The Port of Malongo in Angola is currently undergoing a major facelift.
A completely new harbor area is being created, and the old part is demolished. The new part will also be deepened to allow access for sea going vessels and the buried structure of old dock on seabed will be demolished.
The total maximum dredging depth is -6m; and the structure of old dock will be cut down to -7,0m. The entire job involves moving a total volume of 250.000m³ of soil. This soil is mainly relatively recently deposited fine to medium sand.
The job is tackled using 3 Damen DOP dredge pumps. Each submersible dredge pump has its own specific job.
One DOP250 is attached to a wire crane using a chain spread. Its jet water-assisted sand mining head combined with the submersed location of the pump ensure a high mixture concentration. The wire crane is located on the jetty.
The DOP pumps the mixture over some 450m using d250 and d300 mm dredge piping. When the job on the jetty is finished, the DOP250 will be mounted onto the Conduril MultiCat vessel to complete the dredging in the harbor.
The second DOP250 is fixed to the boom of an excavator and located on the shore.
The DOP, fitted out with a cutter head, breaks up the compacted soil and pumps the material to the same location as the first DOP. This is a temporary storage facility on the beach; the discharge distance is only 200 m.
Source: Dredging Today