TM Edison, the DEME–Jan De Nul consortium, has installed the 23rd and final concrete caisson for Princess Elisabeth Island, completing the offshore foundation works about 45 km off the Belgian coast. Each caisson weighs roughly 22,000 tonnes and measures about 57 by 30 by 30 metres; together they form the island's protective outer perimeter. The caissons were built in Vlissingen, the Netherlands, with construction starting in September 2023 and the final unit floated in January 2026.
Project owner Elia Group says the foundation stage finished within the planned schedule. Sand filling now follows inside the caisson perimeter, ahead of platform preparation for high-voltage substations. The island is designed to connect Belgium's second offshore wind zone to the mainland grid and to host future international links, including a potential UK connection.
