Abstract A series of analyses are carried out to predict the structural crashworthiness of a ship during a collision. The numerical configuration is verified by structural simulations based on a laboratory experiment wherein a penetration test is considered as the experimental reference. Comparative observations of structural behaviour are carefully conducted to ensure the reliability of the present method for conducting large-scale collisions. At this stage, the proper procedure and configuration for structural calculations subject to accidental loads are determined. The second stage addresses the calculations for various side collision scenarios. The simulations consider a double hull Ro-Ro passenger ship being struck at various locations, and the overall behaviour of the side hull along the longitudinal axis is observed. The main study considers the target location and striking speed to obtain adequate data related to crashworthiness criteria, i.e. the internal energy and extent of damage. Finally, the criteria of various scenarios are summarized. Further calculations comparing the results with a safety factor are presented together with a consideration of structural behaviour to estimate the safety limit within the confines of strait territory.