Trade-off between modularity and optimisation in the hydrodynamic design of high-speed electric ferries

The challenge of introducing "greener" alternatives to internal combustion engines in the maritime industry has led to the introduction of fully electric ships. However, serious challenges arise when a battery-driven vessel needs to operate at high speeds, due to the exponential increase in energy storage requirements and the corresponding battery weight. Hence, optimised hydrodynamic performance becomes the key design aspect. Meanwhile, modularity in the shipbuilding industry allows the production of systems using the same components and standard interfaces, which may be used in various applications, thus leading to potential cost reduction in design and production. Yet, hull form optimisation and modularity are sometimes two contradicting design approaches. H2020 European Union project "TrAM – Transport: Advanced and Modular" aims to introduce the benefits of modularisation in the design of battery-driven ships by implementing state-of-the-art "Industry 4.0" holistic ship design and production methods. In this paper, the trade-off between hull form optimisation and modularity is studied. Two design approaches –based on optimisation and modularity– are compared and their impact to the hydrodynamic performance of high-speed catamaran electric vessels is discussed.