Theoretical Analysis of the Relationship between Accident Rate of a Fleet of Vessels and Age Distribution of the Fleet

Abstract

It is well accepted that the age of a seagoing vessel significantly influences her probability of being involved in a marine accident. This implies that the accident rate of a fleet of vessels (e.g. the world fleet as a whole, individual shipping company fleet, etc.) will depend on the age structure of the fleet. Perhaps due to its seeming obviousness, this fact has hitherto (to the author’s knowledge) not been given careful consideration in the maritime safety literature. This paper attempts to fill this gap by developing a theoretical equation that relates accident rate of a fleet of vessels to numerical characteristics of its age distribution. The equation shows that the fleet accident rate depends not only on the average age of ships, but also on other parameters of the age distribution of the fleet.