International Dredging Review

International Dredging Review

Damen supplied two dredge pumps for the 3200-cubic-meter (about 2447-cubic-yard) trailing suction hopper dredge Charlock. One semi-axial dredge pump is fitted on the trailing pipe and the other pump is mounted inboard. Damen said both dredge pumps work in series enabling a more efficient dredging process.

The semi-axial dredge pump is the newest to the Damen line of pumps. The Charlock’s pump type OBP9080HA is lightweight reducing the required hoisting capacities of the gantries and winches on-board. The limited cross section minimizes the drag forces in the drag arm. The semi-axial pump is equipped with a 1200 kW electric motor and delivers some 16000 cubic meters/hour of mixture at 50 percent concentra-tion and at an excellent efficiency of 85 percent.

The cast dredge pump wear parts have been designed in close cooperation with the foundry. All cast elements including the two-parted pump casing have been sized to make use of the foundry’s process to boost the casting accuracy and reduce the risk on mis-casts. The various wear parts can be cast in different materials de-pending on the material to be dredged.

The semi-axial dredge pump will work in se-ries with the Damen inboard dredge pump type BP8065MD. The low pressure semi-axial dredge pump delivers the dredged mixture with minimal head at the inboard dredge pump. This single-walled centrifugal dredge pump either delivers the mixture to the hopper during loading or it can also pump ashore using the bow coupling unit or rainbow. The inboard BP8065MD dredge pump is driven by a 3200 kW electric motor.