MARIN, Ocergy and some members of the RECORD 15+ consortium during the model tests.

From concept validation to FEED studies, model testing remains a cornerstone of offshore innovation. Ocergy’s goal was to obtain the highest quality data to validate numerical models that contribute towards its Integrated Load Analysis. Thanks to months of preparation and close collaboration with MARIN, the Ocergy team was able to run simulations near-real time, matching the environmental conditions and model parameters being tested in the basin. This dynamic working method fostered deep technical discussions and ensured maximum value from the test campaign.

Over the past decade, offshore wind turbine sizes have shattered expectations, and floating wind technology is unlocking access to deeper waters with more consistent energy yields. The latest OCG-Wind™ design is engineered to meet the demands of these larger turbines, featuring tower frequency tuning that extends above the blade rotational frequency; the so-called stiff-stiff configuration.

While the project may appear routine—measuring motions, accelerations, and wave overtopping across various conditions—it was anything but. Ocergy brought a highly technical and well-considered set of model test specifications, drawing on proven elements from previous projects. The challenge lay in integrating these components into a single, cohesive system without compromising quality.

• A standout feature was a six-component measurement frame housed within one of the outer columns. This setup enabled precise measurement of forces and moments under varying wave, wind, and current conditions. The mooring system’s fairlead was seamlessly decoupled from the column, ensuring that environmental loads were measured independently of mooring forces.

• Wireless measurement technology has been transformative for MARIN’s floating wind tests, eliminating cable stiffness that can distort motion and eigenperiods.

• Air scaling is rarely used in such tests, but Ocergy’s Compressed Air Trim System (CATS) demanded innovative modelling techniques. These efforts provided high-quality load data to validate Ocergy’s design calculations.

• Scale selection was critical for modelling a 15+MW floating turbine. MARIN Project Engineer Ruud van der Veeken balanced extreme survival conditions, instrumentation weight, and air-scaling for the ballast system—all while ensuring the nacelle height fit beneath the carriage.

Ocergy is currently advancing two high-profile demonstrator projects that are turning heads in the floating wind industry:

• In the Culzean Wind Project, which has been selected by TotalEnergies for the Culzean field in the North Sea, the OCG-Wind™ platform construction is completed and will support a 3 MW wind turbine. It will be connected to an offshore gas platform as part of the Scottish Crown Estate’s INTOG initiative, which focuses on decarbonising offshore oil and gas operations.

• The RECORD15 (short for REduced COmmercial Risks with Demo of 15+ MW) Joint Industry Project is an ambitious initiative for which these model tests were performed. This project will culminate in the installation of a 15 MW+ turbine on an OCG-Wind™ floater by 2028.

As floating wind scales up, understanding the towing operation becomes increasingly vital as developers seek to optimise the transport and installation for farms of 10s to 100s of turbines. After weeks of testing in the Offshore Basin, the model was reconfigured and moved to the Seakeeping and Manoeuvring Basin for towing tests. These trials examined motions, accelerations, and towline tensions across various setups, speeds, and environmental conditions—yielding a robust dataset to support Ocergy’s transport strategy.