Wave flume investigation on different mooring systems for floating breakwaters

This paper investigates on different types of mooring systems for floating breakwaters (FBs): chains with different initial tensions or piles. The principal aim is to describe the wave transmission and the statistics of the loads on the moorings. The latter analysis is particularly innovative because it defines in the details the condition of snapping, that can be reached along the chains and is frequent in many practical cases. Physical model tests have been carried out in the wave flume of the Maritime Laboratory of the University of Padova. The tested structure resembles typical FBs located in Italian lakes in scale 1:10. Regular and irregular waves were generated. Stiffness of the mooring systems was modified by varying the initial stress and the results obtained by the tests are in depth described. Simple numerical simulations, based on irrotational flow, which are commonly used for design of moorings, were seen not to be suitable to describe the maximum loads. The added value of a more detailed investigation, in particular by means of physical testing, is established.