Descent and positioning:
The dredging grab is slowly lowered to a predetermined underwater position under the tow of a crane or dredging vessel.
During descent, the grab remains closed to avoid collision with underwater obstacles.
Open the grab:
When the grab reaches the predetermined position, the control system will issue an instruction to start the opening and closing mechanism of the grab.
By adjusting the tension of the rope or hydraulic system, the clamshell or more shells (jaws) of the grab bucket gradually separate to form an opening to grab the material-issue instructions on how to start the opening and closing mechanism.
Grab materials:
After the grab opens, materials (such as sand, rocks, etc.) will be sucked or squeezed into the inside of the grab.
According to the properties of the material (such as particle size, viscosity, etc.), the opening and closing speed and strength of the grab need to be adjusted accordingly to ensure that the material can be effectively grabbed.
Closed grab:
When the inside of the grab bucket is filled with materials, the control system will issue instructions again to make the opening and closing mechanism of the grab bucket work in reverse.
The clamshell grab bucket gradually closes, tightly wrapping the material inside.
