• Pioneering Spirit installs 900-MW North Sea offshore converter station
• Project is a major step for Allseas in the offshore renewables market
• Allseas committed to delivering sustainable solutions to facilitate energy mix

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 4 September after a 12-day campaign, 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 metres deep into the seabed to secure the foundation jacket.

The project confirms Allseas can adapt Pioneering Spirit’s single-lift capability to provide fast and efficient
transport and installation solutions for the fast-growing offshore wind market, strengthening our ambition to
become a key contractor in the renewables space.

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 on line in 2023.

Allseas is committed to driving sustainability offshore by pioneering solutions onshore to facilitate the transition
and safeguard energy affordability.
Pioneering Spirit’s size and versatility delivers high workability all year round, fast-tracking the development
cycle and enabling our clients to realise their project ambitions sooner.

Creative concepts for new challenges
DolWin kappa follows substation installations end 2021 / start 2022 for the Hollandse Kust Zuid (HKZ) offshore
project off the Dutch coast for German-Dutch green grid operator TenneT, and the Saint-Nazaire wind farm in
France.
Allseas is also developing new concepts for the installation of next generation turbines and foundations required
to meet growing demand for renewable offshore energy.

Source: Allseas