This study presents an analysis of the effects of sudden damage, and progressive deterioration due to corrosion, on the ultimate strength of a ship which has been collided by another vessel. Finite element analyses (FEA) of collision scenarios are presented where factors are varied e.g. the vessels involved in the collision, and consider-ation of corroded ship structure elements and their material characteristics in the model. The striking ship is a coastal tanker, the struck ship is either a RoPax ship, or, a coastal oil tanker vessel. The ultimate strength analy-sis of the struck vessel accounts for the shape and size of the damage opening from the FEA. The Smith method is used to calculate the ultimate strength of intact and damaged ship structures during biaxial bending. The study shows how corroded, collision-damaged ship structures suffer from a reduction in crashworthiness and ultimate strength, how this should be considered and modelled in FEA.