The grab dreger vessel is used for dredging sluges in waterways, harbors, lakes etc.as dredge and drainage engineering ships.

There are several control systems provided to improve dredging efficiency and accuracy as following (including but not limited to):

1. PLC and visual simulation system

PlC system can greatly improve and facilitate operation of speed control and halt with load in the mid-air.Visual simulation system is able to achieve visualization and intellectualization in depthkeeping digging and horizontal digging.

2. Depthkeeping digging system
This crane is provided with depthometer, according to which the operater is able to set dredging depth to improve the dredging quality and avoid wast of overexcavating.

3. Satellite positioning dredging construction management system
This system is is used to indicate location of the hull and working track of the grab bucket anywhere and anytime to ensure high efficiency and accuracy of dredging construction quality.

4. Horizontal digging control system
This system is able to store several kinds of grab working processing program and provided with manual input type depth correction function. Thus smooth working faces are able to achieve.

5. Depth correction system
While working , the grab may be affected by dredger slewing, luffing hull tilting. The depth conrrecion system can revise the tolarance.

The grab buckt linked with wire rope goes down into the earth by its deadwight and closes to grab target materials. Then the grab bucket lift up to a rated height and slews to the target.after offloading cargoes, the grab buckt slews back to the above of dredging point for next circuit.