Development of tool to calculate large angle stability and hydrostatics of a ship using MATLAB

Ship stability is one of the mind-boggling concepts that alludes to the safety of a vessel and those onboard. It is termed as the ability of a ship to return to its upright position, when disturbed. However, this study explicitly aims to focus on determining only the intact stability of the vessel, as a part of general concept of ship's seaworthiness. Specifically, it investigates the intact stability of the model hull form at large angles of inclinations because the metacenter's position does not remain fixed, dissimilar to the instance of small heel angles. In this context, previously used approximate approaches are discussed and in addition to that, an analytical approach has additionally been contrived. This analytical approach relies on the cross curves of stability (KN curves) for formation of statical curves of stability (GZ curves), which is the measure of large angle stability of a vessel. With the aid of this approach, a code has been composed using MATLAB programming language to compute the intact stability of a vessel via offset data provided. The point to ponder here is that this program does calculations without any dependency on a 3D model. The results of this code are extracted in graphical form i.e. body plan, hydrostatic curves and GZ curve, and these results are further on validated using marine design software. On this premise, it is concluded that the analytical approach taken for calculations is appropriate and thus, the GZ curves formed are accurate.