Impact of contemporary ship stability regulations on safety of shallow-draught inland container vessels

Directive 2006/87/EC of the European Parliament and the Council represents a milestone in the on-going process of harmonization of technical standards for inland vessels in Europe. The Directive prescribes various safety requirements for freight and passenger vessels operating on the European inland waterways. This paper focuses on ship stability regulations laid out in the Directive 2006/87/EC in relation to the safety of shallow-draught inland container vessels designed for the Danube. Using the probabilistic analysis of stability of inland vessels exposed to stochastic beam wind, it is demonstrated that deterministic regulations imposed by the Directive fail to provide sufficient level of safety in a number of relevant cases. In addition, the paper presents an overview of environmental conditions used in safety analyses, as prescribed by diverse regulations presently in effect in Europe. It is shown that different rules may apply in the same area of navigation which subsequently leads to unequal safety levels attained by the vessels operating in given waterway. Therefore, the paper offers a universal risk-based alternative to the current safety rules, based on the statistical analysis of roll motion of a vessel in realistic weather conditions.