An Experimental Study on Water Shipping

Shipping of water on ship deck and related loads represents an important concern for the safety, and should be taken into account even at the design stage. Despite this fact a full knowledge about this phenomenon is still far to be achieved. In particular, the relationships between water shipping severity, geometry and motion of the ship and sea-state parameters are not yet understood. In this paper, the water on deck caused on a restrained ship model in head waves is studied experimentally. These conditions are relevant, for instance, for FPSOs, which are ships operated most of the time as oil platforms, without forward motion. Three geometries have been considered to investigate the the role of the bow shape, for several incoming wave steepness. The models have been equipped with transparent-material deck and the water shipping is studied by image analysis. In two cases, the pressure field on the deck has been measured. Finally, impact loads on a vertical wall to mimic a deck structure have been measured.