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Van Oord and joint venture partner Boskalis recently wrapped up work on a capital dredging project in Walvis Bay, Namibia.
By using trailing suction hopper dredgers, Van Oord and Boskalis deepened the 10-kilometre-long access channel to the port of Walvis Bay from -14.4 to -16.8 meters and widened it from 130 to 200m.
In addition, dredgers Vox Alexia and Gateway expanded the harbor basin to a depth of -16.3 meters and expanded it by more than 400m.
However, this capital dredging project was not without its challenges with major one being the presence of excessive concentrations of toxic hydrogen sulfide (H2S) in the dredged sediment.
To mitigate this risk, a large number of health and safety measures were taken during the mobilisation prior to the project, including modifications to the vessels and the installation of dozens of sensors and special H2S filters.
Also, the vessel crews were trained on how to deal with H2S. They were able to measure the concentration of H2S in the air at all times and established safe working protocols on board. A large number of sensors were also installed on the quays of the port area to alert the workers and users of the port in time in case the gas appeared.
Thanks to these engineering and administrative controls, the project was successfully completed without incidents and well on time, the companies said.