MariGreen: HEWIS - High Efficient Windfarm Installation System

The project should help to install offshore wind farms more efficient. The core of the system is the division of the installation into two ship units. The usual „jack-up“ ship remains in the construction site, while the newly developed installation ship delivers the components and is also integrated into the installation. The requirement for this is an optimised motion behaviour of the ship, without minimized ship motions safe operation of the ship‘s crane is not possible.
With this crane, the foundations are transferred to the jack-up platform. From
there they are installed in the seabed. Meanwhile, the installation ship can return to the previous foundation and install the scour protection. So far, this protection against erosion of the foundations has been achieved by two rock layers, a gravel and a cover layer. However, this is expensive, slow and has an impact on the existing ecosystem. In the HEWIS concept, scour protection based on geotextile sand containers is used, which can be put over the foundation with a special lifting gear with only one crane operation and placed on the seabed in a controlled manner.
This system was successfully tested in a model test. In addition to this the installation process of the foundation was investigated and a corresponding installation ship was designed. A method for the simalation of crane operations offshore was developed.
For further information see www.marigreen.eu