For the first time ever special collars were installed around the monopile foundation at seabed level. The ‘collared monopile’ is a design based on a RWE patent. The new technology will provide additional support for lateral loading, increase the bearing capacity and improve the structural integrity of the entire foundation.
In total three foundation collars were successfully embedded into the seabed – each 7metres high, weighing 170 tons. The installation in water depths of up to 25 metres was carried out by the jack-up vessel ‘Sea Challenger’ from Deme Offshore. The space between collar and monopile foundation was filled with grout material, creating a stable connection. RWE will carry out accompanying tests to verify that the collar improves the structural behaviour in comparison with standard monopiles. The detailed design of the collars was developed by the German civil engineering company JBO based on the RWE patent, Bladt Industries was selected as manufacturer and DEME Offshore was responsible for the transportation and installation.