The cutter suction dredger is a combination of mechanical and hydraulic dredging vessels. To ensure the quality of underwater digging depth (i.e., the flatness of the underwater seabed after excavation and the depth of the dredging), it is necessary to use steel piles and their lifting devices or the three-line positioning device mounted on the hull for positioning and moving the vessel forward and backward. The side-to-side swing of the hull is achieved by the two side swing anchors connected to the bridge of the dredging cutter.