The Calculation of Marine Collision Risks

Abstract

It has been recognized for some time that calculations of potential encounter rates based on the speed and lateral distributions of ships using sea routes provide only a partial estimation of the actual collision risk, as all encounters are usually given equal rating, and no attempt is made to include factors such as the degree of domain penetration or the relative speed of the ships. One possible solution to the problem consists in attempting to weight the calculated potential encounter rates according to the most relevant factors, and thus replace the calculated rates by weighted values to provide a relative estimate of collision risk. Goodwin, Lamb and Kemp reported a first attempt at such a procedure in their calculation of weighted encounter rates based on the observed traffic distributions and flow rates in the Sunk Lightship area in the neighbourhood of Harwich. A two-part index was used in the work; the first part employed a weighting factor based on the ratio of the time required for the completion of a manoeuvre involving a specified angle of course change, to the time available as measured from the ‘decision-distance’ at which the manoeuvre was deemed to commence. The second part used a factor based on the time required to pass and draw clear after completion of the manoeuvre.

Autonomous Ship Collision Avoidance Navigation Concepts, Technologies and Techniques

“…Furthermore, a quantitative risk assessment of the possible collision avoidance manoeuvre can be automatically produced by the obtained marine data (Jones, 1978). A similar study of how to provide suitable navigation information for the mariners and a risk analysis of evasive manoeuvres is proposed (Colley et al ., 1984, Lamb, 1985).…”

Decision Support from Genetic Algorithms for Ship Collision Avoidance Route Planning and Alerts

“…It also includes various dynamic and static data, certain and uncertain information, quantitative mathematical calculations, qualitative logical reasoning and so on, and thus entails the expertise of many disciplines, such as navigation, computer science and others. It involves data collection, data pre-processing, division of encounter state, calculations for degree of danger of collision, judgment of encounter conditions, selection of collision avoidance method, optimization of collision avoidance action, setup of navigation restoration decisions and multi-target collision avoidance ; it is a complicated system engineering problem (Jones, 1978, Davis et al, 1982, Lamb, 1985, Lee, 2004, Statheros, 2008. Because the ship itself is a complicated system, it is very difficult to use an accurate mathematical model to describe this system.…”

Modeling of ship trajectory in collision situations by an evolutionary algorithm

“…Apart from adequate preparation for its operation, proper use of the anti-collision system also requires additional algorithms that help the responsible navigator to make correct decisions. Recent tendencies in the automation of ship navigation have led to automatic calculations of the anti-collision maneuver, along with simultaneous quantitative assessment of the risk of collision based on the obtained data [3], [7], [8], [9]. An extension of the conventional anti-collision system ARPA is often desired.…”

“…This was the main reason for applying one operator only in a single generation, as it was easier to evaluate operators' performance 7. For a full discussion on the rst eight operators, see[20] 8. Here and in the rest of the descriptions of operators, \random selection" means selection with equal probability for all outcomes.…”