Allseas’ Pioneering Spirit has successfully installed TenneT’s 900-megawatt DolWin kappa offshore converter station for the DolWin6 offshore grid connection system in the German North Sea.
DolWin kappa was constructed at the Dragados Offshore shipyard in Cadiz, Spain. Siemens Energy was commissioned by TenneT as general contractor to build the system.
Comprising an approximately 5,000-tonne foundation jacket and 11,000-tonne topsides housing high-voltage direct current (HVDC) technology, DolWin kappa is Allseas’ first complete platform installation for the offshore wind industry.
Completed on September 4, 2024, after a 12-day campaign, the installation of DolWin kappa—including piling of jacket foundations—again demonstrates Allseas’ ability to execute technically challenging offshore projects.
Complete Transport and Installation Solution
Designed and built by Dragados Offshore in Cádiz, Spain, DolWin kappa arrived in the Port of Rotterdam in mid-August on Allseas’ cargo barge Iron Lady. In a quick turnaround operation, all components—jacket, topsides, piles and connecting bridge—were transferred to the world’s largest construction vessel for transport to the
installation site.
All components were installed directly from Pioneering Spirit, using both the topside and jacket lift systems. In another first for Allseas, the 5,000-tonne special purpose crane was deployed to drive the 10 foundation piles up to 68 meters deep into the seabed to secure the foundation jacket.
Sustainable Solutions to Facilitate Energy Transition
The installation of DolWin kappa is key to unlocking additional North Sea wind energy capacity, advancing offshore grid expansion in support of Europe’s energy security. TenneT’s DolWin6 connection will provide more than 1 million homes with renewable energy when it comes online in 2023.
