Mechanics of minor ship collisions

Abstract

A structural method is presented by which the critical velocity for a minor collision of a ship striking another ship midships at right angles can be determined rather realistically with a minimum of computational effort. The velocity of the striking ship is defined as critical for a minor collision when the side wall of the struck ship just ruptures. This means the possibility of an oil spill in an oil tanker. The proposed method takes into account the deformability of both collision opponents. The energies absorbed in both ships, up to rupture of the struck ship hull, are computed using internal collision mechanics. The critical velocity can then be determined using external collision mechanics. The method is used for the collision of two equal oil tankers of 141,000 TDW with bulbous bows. The critical velocity was found to be 6.8 knots.