MODERN NUMERICAL TECHNIQUES FOR THE SHIPS SAFETY ESTIMATION IN CRITICAL CONDITIONS

Abstract

In this paper a method for a ship safety estimation at the preliminary stage of design is briefly presented. Solving a few hydrostatic and dynamical problems may be taken into account using the method with special regards to the ships safety estimation in critical conditions. The critical conditions may concern the problems of survivability caused due to the cargo and/or ballast shift, waves and wind impact including the ingress of external water into the watertight compartments of a ship.

The theoretical and computational models are briefly described. Using the computational model the safety assessment may be done for the initial event and scenario development assumed. Then, either some seakeeping, stability, damage stability or survivability related characteristics should be evaluated for the risk assessment. Both the scakeeping and stability characteristics are treated as the initial conditions for the risk assessment regarding the damage stability and survivability, and it usually follows from the hazard scenario development. The risk assessment is the base for the safety estimation. This is done according to the IMO regulations.

The computational model incorporates the modem numerical techniques and is briefly described by introducing the logical structure of design system, logical structure of computational model and a few application methods used.

The model enables to estimate the safety combining the influence of the hull form parameters, arrangement of internal spaces, loading condition including both the cargo distribution and permeability and impact of exciting forces. The exciting forces may follow from both the external and internal sources. And they arc as follows: waves, wind and cargo and ballast shift.