Ocean Engineering 189 (2019) 106346 Available online 5 September 2019 0029-8018/© 2019 Elsevier Ltd. All rights reserved. Parametric design and optimisation of high-speed Ro-Ro Passenger ships Sotiris Skoupas a , George Zaraphonitis b, * , Apostolos Papanikolaou b, c a Lloyd’s Register, 87 Akti Miaouli, 18538, Piraeus, Greece b National Technical University of Athens, 9 Heroon Politechniou str., 15773, Athens, Greece c Hamburger Schiffbau-Versuchsanstalt, 164 Bramfelder Straße, D-22305, Hamburg, Germany A R T I C L E INFO Keywords: Parametric design Multicriteria optimisation High speed craft Ro-ro passenger ship Monohull Twinhull ABSTRACT An integrated methodology for the parametric design and optimisation of high-speed Ro-Ro Passenger vessels of both mono- and twin-hull confguration is presented. The hullform and internal layout are elaborated auto- matically in the NAPA® software environment enabling the multi-objective optimisation of design alternatives with respect to installed propulsive power, transport capacity and economic viability, while considering all major design constraints, including intact and damage stability. Typical application results from the optimisation of two high-speed Ro-Ro Passenger vessels are presented and discussed. 1. Introduction The present paper deals with the optimisation of high-speed Ro-Ro passenger ships, of mono- and twin-hullform type. The optimisation of high-speed vessels for least powering (lowest fuel consumption) and environmental impact (lowest toxic gas emissions, minimal wave wash impact) was subject of intensive research by the authors in the past years (Zaraphonitis et al., 2003; Project FLOWMART, 1999–2003; Papaniko- laou, 2011) and is still of interest today in relation to the development of zero emissions, battery-driven fast coastal PAX vessels, for which the battery weight and space requirements need to be minimised (project TrAM, 2018–2022). Ship design is a synthetic discipline, which is governed by a decision- making process. For many decades, the design spiral (Evans, 1959) pro- vided a perspicuous representation of the traditional ship design pro- cess, illustrating the sequential and repetitive elaboration of a series of design tasks, each repetition carried out in increased detail and accu- racy. The outcome of such a procedure (often characterised as point-- based design) heavily depends on the starting point – the initial estimates of the ship’s main characteristics and the experience of the designer. Modern approaches to ship design, which are implemented in prac- tice by use of appropriate software platforms and tools, introduce the parametric design into the ship design process, enabling the exploration of the huge design space prior to a decision. These approaches are often interrelated to a modular ship design, in which the main parts of the ship (hull, machinery, outftting, navigation bridge etc.) are being considered as modules with certain functionality, connectivity and associated space and weight requirements. Similar approaches are frequently applied to naval and special purpose ship design (see, e.g., Andrews and Pawling, 2002; Bole and Forrest, 2005). They are also interrelated to the set-based design introduced by Parsons et al. (1999), also in naval ship design. Independently and with a different emphasis, a holistic, multi- objective and multi-disciplinary approach to ship design for life-cycle was introduced by Papanikolaou (2010). Typical early applications of this approach to the design of various types of ships and with emphasis on various design disciplines are: Zaraphonitis et al. (2003) (high-speed PAX, hull form/resistance and wash), Papanikolaou et al. (2011) (tanker, overall design/marine pollution, economics), Zaraphonitis et al. (2013) (RoPax & cruise ships, overall design/damage stability/safety), Koepke et al. (2014) (containerships, overall design/effciency and economics). A comprehensive historical review of developments in parametric ship design was recently presented by Nowacki (2019). The above introduced parametric ship design procedure presumes the development and integration of parametric design software tools for the automatic elaboration of design alternatives, once appropriate values have been assigned to a prescribed set of design parameters. This is herein achieved by software tools developed in NAPA®, a well-known ship design software package, facilitating the fully automated elabora- tion of the hullform and the internal layout, along with a detailed assessment of their main technical and economic characteristics. The developed assessment tools enable the thorough evaluation of each design alternative characteristics, including resistance and propulsion, * Corresponding author. E-mail addresses: Sotiris.Skoupas@lr.org (S. Skoupas), zar@deslab.ntua.gr (G. Zaraphonitis), papanikolaou@hsva.de, papa@deslab.ntua.gr (A. Papanikolaou). Contents lists available at ScienceDirect Ocean Engineering journal homepage: www.elsevier.com/locate/oceaneng https://doi.org/10.1016/j.oceaneng.2019.106346 Received 4 February 2019; Received in revised form 13 July 2019; Accepted 20 August 2019