Work on the DolWin4 and BorWin4 offshore grid connections has started in Wietmarschen and Lingen. The construction camps are currently being set up in Wietmarschen. The transmission system operator Amprion has commissioned the Tief4 consortium to carry out the work on the approximately 12-kilometre-long section.

Amprion is connecting offshore wind farms to the power grid with DolWin4 and BorWin4. The lines end in Lingen and run parallel to the A-Nord direct current connection between Emden and Wietmarschen. At about the level of the Ems-Vechte-West rest area, A-Nord and the two offshore lines separate. The civil engineering work from there to the converter station in Lingen will begin in mid-August. The Tief4 consortium commissioned by Amprion will first build a cable protection pipe system into which the power cables will later be pulled.


Two construction camps are already being set up in Wietmarschen on Rupingorter Kirchweg and on Hauptstraße 100. From there, the civil engineering companies will supply the mobile construction site. From the end of June, the pipe strings for the cable protection pipe system will be pre-welded. Their installation will begin in mid-August. This includes both sections in the closed construction method – primarily using the horizontal directional drilling method – and sections in the open construction method.

For example, the horizontal directional drilling method is used when crossing infrastructure or bodies of water. Amprion only needs space for the construction site at the start and end points of such a route. In the open construction method, two trenches are dug with excavators, in each of which two cable protection pipes are laid. Amprion is implementing a tried and tested soil protection concept: the different soil layers are removed separately, stored and then refilled in the original order.

Two special crossings are on the agenda for 2025: In the first half of the year, the Dortmund-Ems Canal and the Ems with the FFH area there will be undercut in one go. During the same period, Amprion will cross the IC route between Münster and Emden in the area of ​​the Hanekenfähr substation using pipe jacking, another method for trenchless pipe laying.


The largely parallel offshore grid connection systems DolWin4 and BorWin4 are among the most important energy transition projects in Germany. They are both scheduled to go into operation in 2028. From the North Sea wind farms, the cables initially run 60 and 125 kilometres at sea, respectively. They pass under the island of Norderney and reach the coast in the Hilgenriedersiel area. From there, they run around 155 kilometres as underground cables towards the Hanekenfähr substation in Lingen (Ems), where Amprion will connect them to its transmission network. The Emsland nuclear power plant there went offline in April 2023. The resulting loss of generation capacity will be replaced by 1.8 gigawatts of offshore wind energy via DolWin4 and BorWin4.

Image source: Courtesy of Amprion

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