Van Oord has been conducting final tests of its remotely controlled-trencher Deep Dig-It as part of the preparation for the subsea cables installation on the Hollandse Kust (South) offshore wind farm project in The Netherlands.
TenneT awarded the Van Oord-Hellenic Cables consortium in 2018, to build the connection from land to sea for the Hollandse Kust (South) offshore grid project, with scheduled completion in 2022.
Four cables will have to be routed into the North Sea seabed and buried more than 5 metres for the first ten kilometres of the offshore cable route to be able to cross the Rotterdam Maasmond shipping lane.
The Deep Dig-It is a so-called “Tracked Remotely Operated Vehicle” (TROV), which drives unmanned over the seabed, creating a deep trench for the cables, while simultaneously inserting the cables and then closing the trench again, Van Oord explains.
The trencher weighs 125.000 kilos, is more than 17 metres long, well over 8 metres high, and 11 metres wide. It has an installed power of 2,500 HP, making it possible to bury cables into very hard soils and well over 5 metres.
The Deep Dig-It will be controlled from Van Oord’s offshore installation vessel MPI Adventure, which is equipped with a crane that launches and recovers the trencher into the sea.