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The paper presents a new formula for the stability of cube armoured roundheads. The formula is based on physical model tests in Aalborg University which both long crested and short crested waves of different wave steepness were used. The slope of the radius of the head were varied in order to explore the influence of the geometry on the armour stability. Besides cubes with mass density 2.4 t/m3, cubes with mass density 2.80 t/m3 were used in order to include the effect of mass density in the formula. The damage predictions given by the formula have been compared with prototype hand performances for a number of breakwaters. The paper presents a new formula for the stability of cube armoured roundheads. The formula is based on physical model tests in Aalborg University which both long crested and short crested waves of different wave steepness were used. The slope of the radius of the head were varied in order to explore the influence of the geometry on the armour stability. Besides cubes with mass density 2.4 t/m3, cubes with mass density 2.80 t/m3 were used in order to include the effect of mass density in the formula. The damage predictions given by the formula have been compared with prototype hand performances for a number of breakwaters.

Aim of this contribution is to investigate the relevance of the layout on the performance of floating breakwater schemes under oblique waves. An experimental investigation was carried out in the wave basin of the Maritime Laboratory of Padua University, Italy. The facility dimensions are 3.8m x 20.6m x 0.8m. Several regular and irregular longcrested waves were generated and two different layouts (I- and J-shaped) and three obliquities (0°, 30°, 60°) were tested. With increasing wave obliquity, wave transmission decreases, mooring forces due to snapping decrease and link forces slightly increase. The J-shaped configuration determines basically the same effects with regards to both transmission and loads. The maxima of link forces are not much greater than the average loads and this is relevant for fatigue and reliability considerations.

By comparison of overtopping discharges recorded in prototype and small scale physical models it was demonstrated in the EU-CLASH project that small scale tests significantly underestimate smaller discharges. Deviations in overtopping are due to model and scale effects. These effects are discussed in the paper and it is explained why it is impossible quantitatively to identify model and scale effects by comparison of the performance of prototype and small scale models. For such identification are needed special dedicated tests. The paper presents such a test which identify the scale effect in the rubble armour on the upper part of the slope. This effect is believed to be the main reason for the found deviations between overtopping in prototype and small scale tests. By comparison of overtopping discharges recorded in prototype and small scale physical models it was demonstrated in the EU-CLASH project that small scale tests significantly underestimate smaller discharges. Deviations in overtopping are due to model and scale effects. These effects are discussed in the paper and it is explained why it is impossible quantitatively to identify model and scale effects by comparison of the performance of prototype and small scale models. For such identification are needed special dedicated tests. The paper presents such a test which identify the scale effect in the rubble armour on the upper part of the slope. This effect is believed to be the main reason for the found deviations between overtopping in prototype and small scale tests.