DOP Submersible dredge pumps

3 DOP dredge pumps create new harbour


Location: Port of Malongo, near Cabinda, Angola
Period: Q3/2019
Product type: DOP250 with sand mining head and cutter head
Contractor: Conduril Engenharia for CHEVRON – Oil and gas company

Close cooperation between 3 DOP dredge pumps on harbour project

In Angola, the Port of Malongo is undergoing a major facelift. A completely new harbour area is being created, and the old part is demolished. The new part will 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 DOP dredge pumps. Each submersible dredge pump has its own specific job.

A good project overview shows 2 DOP pumps at work on the harbour project

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 450 m 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.

Both DOP pump seen in the back ground pump the sediments to the storage facility

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.

One dredge unit is an excavator with DOP onto its boom, located on shore

Now the 3rd DOP250 comes in view : this DOP is used to pump the sediments to their final location, a disposal area some 800 m away. Moreover the DOP aims to keep the soil levels in the storage facility as low as possible.

One dredge unit is located on the jetty, the other is located on shore

The delivery included a complete Dredging Package ensuring a quick and easy project start. The package included hydraulic hoses as well as discharge hoses and a batch of spares. Furthermore local support has been assured as the Damen Service Agent in Angola was present to give hands-on advice.