The first of 27 Vestas V174 – 9.5MW turbines has been installed at the Arcadis Ost 1 wind farm.

Thialf installs 1st wind turbine using novel RNA method-Arcadis Ost 1

Image source: Heerema Marine Contractors (HMC)

Using a unique floating installation method, developer Parkwind, together with Heerema Marine Contractors (HMC) and Vestas, oversaw the installation in the Baltic Sea. HMC said the process has been three years in development and has two main advantages: the first is zero seabed interaction especially important in areas of significant water depth or challenging soil conditions; the second advantage being a shorter installation cycle.

To speed up the installation process, assembly and lifting operations are happening in parallel. One of installation vessel Thialf’s two main cranes lifts the pre-assembled turbine tower to the foundation, whilst the second main crane is used to pre-assemble the WTG in parallel.

For the latter, HMC developed a method where the rotor nacelle assembly (RNA) lift takes place on a so-called “support” tower onboard the crane vessel. The support tower provides a stable platform to allow a fast and secure assembly of the nacelle and the blades, said HMC. Once pre-assembled the complete RNA is lifted as one piece onto the turbine tower in only one lift.

Eric Antoons, co-ceo of Parkwind commented:Arcadis Ost 1 will soon be one of the world’s most advanced wind farms, thanks to its design, components, and installation method, all brought together by exceptionally talented teams. Now, with the first turbine installed, we trust that the project teams will successfully install the remaining 26 turbines.”

Arcadis Ost 1 is a 257 MW wind farm, developed by Parkwind, and located in the German territorial waters of the Baltic Sea, northeast of the island of Rügen. Final commissioning is planned in 2023.