Mammoet has successfully completed the installation of four 7MW wind turbines at the Nissum Bredning near shore wind farm in Denmark. Conventional offshore wind power projects are generally installed using specialist installation vessels in waters up to 30 meters deep. Located in the Bay of Thyborøn, Nissum Bredning cannot be accessed by these specialist vessels due to the seabed conditions and shallow water depths of only three meters. The conventional approach would have made dredging imperative – a time consuming and costly operation.
Mammoet proposed a barge with an integrated ballasting system which allowed it to be lowered and grounded onto the seabed. This provided the necessary stability for the operation while eliminating the need for dredging. The solution effectively resembled an onshore installation and also simplified matters, as now the lift could be performed with a LR11350 crane, a land-based crane which among others is used for onshore wind power projects.
Mammoet’s approach overcame the challenging near shore environment to safely install all four wind turbines. By excluding dredging from the process, the method saved time, costs and resources.