Ship bow impact force in head-on collision

This paper presents simplified analysis procedures for ship (with bulbous bow) bow impact force and bow damage assessment in ship head-on collisions. The theoretical background for ship bow crushing analysis is described and the result is expressions for the crushing force and bow damage as a function of an impact strength. The impact strength, depending on the internal stiffening of the ship bow and materials, is determined by two different approaches: Approach A- uses world-wide published experimental model test data; Approach B- uses theoretical calculation results from crushing analyses of full-scale sea-going ships. Applying these data for the impact strength into the theory, formulas for bow impact forces and bow damages are developed. The formulations are compared with published existing methods and validated with the data from full-scale ship collision accidents and FEA simulation results. The developed procedure has a sound physical foundation and can be used as a tool in risk analyses of ship-ship collisions, ship collisions against offshore structures such as oil and gas installations and windfarms, and bridge structures.