INTRODUCING OPERATIONAL INFORMATION INTO EARLY STAGE SHIP DESIGN USING QUEUEING NETWORKS

Author(s):  
K Droste ◽  
J J Hopman ◽  
A A Kana ◽  
B J Van Oers

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.

2020 ◽  
Vol 162 (A2) ◽  
Author(s):  
K Droste ◽  
J J Hopman ◽  
A A Kana ◽  
B J van Oers

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.


2014 ◽  
Author(s):  
M. Harbison ◽  
W. Koon ◽  
V. Smith ◽  
P. Haymon ◽  
D. Niole ◽  
...  

As a result of enhanced performance and mission requirements for Navy ships, ship design has dramatically increased the use of higher strength, lightweight steels and various local reinforcements, e.g., deck inserts, ring stiffeners, etc., in foundation designs to satisfy the design requirements for supporting machinery, consoles, and weapon systems among others. In additional to operational loading requirements, most of these foundations must also be designed to satisfy shock, vibration and other combat system requirements. While the same piece of equipment may be used in other ship contracts, the foundations are uniquely designed and require a separate analysis and drawing package. Computer modeling and Finite Element Analysis (FEA) have helped reduce the labor required to analyze foundations, but the high number of “unique” foundations as well as changes which necessitate a new analysis still create a large workload for engineers. This is further compounded by increased costs in production due to greater numbers of unique parts and materials that must be marked, stored, and retrieved later for fabrication. This goal of this project was to determine the cost-savings potential of leveraging past foundations work in designing, analyzing, and drawing foundations in the future. By the project’s conclusion Ingalls will have created a database for rapid access to previously-generated foundation information, the framework of which will be publicly available for all shipyards to populate with their own foundation information.


2015 ◽  
Author(s):  
William A. Hockberger

The Quadrimaran was invented in France in the mid-1980s by Daniel Tollet. It was an inspired design and a radical departure from traditional ship design by a man from outside the marine industry unconstrained by industry technical practices and education. Technical experts could see it would entail more structure and subsystems than other high-performance vessels, but its promise was that those penalties would be more than offset by its claimed low power and fuel consumption. A prototype/demonstrator, Alexander, was built in 1990 and operated for five years carrying and impressing many hundreds of riders. Alexander performed beautifully and appeared to bear out what was claimed. Contracts for several Quadrimarans of different sizes came quickly, especially considering how conservative an industry this is. That was significantly due to Tollet's personal charisma and skill in selling riders on the dream of carrying passengers and freight over the water fast and in comfort, yet economically. Great skepticism prevailed in some quarters, especially among naval architects knowledgeable about AMVs (advanced marine vehicles) and early-stage whole-ship design. At technical meetings, one Quadrimaran principal would comment, for example, "Why would you carry freight across the Atlantic at 38 knots on 230,000 horsepower (a reference to the planned Fastship Atlantic TG-770) when you could do it at 60 knots on only 65,000 horsepower?" Listeners would ask how this could be possible, and he would assert again that the Quadrimaran could do it, but would decline to explain. Respected technical people were working with Tollet and his company and becoming convinced of the Quadrimaran's merit. Along with the contracts came engineers with experience in ship detail design and construction (very different from early-stage whole-ship design), or responsibilities for assessing and approving ships for service. Others were with engine and equipment suppliers. Their opinion that there was something unique and special about the Quadrimaran gave it credibility and influenced more people to accept the major claims made for it. Some dismissed the most extreme claims but still accepted the idea that the Quadrimaran was capable of unusually high performance - considerably less than was being claimed, perhaps, but high nevertheless. In hindsight it is clear the skeptics were right. Results never met expectations, nor could they have. In reality, the Quadrimaran has aspects that inherently prevent it from achieving the characteristics and performance its inventor believed attainable. It cannot be built in a commercially useful size and actually perform as intended. Why this is so will be explained. A crucial fact in the Quadrimaran's history is that Daniel Tollet and his close associates believed strongly that naval architects and engineers who had been immersed in working with the existing ship types would be unable to give the Quadrimaran the very different treatment they believed it required. (Their own educations and professional work were nontechnical.) Such people were excluded from the development of Quadrimaran designs, and the belated discovery of many fundamental technical problems can be attributed to this. The company Tollet established had a number of names over the years, and other associated entities were created at times for various purposes. In this paper they are referred to collectively as QIH (Quadrimaran International Holdings) so as not to confuse things unnecessarily. In 2004 QuadTech Marine LLC was established and acquired the Quadrimaran patent (US Patent No. 5,191,849) and related intellectual property from QIH. QuadTech laid out an extensive R&D program to close gaps in the technical background and address identified issues. In the process, additional information on earlier QIH projects and products was obtained and studied, which brought to light problems that significantly compromised the Quadrimaran's prospective performance and utility. The resulting much-reduced set of potential uses and users led the company to effectively stop pursuing Quadrimaran projects after 2009. (Note: The author was Chief Technology Officer for QuadTech Marine during 2006-9, studying the Quadrimaran and planning the R&D.)


2017 ◽  
Vol 33 (02) ◽  
pp. 81-100
Author(s):  
Rachel Pawling ◽  
Victoria Percival ◽  
David Andrews

For many years, the design spiral has been seen to be a convenient model of an acknowledged complex process. It has virtues particularly in recognizing the ship design interactive and, hopefully, converging nature of the process. However, many find it unsatisfactory. One early criticism focused on its apparent assumption of a relatively smooth process to a balanced solution implied by most ship concept algorithms. The paper draws on a postgraduate design investigation using the University College London Design Building Block approach, which looked specifically at a nascent naval combatant design and the issues of size associated with "passing decks" and margins. Results from the study are seen to suggest that there are distinct regions of cliffs and plateau in plots of capability against design output, namely ship size and cost. These findings are discussed with regard to the insight they provide into the nature of such ship designs and different ways of representing the ship design process. The paper concludes that the ship design spiral is a misleading and unreliable representation of complex ship design at both the strategic and detailed iterative levels.


2007 ◽  
Vol 14 (3) ◽  
pp. 21-26 ◽  
Author(s):  
Tomasz Cepowski

Approximation of the index for assessing ship sea-keeping performance on the basis of ship design parameters This paper presents a new approach which makes it possible to take into account seakeeping qualities of ship in the preliminary stage of its design. The presented concept is based on representing ship's behaviour in waves by means of the so called operational effectiveness index. Presented values of the index were calculated for a broad range of design parameters. On this basis were elaborated analytical functions which approximate the index depending on ship design parameters. Also, example approximations of the index calculated by using artificial neural networks, are attached. The presented approach may find application to ship preliminary design problems as well as in ship service stage to assess sea-keeping performance of a ship before its departure to sea.


1993 ◽  
Vol 9 (03) ◽  
pp. 188-201
Author(s):  
James R. Wilkins ◽  
Gilbert L. Kraine ◽  
Daniel H. Thompson

This paper presents the results of a project that has been carried out under the sponsorship of Panel SP-4, Design/Production Engineering, of the Ship Production Committee of the National Shipbuilding Research Program. Two methods for evaluating the producibility of ship designs and /or ship design alternatives have been developed, one of which provides quantitative results in man-hours or dollars. The other method provides relative results based on weighting factors developed for specific ship projects and the design phase during which the alternatives are being considered. The second, relative, method also can be used for evaluating all of the other parameters which must be considered in making a decision to proceed with any design change, including total cost, performance, schedule, and risk. The two methods are described in some detail and examples of application of each of these two methods to specific design alternatives are presented.


Author(s):  
Beverly J. Becker ◽  
Gregory A. Kaepp

Abstract A knowledge-based Bumper Design System (BDS) has been developed which automatically generates optimized conceptual bumper beams which meet manufacturing and product performance requirement. The BDS has captured and refined the corporate design knowledge of the product design engineer, the CAD designer, the CAE analyst and manufacturer. The BDS enables the bumper design engineers to evaluate multiple design alternatives quickly and early in the design process. It also automates repetitive bumper analysis tasks. The purpose of the paper is to describe the BDS. A description of the Knowledge Based Engineering (KBE) methodology used to create the BDS is given, as well as an overview of bumper designs and design requirements. An overview of the BDS software design, user interface, and a sample run are also presented.


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