Fabio Amico, Structural Project Manager at Iv-Consult, continues: “The tendons are placed in the mast of the wind turbine and are released by the floats, causing the ‘gravity base’ to submerge and sink to the seabed. When the ‘gravity base’ is positioned on the seabed, the tendons are tensioned, and the float is pulled underwater. Because the tendons are in the mast, the height thereof determines the maximum water depth. However, we wanted a system that would be suitable for greater water depths, and it has taken a great deal of brainstorming to suitably adapt the concept for this.” Our concept involves a so-called ‘jacking platform’ at the top of the mast and directly below this a rotating platform from which the tendons are hung. A securing platform is at the bottom of the mast. By means of ‘strand jacks’ the tendons are successively lifted, lowered (causing the ‘gravity base’ to descend) and subsequently fixed to the lower platform. The rotating platform then ensures that subsequent tendons are suitably placed. The procedure is repeated until the ‘gravity base’ is positioned on the seabed and the tensioning of the tendons can commence. Eventually, the wind turbine is partially submerged. The concept is suitable for water depths of approximately seventy to five hundred metres and, as an alternative to the ‘gravity base’, the system is easily adaptable for applying so-called ‘suction anchors’.