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Modification split hopper dredger

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Hydraulic grab crane Integration

Modification split hopper dredger

Hydraulic grab crane Integration

For unloading in various ports, DEME decided to equip their vessel VLAANDEREN XXI with its hydraulic grab crane. For this deck arrangement needed to be redesigned and the crane support integrated into the split barge construction.

The split hopper dredger ’Vlaanderen XXI’ is frequently engaged in gravel dredging with the delivery of the gravel to various North Sea ports between Le Havre, France, and Flushing, The Netherlands. For unloading in the various ports, the Operational Manager used its mobile hydraulic crane, traveling by road between these ports. This became highly unpractical. Therefore the Belgian owner DEME decided to equip the vessel with its hydraulic grab crane. To install a Sennebogen hydraulic crane with grab, Vuyk Engineering Rotterdam was requested to redesign the deck layout.

Specifications

Launched in
2007
Depth
33.00 m
Capacity
1635 m
Hopper load
2290 t
Suction pipe diameter
650 mm

Due to the split hopper setup, the crane support had to be placed on one side of the hopper, as close as possible to the centreline of the vessel. A construction was created in the centre of the hopper area to support the crane foundation on the SB side. The existing overflow had to be relocated to the centre of the hopper. To avoid contact between the crane and overflow during splitting, the overflow was also placed on the SB side. The large hole in the construction, serving as crane foundation required a FEM calculation to ensure the necessary strength in all directions.


The loading system was redesigned, because of the relocation of the overflow and the limitation of the original system for sand and silt only. Loading openings were positioned at the fore and aft side of the hopper area. Overboard discharges with grids were created to wash a substantial amount of sand overboard before the gravel enters the hopper.


After conversion, an inclining test was conducted and a new stability booklet, approved by the Flag state Authorities, could be handed over to the Operational Manager. Early September 2007, the vessel’s trails were successfully executed and the vessel is now fully operational again.
 

Location