Cargo Hold Structure Optimization of Small and Medium-Sized Duplex Stainless Steel Chemical Tankers

A mathematical model of optimization for cargo hold structure of small and medium-sized duplex stainless steel (DSS) chemical tankers based on the rule is described.The weight of DSS is defined as the objective function.The explicit formulas of the relevant rules,the explicit geometric relations formed by the structural arrangement and the implicit constraints such as layout,lines,expert experience,workmanship and so on are taken as the constraints.The design variables and the algorithm are determined by analyzing the logical relations among the factors.Besides,the efficiency of the optimum algorithm is improved by utilizing the distribution law of the optimal corrugations.Finally,the comprehensive optimization of the cargo hold DSS is accomplished by C++ programming.The weight of the optimized scheme of the example is 4.93% lower than that of the original scheme.The finite element analysis results show that the optimized scheme is satisfied with the requirements of the rules and has a good structure performance.The optimization method based on the rules and accomplished by the programming is practical for structural preliminary design.

Assessing the Potential Impact on Previous Maritime Accidents Had the HNS Convention Been Applied

The HNS Convention(International Convention on Liability and Compensation for Damage in Connection with the Carriage of Hazardous and Noxious Substances by Sea,2010)covers any damage caused by the carriage by sea of hazardous and noxious substances in the territory or territorial sea of a State Party to the Convention.The costs of preventive actions,i.e.measures to avoid or minimize damage,are also covered wherever taken.The HNS Convention includes preventive measures as any reasonable measures taken by any person after an incident has occurred to prevent or minimize damage,i.e.actions such as clean-up or removal of HNS from a wreck if the HNS presents a hazard or pollution risk.It seems that after the CLC(Civil Liability Convention),much environmental legislation has lost the concept of pro-activeness/prevention of an environmental hazard and is more focused on compensation and reactiveness.This approach is not consistent with the purpose of environmental legislation and the examination of the basic principles of the HNS Convention in parallel with distinctive environmental hazards proves this theory of reactive strategy.The methodology is based on the exploratory research principles and the legal doctrine,utilizing legislation and case law as the primary source of data,aiming to examine the effects of the HNS’s entry into force by studying cases that are inside its authority and scope.