Identification of Ship Domain Shape to Degree of Ship Collision Risk on Head-on Encounter Situation

Abstract Ship collisions are one of the marine accidents that can occur at any time, causing significant material and cargo losses. Lack of awareness of collision impacts and human factors are primary issues for ship collisions. Consequently, ship captains and technology have devised an imaginary area known as the ship domain. This ship domain is an imagined region used to define safe conditions around the ship. With the presence of a ship domain, collision risk can be reduced. This paper investigates the influence of ship domains on collision risk assessment during head-on encounters. To simulate realistic ship movement conditions, the manoeuvring mathematical group (MMG) model is used to predict ship movements. Additionally, fuzzy logic calculations and the closest point of approach (CPA) are employed to help identify the effectiveness of ship domains. Numerical simulations are conducted using three different ship domain shapes: egg, circle, and ellipse. The results indicate that the shape of the ship domain does not significantly influence collision risk assessment in head-on encounters. Instead, the division of the ship domain plays a more crucial role in evaluating ship collision risk.