A Study on the Strength of Double-Hull Structures in Collision

The purpose of this work is to examine in some detail the feasibility of a collision protection method which utilises square panels, placed between the hull plating and an inner shell. The method would appear to be applicable to protective structures against a minor collision, as an alternative to deck structures which are used for protection of nuclear powered ships against a major collision.The experiments were carried out on double-hull models penetrated statically by a rigid bow model, in order to make a reasonable estimation of the amount of energy absorbed in the hull plating which is neglected in the design procedure due to Minorsky. Two typical humps are seen quite clearly in the load-penetration curves ; the first one is mainly due to the membrane force in the hull plating and the second due to the ultimate strength of vertical girders. The humps have an important influence on the capacity for absorbing the energy in a collision. Considerable amount of energy was found to be absorbed by the hull plating in a minor collision.