ON THE PERFORMANCE ANALYSIS IN SHIP FIRE SAFETY DESIGN

With the ratification of IMO’s resolution MSC.99 (73) on 1st July 2002, in many classification societies, fire ship codes are shifting from prescriptive (rules in SOLAS) to performance-based (as long as an adequate level of safety is maintained) for technical, economic and social reasons. This change is made possible by progress in fire safety technologies, including the development of engineering tools that are required to implement performance codes. The performance-based design is a design activity that is based, on the analysis of a “phenomenon”, developed in case of fire event, and on the verification of adopted providences. The success of performance-based codes depends on the ability to establish performance criteria that will be verifiable and enforceable. The performance criteria should be such that designers can easily demonstrate, using engineering tools, that their designs meet them and that the classification societies can enforce them. This paper firstly presents and discusses the fire models for ships, deriving from those ones of buildings, which can be utilized to simulate the development of a fire event in a compartment or groups of compartments. Successively a study on the performance criteria, which can be currently used by fire protection engineers in designing fire safety in ships, is carried out. This includes deterministic and probabilistic design criteria as well as safety factors. The deterministic criteria relate mainly to life safety levels, fire growth and spread levels, fire exposure and structural performance. The probabilistic criteria focus on the incident severity and incident likelihood. Additionally, the inclusion of safety factors permits a conservative design and allows for a smaller margin of error due to uncertainty in the models and the input data. Finally, two examples demonstrate the practical applicability of the proposed performance criteria and their practical engineering relevance.