HOLISTIC APPROACHES TO CONTAINERSHIP DESIGN

摘要

High fuel prices, low freight rates and environmental concerns have influenced the design and operational characteristics of all types of ships. In recent years particularly container ship designs were considerably changed towards a new generation of ECO-ship designs. These designs correspond to ships with lower emissions, lower operational costs and increased competitiveness compared to traditional tonnage. This paper presents a holistic, multi-objective optimization procedure for the design of such containerships. It encompasses the development of parametric models for the optimization of medium size vessels (capacity between 3,500 and 4,000 TEU) with emphasis on the Intra-Asian trade. Fully parametric geometric modeling and design simulation techniques are employed in the framework of the CAD/CAE environment of FRIENDSHIP-Framework. They include sophisticated assessment tools for the evaluation of critical ship design attributes, such as ship's weight, stability, resistance and powering for common operational conditions. The developed multi-criteria and multi-staged optimization approach enables the effective exploration of an extended design space (with the utilization of genetic algorithms-NSGA II) targeting the minimization of the Required Freight Rate (RFR), next to the Energy Efficiency Design Index (EEDI) and additionally the minimization of ballast water carriage for the common operational conditions (zero ballast in several practical loading conditions). Further emphasis is put on enhancing ship’s port efficiency to reduce time in port and consequently allow the reduction of transit speed between ports, with obvious positive effects on fuel consumption and emissions.