The assessment and control of risk of collision
This thesis, as its title implies, is a unique step in the management of risk of collision, which may arise in a two-ship encounter. This work advances the development established in the author's M. Phil thesis. It is suggested that the contemporary technique of collision avoidance based solely on CPA criteria is inadequate for risk analysis. The proposed strategy for handling risk of collision revolves around the introduced hypothesis for dealing with risks having various probabilities of occurrence resulting in various degrees of severity. The risk values are obtained by computing the geometrical probability of collision based on the following definition :- " The risk of collision can be measured by the ratio of the ways available for a collision to occur to all the possible ways that could be considered by the obser ving vessel." Based on this hypothesis several approaches to the presentation of the risk of collision are described separately in the thesis's units together with their application, merits and demerits. It is found that the introduction of the assessment and control of the risk of collision by lneans of the proposed risk criteria has converted the vague awareness given by the traditional methods, to a definite risk criteria which could provide alternative ways of assessing any situation. The restructuring of the information clearly provided to the mariner gives him a much greater insight into the level of the risk which he is accepting in any situation. A strong risk controllability can be achieved if it is characterised by a relatively high degree of constraints in the fonn of regulation. These regulation should acquire features that will pennit them to discriminate, act upon, and respond to aspects of the situation variety. Due to the fact that certain statements within the International· Rules are not clearly defined and are thus open to individual interpretation, some mathematical definitions of risk of collision and close range situations are established. The analysis and testing of specific examples has proved that these methods work and are able to provide the mariners with a cammon language in resolving collision avoidance problem.