The aim of this paper is to critically assess the methods used for the evaluation of wave-induced loads on ships examining analytical, numerical and experimental approaches. The paper focuses on conventional ocean going vessels and loads originating from steady state and transient excitations, namely slamming, sloshing and green water, for the latter, and including extreme or rogue waves, as well as the more occasional loads following damage. The advantages and disadvantages of the relatively simpler potential flow approaches against the more time consuming CFD methods are discussed with reference to accuracy, modelling nonlinear effects, ease of modelling and of coupling with structural assessment procedures, suitability for long term response prediction and suitability for integration within design and operational decision making. The paper also assesses the uncertainties involved in predicting wave-induced loads and the probabilistic approaches used for the evaluation of long term response and fatigue analysis. The current design practice is reviewed and the role of numerical prediction methods within the classification framework and goal based design approach discussed. Finally the suitability of current developments in prediction methods to meet the needs of the industry and future challenges is assessed.

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The passing ship effect on berthed vessel is a well-known problem and is studied over many years. These interaction effects induce dynamic loads in the mooring system that can exceed the design values and lead to severe accidents. A study has been conducted to analyze the effect of various parameters such as passing ship speed, separation distance, depth to draft ratio and waterway geometry on the hydrodynamic interaction effects between berthed and a passing ship. Numerical simulation for three-dimensional unsteady viscous flow have been conducted using the overset mesh methodology and solving the Reynolds-averaged Navier-Stokes equations with k-v shear-stress transport turbulence model for various cases, and interaction effect on berthed ship have been calculated. The method recommended in this study is validated by comparing the computational fluid dynamics (numerical) results with existing model scale experiments and mathematical curves from empirical formulas. The hydrodynamic interaction forces are computed for five types of waterway geometries. The magnitude and time histories of the forces and moment on the moored ship for various cases are analyzed to evaluate the effect of various parameters such as waterway geometries and separation distance. The results and conclusions made by this study can give definite guidance on safe maneuvering of a ship passing by a moored ship.

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For ships, barges and similar long offshore structures roll natural period generally falls within the frequency range of a typical wave energy spectrum generally experienced by them. This causes dynamic amplification of rolling motion. For these structures the roll damping is highly nonlinear. Therefore it is of utmost importance that good estimation of roll damping is made for such structures. Linear radiation diffraction theory can not predict damping for roll motion as good as for other degrees of freedom. For ships and barges radiation damping (in case of roll) is generally quite small compared to the total damping in the system. Hence, additional damping needs to be added for solving roll motion equation.