The challenge

The Western Scheldt is one of Europe’s most difficult navigable rivers. Tens of thousands of ships are being piloted on the narrow Western Scheldt 24 hours a day, by the efforts of the Dutch and Flemish pilotage. The port Koopmanshaven in Vlissingen (Flushing) is the home port of the Pilotage. Shallow depths has been formed in the Koopmanshaven due to strong currents and soil erosion. The pilot vessels run aground in the muddy waters and scraping against large stones on the seabed, causing a lot of delays and problems. In addition, there have been concerns about the decay of the quay walls, slopes, berths and mooring constructions in both the Koopmanshaven as the adjacent port Vissershaven.

Our contribution

Walhout Civil was being contracted urgently by the Client for diving inspections and bathymetric surveys in order to get a better understanding of situation of the seabed. Large amounts of soil material and stones where discovered during the inspections and low tide. The bathymetric survey was executed by use of a new RCV Remote Control Hydrographic Survey Boat, a floating drone capable of performing sharp measurements up to < 20 cm under the water level. The drone was been able to make measurments at normally, unreachable locations, like under the landing stages and mooring constructions. Walhout Civil made a dredging program for the Koopmanshaven based on the conducted research. Besides, the objects and assets in the Koopmanshaven and Vissershaven have been thoroughly inspected. Based on a Dutch method for condition measurements (NEN norms), maintenance and restoration plans has been prepared. A summary of our activities:

  • Dive inspections
  • Bathymetric survey
  • Integral meetings with Pilotage and stakeholders
  • Desk and archive studies
  • Inspections and NEN-condition measurement of assets
  • Dredging program, maintenance and restoration plans

Copyright pictures: DNA-Beeldbank, Aerophotostock (with permission)