Dredging is the process of the removal of silt and other debris from the bottom of a variety of bodies of water including the ocean, rivers, and canals. Sand and silt naturally wash downstream causing it to collect in harbors and waterways and will need to be removed frequently to maintain and increase the depth of the navigation route, anchorages, or berthing area, to allow for boats and ships to move safely without touching the bottom and incurring damage. There is also a type of dredging referred to as environmental dredging. This is done to reduce the amount of exposure of fish, wildlife, and people to contaminants and prevent it from spreading further across the ocean. This is because the sediments collected around cities are filled with a variety of pollutants.
The process of Dredging
The dredging process mainly involves excavating naturally deposited sediments or manmade debris from the bottom of bodies of water. This can include things like rocks, construction debris, bottom sediments, refuse, and organic matter. The process itself involves digging up all of the gathered sediments from one place and disposing of them somewhere else. This is done by either using suction or scooping devices, often called a dredger. This needs to be done regularly and frequent maintenance is needed in bodies of water that are susceptible to becoming silted with sediment, sand, or mud.
The importance of dredging
Dredging is of huge importance in the maritime industry as it has many benefits, such as making way for safe voyages to be practiced by pacifying underwater traffic and maintaining clearance. It is also often used to collect shellfish and molluscs, as well as for harvesting pearls and other ocean gems. It also aids in channelizing the construction of a network of bridges, dams, and other civil engineering works in bodies of water. Not only does it offer these benefits, but it also benefits the environment by assisting in making the marine ecosystem pollution-free, as it aids in eco-friendly disposal of deposited polluting toxins and other harmful materials and helps to preserve the oceans flora and fauna.
Methods of Dredging
The dredging process is a combination of digging soil in the water bed and removing it from the excavated area. There are two methods mainly used for dredging; one being mechanical dredging and the other, the most commonly used method, hydraulic dredging. Mechanical dredging is when the sediments are picked up by using mechanical tools like bucks and grabs. This is often carried out near a shoreline and if it is close enough to the shoreline the sediments can be directly transferred onto a truck to be removed. Hydraulic dredging is conducted by removing sediments from the site by way of a pump that sucks into a pipe that is used to transport the sediment. It is then mixed with water and made into a mixture that makes it easier for the pumps to transfer it.
Types of ships or vessels used for dredging
Dredging can be further classified into what types of dredging ships or vessels are used. Mechanical dredgers make use of a bucket dredger this is usually fixed and rotates in an arc by winches around the dredging site. There is also a grab type dredger which is a stationary dredger that has a grab as a dredging tool which is two scoops that are operated hydraulically. The backhoe dredger is a stationary type, that is usually attached to a barge near the banks. With hydraulic dredgers there are tools such as the suction dredger, that is stationery and normally used for mining sand it has a suction pipe to bring sand up. There is a cutter suction dredger that is also stationary with a cutter head. There are many ways to conduct dredging, dependent on what your needs are, so give us a call and allow us to assist you in ascertaining which method will be best suited to you.