Statistical design of fenders for berthing ship

Recently, ship size increases so fast. For instance, size of modern container ships became more than 100,000 DWT. At some port where berth are not sufficiently constructed to meet above those ships in full laden. As the result, ships larger than design ship is to be obliged to adjust its draft at berthing. Even if the berth water depth is secured, virtual approach velocity must be decreased less than design approach velocity. Usually, standard ship size is determined by means of statistical analysis of registered ship as the 75% or 95% confidence value. Therefore, entrance ship size may exceed the standard ship size. Furthermore, ship's approach velocity is random variable. This study is an attempt to design a fender for berthing ship by means of statistical method. Those values such as ship size, virtual mass of ship, approach velocity and energy absorption of a fender are treated as random variables. Size of entrance ships are investigated at the major container berths. Then, the statistical analysis was proceeded by using those results of statistical analysis on approach velocity and ship size in order to obtain the probability of failure and safety factor for fender design.