Nowadays, sustainable navigation is becoming a trending topic not only for merchant ships but also for pleasure vessels such as motoryachts. Therefore, the adoption of a hybrid-electric propulsion system and the installation of on-board storage devices could increase the greenness of a megayacht. This paper analyses the performance of three commercial propulsive solutions, using a dynamic operative profile and considering the influences of the smart berthing infrastructures. Results compare the yearly fuel consumptions of the analysed configurations for a reference megayacht.

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The increasing interest in air pollutant emissions reduction also influences the shipbuilding industry. In this sense, hybrid-electric propulsion is a promising solution for green navigation, ensuring a Zero Emission Mode navigation close to coastal areas and harbors. Hybrid-electric propulsion is a convenient choice not only for new units but also for the retrofitting of outdated ones. This paper deals with an example concerning the retrofitting of a small passenger vessel, where the study of the application of hybrid-electric systems was possible only thanks to reverse engineering techniques for the identification of the internal spaces. The final hybrid configuration refers to a slow-tourism operative profile in the North Adriatic area.

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Nowadays, fire-doors optimization is approached by using consolidated design guidelines and traditional materials, such as rock wool. Then, selected solution is directly tested in a mandatory fire-test. Unfortunately, few pieces of information could be retrieved either if the test succeeds or fails, which makes both improvements in the design and use of innovative materials difficult. Thus, in this work, a self-consistent finite element method (FEM) analysis is developed and assessed against experimental fire-test results, highlighting the critical parameters affecting the numerical simulations. Using this tool, a new fiberglass-containing foam, with improved acoustic and mechanical properties, as compared to the rock-wool, is studied as a potential insulating material for on-board fire-doors. The assessment of the performance of the new material demonstrates that, contrary to common believe, the effective thermal insulation capacity is not necessarily the critical factor in determining the fire-resistance of a fire-door. Using the validated FEM analysis, it has been proven that the reduction of the thermal bridges originated at the door edges allows, firstly, for the attainment of a fire-door 37% thinner and 61% lighter with respect to a traditional one, and, secondly, the use of new material as insulator in fire-doors that, even if less thermally capable, could improve other properties of the door, as an example its soundproofing.

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Sustainable mobility is one of the most challenging issues for passenger transport inside environmental protected areas and ecologically fragile environments. To reduce the pollutant emissions, the adoption of electric or hybrid-electric solutions for crafts propulsion is a suitable option for green navigation. However, the operation in restricted basin leads also to specific critical issues for the vessel sailing, as dealing with shallow or restricted waters and transit under low air-gap bridges. The combination of these constraints with the adoption of a hybrid-electric propulsion system increases the design difficulties also for a small craft, requiring the use of advanced simulation models to assess the vessel performances. This work presents a simulation model for a small passenger craft that will operate in the Grado Lagoon. The model combines the hydrodynamic issues of manoeuvring and propulsion in restricted water with the simulation of the electric loads and capacity of the energy storage system installed onboard. The simulations performed with the developed simulation system are in accordance with data measured during trials on a prototype of the vessel. The developed model is a powerful tool for designers in order to rapidly assess the green capabilities of new projects since the early design stages.

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Passenger ships evacuation analysis is nowadays a required step in the ship design process. In this sense, a new set of international Regulations has been issued to improve the survival ability of passenger and ro-ro ships. The 'Safe Return to Port' Regulation is referring to the need to grant adequate ship functionality when a casualty occurs (e.g. fire or flooding), requiring the ship evacuation when damage exceeds a given threshold. For such a reason, the evacuation analysis is mandatory for both new and existing passenger and ro-ro ships, since the early stages of design. The International Maritime Organisation Guidelines prescribe the examination of additional scenarios besides the standard ones. The present work presents a case study for the evacuation of a 4906-person cruise ship, considering the specific example of the open deck, which is one of the additional scenarios required by regulations. The advanced calculation method has been used to simulate the evacuation process, using software EVI.

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The continuous increasing attention to environmental sustainability and air pollution reduction for transport systems, requires not only to adopt new technologies and innovative solutions to limit vehicles emissions, but also to study their life-cycle. In case of inland navigation, the operation close to urban areas or in natural protected environments requires the adoption of a green propulsion. Moreover, especially for small crafts, the problem of ship disposal at the end of life is of high importance, even once plastic materials should be disposed, due to high costs and process complexities. For such a reason the design of a new generation green passenger craft requires the analysis and knowledge of multiple engineering fields, that could lead to a fast and successful design only by means of an integrated approach. In the present work, this approach will be applied to the design of a passenger craft, adopting an hybrid electric powering system and build with strip planking process for wooden ships. The description of the construction process will be here described together with the on-board electric power system. The integrated approach allowed also to directly evaluate the vessel operative profile and asses whether the vessel could perform a Zero Emission Mode navigation.

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Tethered escort of ships is performed by specially designed tugs linked by a tow-line to a strong point aft of the assisted ship. In fact, the tug is called to control the course and speed of the assisted ship in an emergency situation), so reducing the risk of grounding or collision. A substantial number of studies about ship casualties shows the grounding as the predominant accident when the ship is approaching the harbour or narrow fairways. In order to take part in escort operations, a tug must be provided with the additional service notation escort tug, which confirms its specific capabilities in accordance with particular stability criteria that will be harmonised by International Maritime Organisation from 2020. In case the tug should be propelled with Liquefied Natural Gas, then dedicated issues related to containment system should be solved. Through this paper, an overview will be given upon the possible escort operations that an escort tug could face during his operational life, together with the possible types/configurations of tugs that can be used for this kind of operations. Moreover an example will be given on the determination of escort performances by means of a self developed code on a sample tug.

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In order to improve the survival capability of passenger and ro-ro ships in event of fire or flooding, in the last few years a set of international Regulations has been issued. In particular, the Regulation SOLAS “Safe Return to Port” is addressed towards design criteria able to guarantee adequate functionality of the ship when a casualty occurs. The Regulation requires the evacuation of the ship when a given threshold of damage (i.e., fire and flood) is exceeded. The evacuation analysis has become of primary importance even in the early-stage design. Indeed, the new amendments to SOLAS Regulation II-2/13.3.2.7 makes the evacuation analysis mandatory for both new and existing passenger and ro-ro ships since the early steps of the project. In this paper, the current IMO Guidelines have been analysed, and a case study for the evacuation of a 3600-person cruise ship has been carried out by means of both a simplified and an advanced method. To perform advanced calculations, two different software, based on virtual reality, have been used and the results have been compared with simplified method ones.

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The increasing focus on navigation sustainability is forcing the utilisation of alternative power sources on board of inland vessels. The adoption of Liquefied Natural Gas is for sure a good option to reach the imposed targets on pollutant emission reductions. However, the issues related to the gas storage on board increase the hazards for people and environment in case of failures compared to a diesel fuelled vessel. In this sense, the analysis of risks is of primary importance. Traditionally, the failure and risks individuation is mainly based on qualitative consideration. In this study a procedure to quantify the risk is proposed and is tested on two inland waterway vessel having two different LNG propulsion systems installed on-board. The proposed method is aimed to give a quantitative comparison between two designs.

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The European Inland Waterway Transport (IWT) is a viable and effective alternative to road and rail transport of persons and goods on the European network. Currently, the IWT is less exploited than the 'traditional' transport despite the European inland waterway network spans more than 29000 km and includes over 400 important ports and terminals. The design of inland waterway vessel is heavily affected by the environmental constraints and the Rule framework. About the latter, in the last few years several organizations played an important role in the definition of the Rule framework in Europe: the United Nations Economic Commission for Europe (UNECE), the European Union and various local area commissions. The tendency of international regulations is to make inland waterway decarbonised by reducing pollutant emissions through ships with zero-emission propulsion. Moreover, the design is also affected by environmental constraints like width and depth of the canals, air draft, etc. In this paper, a 'new concept' for inland waterway vessel, which considers the modern national and international regulations and the environmental constraints, has been defined. A case study and the results obtained have been analysed.

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Nowadays, it is of paramount importance reducing the pollutant emission also of small crafts operating near the coast. This action is an essential issue to preserve the marine and coastal environment. In this paper, the design of a coastal-navigation multipurpose craft to be used in North Adriatic Sea area is presented. The particular service areas are characterized both by inland waterways with shallow and restricted waters and by open sea. Hull-form of the craft along with hybrid-electric propulsion have been properly designed in order to obtain an efficient solution for the different operational conditions. Specifically, the hybrid-electric power system has been conceived to allow the Zero Emission Mode navigation for a reasonable range.

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The general increase in size of merchant ships requires the use of tugs with higher performances in terms of versatility, efficiency, towing capability and powering. Escort operations are carried out by special tugs through a towline connected aft of the assisted ship in order to control course and speed in potentially dangerous areas, so reducing the risk of grounding and collision. Steering and braking forces are developed by the escort tug which works as a large "remote rudder". The "escort tug" service notation is assigned by Classification Society through full-scale tests or by computer model simulations able to evaluate the maximum steering force developed at different speeds. The paper deals with a method for the prediction of the escort capabilities of a tug through the quasi-steady solution of the dynamic equilibrium, and also the compliance with specific intact stability criteria. A case study for a tractor-tug is presented.@en

Sustainable mobility is an essential issue to take for the town planning of a great city. When a high tourist flow is present, the city should be provided of low pollutant emission vehicles for the public transport in order to preserve the environment. Venice is an UNESCO World Heritage Site, where the urban public transport is almost exclusively carried out by boats. This paper deals with the design of a new small passenger craft to be operated in the Venice Lagoon with hybrid-electric propulsion. An innovative hullform has been conceived in order to get wave reduction useful to lower both the impact on the foundations of buildings and the energy consumption of the craft. Moreover, a suitable LVDC Integrated Power System has been adopted to enable the Zero Emission Mode navigation.

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Pleasure craft market has significantly decreased in 2008. Market data highlight that this drop concerns principally vessels with a length between 37 and 60 m, especially for sailing yachts. For this reason a new concept-design for this market segment has been studied, developing a new vessel which harmoniously integrates hull and superstructures in accordance with modern design. As reference, firstly a hull form of the Delft systematic series has been considered, but successively the hull geometry has been modified to drawn more slender forms in order to reduce resistance, and consequently fuel consumption during the transfer by motor, without sacrificing the internal habitability. In fact, a particular attention has been given to the definition of the internal spaces, considering new solutions for both subdivision and zoning. Moreover, a hybrid propulsion system has been adopted, so to obtain an effective ‘green ship’.@en