International Dredging Review

International Dredging Review

Last summer Dutch dredging company Geluk contracted Damen Dredging Equipment to replace the hydraulic drive on its sand mining dredge Maas with an electric drive for an efficiency gain of more than 28 percent.

Geluk specializes in aggregate dredging as well as construction reclamation maintenance and other dredging projects.

Included in the project was removing the hydraulic drive and engineering and installing a new gear box generator and CAT engine.

Damen built the Maas in 1986 for Geluk who has been operating it ever since.

The Maas is a 600mm (24-inch) discharge diameter sand mining dredge 52 meters long 8.9 meters wide with a maximum dredging depth of 43 meters.
A Damen submerged dredge pump is integrated in its suction ladder.

The cost of the refit operation was justified as the Maas is of a robust design and has been kept in very good condition. Beside the efficiency gain the change to electric power reduced the sound level eliminated the environmental concerns of working with hydraulic oil and simplified the assemby and dis-assembly of the dredge.
The ladder and the pontoon were transported to Damen’s Nijkerk yard where all work was carried out.

The service department removed all hydraulics from the ladder and pontoon and adapted everything to the new electric components. These include a 450 kW submersed electric motor with mechanical shaft seal plus a one-stage gear box and an elastic coupling on the ladder. In the aft side pontoon a 530 kW generator was installed plus a new Caterpillar C32 diesel engine. After installation of all components the ladder and side pontoon were connected to the dredge and engineers then conducted testing and commissioning.

The Maas returned to work immediately at the Kraaijenbergse Plassen project in the East of the Netherlands. Thanks to the sound level reduction an earlier aborted dredging project can now be finished.

The Kraaijenbergse Plassen reconstruction is one of the largest earth removal operations in the Netherlands inland waterway network.

The area is along the River Maas in the Cuijk region where a good source of construction sand is located. The local authorities are now reclaiming the area as a recreational and protected wildlife area existing alongside the sand mining activities.

The task is to excavate industrial sand at a depth of 25 meters (82 feet) as well as to extract fill sand on a slope gradient of 1:3.

Both the industrial and the fill sand are intended for the Dutch market. The quantities are substantial: the total volume to be reclaimed is more than 6.5 million cubic meters (8.5 million cubic yards) and the fill sand to be loaded amounts to more than six million cubic meters (7.8 million cubic yards). The waterline to be constructed measures more than seven kilometers. In total an area exceeding 38 hectares (93.9 acres) will be created.

The area will include islands marshland a waterside campsite and shores intended for recreational use with slope gradients of 1:6 and in places 1:3. The 1:6 slopes will be filled using spray pontoon.

Geluk BV extracts the required sand from the bed of the lake to a maximum depth of 40 meters (131 feet). Every year one million cubic meters of fill sand is extracted by the dredge IJsselmeer and loaded onto ships after screening.

Geluk has over 150 years of experience in dredging and operates in The Netherlands and other Western European countries. Geluk has a large fleet of stationary dredges boosters and DOP pumps. The company Web site is: