Heerema Marine Contractors’ vessel Aegir has installed the Delft Offshore Turbine (DOT) at the Princess Amalia offshore wind farm (Prinses Amaliawindpark) in the Netherlands.
The installation was conducted via a Slip Joint connection, which means the turbine is slid over the monopile without the use of grout or bolts.
This is the first time that such connection is deployed offshore, enabling the installation to be completed in less than an hour, faster than usually, according to Heerema.
Aegir loaded the fully assembled turbine at the quay of Sif Rotterdam and installed it at the site offshore Ijmuiden in floating mode on Dynamic Positioning (DP).
The DOT monopile was installed at the 120MW wind farm in June by using the vessel’s Vibro Lifting Tool, a hybrid of a vibro-hammer and lifting tool that removes the need for other tools required for picking up, upending and driving the pile to final penetration. Sif manufactured the monopile with antifouling coating, as well as the Slip Joint.
The Slip Joint Offshore Research project (SJOR) was initiated by DOT BV in 2016 and is a collaboration between TU Delft, TNO, Van Oord and Sif group, as well as project stakeholders Eneco and Heerema Marine Contractors.
Eneco’s Princess Amalia comprises 60 2MW Vestas turbines which have been operational since 2008.