Every day a race against time

On behalf of the Belgian network operator Elia, Martens en Van Oord removed old groynes (sturdy stone dams that run across the beach and into the sea) and cleared a number of cable routes on the beach near Zeebrugge.

Possible ordnance

In May 2017 the work started on setting up a work site. MvO installed a screening plant with a 6-metre-high container wall around it, which was meant to shield the work site. This was required because unexploded ordnance (UXO) could still be present in the soil. This was also the reason why two UXO experts from BODAC were hired. During the work they were present to analyse the excavated soil with metal detectors and check the residue on the belt for possible UXO during screening.

Safety versus speed

The sand was being excavated to a depth of four metres below ground level. For this we used a bulldozer and two tracked cranes. Because of the necessary detection work, the excavation was performed in layers.

All the sand was screened for irregularities such as rubble and wood to ensure that the future cable route could be delivered clean. As the beach had to be freed up again before the start of the tourist season, only two groynes were removed during the initial phase of the project.

The construction of the three cable routes followed from November onwards. During the execution there were, however, challenges that had to be taken into account. Because of the tides, for example, work was only possible during low water. Additionally, due to the presence of possible ordnance and the depth of the work, various safety measures had to be taken.

From start to end
The project was successfully completed and finished. One interesting fact was that, at the other end of the NEMO cable route near the English town of Ramsgate, MvO colleagues were also working. They assisted in identifying a number of potential unexploded pieces of ordnance: MvO was pulling both ends of the underwater NEMO cable!