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Massive indoor ocean basin:
Never before have such high demands been placed on concrete
Deviations must stay within millimeter precision. Even the curvature of the Earth has to be taken into account when building the world’s most advanced labs.
It was no easy task for Statsbygg when the Norwegian Ocean Technology Centre was given the green light to put shovels in the ground at Tyholt in Trondheim, Norway.
Statsbygg oversees the Norwegian government’s building and property development affairs.
“I have never had a more challenging task in my entire career,” says project manager at Statsbygg, Arild Mathisen.
The huge construction pit will house two state-of-the-art test basins. Vegar Johansen is CEO of SINTEF Ocean. He says they have already received inquiries from customers who want to be first in line when everything is ready. There is still a great need for testing beyond computer simulations.
“There’s simply a lot that cannot be simulated or calculated, even with advanced computer programs. It’s when we combine simulations and physical tests that we can see what may need to be changed and adjusted,” says Johansen.
Testing ship models, a cage, or offshore wind turbines in the basins can be conducted under realistic conditions.
“The tests provide us with reliable and absolutely necessary data for how the structure would handle conditions at sea,” he explains.
Grey hair and sky-high requirements
When the experts at SINTEF Ocean set up the specifications for the wave and current facility in the Ocean Basin, they found that what they needed did not exist.
“We had to connect experienced engineers in the construction industry with specialists and researchers at NTNU and SINTEF to find a solution,” Johansen says.
And that is precisely what has given Statsbygg project manager Mathisen his grey hairs. The requirements for accuracy and quality at all levels are rigorous, but also absolutely necessary for the basins to carry out the tests they are built for.
“We have to get this right. It’s what will set the Norwegian Ocean Technology Centre apart from all other facilities,” says Mathisen.
The quality of waves, currents, and measuring equipment is 'beyond state of the art.' They also require very specialised components.
Shavings and loose pieces of steel in the pool are a no-go for the advanced flow system. Therefore, Nordic Steel has prefabricated 2,500 components in stainless steel – almost like a giant Lego Technic set to be assembled.
“Everything has to be screwed and bolted into place. The concrete work, the rails, and the fastening plates have to be accurate to the millimetre,” says Dariusz Fathi, research director for ships and ocean structures at SINTEF Ocean.
Extreme conditions and unmatched concrete
The flow system will be powered by approximately 90 pumps. They push water equivalent to 2.5 times the amount of the river water in Nidelva around the ocean basin.
That is necessary when future structures are required to be tested with both waves and currents.
Water volumes on this scale are sometimes necessary in order to recreate extreme environmental conditions.
“With the wave and flow system here, we’ll be able to create complex wave systems that are more similar to real conditions. We’ll have the world’s most advanced ocean laboratories with all the options to simulating reality on a model scale,” says Fathi.
Neither Fathi nor Johansen are aware of any other labs capable of testing ships and structures in realistic sea conditions, in terms of their seaworthiness, manoeuvrability, and energy efficiency.
The concrete used is also far from standard. It needs to be membrane-free and 100 per cent waterproof. It also has to withstand extreme forces from waves. Concrete experts have worked closely with the contractor HENT.
The result is a type of concrete that has not been used anywhere else.
Blue whales, Earth’s curvature, and millimetre precision
The seakeeping basin is 180 metres long. That is equivalent to a Hurtigruten cruise ship and an Olympic swimming pool.
When the model boats are to be tested there, a special vehicle weighing just under 200 tonnes is driven on rails along the entire basin. That's about the weight of the world’s largest animal, the blue whale. Or four railway cars, if you prefer.
This special vehicle makes it possible to test fast-moving vessels in all conceivable wave directions at up to 80 knots. That is almost 150 km/h.
For the tests to be good enough, there is no room for deviation. The tests must be able to be repeated several times under exactly the same conditions. So absolutely no external reasons can move even a millimetre. This affects the support systems in the roof and walls.
Large amounts of extra reinforcement have also been used in the concrete to strengthen the building. But even that is not enough. The curvature of the Earth is also included in the calculations. The special vehicle must follow the Earth’s radius, which in this basin is between six and seven millimetres.
Since 1939, the research community at Tyholt has been involved in developing most of the components in ships and floating structures. Almost all the oil platforms on the Norwegian continental shelf have been tested in the Ocean Basin. This has given Norway a unique position and created enormous income for the state and the business community.
With the new centre, Johansen expects he will be able to continue to contribute to the nation’s revenues and maintain the social welfare state.
A paradise for students and researchers
Students will have their own building in the new centre with their own laboratories where theory can be put into in practice.
“We educate candidates for the entire maritime industry and have many research projects where these laboratories will be useful,” says Sverre Steen, a professor at NTNU.
The students’ playground will be called Archimedes’ House. It will be located under the same roof as the ocean basins and the office and teaching building that are already completed. The teaching building has received BREEAM Outstanding rating, the highest international certification for sustainable buildings.
The proximity between students, researchers, and labs means that students become part of the research and can contribute ideas and development proposals. The goal is for the building to facilitate interaction between people, machines, and the environment. They will not just be traditional laboratories.
“Being able to physically see what they learn theoretically is invaluable when today’s students lack practical experience from ships or industry,” says Steen.
What students learn here, they will take with them into working life.
A green future
Customers at the ocean basins test ships, cages, offshore wind structures, floating solar panels, and other floating structures. They are tested to check that the design is safe and can withstand increasingly demanding conditions at sea – before investing in construction.
“When Norwegian marine industries are expected to develop more profitable and sustainable solutions, it matters whether the construction is tested in Trondheim or abroad. Increased competence and knowledge in Norway is an investment for all of us. The investment here contributes to jobs and has ripple effects along the entire coast,” says Johansen.
The founders of the Ship Model Tank were extremely forward-thinking when they planned and built the Towing Tank, which was completed already in 1939.
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