Dredging packages from De Groot Nijkerk

IHC Holland may be the Netherlands? best known dredger builder, but several other smaller concerns – such as De Groot Nijkerk, part of the Damen group of companies – are also highly successful, and innovative in their own right. Among De Groot Nijkerk?s latest projects is a bucket dredger that it is helping to convert into a specialised slope profiler on behalf of Dredging International in Singapore. De Groot Nijkerk has supplied a new, electric drive for the slope profiler, and a set of unique dredge pumps – six in total – which are fitted directly on to the dredgehead. The pumps in question are electrically driven versions of De Groot Nijkerk?s DOP type pumps. The type E-DOP1815 pumps fitted to the slope profiler have a mixture capacity of approximately 600m3/h at 110kW and 980 rev/min. The multi-function DOP pumps were selected because they were deemed the most suitable means of removing solid matter from a restricted area, to a specific depth, then pumping the material via a discharge pipe over a considerable distance. Also recently ordered from the company is a dredging equipment package consisting of a 3,500mm trailing suction pipe, plus jet-water pipe, cardan hinge, draghead and turning gland. The package also includes all of the necessary gantries, slide flange carriage and winches, plus a De Groot Nijkerk type BP3530/850 pump, valves and dredging instrumentation. The trailing suction pipe system will be mounted on a 600m3 grab hopper dredger working at the Port of Poti in Georgia, the former Soviet republic. The dredger, Niko Nikoladze, is due to be delivered by the end of this year. Recently delivered by the company was a CZ450S stationary dredger for an unspecified customer in Africa. This innovative dredge is capable of operating both as a cutter suction dredger, and plain suction dredge. This vessel has a delivery pipe with a diameter of 450mm. The ladder can be equipped with a hydraulically driven 110kW cutter unit ? for which De Groot Nijkerk supplied a pick-point cutterhead as well as a plain knife type cutterhead – or fitted with a jet-assisted plain suction head for sand-winning operations. The newly delivered vessel is fitted with Type BP45-1100 Grotius dredge pump with closed impeller, and is driven by a 746kW Caterpillar 3508B diesel engine, through a Reintjes gearbox. A 242kW Caterpillar 3406B auxiliary engine has also been installed in order to drive the gland-water pump, the cutter-flush pump and the hydraulics. The ladder winch, the side wire winches and the anchor boom winches are all hydraulically driven, as is the jet water pump, a 400m3/h, 5-bar device.