ABSTRACT
There has been considerable modelling and wave basin validation of the multi-mode, multi-float wave energy converter M4. Moorings have been of single point type (SPM) with light inextensible cords and a small spherical buoy. Large mean mooring forces and peak loads were produced in large waves. Here we consider elastic mooring cables attached fore and aft to the base of the bow float in the 6 float (2 PTO) configuration. The model is run for the same float configuration and same wave conditions as the SPM, with the measured mean forces input. The results indicate that line tensions will be larger in operational conditions while peak loads in extreme waves will be smaller but still large, up to about 1000 tonnes at full scale, but this would be spread over several cables in practice. This suggests hybrid SPM with elastic cables may be a good option.
