1 Department of Naval Architecture and Offshore Engineering, Technical University of Denmark
An outline of the whole probabilistic concept of ship subdivision is given, comprising the latest advances in determination of pi and s1 factors - the two probabilistic factors that form the basis of the new regulations.The method for calculating the pi factor for dry cargo ships is thoroughly presented and compared with the original method, developed by IMO inthe late 60's for passenger ships. After that, a review is presented of the past efforts to develop an estimate for the factor si - the most difficultand controversial part of the new subdivision regulations based on the probabilistic concept. This may facilitate our present efforts in developing a sound assessment, consistent with the results of damage stability model tests. A new method is provided regarding the capsizal probability, based on the theory underlying numerical simulations of damaged ship behaviour in natural sea conditions, assuring a high accuracy of prediction for the si factor.