Naval Design Research Articles

Quantifying Flexibility for a Ship Power and Energy System Design

The pace of technology maturation and the uncertainty in magnitude and characteristics of future load types on Navy ships drive the need for robust power and energy system architectures that can adapt to future perturbations in requirements. The Naval design community needs a consistent method for evaluating ship system flexibility in the early design stages when informed decision making provides the greatest opportunity to influence the system’s performance and lifecycle cost. The research presented herein develops quantitative, measurable metrics and applies them to applicable case studies for Naval power and energy system flexibility: the capability of the system to accommodate change in response to perturbations in requirements.

A Review on Navigating Sustainable Naval Design: LCA and Innovations in Energy and Fuel Choices

The naval sector holds paramount importance for the global economy, yet it entails significant environmental impacts throughout the entire life cycle of ships. This review explores the application of life-cycle assessment (LCA) in the naval sector, a methodology for evaluating the environmental impacts associated with all the life stages of a product or service. LCA analysis in the naval context is essential for identifying and mitigating environmental impacts, thus promoting more sustainable development of the sector. This work provides a comprehensive overview of current LCA applications in the naval sector, highlighting major environmental impacts, in particular focusing on greenhouse-gas emissions and climate change. Additionally, this study integrates an analysis of greenhouse-gas emissions using a normalization approach, which has enabled the comparison of various types of fuels and ships, thereby enhancing our understanding of their environmental impacts. Moreover, the limits and challenges to applying LCA in the naval sector are discussed, offering insights for future research and developments in the field. This review aims to raise awareness among policymakers, designers, and operators in the naval sector about the importance of adopting LCA for more sustainable and responsible management of naval activities, thereby contributing to the protection of the marine and global environment.

ROBERT SEPPINGS, A VISIONARY STRUCTURALIST

The prolegomena of graphical statics in shipbuilding are uncertain and can only be deduced from a thorough reading of some authors’ writings. Among them, Robert Seppings excelled for his innovative ideas especially concerning the increase of resistance of vessels, in particular with respect to the hogging phenomenon, by using reticular structures. The intent of this article is to tell a short story of the innovations and improvements that have taken place in wooden shipbuilding starting from the ideas of Seppings, regarding naval design engineering as well as the architecture of shipyard buildings. The importance of these ideas is proved by the fact that once entered the shipyard they were in use until the second half of the 19th century when they were finally replaced by the use of iron and steel. For these reasons, Seppings’ ideas and drawings are a precious part of the maritime heritage which deserves to be remembered.

Curved grid‐scored foam core sandwich composites under low‐velocity impact loads: Effects of curvature, stacking sequence, and core finishing

AbstractThe objective of this paper is to experimentally investigate how material and geometric parameters, including face sheet layup, curvature, and core finishing, affect the contact force‐displacement behavior, absorbed energy, and damage modes of curved sandwich composites with grid‐scored foam under low‐velocity impact loads. An instrumented drop‐weight testing machine with a hemispherical impactor was used to perform low‐velocity impact tests at different energy levels. Angled‐ply stacking had the maximum contact force and impact resistance for low curvature radii. In the event of penetration, the impact energy absorption of all curved sandwich panels increased as the curvature increased. The core finishing influenced the contact forces of the curved and flat sandwich panels but not the penetration energy. The curvature and face sheet layups affected the delamination size and pattern. Angle‐ply and cross‐ply face sheets with the smallest and maximum radius of curvature, respectively, decreased penetration depth. The resin‐filled channels reduced foam cell impact damage and face‐core debonding. LVI penetration resistance was found to be highest for angle‐ply stacking and knife‐cut foam at small curvature radii. The proposed research will also provide naval designers with valuable insight into the impact response of sandwich structures used in curved parts of the hull and deck.Highlights The effect of curvature on the LVI responses varied due to face sheet layups. Core finishing affected contact forces, but not the absorbed energy. Curvature and face sheet layups affected the damage modes. Resin‐filled channels limited damage area and acted as stoppers for debonding.

The pipelines and cable trays location problem in naval design

This paper deals with the determination of optimal locations for pipelines and cable trays in naval design. The problem consists of finding the number and types of cable tray routes to be created between various devices in order to minimize a user defined cost function. We reduce the problem to an ad hoc min-cost multicommodity flow problem with additional constraints imposed by technical requirements. This problem is solved for small-sized instances by using off-the-shelf optimization solvers. We also develop an exact relax-and-cut strategy that allows to handle medium-sized instances. For larger instances, we propose a family of heuristic algorithms consisting on the combination of two phases: (I) Construction of initial cable trays paths; and (II) Transformation to feasible cable trays verifying the technical requirements. For each of them, we also propose different strategies which give rise to several algorithms. These algorithms are compared on a computational experience using two types of instances: the first one based on random instances of different sizes and the second one based on instances with well-defined corridors to asses the availability of our methodology to enforce the creation of cable trays. Finally, we also analyze a real size case study provided by our industrial partner, Ghenova, a leading Naval Engineering company, validating our proposal to find solutions for this problem.

Metodología para el análisis estructural de una cubierta principal de un buque FPSO soportando una grúa sobre orugas

Offshore cranes placed on the surface of Floating Production Storage and Offloading (FPSO) vessels affect the structural response of their main decks, which can alter the safe operation of the FPSO vessels. Generally, classification societies rules are used to predict the structural strength of the main deck of FPSO vessels. However, these classification societies rules are limited to estimate the variation of the structural performance of the main deck caused by the operation of offshore cranes under different hydrodynamic conditions. Here, we present a methodology to determine the alteration of the structural behavior of a main deck of FPSO vessel due to different operation conditions of a board offshore crane. This methodology considers the hydrodynamic response for two ultimate limit states: operating and storm conditions from 1000 m water depth in Gulf of Mexico with a return period of 10 and 100 years, respectively. The methodology includes finite element method (FEM) models of the main deck supporting an offshore crane to predict its structural response. The maximum von Mises stress of the main deck does not overcome its maximum permissible stress, which allows a safe operation of the FPSO crane. The proposed methodology can be used to estimate the structural behavior of main decks of FPSO vessels that are modified for supporting offshore cranes, regarding the hydrodynamic response for each FPSO under the operation and extreme conditions in its location. Thus, naval designers could select the better structural modifications of the main decks that decrease their costs of construction and maintenance.

Designing the internal reinforcements of a sailing boat using a topology optimization approach

In naval design it is common practice to define an internal regular web frame made of longitudinal elements and transversal sections with the purpose of giving stiffness to the whole structure and, at the same time, promoting lightness. In this work, FEM simulation and Topology Optimization (TO) tools are implemented to present a different approach in placing the reinforcements inside the hull of a sailing dinghy. The methodology proposed in this paper considers as a starting point the volume inside the hull and the deck completely filled with material and the result after the simulations is a free form shape of the sailboat reinforcements. The TO procedure is based on two different input FEM solutions: one is the result of a structural analysis on the boat loaded with real forces acting during navigation and the other one is the result of a modal analysis aimed to extract natural frequencies of the structure. The result must fulfil several requirements such as weight, stiffness and stress. TO models have been compared with a traditionally designed sailboat with the same total mass and relevant improvements have been obtained in terms of local stiffness and reduction of moments of inertia.

Human-centred model of single window using the example of Port of Bar, Montenegro

For the past 60 years, human-centred design (HCD) has been considered a preferred design approach for maritime single windows and ways to understand user needs. The idea proposed in this paper is a very effective way to integrate HCD into the maritime single window floor by engaging stakeholders in maritime, which is suitable for human development and participation. This was done through a panel discussion with an end-user model, with a particular focus on the navigation of commercial vessels. This study aims to increase the impact of maritime single windows and HCD knowledge on ship design and operation, by understanding where and how to integrate them and as well as where and where to hang of curtains. This paper presents HCD and the basic criteria for obtaining benefits at the physical, mental, psychosocial, organisational and sociopolitical levels, resulting in safe maritime operations, by showing the example of Port of Bar, Montenegro. The results show that successful integration of a human and naval design concept is required to be implemented in legislation to meet the demands of users and other stakeholders.

THE ZOOM YEARS: UCL MSC STUDENT WARSHIP DESIGNS THROUGH THE PANDEMIC

The global pandemic placed enormous strain on teaching, both for staff and students. This was most keenly felt in group projects, such as the UCL postgraduate ship design exercise, the 2019-20 cohort facing intense disruption as they switched “modes” half-way through the year. Despite this, the students were able to develop some innovative designs to meet challenging requirements. This paper provides an overview of the main themes for the last two years, both in the requirements set by staff and particularly the design response, which has included aspects such as optional crewing and future fuels, concluding an update on recent and future developments in the course that are most relevant to naval design.

Network flow based approaches for the pipelines routing problem in naval design

In this paper we propose a general methodology for the optimal automatic routing of spatial pipelines motivated by a recent collaboration with Ghenova, a leading Naval Engineering company. We provide a minimum cost multicommodity network flow based model for the problem incorporating all the technical requirements for a feasible pipeline routing. A branch-and-cut approach is designed and different matheuristic algorithms are derived for solving efficiently the problem. We report the results of a battery of computational experiments to assess the problem performance as well as a case study of a real-world naval instance provided by our partner company.

Mathematical Programming Approaches for the Pipelines and Cable Trays Location in Naval Designs

Mathematical Programming Approaches for the Pipelines and Cable Trays Location in Naval Designs

Revenue management in liner shipping: Addressing the vessel capacity challenge

An empty slot on a container vessel can be impossible to fill due to complex seaworthiness and port requirements. This vessel capacity challenge is well known in the industry, but it is hard to address in practice. For that reason, revenue management (RM) methods in liner shipping rely on simple capacity models based on maximum volume, weight, and number of refrigerated containers. In this article, we challenge this status quo by introducing the standard capacity model (SCM). The SCM is a linear programming feasible set that includes all major capacity reducing aspects of container vessel and port operations such as naval design, stability, stress forces, lashing forces, trim, draft, restows, and quay crane work time. We apply the SCM to a state-of-the-art RM method and optimize yield over a 90 days period of Maersk’s Asia-Europe services in 2018 with 296 port calls. The model solves to optimality in less than 25 min and shows that the simple capacity model used in RM today can overestimate yield by more than 20% compared to the SCM. This is substantial in an industry, where profit margins of a few percent are the norm.

Quantifying The Impact That Coxswain Behaviour Has on Whole Body Vibration - Simulator Trial

A common risk to personnel is from Whole Body Vibration (WBV) and shock when transiting at speed in heavy seas, and much research has been done by maritime organisations to reduce this risk and the associated health impacts. It is well known that coxswain ‘driving style’ can radically affect exposure levels for a given sea state and sustained transit speed. A data-driven approach to define what makes a good coxswain from a WBV perspective is currently being developed by the Naval Design Partnering team (NDP). In phase 1, a systematic coxswain behaviour tracking methodology has been developed and demonstrated using a motion platform-based fast craft simulator at MARIN. The performance of several experienced volunteer coxswains from MOD, RNLI and KNRM has been evaluated based on a set pattern of tests. The advantages of using the simulator, over a sea trial, have been demonstrated: it is more repeatable, more controllable, accurate and more accessible. The potential disadvantages of the approach are also discussed with reference to feedback gathered from coxswains. Analysis has shown effective throttle control is much more important than steering to reduce WBV. Several interesting trends in WBV reduction potential have been shown which it is thought, with further validation, could aid mission planning, mission execution and provide data for training autonomous feedback/control algorithms. Further work is required before the findings of this study can be fully exploited. These subsequent phases, which include sea trials, aim to provide validation and further evidence to support the initial findings.

How Actors Effect Shifts in Strategic Trajectories: The Role of Temporal Nexus Events

We apply a temporal view to an event at the intersection of two activity streams in a naval design and construction company. This view shows how, at this event, actors revived a solution that had been proposed several years before within one stream by using it to address an imminent problem in a second stream, which eventually produced a shift in the company’s strategic trajectory. The temporal orientation of the event’s activity contrasted with the temporal orientations of the two intersecting activity streams. The temporal orientations of the two intersecting streams proved nevertheless vital for the event’s generation of the strategy shift. We suggest the label “temporal nexus events” for these intersectional events. We propose a process model for how actors reach back in time along activity streams while drawing upon those streams to implement novel solutions that harbor the potential for a strategic shift.

Shipbuilding 3D CAD Tools as an Integrated Solution from Concept to Product

In the naval design process, there is still no consensus on the use of 3D CAD (Computer Aided Design) systems in the early stages of design. However, the integration capability of different modules is currently making their incorporation in the initial stages more appealing. The objective of this paper is to study the early stages of design as part of the whole process and to demonstrate the convenience of using a single 3D tool during the whole project. Therefore, its impact on the whole design process will be analysed by considering the basic and early design capabilities of current CAD systems, reviewing how the main naval architecture and marine engineering demands match the features and what is the solution provided by the CAD for each case. The methodology presented offers advantages from a technical, economic and time point of view.

Yachting rule of art

Art and architecture have been unbreakably linked together for centuries, and the question that spontaneously arises is why it cannot be the same for art and yacht design. The field in which the research is carried out is placed at the crossroads between art and architecture, of which yacht design can be considered a category. There is a lack of references to the artistic field in the yachting sector in literature, so the parallelism between architecture and “floating” architecture is performed: the ships are the emblem of closure, and the stylistic evolution has begun bearing fruit in recent years. The paper aims to outline the current state of the art of the relationship between art and yachting. The first part analyses the relationship between art and architecture, while the second part discusses art concerning naval design: here, the case studies analysis highlights how art onboard is still considered an accessory rather than a backbone of the project.

QUANTIFYING THE IMPACT THAT COXSWAIN BEHAVIOUR HAS ON WHOLE BODY VIBRATION - SIMULATOR TRIAL

A common risk to personnel is from Whole Body Vibration (WBV) and shock when transiting at speed in heavy seas, and much research has been done by maritime organisations to reduce this risk and the associated health impacts. It is well known that coxswain ‘driving style’ can radically affect exposure levels for a given sea state and sustained transit speed. A data-driven approach to define what makes a good coxswain from a WBV perspective is currently being developed by the Naval Design Partnering Team (NDP). In phase 1, a systematic coxswain behaviour tracking methodology has been developed and demonstrated using a motion platform-based fast craft simulator at MARIN. The performance of several experienced volunteer coxswains from MOD, RNLI and KNRM has been evaluated based on a set pattern of tests. The advantages of using the simulator, over a sea trial, have been demonstrated: it is more repeatable, more controllable, accurate and more accessible. The potential disadvantages of the approach are also discussed with reference to feedback gathered from coxswains. Analysis has shown effective throttle control is much more important than steering to reduce WBV. Several interesting trends in WBV reduction potential have been shown which it is thought, with further validation, could aid mission planning, mission execution and provide data for training autonomous feedback/control algorithms. Further work is required before the findings of this study can be fully exploited. These subsequent phases, which include sea trials, aim to provide validation and further evidence to support the initial findings.

An efficient computational framework for naval shape design and optimization problems by means of data-driven reduced order modeling techniques

This contribution describes the implementation of a data-driven shape optimization pipeline in a naval architecture application. We adopt reduced order models in order to improve the efficiency of the overall optimization, keeping a modular and equation-free nature to target the industrial demand. We applied the above mentioned pipeline to a realistic cruise ship in order to reduce the total drag. We begin by defining the design space, generated by deforming an initial shape in a parametric way using free form deformation. The evaluation of the performance of each new hull is determined by simulating the flux via finite volume discretization of a two-phase (water and air) fluid. Since the fluid dynamics model can result very expensive—especially dealing with complex industrial geometries—we propose also a dynamic mode decomposition enhancement to reduce the computational cost of a single numerical simulation. The real-time computation is finally achieved by means of proper orthogonal decomposition with Gaussian process regression technique. Thanks to the quick approximation, a genetic optimization algorithm becomes feasible to converge towards the optimal shape.

Оценка эффективности управления особой экономической зоной промышленно-производственного типа «Лотос»

The article highlights the importance of creating and operating the special economic zones in Russia in order to increase the investment attractiveness and competitiveness of the entities and strategically important industries in the Russian Federation. Traditionally, shipbuilding has been a priority economic activity in the Astrakhan region, which has led to creating an industrial special economic zone Lotоs, whose purpose is defined as formation of a local chain of shipbuilding and machine-building products in the south of Russia. The effectiveness of special economic zones is an integrated characteristic of the management company's ability to achieve the goals 
 of creating and operating a special economic zone. As a result of the analysis of investment attrac-tiveness of the industrial special economic zone Lotоs, the problem areas of the management company's activities were identified: creating infrastructure facilities and attracting residents and investors. The substantial characteristic of investment projects of the residents (type of economic activity and its compliance with the objectives of the industrial special economic zone Lotоs, expected period and volume of investment, employment status, level of multiplicative effect on the regional economy) allowed formulating a conclusion about the necessity of differentiation of the state support for the investment projects of residents. There have been given the substantial characteristics of the projects of the residents: Shipbuilding Plant Lotos, JSC; Hexa-Lotos, LLC; Svoi, LLC; MedInTech, LLC; Atef-Russ, LLC; Marine Composite Shipbuilding, LLC; InProect, LLC; Protelux Lotоs, LLC; Stroyliderplus Lotоs, LLC; Helios Systems, LLC; Azka Composite, LLC; Naval Design International, LLC; Roza, LLC, etc. There have been offered the recommendations for the management company on developing a strategy for attracting residents and investors and establishing special preferential treatment for investment projects that are of strategic importance for the development of the regional economy and international cooperation are proposed.

Predicting the Future Capacity and Dimensions of Container Ships

Since the introduction of the container ship, there has been an impressive increase in its use to take advantage of economies of scale. In the last two decades, the capacity of vessels has trebled. Currently, vessels of 23,000 TEU (20-ft equivalent unit) sail the seas. With the exponential growth experienced in this sector, the question arises if it is possible to reach a peak capacity, as has occurred with bulk cargo vessels and, recently, aircraft. This paper aims to predict the possible size and dimensions of a new generation of mega container ships. Based on economies of scale, port infrastructure, demand, environmental trends, and naval design criteria, the limit to ship size has been estimated. The results suggest that additional increases in ship size are still possible. The aim of this study is to help port authorities to understand the needs of the shipping container industry and to calculate the expansion and investment necessary.