Dredging Equipment and Coastal Sediment Dynamics Definitions

Mechanical Dredges

• Bucket Dredge (Stationary): It is a stationary type dredger that does not propel itself, performing operations to fill an auxiliary hopper.
• Articulated Bucket Dredger: Consists of a pontoon housing a jib crane on its deck. A wiring system supports the bucket shell at its extreme, which consists of articulated jaws.
• Rigid Spoon Dredger: It has a front bulldozer blade installed on a spud pontoon. The entire assembly is mounted on a rotating raceway attached to the pontoon.
• Dragline Dredger: Consists of a float (pontoon) housing a tower operated by a cable system with corresponding drum gear, driven by mechanical or hydraulic motors, and equipped with the necessary work accessory at the tip.
• Backhoe Dredger: Consists of a pontoon on the deck of which conventional land excavation machinery (backhoe) is located.

Dredging Auxiliaries

Equipment used to support dredging operations:

• Barges
• Tugboats
• Pipes
• Rock Breakers
• Positioning Means

Coastal Dynamics

A set of physical mechanisms that control the movement of sediment along the coast.

Coastal Geomorphology

The study of coastal forms and features.

Coastal Landforms

Tombolo

A sedimentary landform, typically a bar, that forms a narrow strip of land connecting an island or large offshore rock to the mainland, or connecting two islands or rocks.

Sedimentology

Characterization of sediments on low coasts, beaches, and coastal deposits of loose materials.

Wind and Wave Generation

Wind acts as the generator of waves and the mechanism for sea transport.

Dunes

Accumulations of sediment that adopt consistent patterns of simplicity of form, accuracy of repetition, and geometric order.

Conditions Necessary for Dune Processes:

• Large contributions of materials.
• Transport along a free coastline.
• Strong winds.
• Low humidity.

(Material availability and wind are the most important factors.)

Transverse Dunes

A series of long ridges separated by depressions, oriented at right angles to the prevailing wind. Coastal dunes are usually of this type.

Waves

Waves are generated when the wind exceeds the critical velocity of 1 m/s near the surface. Under the action of wind, waves grow in height, wavelength, and period up to a maximum size that depends on the wind speed, the duration it has been blowing, and the size of the generation area (*fetch*).