Marine Vessels overHaulings

Mechanical dredgers

Mechanical dredgers come in a variety of forms, each involving the use of a grab or bucket to loosen the in-situ material and raise and transport it to the surface.
A Bucket Dredger is a stationary dredger, fixed on anchors and moved while dredging along semi-arcs by winches. The bucket dredger is one of the oldest types of dredging equipment. It has an endless chain of buckets that fill while scraping over the bottom. The buckets are turned upside down and empty moving over the tumbler at the top. The dredged material is loaded in barges.

Bucket ladder dredger

A bucket dredger is a stationary dredger that is equipped with a continuous chain of buckets, which are carried through a structure, the ladder (Figure 6- 2. This ladder is mounted in a U-shaped pontoon. The drive of the bucket chain is on the upper side. The bucket dredger is anchored on six anchors.

Hydraulic dredgers

The principal feature of all dredgers in this category is that the loosened material is raised from its in-situ state in suspension through a pipe system connected to a centrifugal pump. Various means can be employed to achieve the initial loosening of the material.

Trailing suction hopper dredger.

A trailing suction hopper dredger is a ship that has a full sailing capacity used to maintain navigable waterways, deepen the maritime canals that are threatened to become silted, construct new land elsewhere or replace sand eroded by storms or wave action on the beaches. This is made possible by large powerful pumps and engines able to suck sand, clay, silt, and gravel.