COMPARISON BETWEEN DIFFERENT SURVIVABILITY MEASURES ON A GENERIC FRIGATE

Choosing suitable survivability measures is a demanding task that has to start early in the ship design process. Throughout the design process there is a need for compromises that will define and sometimes limit future operations or capabilities. In this study generic survivability measures are compared. The study also examines the sensitivity of the calculated probabilities to changes in the threat description. The result shows that it is important to investigate the total effect of a hit over a set of relevant ship functions defined for example by survivability levels. The calculations for different threat definitions show that the changes in survivability are substantial when the threat definition is changed. Moreover, the effects of different hit assumptions differ between weapon types. This must be treated as an uncertainty which also should be reflected in the output and weighted into the decisions made, based on the survivability analysis.

CONCEPT DESIGN FOR A SUEZMAX TANKER POWERED BY A 70MW SMALL MODULAR REACTOR

This paper describes a preliminary concept design study for a Suezmax tanker that is based on a conventional hull form with alternative arrangements for accommodating a 70MW Small Modular Reactor (SMR) propulsion plant. Emerging nuclear technology concepts, associated design risks and technical options available are outlined within the context of risk based ship design. It is concluded that the concept is feasible and the adoption of the technology would be compatible with the target application. However, further maturity of nuclear technology solutions and the development and harmonisation of the regulatory framework will be necessary before implementation of the ideas presented would be viable.

STUDY OF AIRFLOW AROUND SHIP WITH RIGID SAIL ARRAY AND POTENTIAL ARRAY PROPULSIVE POWER

An array of rigid sails installed on a large powered ship could provide a viable means to reduce fuel oil consumption (FOC) and emissions by using the power of the wind as a source of supplementary propulsion. This paper describes the study of airflow around a concept ship design fitted with 14 segment rigid sails (SRS) using a virtual wind tunnel software application and also investigates the propulsive force that a fixed sail array could provide using computational fluid dynamics (CFD) analysis.

INTRODUCING OPERATIONAL INFORMATION INTO EARLY STAGE SHIP DESIGN USING QUEUEING NETWORKS

During the early stages of ship design a set of requirements needs to be identified, accounting for financial and technical feasibility, and operational effectiveness. This process of requirements elucidation creates a need for information regarding various design alternatives and their effect on the feasibility and effectiveness of the design requirements. When one considers internal layout and process driven ships, ships where the arrangement of spaces has a strong influence on the effectiveness of the ship's operational processes, a gap in available methods has been identified. This paper proposes a method based on queueing networks that allows a naval architect to study the effects of different arrangements on the execution of various sets of operational processes. Using this model a better understanding of the interaction between the ship's arrangement and its operational processes can be obtained. This understanding can improve the requirements elucidation process and can lead to the development of better design requirements.

150 YEARS OF SHIP DESIGN

As part of writing a short article entitled “Ship Design – From Art to Science?” [1] for the Institution’s 150th anniversary celebratory volume [2], the author consulted the Institution’s centenary book by K C Barnaby [3] to get a feel for the formative first hundred years of ship design recorded in the learned papers presented to the Institution. This consultation was motivated by consideration of the papers in the first volume of the Transactions of 1860, which, surprisingly, contained no papers directly on ship design, either on ship design in general or through describing the design intent behind a specific new ship. Rather, like the very first paper by Reverend J Woolley, the remaining 1860 papers concerned themselves with what could be called the application of science (and mathematics) to the practice of naval architecture as an engineering discipline. However this initial focus broadened out in subsequent volumes of the Transactions so that both technical descriptions of significant new ship designs and, more recently, papers on the general practice of ship design have also figured, alongside the presentation of progress in the science of naval architecture. Given that the vast bulk of ships built over this period have been designed like most buildings to a set pattern, or as we naval architects would say based on a (previous) “type ship”, those designs presented in the Institution’s Transactions, and the few other collections of learned societies’ papers, are largely on designs that have been seen to be of particular merit in their novelty and importance. Therefore this review looks at the developments in ship design by drawing on those articles in the Transactions that are design related. In doing so the papers have been conveniently broken down into the three, quite momentous, half centuries over which the Institution has existed. From this historical survey, it is then appropriate to consider how the practice of ship design may develop in the foreseeable future.

HUMAN FACTORS IN SHIP DESIGN AND OPERATION: A PRELIMINARY SURVEY OF THE THEORETICAL CONSTRUCT

This technical note presents an analysis of the underlying factors of human factors in ship design based on questionnaires distributed on two offshore supply vessels operating in the Norwegian Sea. The concept of human factors in ship design is still evolving. The purpose of this paper is to present a preliminary model of the human factors construct by using a factor analysis method. The results confirm the existence of controllability, workability and habitability as the principal factors of human factors in ship design. Three other factors that emerged are cargo facilities, reliability, automation and maintainability (RAM) and interfacing complexity. Bridging variables found between these factors include elements such as safety, manoeuvring, engine room and bridge design. A preliminary model of how the components or parts relate to human factors in ship design and operation is developed. The model also indicates the parties who are responsible for the various aspects of ship design from a human factors perspective.

CONCEPT DESIGN FOR A SUEZMAX TANKER POWERED BY A 70 MW SMALL MODULAR REACTOR

The authors are to be congratulated on a well- researched and timely technical paper. I am pleased to express my personal opinion on the subject. COSCO was intending to initiate a study in December 2009 on nuclear powered ship design in order to reduce GHG emissions from shipping. However, this plan was aborted three years after, following the catastrophic accident at the Fukushima nuclear power station in Japan during March 2011. This intensified political and public opposition to nuclear power to the extent that Germany has since adopted plans to decommission its entire nuclear infrastructure. However, confidence is beginning to re- emerge - confidence which I share. With increasing attention being given to GHG emissions arising from burning fossil fuels for global aviation and marine transport, together with the excellent safety record of nuclear power in the marine environment and the development of the new generation of SMRs, it is quite conceivable that renewed attention will be given to the application of nuclear power in merchant ship propulsion. In producing this paper, the authors have made a significant contribution in the field of innovative ship design development. They have demonstrated the feasibility of applying the latest generation of nuclear reactor to commercial ship propulsion. Whereas nuclear power has been widely used in vessels of a number of navies and icebreakers, it has yet to be adopted for commercial ships other than a small number of research projects. This paper has provided good rationale for accommodating nuclear power in merchant shipping including speed and range requirements, required specific volume on board, environmental considerations etc. The study has also considered the risks associated with design and the arrangement of nuclear systems including location of the SMR, type of propulsion options and other safety- critical issues, not least the radiological risk to persons on board, involved in maintenance and in port.

CHOOSING THE STYLE OF A NEW DESIGN - THE KEY SHIP DESIGN DECISION

As a former senior designer of naval vessels and, more recently, a leading researcher in ship design, the author has previously presented a description of the ship design process in terms of the important decisions a ship designer makes in concept exploration. Such decision are made consciously or unconsciously in order to produce a new design or, preferably, any design option. It has been contended in many publications that the first real decision that a ship designer makes, in order to proceed, is the selection of the “style” of the design study or of a specific design option. This term was adopted in order to cover, not just a host of design issues and standards implicit in a given study, but also, at this very initial step, the overall characteristics of any particular study. So the term style could be said to be doubly important. The current paper considers the nature of the early ship design process for complex multi-functional vessels and then retraces the origins of the particular use of the term, where it was seen as the last of the five elements in Brown and Andrews’ 1980 encapsulation of the ship design issues that matter to the naval architect, incorporated in the term “S to the 5th”. This leads on to consideration of the various aspects of design style, many of which could be considered “transversals” as they apply across the naval architectural sub-disciplines and to the component material sub-systems comprising a ship. One of the distinctive advantages of the architecturally driven ship synthesis or Design Building Block approach is that it can address many of these style issues in the earliest descriptions of an emergent design study. Examples, drawing on a range of built Royal Navy ship designs, are presented to show their top-level style characteristics, followed by a series of ship design research studies illustrating how the impact of specific component style aspects can be investigated in early stage ship design, using the UCL Design Building Block approach. Finally, recent research led investigations into integrating ship style into early stage ship design are summarized to demonstrate why the choice of “style” is seen to be The Key Ship Design Decision.

A COMPREHENSIVE APPROACH TO SURVIVABILITY ASSESSMENT IN NAVAL SHIP CONCEPT DESIGN

Alongside deploying weapons and sensors what makes a warship distinct is its survivability, being the measure that enables a warship to survive in a militarily hostile environment. The rising cost of warship procurement, coupled with declining defence budgets, has led to cost cutting, often aimed at aspects, such as survivability, which may be difficult to quantify in a manner that facilitates cost capability trade-offs. Therefore, to meet ever-reducing budgets, in real terms, innovation in both the design process and the design of individual ships is necessary, especially at the crucial early design stages. Computer technology can be utilised to exploit architecturally orientated preliminary design approaches, which have been conceived to explore innovation early in the ship design process and the impact of such issues as survivability. A number of survivability assessment tools currently exist; however, most fail to integrate all the constituent elements of survivability (i.e. susceptibility, vulnerability and recoverability), in that they are unable to balance between the component aspects of survivability. Some of these tools are qualitative and therefore less than ideal in specifying survivability requirements, others are aimed towards the more detailed design stages where implementing changes is heavily constrained or even impractical. This paper presents a survivability assessment approach combining various tools used by UCL and the UK Ministry of Defence, as well as a new approach for recoverability assessment. The proposed method attempts to better integrate and quantify survivability in early stage ship design, which is facilitated by the UCL derived, architecturally focused, design building block approach. The integrated survivability method is demonstrated for a set of naval combatant concept designs and for two replenishment ship studies to test the robustness of the proposed approach.

HANDLING TEMPORAL COMPLEXITY IN THE DESIGN OF NON-TRANSPORT SHIPS USING EPOCH-ERA ANALYSIS

A core aspect of temporal complexity in the design of non-transport vessels is the uncertainty related to the future market and contract opportunities, and the corresponding changeability that should be incorporated into the ship design to meet this uncertainty. The development of an appropriate design specification for a new ship represents a core strategic decision for ship owners as part of a fleet renewal or expansion programme, with a high financial risk and a long time horizon of typically 20-30 years. This type of temporal complexity is one out of several complexity aspects to be handled as part of a ship design process. In this paper we model possible realizations of an uncertain future for a vessel using the Epoch-Era Analysis (EEA) method. Here, we use the epochs as the primary instrument for capturing major market developments, such as the opening of new offshore areas, new emission regulatory regimes, or the availability of new, disruptive technologies. From these, more specific epoch variables are derived, for which specific contract opportunities can be generated. The epoch-specific performance of the vessels is found by solving a Ship Design and Deployment Problem (SDDP) of concurrently identifying both a preferable ship design and the corresponding path of consecutive contracts that maximizes total revenue. We present a case study related to the design of an Anchor Handling Tug Supply (AHTS) vessel. The study illustrates the complexity in striking the correct balance between optimizing the vessel for an initial scenario, while at the same time providing addition performance capabilities to be competitive in the context of future market requirements.