Fishing vessels safety and IMO stability criteria

As it is well known, nowadays I.M.O. suggests using for the intact stability of every kind of ship, included fishing vessels having lenght of 24 m and over, both the general statistical intact criteria (Resolution A. 168) and the severe winf and rolling criterion (Resolution A. 562). Consequently for all the ships the check of the intact stability standard conditions in the preliminary design stage is becoming very difficult dur to the necessity to know both the righting arm curves and the geometrical characteristics and distributions of the superstructures. Therefore the first aim of this paper is to provide the naval architect with a suitable tool to verify hull stability in the preliminary design stage. By the analysis of the results obtained through the systematic hull series, the author's second aim is to show the influence of the geometrical and loading parameters on the I.M.O. stability criteria. By taking into account the comparison between weather stability criterion and the statistical criteria it could be possible a reduction of the indices considered in the actual statistical criteria and an integration of the statistical criteria with the weather criterion.