Literature published on the problem of ship slamming in waves is reviewed from the point of view of someone working at a ship research institute. Such an institute is confronted with rather practical questions regarding the acceptability of certain design parameters such as the acceptable amount of bow flare angle for use at sea. The importance of these questions is illustrated by noting that actual slamming or the presumed danger of slamming is the main reason for ship operators to reduce speed or to change heading. The review shows that such questions cannot yet be answered. The problem of the local effect of the impact is very complicated owing to the importance of air inclusions, bubbles in the water, compressibility of water and cavitation effects. Only a computational method properly including all these effects will give an accurate answer; also model tests will not be capable of doing this, if only because the methods to extrapolate the results of models to full scale are not yet developed. The problem of the global response of the ship to a wave impact is closer to being solved. A two-stage approach is proposed, consisting of a computational fluid dynamics method for individual impacts and an approximate method to be included in long-term simulations. However, to arrive at a realistic longterm distribution, one has to account for the seamanship of the captain; avoiding the worst conditions or adapting the ship speed and course has a large effect on the actual extremes. Research on this topic has hardly begun.

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In order to meet an increasing demand of amphibious lift capacity and logistic support, the Royal Netherlands Navy decided to procure an amphibious transport vessel (ATS), designed as a Landing Platform Dock (LPD). In the first part of this paper an outline of missions and tasks is provided, followed by a description of the preliminary design which has been produced by the Directorate of Materiel of the Royal Netherlands Navy. The ATS, now in the final stage of the forward design phase, will be able to transport a number of landing craft, six LCVP MK HI of the R Nl Navy or four LCVP MK 9B's of the Royal Navy, in a well dock. A major requirement is that embarking and disembarking operations will be possible for sea conditions up to Sea State 4. These operations can only be possible with low wave motions in the well dock. An extensive research program was carried out to investigate the hydromechanic aspects of the well dock design, in order to assess the safety of embarking and disembarking of landing craft and to minimize wave motions in the dock. After performing reference seakeeping tests with a model of a proven design (Fearless class, RN) at MARIN, a preliminary design of the ATS was tested: motion and wave measurements as well as observations with radio controlled models of landing craft. A number of options for improvement of the well dock configuration were investigated. The research provided insight in the relation between design and environmental parameters and wave motions in the dock, and resulted in a well dock design optimized for embarking and disembarking operations within design constraints.

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