Second transformer platform jacket installed for HKZ offshore wind project

  • Jun 28, 2021
  • Petrofac

The second jacket of TenneT's offshore transformer platforms for the Hollandse Kust (zuid) wind farm has been safely and successfully installed in the North Sea.

Located 22 kilometres off the Netherlands coast, the 2,852-tonne heavyweight is the foundation on which the transformer platform will be placed, before the connection of the wind farm, which will be ready for use in 2022.

The jacket was put in place using Heerema Marine Contractor’s heavy lifting vessel, the Sleipnir. This mammoth ship is the largest in their fleet and the world’s most sustainable semi-submersible crane vessel. Sleipnir performed these operations while running on LNG fuel, reducing emissions by a substantial amount compared to traditional marine gas oil crane vessels.

The installation of the second jacket is an important milestone. Marco Kuijpers, TenneT's Director Offshore Projects said: "The past year has been characterised by uncertainty and challenges due to the COVID pandemic. Not only for TenneT, but also for our contractors and suppliers. Nevertheless, together we succeeded in achieving this performance. We can be proud of that."

At 50 metres long, 34 metres wide and 44 metres high, the jacket is anchored to the seabed by six piles, each weighing 162.5 tonnes, to form the foundations for the second of the two transformer stations that we are delivering for TenneT as part of the HKZ project. The transformer platforms will have a capacity of 700 MW each. The first jacket for the wind farm was installed in September last year.

The North Sea is now one of the world’s most important offshore wind hubs – find out more on how Petrofac is a key partner here.