LIMITATIONS OF RISK ASSESSMENT METHODOLOGIES FOR FIRE IN TRANSPORT TUNNEL SYSTEMS

This paper outlines how traditional risk methods can be improved by a new methodology for measuring risk based on the inherent risk potential of a system. The new method has the capacity to incorporate engineering and human factors and calculates the synergy of outcomes when the design is moved into the operational phase within the real risk environment. It is the hypothesis of this paper that traditional risk measurement approaches, while laudable and useful, cannot achieve the design goal of protecting life because the traditional conceptual understanding of risk is flawed by a failure to interpret the almost infinite sets of risk factors that will impact on the design over the life-time of the system. This is highlighted by analysis of fire in a transport tunnel which used worlds best practice for design but can still give rise to catastrophic outcomes from foreseeable events. The new risk methodology postulates a set of seven steps in a risk management approach that assesses the capacity of controls to protect the critical functions of the system – the most critical being that of protection of any person from death or irrecoverable injury – and provides for the introduction of new controls to manage foreseeable loss events.