Interaction of Ice Force in Ship-Ship Collision

The maritime transportation system in the Northern Baltic Sea (NBS) is complex and operates under varying environmental conditions. The most challenging conditions relate to the presence of ice-cover, which for the NBS e.g. for the Gulf of Finland or Bay of Bothnia, can remain up to several months. The number of maritime accidents in these two areas is the highest during winter season, which can involve accidents like groundings, collisions, damages due to the ice etc. The paper presents the model to predict the ice interaction in ship-ship collision dynamics. The ice forces are included in the time-domain simulation model and also in a simplified model based on the momentum conservation. The simplified model is proposed for a rapid estimation of increase in deformation energy due to the presence of ice forces. The analysis shows that the ice influence depends strongly on the ship mass, ice thickness and collision speed. The maximum increase in the deformation energy in the studied collision scenarios was up to 19%.