Second Generation Intact Stability criteria: Analysis, Implementation and Applications to significant ship typologies

The following doctoral thesis addresses all the stability failures embraced by the Second-Generation Intact Stability criteria (SGISc). These criteria are under finalization within the sub-Committee at the International Maritime Organization (IMO). SGISc are one of the most discussed topic since the session in 2008 and they drew the attentions not only of the international scientific community but also of other stakeholders such as designers and shipyards. It is forecast that the second-generation criteria will be finalized and published in an official document at IMO by 2020 session. The new regulation has introduced a modern method to apply the criteria that is called multi-layered approach: it consist of three different vulnerability level with increasing accuracy and complexity. One of the aims of this dissertation is to evaluate, both qualitatively and quantitatively, how the SGISc will affect existing vessels and new projects. To chase this main object, it has been necessary to develop a set of computational codes, for each stability failure and vulnerability level, integrated with an existing in-house software already developed. Before beginning to compile the codes, the phenomena physics behind each stability failure has been studied together with a detailed analysis of the regulations texts. Subsequently, a comprehensive campaign of application on a representative mega yacht unit and on a Ro-Ro pax ferry has been carried out in order to verify and validate the computational codes developed. Navy vessel and container-ship have been included in the analysis because they are deemed to be vulnerable to the phenomena addressed by SGISc. To identify a relationship between the stability failures and main design parameters, a set of parent hull variations has been carried out. To better understand which parameters are more relevant in each specific phenomenon, it has relied on a useful tool adopted in systems engineering: the Design Structure Matrix (DSM). Thanks to DSM it has been possible to classify the direction and the magnitude of relationships among parameters introduced by the SGISc.