Swedes grab BorWin 3 gig

Petrofac, working alongside Siemens, has awarded Trelleborg’s engineered products operations a contract for the floatover installation of the converter platform for TenneT’s 900MW BorWin 3 offshore wind grid connection system.

The HVDC converter station will be located about 130km off the German coast in the North Sea.

Swedish company Trelleborg said its leg mating units will make a floatover transition possible by damping the forces created as the topside’s load is transferred to the jacket foundation.

The legs consist of steel structures filled with elastomeric pads, which are designed to take up the static and dynamic forces of the topside structure, as well as the horizontal forces due to open sea motions during installation, Trelleborg said.

In addition, the company said, deck support units are fixed on the barge that will transport the platform’s topside to the offshore site to combat the destabilizing effects of adverse weather and sea conditions.

It has started fabrication of the legs and support units, which are scheduled for delivery in 2018. The project is due for completion in 2019.

TenneT contracted a consortium of Siemens and Petrofac to design, build and install the BorWin system.

Siemens will supply the HVDC transmission technology, while Petrofac will be responsible for the construction and installation of the platform.

Trelleborg marketing manager for engineered products Vincent Tan said: “BorWin 3 is only the third wind farm converter project in the world to utilise floatover technology, so it is a significant project not only for Trelleborg, but the industry too.

“For the installation of the 18,500 metric tonne topside onto the substructure, we have been contracted to supply six sets of leg mating units and the same amount of deck support units.”

Image: impression of the HVDC platform (Petrofac)