bluuebunny/crossref_metadata_2025 huggingface dataset:
The Shift to Formalized Shipbuilding Standards
Authors: Walker Larry M.
Published: January 2021

In today's shipbuilding environment it is important for U.S. yards to adopt a philosophy of constantly improving systems of both production and service. For years our industry has depended upon a "captive market," that of the U.S. Government. With present cutbacks in military spending the U.S. shipbuilding industry must become a competitive force in the world marketplace. To achieve this goal there are many areas our industry must address; one of these is implementing improved shipyard standards. Time and again U.S. yards "reinvent the wheel" as they face a new contract, while our foreign counterparts have well known, commercially viable national standards. The lack of such standards in the United States, be they internally generated by an organization such as the Society of Naval Architects and Marine Engineers or adopted from an internationally recognized body, such as the International Organization for Standardization (ISO), is an area that must be addressed by our industry if we are to remain competitive in today's marketplace.
Corporate Repair Philosophy and Measuring for Continuous Improvement at Philadelphia Naval Shipyard
Authors: Baun Lawrence R. , Gorgone Robert G.
Published: January 2021

Initial zone technology implementation at the Philadelphia Naval Shipyard (PNSY) in 1986 set the stage for one of the most significant shifts in culture and repair philosophy ever witnessed at a public naval shipyard. Attempting to fundamentally change the way the shipyard conducted business forced senior and middle management to completely understand the dynamic and interrelated processes that were utilized to perform depot-level work. Through the Philadelphia Quality Process (PQP), this understanding was achieved and changes that were necessary to shift from a Ship Work Breakdown Structure (SWBS) to a Product Work Breakdown Structure (PWBS) began. As all quality processes will point out, measurement is the key to obtaining the necessary data to make corporate decisions. As the zone technology model was refined from 1987 through 1991, the understanding of "how we do work" continued to improve. Attacking processes that are sluggish, manual, and not responsive enough to support the manufacturing process is the direct result of meaningful measurement-focusing management attention. This paper points out that the emphasis of the shipyard is now on the total "manufacturing process" rather than just "odds and ends" of planning and production. The utilization of zone technology provided the environment and attitude that supported improvements from within. Shipyard goals remain constant: improve producibility, reduce cost, and maintain quality. Continuous measurement, analysis, and action to improve the shipyard's manufacturing process has been the mechanism used to achieve those goals.
Design of Longitudinal Beam Layout on a Curved Shell Based on the Production-Oriented Design Concept
Authors: Honda Kohji , Tabushi Noriyuki
Published: January 2021

A VLCC (very large crude oil carrier) has approximately 1000 curved longitudinal beams, many of which have three-dimensional complicated curvatures. Due to the shortage of highly skilled workers and the need to keep costs down, production and structural designers have worked to reduce the number of such beams. In order to meet the requirements of production, the authors' company has attempted several design approaches for the longitudinal beam layout to reduce the number of beams that have complicated curvature. Recently, through the application of a computer-aided design system, which has been improved for shipbuilding based on the Calma's system, a new design method for the longitudinal beam layout has been successfully developed. A significant number of beams with a twisted configuration have been eliminated and replaced with beams of simpler, two-dimensional shapes. This paper shows the transition of these design approaches, and the application of the new design to building a VLCC.
A Conceptual Design Study of the Construction of Hydrodynamic Control Surfaces
Authors: Karstensen A. D. , Fairlie-Clarke A. C. , Winkle I. E.
Published: January 2021

Hydrodynamic control surfaces are traditionally built as steel fabrications. While this gives a very strong structure, it is rather heavy and costly, it is difficult to achieve smooth surfaces, and the steel is susceptible to erosion, corrosion and marine fouling. This paper describes a conceptual design study aimed at creating a competitive advantage for the manufacturers of control surfaces by using modern materials in a composite structure. The conceptual design process, as applied here, starts by specifying the design requirements for the construction of control surfaces and listing a set of criteria against which the concept designs can be evaluated. A total of six concept designs are described and evaluated in comparison with a traditional steel fabrication, and one concept is selected for further development. This comprises a light steel frame structure with thin steel inner face plates enclosing an inner core that is filled with polyurethane foam. The surface shape is also formed with polyurethane foam poured between the face plates and a surface mold plate. Finally, the surface is sprayed with a polyurethane elastomer coating.
An Engineering Product Model Based on STEP Protocols
Authors: Higney James T. , Ouillette Joanne J.
Published: January 2021

Draft STEP (Standard for the Exchange of Product Model Data) application protocols, developed by the Navy Industry Digital Data Exchange Standards Committee (NIDDESC), have been issued to define the information content of a product model for a ship. The work reported in this paper combines the existing CAD models of the DDG51 Class design with a newly developed non-graphic database so that the overall information content complies with the STEP protocols. This work represents the first-time implementation of the application protocols and is a significant step in the Navy's plan to do the design of variants of the DDG51 Class totally in computer-aided design (CAD). The combined graphic/non-graphic database is referred to as the DDG51 engineering product model. Emphasis has been placed on populating the non-graphic database with the information necessary to perform all required engineering analyses. The basic schema described in this paper may be extended to support other areas of interest, such as logistics support.
Measured Imperfections and Their Effects on Strength of Component Plates of a Prototype Double Hull Structure
Authors: Pang Alan AhKum , Tiberi Robert , Lu Le-Wu , Ricles James , Dexter Robert
Published: January 2021

The U.S. Navy is currently studying the use of double hull designs in high strength low alloy (HSLA) steels for surface combatant ships. A full-scale prototype double hull module was fabricated, from which multicellular box column specimens were cut for compressive tests to failure. Initial imperfections, i.e., initial plate deflections and welding residual stresses, affect the stiffness and strength of welded members. This paper describes the measurement of these imperfections and the analysis of their effects on the component plates of the cellular box specimens. Initial deflections were measured in the laboratory, where the maximum values did not exceed the Navy's guidelines or proposed values of several researchers. Residual stresses in a box specimen were also measured in the laboratory under more controlled conditions. Using the measured imperfections, the plate arrangements were analyzed using the finite element method. The imperfections were found to reduce the stiffness and strength of the plates. The results show that for accurate prediction of the strength of welded plates, initial imperfections must be taken into account.
Small Ship Producibility
Authors: Leake James M. , Calkins Dale E.
Published: January 2021

The focus of this research has been producibility improvement in small shipyards. Producibility is here taken to mean ease and economy of manufacture—the balancing of technical considerations with those affecting a product's manufacture. Drawing from the well-developed ideas of group technology shipbuilding as they are currently applied in the world's most productive large shipyards, product-oriented work break-down structures (PWBS) for two small steel ships to be built in small shipyards have been developed. These work breakdown structures provide the basis for the small ship generic PWBS presented here. As part of this work a 3D surface computer model and a hypertext document were created in order to illustrate certain group technology shipbuilding principles.
Analysis of Competitiveness in Commercial Shipbuilding
Authors: Hengst Sjoerd , Koppies J. D. M.
Published: January 2021

The paper consists of two elements:analysis of the competitiveness of the Dutch shipbuilding industry, andstructural and organizational changes in Dutch shipyards since 1983, based on market approach and cost reduction.

The objective of a study completed in 1993 was to gain insight into the competitive position of the Dutch shipbuilding industry for seagoing merchant ships. Different indicators were developed and analyzed for the period 1984–1992. Labor cost and exchange rates are the two parameters which enable assessment of the development of labor cost, which is calculated in U.S.$ per cgt.* For selected countries the level of productivity (and thereby the labor cost per cgt) has been adjusted to an estimated degree of subcontracting. The Netherlands shipbuilding industry shows an average share in the AWES** production of about 8%-9% in the period 1984–1992. This indicates that a competitive position has been maintained. Some Asian countries and Poland show a lower level of labor cost per cgt than the Netherlands. The changes in structure and organization of the Dutch shipbuilding industry, which concentrates mainly on niche markets and special types of vessels, is discussed. The niche-market approach has been leading to product specialization at several yards. The expectations for the shipbuilding market in Western Europe was discussed briefly.* A common measurement of production of the shipbuilding industry is Compensated Gross Tonnage (cgt), which is defined as a unit of shipyard capacity, derived from multiplying the gross tonnage by a coefficient reflecting the "standard man-hour" required for production of the type of ship under consideration. These conversion coefficients give an indication of the required shipbuilding capacity--expressed in man-hours—to produce one gross ton, which takes into account the complexity of the production. If more yard capacity is required to produce one gross ton, the conversion coefficient has a higher value. The conversion coefficients are determined by the working party of the Organization for Economic Cooperation and Development (OECD).** AWES: Association of West European Shipbuilders, including the countries of the European Union (EU) as well as Finland, Sweden and Norway. The national shipbuilders organizations are represented in AWES.
A Comparative Study of U.S. and Foreign Naval Acquisition, Design, and Construction Policy and Practices
Authors: Cahill Patrick D. , Bunch Howard M.
Published: January 2021

In an effort to reduce the cost of Navy ships without significantly reducing capability, the U.S. Navy has performed a series of ongoing investigations into areas of potential cost reduction. One of these investigations was a literature study done at the University of Michigan Department of Naval Architecture and Marine Engineering to identify and compare acquisition, design and construction practices in a number of different countries. Recommendations for potential cost saving changes to the U.S. Navy system, including reduction of administrative costs, design to cost, and changes in labor policies, were made based on the comparisons. This paper is a modified version of the final report submitted to the Department of the Navy.
Modular Engine Room Design and Construction for the Strategic Sealift Ships
Authors: Jaquith Peter E. , Burns Richard M. , Dunbarr Steve E. , Fontaine B. J. , Nelson Harry A. , Silveira John L. , Thompson Tom D.
Published: January 2021

During the contract design phase of the Strategic Sealift New Construction Program at National Steel and Shipbuilding Company (NASSCO), an innovative Design and Build Strategy was developed to reduce the construction time and cost associated with complex engine rooms. A Concurrent Engineering team was assembled to develop the strategy, and to focus design, planning, material, and production efforts to achieve a highly modular design which allows the installation of the majority of outfit systems and equipment at the more effective Ground Outfit versus Onboard Stage. Due to facility and crane lifting constraints, a modular approach was taken in lieu of the conventional Block Outfit approach. The Design and Build Strategy resulted in rationalized system locations allowing reduced piping, electrical, and ventilation linear footage while supporting a high level of system completion at the module stage. To implement the Design and Build Strategy, a series of cross-functional teams was created to manage the project from contract design through production implementation. This paper describes the process and methods used by NASSCO to design, plan, and construct this modular Engine Room.
Approach to Accurate Production of Hull Structures
Authors: Okumoto Yasuhisa , Matsuzaki Shin-ichi
Published: January 2021

The improvement of productivity in response to changes in the labor force--related largely to a decreasing number of skilled workers--has become a major concern of production engineering in shipyards. The following problems were pointed up by an analysis of production tasks:Most work time is wasted in the repair or adjustment of inaccuracies, such as wide gap, lap, or deformation in structural components, which are accumulated at the preassembly stage.lf the accuracy of fabrication and assembly of hull structures is measurably improved, productivity will rise respectively, and effective mechanization and automation of production can be achieved.

The research and development of new hull block production systems based on the above concept--accurate production---have started at lshikawajima-Harima Heavy Industries Co., Ltd. (IHI). Advanced accuracy standards were planned for the new procedure of hull block assembly, and a new "unit-panel and slit process" has been developed and applied at the IHI shipyard. This paper describes the accuracy control system and the new production line at the IHI yard, as well as some key equipment for the installed process.
Computer Integrated Ship Production
Authors: Pedersen Einar , Hatling John Fredrik
Published: January 2021

Wider exploitation of computer integrated manufacturing (CIM) in shipbuilding is inevitable as yards seek continuing improvements in productivity and quality to sharpen competitiveness. The buzz word CIM has been used in many ways through the years. The correct interpretation may be the integration of all computer systems directly supporting the definition and production of the ship. This comprises CAD and also administrative systems such as planning and material control programs. CIM in this paper is defined as optimal utilization of CAD data and planning data in shop floor production, including feedback to the planning system and accumulation of quality data. The paper defines the state-of-the-art of CIM solutions at shipyards, and outlines a case study of one larger CIM installation. The case presented shows the structure of one installed system, and outlines the experience gained through planning, preparation and installation of the system. The case also includes cost budgets for the installation, including necessary training for planners and operators. Important organizational issues when planning the structure of CIM based production is described in the case. Terms such as Central Work Preparation and Local Work Preparation are introduced. The tasks performed in each area that add value to the CIM data files are described. At the end of the paper, the authors have outlined some future thoughts on further developments of CIM at shipyards. Important issues are, e.g., on-line production simulation systems capable of constantly updating the planning system in order to ensure the highest possible productivity and to support just in time (JIT) philosophies in all areas of the production.
Hexavalent Chromium Exposure Levels Resulting from Shipyard Welding
Authors: Kura Bhaskar , Mookoni Praveen
Published: January 2021

The Occupational Safety and Health Administration is expected to reduce permissible exposure limits of hexavalent chromium from 100 ng/m3between 5 to 0.5 fig/m3. A Navy Industry Task Group study revealed that the impact of proposed regulations on the shipbuilding industry is significant. The estimated cost of compliance by the Navy facilities could be as much as $46 Million/year besides a one-time cost of about $22 Million. Also, the task group estimated that the cost of $9 Million. This paper presents the results of a study undertaken at the University of New Orleans in support of the Navy/Industry Task Group efforts. The study included assessments of Cr(VI) exposure levels for two specific welding processes and three welding scenarios. Airborne particulate matter was collected using personal samplers for two specific welding processes, Gas Metal Arc Welding and Flux-Cored Arc Welding. Two base metals, HY100 and DH36, were considered for Flux-Cored Arc Welding and one base metal, HY100, was considered for Gas Metal Arc Welding. The samples were analyzed for Cr(VI) using OSHA Method 215. Based on the data generated, it can be concluded that Gas Metal Arc Welding and Flux-Cored Arc Welding on HY100 steel result in 8-hr. worker exposures less than 0.5 fig/m3 in a laboratory type setting, though the same levels of exposure may be difficult to be achieved in the field. Flux-Cored Arc Welding on DH36 resulted in exposure above 0.5 ng/m3, again in laboratory type setting.
Enabling the Shipbuilding Virtual Enterprise
Authors: Bolton Richard W. , Horstmann Paul , Peruzzotti Darcy , Rando Tom
Published: January 2021

Shipbuilding in the United States is characterized by large teams of suppliers and subcontractors who collaborate and support shipbuilders. It is important that these shipbuilding teams function as a single integrated organization: A Virtual Enterprise. The inefficiencies and impediments caused by each team member using their own choice of information technologies, software, data management and processes must be addressed to increase overall US shipbuilding efficiency and cost effectiveness. The NIIIP SPARS project is developing the information infrastructure and protocols to enable shipbuilding Virtual Enterprises that will improve collaboration and information exchange within the US shipbuilding community.
Concurrent Development of the SENESCO Shipyard
Authors: Gebhardt Laurence P. , Jarvis Robert G.
Published: January 2021

This paper describes the concurrent development of the Southeastern New England Shipbuilding Corporation (SENESCO) shipyard at Quonset Point, Rhode Island. Electric Boat Corporation formerly used the facility in the production of nuclear submarines. The company was founded to help convert these facilities and to help revitalize commercial shipbuilding in the Northeast region. Basic research and development for the shipyard emerged from a MARITECH project completed in 1996. Company founders persisted to raise $6.75 million, execute a long-term property lease, attract a management team, obtain a contract, hire a core workforce, and get started.
Bulldozers or Ships—What’s the Difference?
Authors: Jutla Tarsem , Crilly Pat , Kelly Gordon
Published: January 2021

This paper explains Caterpillar's approach to maintaining leadership position in designing and manufacturing fabricated structures, and highlights some of the technologies that are used to make welded steel components. Caterpillar's customers continue to look for maximum value from our machines and, to meet their increasing expectations, investment in new technology is a necessity. To build lightweight, high quality, long life structural components, Caterpillar uses state-of-the-art design tools, process simulation technologies and the latest manufacturing processes. It is the authors' perception that there are many synergisms between ship construction and the manufacture of earthmoving equipment. This paper debates networking between the two industries for cross-industry technology development and knowledge transfer. This can potentially improve the competitiveness of the United States in the ever-increasing global marketplace.
Enabling Shipbuilding Supply Chain Virtual Enterprises
Authors: Bolton Richard W.
Published: January 2021

The Shipbuilding Partners and Suppliers (SPARS) Consortium proposes to deploy shipbuilding Supply Chain (SC) Virtual Enterprises (VEs) which will integrate the shipbuilding supply chain composed of customers, partners, subcontractors, and suppliers. Virtual Enterprises enable sourcing and supply chain integration to provide business process interactions among shipyards and suppliers that are transparent of the underlying processes and computing environments of the participants.
Strategies and Outcomes in the Two Sectors of the Japanese Shipbuilding Industry
Authors: Koenig Philip C. , Narita Hitoshi , Baba Koichi
Published: January 2021

The Japanese ocean-going shipbuilding industry has evolved into two distinct sectors and today's second tier or medium-sized firms build close to half the nation's output of large ocean-going vessels. Many vessels recently delivered by the major and the medium-sized shipbuilders are of similar size and complexity. However, the medium-sized shipbuilding companies of Japan differ considerably from the majors in business strategy and corporate structure. To date, studies published in English on the Japanese shipbuilding industry have focused mainly on the seven major firms. In this paper Japan's medium-sized shipbuilders are introduced. Their competitive environment, operations, and strategies are compared with those of the seven major firms. The relative strengths and weaknesses of the major and medium-sized shipbuilders are considered and the role of technological development in the long-term prospects of both is discussed.
Block Construction of Small Ships and Boats Through Use of Developable Panels*
Authors: Oetter Rolf , Barry Christopher D. , Duffty Bryan , Welter Joel
Published: January 2021

The authors propose a simple method to improve productivity for construction and subsequent outfitting of typical hard-chine boats. This method uses CAD/CAM definition of the structure to manufacture the bottom and sides, decks and bulkheads of the boat as independent panels. The system divides such craft into construction modules by surfaces instead of by blocks as in standard shipbuilding practice. Since all of these panels are developable, an adjustable jigging system supports them essentially horizontally on their rulings. Transverse stiffeners are then welded to the panels. The system and details are optimized for maximum use of downhand welding and weld pacers. This system, however, requires specialized software to develop piece parts and to efficiently derive these modules from the product model. The developable panels can be outfitted with machinery, foundations, piping, wiring and insulation. Bottom and side panels can be tipped up, joined and more outfit installed in stages optimized for lifting and ready access. The deck is built and outfitted inverted, and then joined to the open hull. The bulkhead details and deck framing are also optimized to allow ready outfitting and subsequent joining of the deck as a unit. The easy access to the panels also allows effective, low-cost surface preparation and painting, so this system has benefits for both steel and aluminum construction.
5S—A Tool for Culture Change in Shipyards
Authors: DiBarra Camilla
Published: January 2021

5S is a successful education/change management program that has been used in many industries to institute a culture of orderliness in the workplace. 5S programs are common in the automotive, aerospace and many other industries. The U.S. shipbuilding and repair industry has recently embraced 5S objectives despite the fact that shipyards view their operations as unique from other industries. A possible reason for this decision is the culture change leverage that a 5S program can provide. The elements of 5S that make it a powerful change program that is effective in a wide variety of industries are: simplicity of concept, commonsense approach, creation of a common purpose, employee driven changes, principle-based ideas, focused events, a structure for sustaining and structured continuous improvement. The author provides examples of specific 5S applications in ship repair as well as a discussion of the elements that make 5S an effective culture change tool.
As-Built Product Modeling and Reverse Engineering in Shipbuilding Through Combined Digital Photogrammetry and CAD/CAM Technology
Authors: Goldan Michael , Kroon Robert J. G. A.
Published: January 2021

Ship repair, as a technological "lesser brother" of shipbuilding, still contains major elements of manual labor. In the past years, ship repair and the conversion of ships and offshore structures came to rely increasingly on modern computer-aided design and manufacturing (CAD and CAM) information systems for speedy generation of the required engineering information. An often-encountered problem is the lack of product information in electronic form or in any other form. Such information is needed for engineering of new parts for damaged or converted ships and platforms. In such cases one needs to build the virtual product model from the existing as-built object up to an engineering-detail level; hence, the terms "as-built modeling" and "reverse engineering." The paper presents the results of a multiyear project with the code name AMORES, which focuses on improving lead time and economic efficiency in ship and offshore platform repair and conversion in the Netherlands. Existing and newly developed photogrammetric measuring techniques were used to generate as-built models of double curved three-dimensional surfaces of ships and platforms. These were fed into standard CAD/CAM systems to engineer and manufacture new ship hull or platform parts to replace damaged areas. The main advantages of the new method are savings in lead time (measurements, engineering) and the replacing of costly manual labor by modern digital photogrammetry. The paper will focus on the new developments, the experienced difficulties, and the advantages of this new technique in ship repair.
Fabrication and Engineering Technology for Lightweight Ship Structures, Part 1: Distortions and Residual Stresses in Panel Fabrication
Authors: Huang T. D. , Dong Pingsha , DeCan Larry , Harwig Dennis , Kumar Ramesh
Published: January 2021

An increase in shipboard applications of lightweight structures has been evident over the recent years in both military and commercial vessels. Ship panel distortions generated through various stages of production (e.g., material handling, blast and paint, panel fabrication, subassembly, assembly, outfitting, and erection) have emerged as a major obstacle to the cost-effective fabrication of these lightweight structures. This problem is particularly challenging for naval ships that are built with relatively thin plate and require fair surfaces to maximize hydrodynamic performance and minimize radar signature. With a recent major initiative funded by the U.S. Navy, a comprehensive assessment of the lightweight panel fabrication technology has been undertaken. This assessment took into account the residual stresses of thin plate conditions during the material handling, cutting, fitting, and welding processes. A series of test panels with varying degrees of complexity representing the typical shipboard applications were designed and used to quantify dimensional variations through the entire fabrication processes in a production environment. A light detection and ranging (LIDAR) measurement system was used to analyze panel distortion topography resulting from different processes. Welding attributes, stiffener assembly sequence, and material handling methods were systematically monitored and evaluated to identify areas for fabrication improvement. Advanced computational tools were further developed and used to establish the underlying distortion mechanisms and critical process parameters in these panel structures. Some of the major findings include the following:local buckling is the dominant distortion mechanisms in lightweight panel structures;special care must be exercised in material handling of lightweight structures in preventing long-range permanent deformation;dimensional accuracy from thermal cutting can have a significant impact on buckling distortions, particularly for different thickness combinations in complex panels;any effective mitigation techniques for minimizing buckling distortion should either reduce the buckling driving force (fabrication induced stresses) and/or increase the buckling resistance (e.g., panel geometric parameters and assembly procedures);butt welding of plates to make panels requires a low heat input narrow groove process to minimize distortion prior to fillet welding of stiffeners;precision fillet welding process with automatic seam tracking offers the potential to minimize overwelding.
Enabling Interoperability Between US Shipyards
Authors: Benthall L. , Briggs T. , Downie B. , Gischner B. , Grau M. , Kassel B. , Wood R.
Published: January 2021

In recent decades there have been numerous computer advances put to use in US shipyards in areas ranging from design through manufacture. These tools have generally worked well and improved productivity in their specific areas. However, these tools were largely installed as isolated "islands of automation" and did not necessarily function smoothly together, even though each tool performed its own function successfully. At the same time, the market situation in the shipbuilding industry required shipyards to team together and work jointly on most new design and construction contracts. The problem of needing enhanced interoperability among the many new computer tools and systems has been addressed by several projects funded under the National Shipbuilding Research Program (NSRP). In particular, the Integrated Shipbuilding Environment (ISE) Project, the HARVEST Project, and the Integrated Steel Processing Environment (ISPE) Project have all focused on resolving these problems. There are also several Small Business Innovation Research projects that have addressed these issues. They have employed the use of Standard for the Exchange of Product Model Data (STEP), eXtensible Mark-up Language (XML), and various Web technologies to achieve these lofty goals. This paper summarizes the many accomplishments of these tasks in helping US shipyards develop integrated systems and become more productive. The theme is enabling interoperability between US shipyards, and it discusses data exchange needs from various business viewpoints. The presentation will start with a review of the paper and then show highlights of the ISE Year3 Demo presented in April 2003.
Risk Evaluation at the Preliminary Design Stage of a High-Speed Craft
Authors: Birmingham Richard , McGregor Jon , Delautre Severine , Astrugue Jean-Claude
Published: January 2021

Due to the congestion of the traditional transport infrastructure across Europe, the EU has developed the EU Common Transport Policy. This policy endorses the use of waterborne craft to ease onshore congestion. In addition to this there have been follow-up measures in the form of "short sea shipping" and lately the concept of "quality shipping" has surfaced to allay concerns arising from the standards of shipping. It is with this backdrop that an increase in demand for high-speed craft (HSC) has occurred. This in turn has created new concerns of how the safety of HSC can be assured when there is such a lack of historical data. To deal with these concerns, there has been a call for new design tools and methodologies to be developed that raise the profile of safety issues from the very beginning of the design process. It was with this in mind that funding was granted for an EU project called Safety at Speed (S@S), the details of which are described in the paper. S@S is made up of 15 partners spread throughout the EU. The partners come from all areas of the marine industry, including universities, designers/builders, class societies, and operators. The project has been split into six research areas. These are collision and grounding, motions, foundering, containment of damage and fire, integration, and case study. The paper is written from the perspective of the integration work package and describes in detail the driving "vision" behind the project. The perceived structure of the project is examined. The problems that the partners have had to overcome are laid out. These problems have led to an evolution of the interrelationships of work packages. The paper goes on to discuss the use of parameters and how their different forms can be incorporated into the design tool with reference to vast fluctuations in quality of input data. Finally, there is a discussion of how the output results from use of the tool, both for risk and cost, can most usefully be presented.
An Integrated Approach to Determine Optimal Process Information of Large-Scale Line-Heating Process With Deformation Simulation
Authors: Shin Jong Gye , Kim Yong-Gyun , Nam Jong-Ho
Published: January 2021

In shipbuilding industries, line heating has been used to fabricate plates of compound curvature. Line heating is a labor-intensive, time-consuming, and manual process carried out only by skilled workers. To enhance productivity as well as accuracy, it is imperative to automate such a process. A kinematic analysis has been introduced as a way to suggest a layout of computed heating lines. However, no verification of the resulting heating lines has been made either qualitatively or quantitatively. In this paper, an integrated system that performs the deformation simulation of plates with compound curvature is developed. This system generates optimal process information for the fabrication of curved plates using the line-heating process, by combining kinematic analysis, thermo-elasto-plastic analysis, and object comparison. The integrated system is implemented and verified by large-scale curved models used in shipyards.
Plate Residual Stress Effects on Dimensional Accuracy in Thermal Cutting
Authors: Dong P. , Cahill P. , Yang Z. , Mattei N.J.
Published: January 2021

Dimensional inaccuracies induced by thermal cutting processes have not received sufficient attention in the open literature. A series of recent research initiatives, including this one, have demonstrated that thermal cutting can contribute significantly to dimensional inaccuracies in the form of two major mechanisms:thermally induced part distortions andplate movements as the residual stresses in the original plate are relieved to achieve new equilibrium conditions during cutting. For the former, laser cutting and managing heat sink conditions are effective in minimizing the cutting-induced distortions. For the latter, considerations must be given to the residual stress conditions in the plates to be cut so that a proper cutting sequence and layout plan can be developed to mitigate the plate residual stress effects on part/plate movements during cutting.

In this paper, a major research program recently completed under the auspices of the Gulf Coast Regional Maritime Technology Center will be summarized. Some of the major findings are as follows:Although steel mill processes and parameters vary significantly from mill to mill, the important residual stress features that are relevant to cutting accuracy are dominated by only a few mill process parameters.Localized short-range residual stresses are not detrimental to cutting accuracy, even if the short-range residual stress magnitude can be high. Long-range residual stress distributions that achieve equilibrium conditions at a length scale of plate width are most important for cutting sequence planning purposes.As a result, a generalized residual stress distribution (long range) has been established for cutting planning purposes, although the detailed features may vary from mill to mill.Through a detailed series of parametric analyses using advanced modeling techniques, it was found that cutting sequencing is very important in mitigating the plate residual stress effects.It is important and practical to ensure the consistency in steel conditions so that a set of cutting procedures can be developed for mitigating plate residual stress effects on cutting accuracy, rather than trying to eliminate residual stresses in mill plates.
Knowledge Management With XML Integrated Within the Full Specification in Ship Design Processes
Authors: Ying-Han WU , Heiu-Jou Shaw
Published: January 2021

The full life cycle of as large and complex a product as a ship consists of feasibility and requirements analysis from the design and production stages, through maintenance, upgrading, decommissioning, and demolition. Many design tasks need to be informed by the perspective of what will be needed over the ship's entire lifetime. The building of a ship is a very complicated process with many concurrently running activities. Given the complexity and enormity of shipbuilding projects, effective management, knowledge application, and strategy implementation to promote the value of a shipyard are important issues. Due to rapid development in information technology and the internet, many shipyards have already applied information systems to increase profits and improve their manufacturing methods. Knowledge management will also be easily accomplished by means of information technology. New technology must enable the prototyping of complex multimodel manufacturing systems to coordinate the design efforts of the multidisciplinary teams required to design manufacturing systems. In this paper, we discuss the combination of collaborative management methods with the advantages of the internet, the building up of a virtual knowledge-sharing environment in the construction process, the use of XML standard for storing full specification data, and how to proceed with such knowledge management activities. Technology can also enable the systematic integration of new design tools to easily upgrade new design domains and methodologies. Internet technologies and collaboration management together can increase the speed of knowledge sharing, allowing workers to get the right information at the right time.
A Generic Methodology for Postdamage Decisions
Authors: Cripps R. M. , Dulieu-Barton J. M. , Jeong H. K. , Phillips H. J. , Shenoi R. A.
Published: January 2021

A generic methodology is developed that enables vessel owners to apply a systematic procedure to make decisions regarding damaged vessels. The methodology is based on the Royal National Lifeboat Institution's experience of composite vessels. It is demonstrated that the methodology is applicable to both composite and metallic structure through two illustrative examples. A detailed description of each part of the procedure is provided in the paper along with a justification of each step. It is intended that the procedure be made available through computer software; how this might be implemented is also described in the paper.
CAD-Plan Connector
Authors: Cahill Patrick D.
Published: January 2021

This paper presents the theory behind Atlantec Enterprise Solutions' CAD-Plan Connector Small Business Innovative Research (SBIR) project and explains the build strategy-based and materials-centric approach to the development of shipbuilding engineering and production schedules. CAD-Plan Connector provides a mechanism for developing a common parts catalog-based materials database for a specific shipbuilding project and a semiautomated method for establishing a build strategy and product work breakdown structure.
Electrolytic Sodium Hypochlorite System for Treatment of Ballast Water
Authors: Hill David W , Herwig Russell P. , Cordell Jeffery R. , Nielsen Bryan C. , Ferm Nissa C. , Lawrence David J. , Perrins Jake C. , Matousek Rudolf C.
Published: January 2021

The potential problems of organisms introduced by ballast water are well documented. In other settings, electrolytic generation of sodium hypochlorite from seawater has proven to be a simple and safe method of handling and injecting a biocide into water. After the hypochlorite oxidizes organisms, it reverts back to the chloride ion. Microcosm-scale testing of this technology combined with filtration, using organisms from Puget Sound, Washington, demonstrated that hypochlorite generation and use may be a viable method to eliminate aquatic nuisance species from ballast water while minimizing disinfection byproducts and residual toxicity. These experiments were conducted at the U.S. Geological Survey Marine Field Station on Marrow stone Island, Washington. Results from the first set of studies of the system showed that hypochlorite levels greater than 3.0 ppm hypochlorite with or without filtration reduced bacteria by more than 99.999%, reduced phytoplankton by more than 99%, and reduced mesozooplankton by more than 99%. Filtration improved efficacy only when hypochlorite concentration was initially less than 1.5 ppm.
US Navy Power Transformer Sizing Requirements Using Probabilistic Analysis
Authors: Robinson Michael C. , Wallace Sara E. , Woodward David C. , Engstrom Gene
Published: January 2021

Sizing power transformers in US Navy ships is an issue that surfaced in the design of a new amphibious assault ship. Previous methods averaged the power output from generators over each transformer and calculated load based on a demand factor curve. This technique is not accurate enough in the contract design stages or for zonal architectures since it artificially averages the electrical loads. The proposed methodology uses a systems engineering approach, applying a probabilistic (Monte Carlo) analysis of the electrical loads at each transformer, based on the electrical load analysis (ELA). This methodology will allow the designer to incorporate risk mitigation into a radial or zonal electrical system design to verify adequacy and reduce cost through probability-based transformer sizing.
Long-Term Retention of Product Model Data
Authors: Kassel Ben , David Patrick
Published: January 2021

This paper discusses strategies for the long-term data retention of Weapons System Information based on the Standard for the Exchange of Product Model data and the development of a set of product model test data.
The Problem of Fatigue on Large High-Speed Craft and the Comparison Between the Behavior of High Tensile Steel and Aluminum Alloy Structures: The View of an International Shipbuilder
Authors: Ferraris S. , Farinetti V. Xian
Published: January 2021

Fatigue is a leading factor in the design of ships and particularly of high-speed vessels, where designers focus their efforts on how to define optimized structural solutions, which often imply higher design stress levels and higher flexibility. Fatigue problems may arise as a consequence of ship response to environmental loads and, locally, to the vibrations induced by the propulsion systems. The paper aims at supplying some information about the experience matured in this field by a big European shipbuilding company, also pointing out the differences between steel structures and aluminum alloy structures. The precautions in design, production, and through-life maintenance needed to prevent fatigue cracks arising after a short service period are also taken into consideration, showing that fatigue problems can be limited, if not avoided, only if every party involved is fully aware of its role and of the possible troubles induced by any deviation from the correct way to act.
Major Factors Affecting Tugboat Ship Design and Construction
Authors: Das Biman , Tejpal Navin
Published: January 2021

Tugboat shipbuilding activities and costs were studied with a view to deal with the ship design and development problems and to suggest possible solutions. The lack of communication among shipyard design engineers, vendors, regulatory authority personnel, and shipyard construction department managers at the start of the preliminary and detail drawings gave rise to errors in material specifications in design drawings. This caused the shipyard a significant amount of rework on drawings, resulting in wasted labor costs and lengthening of the shipbuilding cycle time. The timely and correct vendor-furnished information (VFI) on material specification, while preparing the preliminary and detailed drawings, would permit the elimination/ reduction of errors and changes made in the drawings. A medium-sized tugboat ship costs about $14 million, comprising about $5 million labor cost and about $9 million of construction material cost. The completion time for this kind of vessel ranges from 28 to 38 months. It would be possible to reduce the labor and material costs and completion time substantially with adequate and timely information of material re- quirements from the vendor through VFI. Management tools and techniques, such as concurrent engineering, computer simulation, and program evaluation review technique (PERT) could be applied advantageously to improve tugboat shipbuilding de- sign and development productivity.
An Embedded Prototype for a Distributed and Automated Line Heating System
Authors: Noh Jackyou , Shin Jong Gye , Ko Kwang Hee , Chun Jae An
Published: January 2021

Automated line heating systems have been developed based on stand-alone operation with no consideration of the extensibility and maintainability. In the line heating shop, many of the line heating works are performed simultaneously; therefore, a collaborative and simultaneous automated line heating system is needed. In order to develop such a new line heating system, the current line heating process was analyzed, and then a distributed and automated process was determined, and the parts to be distributed and automated were identified to propose a distributed and automated line heating system based on modularization and network. Information and data flow from production design to robot control have been analyzed and integrated in the system. The system has two main processes: the calculation of the line heating information and execution of a working unit without calculation. A prototype of the system has been developed to study the feasibility of the system. Tests were carried out by using real production design data of a middle-sized Korean shipyard.
Evaluation of Aerodynamic Characteristics of Mega-Yacht Superstructures by CFD Simulations
Authors: Saydam Ahmet Ziya , Gokcay Serhan , Insel Mustafa
Published: January 2021

Air wake distribution around the superstructure of a mega-yacht is a key concern for the designer because of various reasons such as comfort expectations in recreational deck areas, self-noise generation, air pollution and temperature gradients due to exhaust interactions, and safety of helicopter operations such as landing/take off and hovering. The Reynolds-averaged Navier-Stokes (RANS) technique in computational fluid dynamics (CFD) is frequently used in studies on mega-yacht hydrodynamics and aerodynamics with satisfactory results. In this article, a case study is presented for the utilization of CFD in a mega-yacht's superstructure design. The flow field in recreational open areas has been analyzed for the increase in velocity due to the existence of the superstructure. A reduction in self-noise of the mast structure has been aimed by reducing flow separation and vorticity. Time-dependent velocity data obtained with scale-resolving simulations are presented for the evaluation of helicopter landings. The capabilities and limitations of the RANS technique are discussed along with recent developments in modeling approaches.