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The seaway trade market has expanded in the last years and container ship dimensions are constantly increasing for higher cargo capacity. In the early design stage, main dimensions are usually determined based on an existing ship database from which regression formulas are derived. In the present paper, a database of 260 non-sister container ships built from 1979 to 2022, representing 20% of the world fleet, has been considered to derive and compare different types of regressions. Simple regressions have been developed and compared with equivalent formulations available in literature, proving better approximations of the trends. The study has been further extended by multivariable regressions and forest tree algorithms, which allow the use of more than one independent variable and provide a better fitting compared to simple regressions. Forest tree regressions return the highest values of fitting coefficients, but the technique is not of easy application due to the absence of mathematical expressions. The main contribution is the updated set of simple and multivariable regression formulas which have a higher goodness of fit than previous works and can be easily employed by designers in the early design stage and in multi-attribute design procedures. • Database of 260 non-sister container ships built from 1979 to 2022. • Covering 20% of the world container ship fleet. • Main characteristics analyzed by regressions analysis and forest trees. • Simple regression formulas compared with state-of-the-art regressions. • Improved regression formulas for early ship design. [ABSTRACT FROM AUTHOR]

The ropax vessels are designed to provide the transfer of vehicles, cargo, and passengers and to ensure maximum comfort and safety. The absence of a transversal subdivision for all vessel length poses serious threats to ship safety in case of flooding of the garage deck. When the floodwater is not properly and efficiently drained overboard it can have detrimental consequences both on ship stability, due to large free surface effects and, on loads on deck structures due to the pressure of the accumulated water. In this paper, we propose and apply a fast numerical method for the study of the drainage capacity in the garage deck of a ropax vessel assuming a passive drainage system i.e. comprising only scuppers, whereas the investigated flooding scenario depends on fire fighting operations. The effectiveness of the drainage system is simulated accounting for ship dynamics in calm water and in waves, by adopting a hybrid non-linear numerical model. Flooded water is modelled by lumped mass method; the couplings between ship and floodwater dynamics is achieved by the apparent gravity technique. Two scupper configurations are considered, by modifying scupper dimensions and positions on board. Several numerical simulations are carried out assuming also partially inefficient scuppers. The analysis of the obtained results can provide a general support for the design of passive drainage systems. Based on the outcomes of the case study, this research discloses an improvement in the drainage system when more scuppers are allocated at the stern zone. [ABSTRACT FROM AUTHOR]

This paper evaluates the effect of a large-capacity electrical energy storage, e.g., Li-ion battery, on optimal sailing routes, speeds, fuel choice, and emission abatement technology selection. Despite rapid cost reduction and performance improvement, current Li-ion chemistries are infeasible for providing the total energy demand for ocean-crossing ships because the energy density is up to two orders of magnitude less than in liquid hydrocarbon fuels. However, limited distance zero-emission port arrival, mooring, and port departure are attainable. In this context, we formulate two groups of numerical problems. First, the well-known Emission Control Area (ECA) routing problem is extended with battery-powered zero-emission legs. ECAs have incentivized ship operators to choose longer distance routes to avoid using expensive low sulfur fuel required for compliance, resulting in increased greenhouse gas (GHG) emissions. The second problem evaluates the trade-off between battery capacity and speed on battery-powered zero-emission port arrival and departure legs. We develop a mixed-integer quadratically constrained program to investigate the least cost system configuration and operation. We find that the optimal speed is up to 50% slower on battery-powered legs compared to the baseline without zero-emission constraint. The slower speed on the zero-emission legs is compensated by higher speed throughout the rest of the voyage, which may increase the total amount of GHG emissions.

In recent decades, the design of ship propulsion systems has been focusing on energy efficiency and low pollutant emissions. In this framework, diesel–electric propulsion has become a standard for many ship types and has proven its worth for flexible propulsion design and management. This paper presents an approach to the optimal design of diesel–electric propulsion systems, minimising the fuel consumption while meeting the power and speed requirements. A genetic algorithm performs the optimisation, used to determine the number and type of engines installed on-board and the engines’ design speed and power, selecting within a dataset of four-stroke diesel engines. The same algorithm is then adapted and applied to determine the optimal load sharing strategy in off-design conditions, taking advantage of the high flexibility of the diesel–electric propulsion plants. In order to apply the algorithm, the propulsion layout design is formulated as an optimisation problem, translating the system requirements into a cost function and a set of linear and non-linear constraints. Eventually, the method is applied to a case study vessel: first, the optimal diesel–electric propulsion plants are determined, then the optimal off-design load sharing and working conditions are computed. AC and DC network solutions are compared and critically discussed in both design and off-design conditions.

Innovation features huge uncertainties and risks. According to statistics, less than one percent of discoveries and inventions convert successfully into innovations and real applications. The key element in converting innovative ideas into applications is the scientific consciousness of the innovators, which is very important for such open, complex and large-scale system engineering as naval architecture. Due to the lack of early warning for the cognition of dimension, many innovative ideas fail to convert into successful applications. Thus, enhancing scientific consciousness is important for holding the general interest and forming an integral vision of innovation so as to lead innovative design to the correct roads and approaches, and control risks in advance.

The paper presents a method for preliminary estimation of the length of the midship body block, which inserted in the original hull, increases the deadweight of the ship in line with a required quantity. The method may be useful for establishing the scope of conversion to better adjust the ship for transportation tasks. The problem is formulated by using a mathematical model so selected that its solution, under set of assumptions, is obtained in a closed analytical form. The presented method can be useful for application to pre-investment analysis of the ship conversion costs and functional profits.

Engineering design is characterized, in many cases, by the involvement of multiple stakeholders. The variety of stakeholders' expectations with regards to the output and outcome of a vessel design situation, and the differences in background, culture and information asymmetry among stakeholders, make it difficult to arrive at a common set of requirements and a mutually accepted vessel design solution. In this paper, we show how poor handling of expectations in multi-stakeholder arrangements may lead to overspecified design solutions and thereby, negatively affect business outcomes. We propose and test a set of metrics to measure the level of misalignment among stakeholders' expectations to identify and measure overspecification in vessel design alternatives. The measure can be used in tradeoff analysis against cost, in the decision process for selection among design alternatives. Hence, at equal cost, a higher degree expectation fulfillment may be preferred and selected. A case study is presented for the design of an offshore ship design based on a joint-venture ownership. [ABSTRACT FROM AUTHOR]

Increasing propulsion efficiency, safety, comfort and operability are of the great importance, especially for small ships operating on windy sites like the North Sea and the Baltic Sea. Seakeeping performance of ships and offshore structures can be analysed by different methods and the one that is becoming increasingly important is CFD RANS. The recent development of simulation techniques together with rising HPC accessibility enables performance of advanced seakeeping simulations for ships in a full scale. The paper presents CFD seakeeping analysis for a case study vessel in two variants: V-shaped bulbous bow hull form (as built) and innovative hull form (X-bow type). The study presents the influence of redesigning the ship on selected seakeeping aspects. The advanced CFD model, with the application of overset mesh technique, was described in detail. Selected numerical results were validated on the basis of experimental testing in a towing tank and showed good agreement. The approach demonstrated here of performing the CFD seakeeping simulations for the analysis of ship performance in a full scale and close to real loading conditions has direct application to the design process as well as in determination of optimal operational parameters of any ship. [ABSTRACT FROM AUTHOR]

This study focuses on the optimization of ship dimensions by considering hydrodynamic performance in waves. In actual seaways, a ship experiences speed loss due to environmental loads by waves and wind. Therefore, along with calm water resistance, speed loss in waves should be considered in the hull form design in order to improve operational efficiency in waves. However, a trade-off may be needed between total resistance on the ship and the speed loss in waves. To address this problem, Non-dominated Sorting Genetic Algorithm II, which is a multi-objective optimization method, is used to minimize the total resistance on a ship in seaways and the speed loss by additional resistance. In the optimization process, added resistance is predicted using a numerical method based on slender-body theory, Maruo's far-field formulation, and an empirical formula for added resistance in short waves. The speed loss in waves, which can be expressed by a weather factor (fw), is estimated using power–speed curves. This article introduces some examples of the sensitivity analysis of added resistance and speed loss in waves to the variations of ship dimensions. Finally, the optimization solutions on a Pareto front set are compared to a basis ship in terms of hull form, and the corresponding hydrodynamic performances are evaluated. [ABSTRACT FROM AUTHOR]

In the paper is presented a study of the economics of refrigerated cargoes transport with two specialized types of ship. Two modern ship designs are developed for the transport of refrigerated cargo, primarily bananas. One design is a reefer vessel with the ability to load a significant number of refrigerated containers on the main deck. The other design is a container ship specialized for the transport of refrigerated 40 feet containers. Both designs have the capacity to load the same mass of refrigerated cargo. Basic characteristics of the designs are compared, which can be the basis for answering the question: Which type of vessel to choose for the carriage of refrigerated cargo? [ABSTRACT FROM AUTHOR]

Abstract In this paper, we study the relationship between economic performance and flexibility for non-transport vessels. More specifically, we investigate the difference between two means of achieving flexibility: retrofittability and versatility, i.e., the ability of a vessel to satisfy diverse needs with or without change of physical form, respectively. A model is presented to study this relationship, where we first generate design alternatives with relevant, flexible properties before we subsequently evaluate the design alternatives based on their expected discounted economic lifecycle performance. The evaluation model is based on a two-level decomposition of the planning horizon to handle temporal complexity, using scenario planning and Epoch-Era analysis (EEA) for long-term strategic considerations, and Monte Carlo simulation and optimization for medium-term tactical ship deployment. The proposed model is applied to an offshore construction ship design case. Findings indicate that retrofittability can increase economic performance significantly for non-transport vessels operating in an uncertain heterogeneous context. Highlights • This paper studies retrofittability and versatility as two aspects of flexibility in design non-transport vessels. • A vessel can satisfy a diverse set of needs with (retrofittability) or without (versatility) change of physical form. • Epoch-Era Analysis is used at the strategic level and Monte Carlo analysis at the tactical level. • The relationship between investment costs, flexibility, and revenue potential is studied. • Findings indicate that retrofittability significantly can increase economic performance for non-transport vessels. [ABSTRACT FROM AUTHOR]

Charles I's great warship the Sovereign of the Seas is famed for its design, decoration and importance as a tool that heightened the image of English naval supremacy. By exploring its career, size, name and decoration, this article highlights the Sovereign of the Seas’ significance as a national symbol of political and cultural power. It argues that Charles's leading warship was developed as a reaction to naval advances and current affairs in Europe. Through a diverse range of evidence including diplomatic correspondence, printed texts and artwork from both English and French institutions, as well as relating this to similar advances in the Netherlands and Sweden, the Sovereign of the Seas’ development is internationally contextualized. By comparing it with other contemporary warships, most importantly la Couronne of France, it is shown that Charles's flagship was a product of a growing international theatre of maritime activity that was inspired by cultural and political competition, as much as it was by military escalation. [ABSTRACT FROM AUTHOR]

The purpose of this study is to perform the techno-economic analysis of photovoltaic system utilization for lighting and cooling of Ferry Ro/Ro 500 GT. The world is facing a dilemma of increasing dependence on fossil energy with decreasing supply. This situation must be anticipated by all sectors by energy efficiency (EE) and utilizing renewable energy (RE). Especially for RE in the transportation sector, ships as consumers of oil energy can also take advantage of solar energy sources, for example for lighting and cooling. For that purpose, five steps must be taken. First, determine the design specifications. Second, determine the specifications of components of the PV system. Third, calculate the power required for lighting equipment. Fourth, calculate the power required for the cooling system. Fifth, make an investment comparison for propulsion systems between diesel engines and photovoltaic systems. The results show that the energy required for lighting and cooling system as well as for propulsion systems can be placed in the deck area of 148.8 m2 for all system components, such as; PV modules, charge controllers, batteries, and inverter. This study can provide an overview of the use of PV system in designing the environmentally new or renovation ships.

Virtual reality (VR) is increasingly integrated into maritime design processes, and there is a need to better understand how it can support ship designers in their work. Through mapping and interviews, we investigated how VR was used in two design projects in the maritime industry. We explored two questions: What type of design activities and conversations were facilitated by VR as a collaborative medium? When VR was not selected, what other media were used instead, and for what reasons? We found that despite access to VR, most design conversations were facilitated by emails containing screenshots, visual interpretations, and text annotations. VR was used on a few occasions, together with executable files and flythrough videos made with real-time rendered models generated in a game engine, and a web-based 3D model-sharing tool. The use of VR as a collaboration medium was enabled by a variety of design activities ranging from field studies to 2D sketching and 3D modeling. The cases show how VR needed to be integrated with other forms of communication and was seen as a supplement and not the main communication channel for design. The cases also show that the pipeline required for VR scenes creation enabled other forms of collaboration across different supports, such as web-based online collaboration tools. • Use of VR in design process is explored with a user-centered approach. • Two design cases are analysed to identify impact of, and alternatives to VR. • VR needs to be better integrated with existing design tools. • VR leads to 3D asset creation pipeline supporting collaboration across a variety of supports. [ABSTRACT FROM AUTHOR]

The paper presents a method of evaluating the optimal value of the cargo ships deadweight and the coupled optimal value of cargo handling capacity. The method may be useful at the stage of establishing the main owners requirements concerning the ship design parameters as well as for choosing a proper second hand ship for a given transportation task. The deadweight and the capacity are determined on the basis of a selected economic measure of the transport effectiveness of ship – the Required Freight Rate. The mathematical model of the problem is of a deterministic character and the simplifying assumptions are justified for ships operating in the liner trade. The assumptions are so selected that solution of the problem is obtained in analytical closed form. The presented method can be useful for application in the preliminary ship design or in the simulation of pre-investment transportation task studies.

This paper presents the actual method for the calculation of Energy Efficiency Deign Index and analyses the influence of particular variables on the resulted EEDI. Perceived inconsistencies of the actual method of calculation of the attained EEDI are presented with explanation of the influence that the actual calculation has on the design of new ships. Objections are clearly demonstrated on the example of conceptual design of Handy Bulk Carrier. Alternative proposals for improvement of calculation of attained EEDI are introduced. Suggested alterations eliminate observed deficiencies of the existing calculation.

Pada tahap awal desain, untuk mendapatkan desain kapal yang optimum perlu dilakukan analisa untuk menentukan parameter utama dari kapal. Dalam penelitian ini akan dilakukan analisa terhadap pemilihan parameter utama dari kapal ferry catamaran kelas 1000GT untuk mendapatkan desain kapal ferry yang optimal. Parameter utama kapal ditentukan dari optimasi data utama kapal yang mirip yang dijadikan acuan set based design untuk mendapatkan ukuran kapal kapal ferry catamaran yang diinginkan. Geometri bentuk lambung kapal kemudian dioptimasikan dan dianalisa hambatannya menggunakan metode perhitungan, simulasi dan uji tarik. Rencana umum kapal kemudian dikembangkan untuk mendapatkan penataan ruang dan penentuan kapasitas kapal yang otimum. Dari hasil perhitungan menunjukkan bahwa kapal ferry catamaran 1000GT memiliki gross tonnage (GT) sebesar 1130GT dan nett tonnage (NT) 197GT. Dan daya mesin yang digunakan adalah 4 x 810 HP, untuk kecepatan dinas 15 knots.

Propellers usually operate in the ship's stern, where the inflow of the non-uniform wake generates oscillating loads and changes the hydrodynamic performance. Therefore, determination of the forces on propellers and hydrodynamic performance due to a non-uniform wake field are the challenging problems for naval architects and hydrodynamists. The main objectives of the present study are to assess the hydrodynamic performance for a single blade and all the blades. The propeller is a B-series propeller under non-uniform wake field behind the Seiun-Maru (hereafter SM) ship hull. A practical approach is employed to calculate the hydrodynamic oscillating loads of the ship propeller under a non-uniform wake field. Results of the computations on the propeller behind the SM ship, due to a non-uniform wake field, are presented and analyzed using classical mathematical methods over a single cycle. The results show that a variation of thrust with the discussed parameters is the same as that shown for torque, also the blade-frequency of the total force, thrust and torque is an increasing function of radial sections, whereas these parameters decrease with increasing radial blade sections. [ABSTRACT FROM AUTHOR]

Techniques for shape representation and further modification of a hull surface definitely play a key role in both the design of new buildings and in the optimisation of the existing ones. The simplification of the methods is the goal to reach in order to create useful tools for real applications. A new approach for hull shape modification is proposed. It is based on a combination of the Subdivision Surface technique for hull surface modelling and Free Form Deformation for shape variation. The formal relation between the two methods is established by the Free Form Deformation control volume and the Subdivision Surface control polygon, introducing significant simplification to the definition of the transformation. The new approach is described in detail highlighting its benefits. Its effectiveness is finally proved by an example of application on a real hull shape, where a combination of a local and global modification has been analysed. [ABSTRACT FROM AUTHOR]

Energy storage has the potential to reduce the fuel consumption of ships by loading the engine(s) more efficiently. The exact effect of on-board energy storage depends on the ship functions, the configuration of the on-board power system and the energy management strategy. Previous research in this area consists of detailed modelling, design, and comparisons of specific on-board power systems for explicitly defined operational profiles. The necessary inputs for these studies are rarely known initially however, since the effect of energy storage on the fuel consumption is not necessarily always positive, it is essential to know the limitations of fuel savings obtained by an on-board energy storage early in the design stage. To that effect, the paper proposes a set of algebraic formulas for the equivalent specific fuel consumption of on-board power systems equipped with electrical energy storage, which give a quick estimation of the maximum fuel savings obtainable. Depending on the specific fuel consumption of the prime mover, the loading point of the system and the use scenario of the battery, relative efficiency improvements can vary between −48% and 57%. A set of design guidelines is also proposed based on the obtained results. [ABSTRACT FROM AUTHOR]