Experimental study of mooring forces on the multi-float WEC M4 in large waves with buoy and elastic cables

Experiments have been undertaken in a wave basin with the hinged attenuator-type energy converter M4 6-float configuration two hinges for power take off (PTO), moored to single-point buoy. This follows previous experiments inelastic cables giving very high snap loads. The PTO was disengaged these tests. aims are i) use elastic mooring cable reduce loads of system, stiffnesses tested, and ii) study system's dynamic response basic under intermediate large waves. Mooring at fairlead bed, relative pitch angle between floats were measured. Numerical simulations using different models carried out, results compared against experiment results. For waves, showed occasional deck submergence (dunking) limiting angular motion as height increases, effect providing passive end stop. largest peak just less than 40°. extreme up 1/6th those cables. Spectral analyses force made shown be quite complex. • Elastic buoy multi-float WEC waves investigated. In overtopping limited 40° reduced by factor about 6 below inelastic. Increasing elasticity forces. spectra peaks frequencies.