The hydraulic cutter suction type China dredger has a cutting mechanism at the suction inlet. The cutting head will loosens the river bed material and transports it to the suction mouth. The dredged material is usually sucked up by a wear-resistant centrifugal pump and discharged either through a pipe line or to a barge. Hydraulic cutter suction dredgers are widely used in geological areas consisting of hard surface materials (for example,gravel deposits or surface bedrock) where a standard sand suction dredger would be ineffective. In recent years, dredgers with more powerful cutter mechanism have been built in order to excavate harder rock without the need for blasting.