the seabed levelling high spots and ridges, moving the material to near by low spots. Also built up material can be removed from berths and other inaccessible areas into the tidal stream or operating area of a trailer suction dredger. Material is relocated from one place to another along the seabed and the sediment is not raised from the surface of the water.
Modern Day Engineers have also combined a marine plough system with water jets injected at high pressure to be used as a bed leveler, multiplying the effects of a conventional dredging in the normal maintenance of drafts along port quays and port & river entrance channels.
Seabed levelling is a modern day dredging technique used in many ports and harbours. A plough is towed behind a tug along the seabed levelling high spots and ridges, moving the material to near by low spots. Also built up material can be removed from berths and other inaccessible areas into the tidal stream or operating area of a trailer suction dredger. Material is relocated from one place to another along the seabed and the sediment is not raised from the surface of the water.
Modern Day Engineers have also combined a marine plough system with water jets injected at high pressure to be used as a bed leveler, multiplying the effects of a conventional dredging in the normal maintenance of drafts along port quays and port & river entrance channels.
Providing you with a PDF, which shows how the levelling dredgers came into existence and how they are mechanised.
bedlevers.pdf |
Above mentioned Dredgers are the most familiar and heavily used Dredgers all around the globe. There are many more Dredgers, used on water, but are all a bit similar as Above. The Other types are :
There are some very famous projects, done with the help of Dredging Technology. The few are showed below:
1. Palm Islands, Dubai
- Auger Suction
- Jet-Lift
- Air-Lift
- Bucket
- Backhoe/dipper
- Pneumatic
- SnagBoat
- Submersible
- Fishing
- Police Drag
There are some very famous projects, done with the help of Dredging Technology. The few are showed below:
1. Palm Islands, Dubai
2. The Sand Motor, Netherlands
3. Maasvlakte 2, Rotterdam
This post is a very brief explanation of Dredging. Thank you, for reading and going through the post, we hope it was helpful and helped you in knowing something new. Please Follow us for more, and Also send us enquiries in our Contact tab.