The substructures for fixed offshore wind turbines weigh thousands of tonnes. If you are planning to install them at sea, only about five vessels in the world can lift that much weight. So now researchers are testing a completely new alternative.
By Henriette Louise Krogness - Published 13.05.2026
The substructure for an offshore turbine to be installed at a depth of 60 metres weighs up to 2500 tonnes. Now researchers have developed an alternative solution to the giant crane that currently does the job.
Picture for yourself an unusually wide barge that wends its way between the waves. When it stops, two heavy substructures for offshore wind turbines are hoisted up into standing position and made ready to glide down into the sea. This brand new system has now been tested and could become part of Norway’s future offshore wind capabilities.
Using experience gained from the oil and gas industry, Aker Solutions, the Belgian contractor Sarens, and the maritime group BOA recently spent time at SINTEF’s Ocean Basin in Trondheim. There they used models to test the feasibility of employing an extra-wide barge to transport several substructures simultaneously. The results are promising.
Mateusz Graczyk is the engineering director at BOA. He followed the tests from the edge of the pool with great interest.
The barge was tested with both one and two substructures.
“The tests allow us to better understand the behaviour of the exceptionally wide barge in wave conditions during marine operations and transport,” says Graczyk.
At 166 metres long and more than 73 metres wide, this is one of the world’s widest barges. It also can be lowered to a depth of over 30 metres with the deck 22.5 metres below the water surface.
“By using submersible barges for marine operations, we can often avoid using the large and expensive crane vessels. The cargo can either be floated out without a crane vessel altogether or lifted off the barge using smaller, cheaper and more accessible vessels,” says Graczyk.
Successful first step
In the first round, the team conducted tests as part of the WindRise project to determine whether transporting two substructures on the barge at the same time would be possible – followed by raising them into a standing position at their destination.
“We are very satisfied with the tests that we’ve done so far. The results align well with the numerical analyses that we carried out in advance,” says Robert Indergård, a senior research scientist at SINTEF.
The barge is equipped with both a lifting frame and its own hinge system. The tests showed how this system behaved in different wave conditions.
Big ambitions for offshore wind
Both the EU and Norway want to develop offshore wind, and they have high ambitions. The EU wants offshore wind to be able to cover the needs of about 250 million homes, while Norway's goal is 22 million homes.
Norway has an ambition to allocate areas for 30 000 MW of offshore wind production by 2040, according to regjeringen.no.
Strong industry collaboration
The project has brought together many players from Norwegian industry that manufacture, transport and install fixed offshore wind substructures, with the goal to create an efficient and sustainable supply chain that can scale up their distribution.
Europe does not currently have a supply chain large enough to attain the European targets for offshore wind power production.
Gudmund Olsen, the project manager for WindRise at Aker Solutions, followed the tests in the basin and shared what the team is aiming to achieve.
“Our goal is to further develop the jacket design and so that it easy for us to produce. We’ll continue to work on logistics, automation and further development of our production equipment at Verdalen,” says Olsen.
Aker Solutions has designed the substructures for the turbines themselves, while SINTEF, Sarens and BOA have used the design for numerical analyses and the practical tests. For a company that often receives ready-made designs delivered to order, it has been fun to be involved in the design ourselves,” Olsen says.
“What we’re best at is making jackets,” says Olsen and smiles. “Now we have expanded our competence in robotics and automation, so this has been a good exercise for us.”
Work is continuing on how the substructures will be unloaded from the barge and placed in the right position on the seabed.
The players involved in the project say that if they can achieve this, it will help strengthen the Norwegian supplier industry for offshore wind, both nationally and internationally.
It is clear that we must become less dependent on oil given today’s world situation, they say.