d. Auxiliaries

All modern dredgers are equipped with a range of sophisticated electronic control and data-logging systems appropriate to their type. These assist with positioning, loading and recording. VDU displays showing the position and attitude of a trailer draghead, cutter head, backhoe stick and bucket, or even a grab are set in front of the operator. Similar displays show in plan the location of the dredger and, where appropriate, its track and heading. Depth of cut, current dredged depth and slopes are also displayed on the same or separate monitors.

All these aids lead to increased efficiency of operation as they minimize overdredging. They reduce unnecessary travel or coverage (traversing an area already to profile) and improve the precision of dumping, particularly when forming the lower layers of a reclamation or where strict environmental controls exist.

e. Conclusion

Many different types of dredger exist, each with its advantages and disadvantages. The final choice of dredger for any cost and availability. Unless there are specific reasons for not using a particular type of dredger, the choice of type, size and number usually lies with the operator or contractor.