Jan de Nul Group has announced it will add three more water injection dredgers (WID) to its expanding fleet. The seagoing WIDs are converted offshore supply vessels with work being carried out by the Singapore PaxOcean shipyard.
The first WID to be mobilised, Giovanni Venturi, will be sent off on its first project in Argentina. The remaining dredgers Henri Pitot and Henry Darcy will be delivered later in the year.
The WIDs will be fitted with power jetting systems used for low-pressure injection of water into sediments. The process fluidises the sediments, making them move just above the seabed and through natural sediment streams. By doing this, overlying water layers are not impacted and the sediments do not need to be transported by means of hopper, barge or pipeline, turning this process into a cost-effective dredging technique.
The WIDs also have dynamic positioning, swell compensation for stable working conditions at sea, and diesel-electric drives reducing CO2 emissions.
The three vessels are smaller than traditional dredgers, have high manoeuverability and a limited draught. This type of dredger is suited for maintenance dredging works in smaller ports and other services such as seabed levelling for installation services and post-lowering of pipelines and cables in the seabed.