VESSEL REVIEW | Henk Piet – Electric dredger for Dutch civil engineering firm

Netherlands-based marine projects company Koninklijke Oosterhof Holman (KOH) has taken delivery of its newest deep suction dredger, the all-electric Henk Piet.

Custom-built by the TV Dredging division of the Holland Shipyards Group, the vessel has a length of 22 metres and is of modular construction, allowing for easy deployment to work sites, though the vessel is initially deployed at the Fochteloërveen protected area in Friesland province where it will support nitrogen extraction activities.

The Fochteloërveen is notable for being one of the last raised bogs in the Netherlands and therefore in need of periodic dredging. The rainwater that is normally retained in the raised bog runs through leaky quays from the area. In order to prevent the raised peat from disappearing, it is necessary for the old quays to be replaced by sustainable sand quays over a stretch totalling approximately 50 kilometres.

Dredging can be performed up to a maximum depth of 37 metres with the aid of two 600kWh electric pumps. The dredger itself is stationary, allowing it to draw power from the local grid via a shore connection instead of relying on onboard generators that would otherwise emit greenhouse gases. A floating solar farm at a sand extraction site in the nearby town of Weperpolder supplies nine MW of electricity, which is adequate for ensuring continuous dredging operations in Fochteloërveen.

The wheelhouse electronics include a GPS and an echosounder.

Henk Piet is being operated by KOH subsidiary Nautilus Zandwinning.

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