Diagrams of static stability of a ship in rough conditions
When constructing a diagram of the static stability of a vessel in accordance with the requirements of the Rules of Classification Societies, it is necessary to take into account special navigation conditions: icing, the presence of liquid cargo in tanks, etc. In this case, the presence of rolling in the ship caused by the action of waves is taken into account only at the moment of determining the restoring moments. This article provides an analysis of the influence on the static stability diagram of the shape of the water surface (wave profile), on which the inclination occurs. The construction of a complex shape of the volumetric displacement, caused not only by the shape of the ship's surface, but also by a change in the current waterline, has been carried out using solid modeling of the theoretical hull and the volume of the water basin in the Autodesk AutoCAD and Visual Lisp environment. For test calculations, it has been found that the possible deviation of the static stability shoulder and the area under the positive part of the diagram can reach twelve percent, which must be taken into account when carrying out verification calculations.