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.