In 2023, Heerema successfully installed 27 wind turbines at the Arcadis Ost 1 wind farm, which is located in the German sector of the Baltic Sea, approximately 10 nautical miles northeast of the German island Rügen and 40 nautical miles southwest of the Danish island Bornholm. The Arcadis Ost 1 Wind Farm comprises of 27 V174-9.5MW wind turbine generators (WTGs), with a total capacity of 257MW.

Parkwind Ost GmbH contracted Heerema Marine Contractors for the loadout, transport and installation of the WTGs, which were supplied pre-assembled by Vestas. Heerema transported the WTGs from the port of Rønne on Bornholm (the pre-assembly site) to the offshore site and installed the WTGs using Heerema's SSCV Thialf. The Arcadis Ost 1 project was successfully completed in two installation phases, the first installation phase was completed in March and the second in November of 2023. 

The Novel RNA Method

The floating installation methodology included a support tower on the SSCV deck, which facilitated the assembly of the Rotor Nacelle Assembly (RNA) on board using the Guided Root End Positioning (GREP) tool to install the blades. RNA has been proven to be a successful and reliable method of installing wind turbines using floating installation vessels. Installation cycle times have been consistent and competitive with traditional methods, while floating installation offers several specific advantages, such as zero interaction with the seabed, which is particularly important in areas of significant water depth or challenging soil conditions. As well as considerable higher workability as the vessel can freely relocate to optimize heading and installation sequence.