April 6, 2016
DOP Dredges Unexploded Ordnances

(With video and extra pictures) Currently, Dutch contractor Martens & Van Oord in Cadzand, the Netherlands, is dredging both sand and unexploded ordnances (UXOs) to deepen Cadzand’s harbour and replenish the shores.

The village of Cadzand is located in the south west of the Netherlands, on the shores of the North Sea. Its old marina entrance needed to be updated and the harbour was to be deepened. Not a simple job taking into account that conventional Second World War explosives were hidden in the seabed.

Reinforced Screening Installation

Martens & Van Oord uses a Damen DOP submersible dredge pump. The DOP350 was attached to one of Martens & Van Oord’s pontoon-based excavators. The DOP pumped the bottom material – sand and occasionally UXOs – to a reinforced screening installation. From there, another Damen pump was used to bring the screened sand further to replenish the nearby shores.

The submersed dredge pump ensures a continuous process (in UXO-areas) contrary to mechanical dredging.

Sand Mining

For sand mining purposes, a somewhat customised sand mining head with plenty of jetwater was fitted. This DOP head was designed for mining a maximum concentration using pressurised water to fluidise the bottom material.

Picture: DOP pump at work at Cadzand. Below a video (in Dutch, with English subtitles) showing the work being done at Cadzand as well as some extra pictures (please click the pop-out link to view them in their proper dimensions). All pictures by Damen.

DOP semi submerged with floating discharge pipe lineDOP submersible dredge pump at work below the water surfaceThe pontoon based excavator with DOP pump screening installation and booster pump