TenneT is building the Hollandse Kust (South) offshore grid to the north of the Maasvlakte, to connect new wind farms. Four cables will have to be routed into the North Sea seabed for this.
The cables have to be buried more than 5 meters in the seabed for the first ten kilometers of the offshore cable route, as to be able to cross the busy Rotterdam Maasmond shipping lane. For this specific job, Van Oord designed and built the Deep Dig-It trencher, a gigantic and remotely controlled trencher. Van Oord, being part of the Van Oord-Hellenic Cables consortium, is conducting final tests with this enormous machine in the Alexiahaven (harbor) today, in preparation for the actual installation of the sea cables in July.
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. Special about this new trencher is that it is the largest and most powerful machine in its class. The trencher weighs 125,000 kilos, is more than 17 meters long, well over 8 meters high, and 11 meters wide. It has an installed power of 2,500 HP, making it possible to bury cables into very hard soils.
Next to the large power installed, the depth of burial that can be achieved by the trencher is unmatched: well over 5 meters. A lot of Marine ingenuity has been put into the Deep Dig-It, with the development of this new trencher Van Oord responds to a changing offshore wind market and its latest demands.
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 Deep Dig-It into the sea.