Abstract: A base supporting an offshore wind power generator includes a fender portion composed of a pair of cylindrically shaped first fender portion and second fender portion for cushioning an impact when a ship touches the fender portion, and rung portions extending horizontally from the fender portion toward the base and composed of first rung portions and second rung portions installed at predetermined intervals in the vertical direction. A worker on board the ship can safely transfer to the adjacent rung portions when the hull of the ship kept touching the fender portion.

Abstract: A base supporting an offshore wind power generator includes a fender portion composed of a pair of cylindrically shaped first fender portion and second fender portion for cushioning an impact when a ship touches the fender portion, and rung portions extending horizontally from the fender portion toward the base and composed of first rung portions and second rung portions installed at predetermined intervals in the vertical direction. A worker on board the ship can safely transfer to the adjacent rung portions when the hull of the ship kept touching the fender portion.

Abstract: A sea state estimation device includes a time history memory which stores a time history of ship motion data relating to a rolling angle, a pitching angle and a heaving displacement; a hull condition data calculator which calculates current hull condition data of the hull based on the time history of the ship motion data stored in the time history memory; a cross spectra calculator which calculates cross spectra of respective ship motions; a hull response function calculator which calculates a hull response function based on the hull condition data calculated by the hull condition data calculator; and a sea state estimator which estimates a sea state in sea on which the hull is running based on the cross spectra of the respective ship motions calculated by the cross spectra calculator and the hull response function calculated by the hull response function calculator.

Abstract: Provided is a transverse metacenter height estimation device that includes: a history storage means for storing time sequence data of the roll angle of a hull; and a transverse metacenter height estimation means that estimates the transverse metacenter height of the hull on the basis of the time sequence data of the roll angle of the hull, such data stored by the history storing means. The transverse metacenter height estimation device is characterized in that the transverse metacenter height estimation means first calculates a roll natural frequency on the basis of the time sequence data of the roll angle of the hull, sets the calculated roll natural frequency as an observation model, carries out state estimation on the basis of a normal state spatial model in which the transverse metacenter height and the gyration radius of the hull are used as state variables, and thereby estimates the transverse metacenter height.

Abstract: A system for automatically replacing ballast water in a ballast tank of a ship comprises a water inlet port on a part of the ship where the water pressure acting on the ship when in forward motion in the water is higher than the pressure of the ballast water being replaced, a water discharge outlet in the ballast tank and a water inlet passage extending between the water inlet port and the ballast tank for introducing water into the ballast tank at a higher pressure than the ballast water in the tank. In this way the ballast water is forced from the ballast tank through the discharge outlet to be replaced by water introduced through the inlet port. A method for replacing ballast water in the ballast tank of a ship is also provided.