bluuebunny/crossref_metadata_2025 huggingface dataset:
TQM? Inconceivable in Most Shipyards
Authors: Chirillo Louis
Published: January 2021

The idea of Total Quality Management was conceived by Thomas Watson, founder of IBM, who believed in encouraging the employee to regard his own interests as identical to those of the company. The author confronts the paradox offered by Japan's shipbuilders so successfully adopting this "made in the U.S.A." philosophy of inevitable product improvement through worker self-improvement while American yards appear largely to avoid it. A series of insights is presented describing the superiority of TQM and the steps that must be taken to establish it in place of traditional methods.
Improving Overhaul Planning Through Risk Assessment and Risk Management
Authors: Gorgone Robert G.
Published: January 2021

The execution of the overhaul of U.S. naval vessels at a public shipyard is fraught with risk. Far too often the work authorization process is constrained by a limited budget. This situation can result in two common outcomes:The shipyard delivers a ship to the customer that has significant repair work either deferred or incomplete.The deferred or incomplete work is screened back to the shipyard late in the overhaul, forcing an upheaval in the logical planning and execution of the availability.

Risk affects both the shipyard and ship's force because the completion of the overhaul could be affected by late authorized work resulting in the ship not being able to meet her commitments. As Philadelphia Naval Shipyard (PNSV) is an industry leader in Zone or Group Technology execution methods, it is particularly disruptive to work flow to return to geographic areas and perform work in an area out of phase—or even worse—in an area where similar work is already complete. With the innovation of Zone Technology, it was clear that a consistent and effective risk assessment method must be developed to determine the probability of equipment failure during the testing phase of the overhaul and the impact on cost and schedule to the overhaul. The USS Kidd (DD-963) scheduled availability in 1989 proved to be the ideal opportunity to develop and execute a formal risk assessment and management program. The USS Constellation (CV-64) SLEP availability in 1990 afforded the opportunity to refine and expand the risk assessment methodology.
Photogrammetry—Automating the Collection of Shipcheck Data
Authors: Sparacino Peter L. , Arguto William
Published: January 2021

The installation of new or modified systems on board U.S. naval combatants during overhauls requires advance planning shipchecks. One primary purpose of a shipcheck is to document existing shipboard conditions in order to develop engineering drawings for the installation of these new systems. Gathering and documenting existing shipboard conditions has always been a very labor-intensive effort. Also, accuracy of measurements is restricted by congested spaces, dimensions of extensive length, and intricate configurations of systems. Furthermore, the accuracy of the shipcheck information relates directly to the quality of the production installation. Accurate well-planned shipcheck information will reduce production interferences, production costs, and schedule variance. One objective of a planning department is to reduce man-day expenditures required to accomplish a shipcheck while increasing the accuracy of the data gathered. Automating this shipcheck using photogrammetry, specifically ster-eophotogrammetry, can provide a means to achieve these objectives. This paper explores the use of stereophotogrammetry to gather shipcheck data for shipboard distributive systems such as piping, ventilation, cableways, compartment arrangements, and structural components.
Information Required from Planning Yards to Support Zone Logic
Authors: Storch Richard Lee , Chirillo Louis D.
Published: January 2021

For over a decade, the use of zone logic, an operational approach consistent with modern manufacturing practices, has become more common in U.S. shipyards. Regarding naval ships, the most significant difference from traditional system-by-system orientation is the application of an implementation strategy even before basic design efforts begin for any combination of ship alterations (ShipAlts). This imposes a unique challenge to each of the approximately thirteen planning yards which are charged by the Naval Sea Systems Command (NAVSEA) with assessing the costs of, and when authorized, developing designs for proposed ShipAlts. The challenge consists of grouping information during the various design stages in a way that makes planning yard design deliverables anticipate the needs of the implementing yards that will employ zone logic. Simultaneously, these deliverables must be suitable for use by eligible bidders who have not yet made the transformation to modern zone orientation. This paper provides guidance for planning yards. The need for them to act as production engineering surrogates until implementing yards are designated is addressed. Typical planning yard outputs are also described.
Inspection and Feature Extraction of Marine Propellers
Authors: Jinkerson Richard A. , Abrams Stephen L. , Bardis Leonidas , Chryssostomidis Chryssostomos , Cldment Andre , Patrikalakis Nicholas M. , Wolter Franz-Erich
Published: January 2021

Localization is the process of determining the rigid-body translations and rotations that must be performed on the set of points measured on a manufactured surface to move those points into closest correspondence with the ideal design surface. In unconstrained localization all points have equal effect on the determination of the rigid-body transformation, while constrained localization allows a subset of the points to have stronger influence on the transformation. The measured points are physical points in space obtained by direct measurement of a manufactured marine propeller blade. The ideal design surface is the surface description of the propeller blade provided by the blade designer. Given that the measured blade is manufactured from the design surface description, the localization determines a Euclidean motion that brings the measured points of the manufactured surface as close as possible to the design surface. An additional option is to determine an offset distance, such that the Euclidean motion brings the measured points as close as possible to the offset of the design surface. For this optimization problem the offset distance is a seventh parameter that must be determined in addition to the six parameters of the Euclidean motion. After localization, the offset of the design surface that was determined can be used to extract the gross geometric features of the manufactured blade. These features have important hydrodynamic functions and include the camber surface, section thickness function, pitch, rake, skew, chord length, maximum thickness, maximum camber, and the leading-edge curve. The approximation of the camber surface, which is the basis of most of the remaining features, is an intricate problem relying on an extension of the concept of a Brooks ribbon. It requires the solution of a system of nonlinear differential equations and a complicated error evaluation scheme.
The Anatomy of a Ship Activation: SS Hattiesburg Victory and SS American Victory
Authors: Lowry Robert
Published: January 2021

This paper describes the procedure employed by the Maritime Administration to activate two Victory ships from the National Defense Reserve Fleet (NDRF). It also describes the reactivation schedule, work sequences, cost distribution, manpower allocation, material requirements, and lessons learned that would be beneficial for future activations of steam turbine driven dry cargo ships.
Environmental Pollution Control: Regulatory Considerations and a Case in Point
Authors: Ross Jonathan
Published: January 2021

During recent years, the United States has paid increasing attention to controlling and minimizing environmental pollution. One result of this attention is the development of new laws and regulations, enforced by the Environmental Protection Agency (EPA) and by state and local agencies. These new environmental laws and regulations are considerably more stringent than those of past years and they directly impact how shipyards must conduct their operations. This paper discusses these laws and regulations at the national, state (including California, Virginia, and Connecticut), and local levels. With the environmental regulatory background in focus, the paper proceeds to explore the effects of the regulatory trend on one particular segment of the shipbuilding and ship repair industry: floating dry docks. Floating dry docks provide an illuminating example, because of the environmentally sensitive industrial activities carried out on board, such as grit blasting and painting with antifouling paints. The operational norms of floating dry dock pollution control are discussed, starting with present day commercial and Navy facilities, and culminating with the Navy's newest floating dry dock design, the AFDB 10.
Photogrammetry and Multi-Headed Theodolite Systems as Complementary Tools
Authors: Boyer Eric L. , Sparacino Peter L.
Published: January 2021

Foundations for wet accumulator bottles (WABs) are large, complex structures that require fabrication in accordance with exacting dimensional tolerances. WABs are those tanks that store steam for the launching of aircraft off aircraft carriers. The traditional process for fabrication and installation of WAB foundations is a high-risk venture not only from cost and scheduling perspectives, but also from a geometrical perspective. The WAB foundations consist of two units, each with four structural members and two padeyes that require fabrication and installation with respect to an imaginary WAB centerline. Through the complementary use of photogrammetry and a multi-headed electronic theodolite system, the foundations can be fabricated in the shop to the correct shipboard geometry, and installed within tolerances and within cost and schedule. With all of the fabrication completed in the controlled environment of the shop, all structural, fabrication, and installation problems can be alleviated before the actual shipboard installation. This paper explains the methods and techniques for using photogrammetry and a multi-headed electronic theodolite system as complementary tools. It explains the practicality of collecting dimensional data from the existing ship structure using photogrammetry, and using a multi-headed electronic theodolite system to assist in the fabrication of the WAB foundations.
Evaluating the Producibility of Ship Design Alternatives
Authors: Wilkins James R. , Kraine Gilbert L. , Thompson Daniel H.
Published: January 2021

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.
The NIDDESC Ship Product Model: The STEP Solution
Authors: Lovdahl Richard H. , Martin Douglas J. , Polini Michael A. , Wood Ron W. , Gerardi Michael L. , Lazo Peter L. , Wooley Dan
Published: January 2021

This paper presents the purpose, approach, goals and progress of the tasks that make up the standard for a digital Ship Product Model. The Navy/Industry Digital Data Exchange Standards Committee (NIDDESC) Standards will be a part of the Standard for the Exchange of Product Model Data (STEP) International Standard. The STEP standard has a layered architecture in which basic core definitions are used by many industry and product specific standards such as the NIDDESC Standards.
Study of Accuracy Control of Hull Structure
Authors: Okumoto Yasuhisa , Matsuzaki Shin-ichi
Published: January 2021

Mechanization and automation have been accelerated in the Japanese shipbuilding industry, corresponding to the present situation of a decreasing number of skilled workers and the difficulty in recruiting new workers. In order to effectively increase productivity through automation, the current fabrication system has to be reviewed so that it will be suitable to mechanized/automated production. As a result of the survey it was confirmed that geometric inaccuracy of each member at the fabrication and assembly stage precludes introduction of the system and increases the number and variety of adjustments necessary. Accordingly, this paper proposes a new concept to keep accuracy at a high level: numerical simulation of deformation due to cutting, welding, etc., and elimination of the scattering of human skills by mechanization. It also shows some examples of deformation simulation of the plate and block due to gas cutting and welding.
The Effective Use of CAD in Shipyards
Authors: Storch Richard Lee , Chirillo Louis D.
Published: January 2021

In the current severely competitive climate that is challenging shipbuilders everywhere, how information is managed is taking on extraordinary importance. Existing computer-aided design (CAD) systems have not been focused on the most critical information needs, for example, information to serve marketing. This limitation is the result of concentrating primarily on aspects of design and manufacturing without regard for impact on an overall manufacturing system. In this paper the need to extend CAD systems is identified so that they would more fully provide critical data to everyone who has to have understanding of a manufacturing system's capability and availability.
A Plan for Identifying More Producible Structure for Tankers
Authors: Daidola John C.
Published: January 2021

This paper addresses a plan for research and development leading to alternative structural system concepts for tankers. These should decrease labor requirements in design, fabrication, and outfitting phases. The plan begins with addressing those aspects of concurrent engineering which, when applied, will result in the optimum characteristics with least cost from both the builders' and owners' perspectives. The next steps address identifying characteristics of structural systems which offer promise, and the assembly of these into alternative structural system concepts based on their apparent potential for improved producibility. Finally, application of the systems to specific vessels and methods to evaluate the improved producibility are considered.
Design/Production Integration and the Industrial Structure
Authors: Frisch Franz A. P.
Published: January 2021

The naval architect or the designer is considered as the integrator of countless subsystems into the system—called the ship. In order to integrate, he must have in the design phase the freedom to communicate with all levels of production. This communication is the prerequisite to a successful design/production integration. The freedom to communicate can be fostered or impeded by the industrial structure. The structure itself is driven by the economy of scope and scale and by legal requirements expressing views on competition and/or cooperation. The impact of structure and law on communication is sketched in comparative form for the American on the foreign shipbuilding industry. The scope of this paper is restricted to fundamentals.
Visualization of the Conceptual Design Process of Ships by a Graphical User Interface
Authors: Han Soon-Hung , Lee Dong-Kon , Lee Kyung-Ho , Lee Kyu-Yeul
Published: January 2021

To improve ship designer's productivity in the conceptual design process, the concept of visualization has been applied. It transforms a conventional text-based software for the conceptual design of ships into a system with WYSIWYG (What You See Is What You Get) user interface. Most of the decisions which a designer should make in a design process can be made with the help of mouse buttons and graphical objects displayed on a computer screen. In implementing such a graphical user interface (GUI), the concept of graphics standards has also been introduced to increase portability of the developed system. The Motif widget set has been selected as the baseline system software. With the developed functions, both the ship and the design process can be better visualized.
Comparative Design of Orthogonally Stiffened Plates for Production and Structural Integrity—Part 2: Shape Optimization
Authors: Hatzidakis Nicholas , Bernitsas Michael M.
Published: January 2021

To improve the optimal stiffened plates obtained by size optimization in Part 1 of this work, shape optimization is performed. Plate thickness, standardized beam cross sections, and beam spacing are used as discrete design variables. Three different optimality criteria are used for each stiffened plate configuration to produce one weight optimum, one work content optimum, and one total cost optimum structure. Structural, geometric, and producibility constraints are imposed. The former include limits on secondary and tertiary bending stresses, and buckling loads due to primary stresses. Geometric constraints are imposed by symmetry, the requirement for equally spaced stiffeners, and to maintain the basic characteristics of each stiffened panel. Producibility constraints are dictated by standardization in shipyard practice. Configuration 3 is excluded from the shape optimization analysis because its unequal longitudinal stiffener spacing makes its geometry unique. The overall optimum structure for each optimality criterion is identified. Finally, the effect of structural volume on the lifetime cost of the structure due to loss of cargo capacity is assessed.
Naval Shipyard Machine Shop Modernization
Authors: Doehnert Kurt C. , Winton Bob
Published: January 2021

The Naval Shipyard Corporate Operations Strategy … Plan (COSP) defines the vision, goals, and strategies for achieving excellence in shipyard business and operations. The COSP establishes an action for the "Modernization of Naval Shipyard Inside Machine Shop (Shop 31) Practices and Procedures." This paper describes the Naval Sea Systems Command's (NAVSEA) initiative to provide the inside machine shops with the management systems and industrial technologies to meet the challenges of the 21st century. The Shop 31 Modernization Corporate Master Plan addresses the functional areas of equipment, facilities, integrated management systems, human resources, shop operations, and customer/supplier interface processes. This plan is presented as a benchmark for consideration in shop modernization efforts in U.S. shipyards.
Production Integration Via Solids Modeling
Authors: DeVale E. K. H. , Guilbert J. R.
Published: January 2021

The integration of production planning within design has had a positive impact on both the design process and the design products. To effectively accomplish the integration, it is necessary to have a single-D product model of the ship, by which all design disciplines and construction planning personnel can effectively communicate. The authors address the significant changes this new approach has had upon the design community and its deliverables. They provide an overview of the enabling technologies and methods which facilitate construction-oriented feedback in the design phase. They review additional benefits derived from the product model, such as eliminating physical mock-ups.
On-the-Job Training in Line Heating at Astilleros Españoles Shipyards—A Profitable Experience
Authors: Sarabia Antonio , de la Bellacasa Carlos Puig
Published: January 2021

This paper describes the experience in teaching Astilleros Espanoles (AESA) steel fabrication workers the practical use of line heating (L/H) for accurate bending of plates, and the operational deployment of this technology in all shipyards in the group. This project is set within the developing dimensional accuracy improvement program, which is aimed at improving productivity, quality and allowing the implementation of a continuous improvement process. The approach used is for facilitating a systematic technology transfer from Japanese specialists, overcoming initial reluctance, promoting active participation with a commitment from workers and foremen, and assuring practical documentation of experiences in the form of a shop operating manual.
Development of Computer-Aided Process Planning System for Plate Bending by Line Heating (Report 2)—Practice for Plate Bending in Shipyard Viewed from Aspect of Inherent Strain
Authors: Ueda Yukio , Murakawa Hidekazu , Rashwan Ahmed Mohamed , Okumoto Yasuhisa , Kamichika Ryoichi
Published: January 2021

In the plate bending process by line heating, the decisions as to which part of the plate should be heated and in which direction are usually made by skillful workers. However, the number of skilled workers is declining rapidly and in recent years this has become a serious problem in shipyards. To solve the problem, the authors in an earlier report proposed a method to make the decisions based on theoretical analyses focused on inherent strain. The potential usefulness of the method was demonstrated through example problems dealing with mathematical ideal geometry. In the present report, a comparison is made between theoretical predictions and actual shipyard practice in forming curved members of a ship hull, and an attempt is made to visualize the knowledge of skilled workers, which heretofore was invisible, using computer graphic images showing inherent strain. Further, it is demonstrated that the same idea can be applied not only to make decisions on the line heating process but also to design the total plate bending process, including decisions on using the bending roller and the press machine.
Development of Computer-Aided Process Planning System for Plate Bending by Line Heating (Report 3)—Relation Between Heating Condition and Deformation
Authors: Ueda Yukio , Murakawa Hidekazu , Rashwan Ahmed Mohamed , Neki Isao , Kamichika Ryoichi , Ishiyama Morinobu , Ogawa Jun-ichiro
Published: January 2021

An effective plate bending process by line heating can be achieved when the heating conditions are properly selected to produce desirable bending or inplane deformations. To make such decisions on he heating condition, the relation between heating conditions and deformations must be clarified. For his purpose, the authors studied the similarity rule which holds for the line heating process and derived wo parameters governing the deformations. Also, they developed new three-dimensional finite-element method codes as versatile tools to replace costly experiments. The validity of these codes is examined through comparison with an experiment, and they are applied to study the general relations between he parameters and the deformations of plates.
Thermal Spray for Corrosion Control: A Competitive Edge for Commercial Shipbuilding
Authors: Rogers Frank S.
Published: January 2021

Thermal spraying of steel with aluminum to protect it from corrosion is a technology that has been proven to work in the marine environment. The thermal spray coating system includes a paint sealer that is applied over the thermally sprayed aluminum; this extends the service life of the coating, and provides color to the end product. The thermal spray system protects steel both through the principle of isolation (as in painting) and galvanization (as in galvanizing). With this dual protection mechanism, steel is protected from corrosion even when the coating is damaged. The thermal sprayed aluminum coating system has proven to be the most cost-effective corrosion protection system for the marine environment. Until recently, however, the initial cost of application has limited its use for general application. Today a new arc spray technology has reduced the application cost of thermal spraying aluminum to below that of painting. Commercial shipbuilders could use this technology to enhance their market position in the marine industry.
Integrated Ship Design and Its Role in Enhancing Ship Production
Authors: Ross Jonathan M.
Published: January 2021

This paper focuses on an important trend that is increasing shipbuilding productivity: integrating the computer-aided ship design process. The ship design process increasingly is being performed with the help of computer programs, either individual programs that address single aspects of the design or integrated programs composed of modules that address a range of ship design aspects. In the case of integrated computer programs, the ship design process is enhanced through individual program modules sharing their results with each other, preferably from a common database. Modern integrated ship design programs not only improve the efficiency of ship design, they also improve the efficiency and ease of ship production, from lofting and numerical cutting to providing workshop drawings and production information.
Laser Welding Analysis and Experiments
Authors: Yagla Jon J. , Haag Richard S. , Scott Matthew E.
Published: January 2021

A "seamless engineering" approach for mechanical design and laser welding manufacturing combines a method for welding analysis with a method for stress analysis through the development of radiant heating models for use in a nonlinear finite-element computer program. Experiments were performed welding steel plates, using a five-axis computer numerical controlled (CNC) workstation to translate welding specimens under a 5-kW CO2 (carbon dioxide) laser. Thermocouples installed near the weld seam were used to measure the transient temperature field during welding. The measured temperatures were compared with the analytical predictions, and the welds were sectioned so that predictions of properties in the heat-affected zone could be compared with experimental data. This paper presents analytical results using classical methods of analysis and includes solutions for temperature fields, heating and cooling rates, and metallurgical properties in heat-affected zones.
Basic Studies for the Automatic Fabrication of Welded Built-up Beams
Authors: Jang Chang Doo , Seo Seung II
Published: January 2021

In the fabrication of welded built-up beams, longitudinal deformation occurs due to welding. As it prevents improvement of productivity and quality, heating for straightening the welding deformation is necessary. Therefore, control of the deformation due to welding and heating is the base for the automatic fabrication of built-up beams. In this study, techniques to control the deformation are developed. Based on the simple formulas for estimation of the deformation proposed in the previous study, a procedure to calculate the required reverse curvatures to straighten the welding deformation is presented and a method to simulate the fabrication procedure is developed. From the simulation of the fabrication procedure it is concluded that, in heating for straightening, deep-heated depth is more economical than wide-heated breadth in yielding the same curvature. To apply the results obtained to automatic fabrication, welding and heating parameters such as welding current, voltage and speed, and heated depth and breadth are selected and fabrication cost is expressed by the parameters, which are optimized under the constraints. According to the optimized results, the higher welding current reduces the fabrication cost. Results obtained through executing the simulation method described herein can be used in the guidance of welding and heating procedures instead of depending on the experience of skilled workers--and this can contribute to an increase in productivity and quality.
The Geometric Modeling and Interrogation System Praxiteles
Authors: Abrams S. L. , Bardis L. , Chryssostomidis C. , Patrikalakis N. M. , Tuohy S. T. , Wolter F.-E. , Zhou J.
Published: January 2021

After establishment of design requirements and creation of an initial shape, the design process of free form shapes should include interrogation and fairing until a desired shape, with appropriate geometric and performance characteristics, is achieved. Afterwards, the quality of the manufactured product can be determined by comparing measured data with the design model. To permit automated design and manufacturing, mathematical methods and algorithms for the creation, interrogation, fairing, and inspection of curves and surfaces have been developed and integrated into a computer system called Praxiteles. The general layout of Praxiteles, along with a description of design capabilities, is presented. This description covers the areas of input, output, approximation and conversion for data exchange, a summary of some shape creation methods, and a description of some advanced interactive interrogation, fairing, and inspection methods for NURBS curves and surfaces. Examples illustrate some of the features of the system, as applied in the design and inspection of marine propellers. Recommendations for future development of the system are also presented.
Design/Production Integration
Authors: VanDevender W.W. , Holland A.S.
Published: January 2021

The multiple challenges posed by ever-increasing ship sizes, technical complexity, skyrocketing material and construction costs, plus several recently introduced design requirements—such as double hulls and extensive waste treatment systems—have combined to create an increasingly involved and complicated shipbuilding environment. This paper addresses steps taken to increase design and construction effectiveness through use of a shared three-dimensional (3D) database. An improved ability to successfully compete in the highly competitive international shipbuilding market is demonstrated.
Tee-Beam Manufacturing Analysis: Producibility of Panel Stiffening Elements
Authors: Blomquist Paul A.
Published: January 2021

This paper analyzes the manufacturing of tee shapes for stiffening ship structure. The traditional method of deflanging hot-rolled I-beams (producing l/T shapes) has been compared to the practice of fabricating tee-shapes from plate. A group of more than 1700 l/T shapes, used in the DDG-51 class vessel, was used for comparisons. To produce the l/T shapes for one DDG, flanges are stripped from more than 700 tonnes (690 long tons) of I-beams. The flange material removed amounts to 25% of the weight of the original I-beams, totaling approximately 172 tonnes (170 tons). This represents a material loss of 25%, easily in excess of $90 000. Prior review of design criteria for several DDG stiffened plate structures showed that fabricated tees could replace l/T shapes, resulting in weight savings averaging 18%, while still maintaining required strength. An evaluation of methods to produce tee sections was undertaken, and the concept of "net shape" fabrication of tee stiffeners was discussed. Both fabricating and stripping methods were considered, including newer technologies such as plasma cutting and laser cutting and welding. Mock-up testing was performed using several candidate technologies and the results compared. Plasma-arc cutting reduced distortion on 12.2 m (40 ft) test beams by 50% compared to oxyfuel methods. Economic analysis revealed that fabricated tees were less costly to produce than deflanged I-beams, and that handling functions were the greatest cost element of the traditional oxyfuel cutting methodology.
Development of Integrated Shipyard Pipe Production Facility
Authors: Jones Emlyn L. , Watne Terry
Published: January 2021

Jesse Engineering Company of Tacoma, Washington is the parent company of the Wallace Coast Machinery Company, which has designed and built pipe bending machines for many years. Working on a pipe bending machine application led to a complete pipe production modernization project in Southern China. Engineers jointly developed the design specifications for the machinery and automated controls. The overall engineering requirement was to automatically collect and sort the pipe processing requirements; route and track each spool through the shop; and provide automated bending, cutting, flange welding, and bending of the pipes. This paper describes and illustrates the shipyard system and explains the machinery and features of the new pipe production facility.
Catalogue of Ship Producibility Improvement Concepts
Authors: Bunch Howard M.
Published: January 2021

This catalogue is the product of a multi-year project to organize information relating to the improved producibility of Navy ships. This information is largely of a qualitative nature, and deals with all aspects of ship design and construction. Individual suggestions are presented in the form of very short abstracts. These are organized according to the Navy ship Work Breakdown Structure (WBS) coding system. The catalogue is intended to provide a ready reference of producibility information for the student and naval designer. This report has been prepared under the Memorandum of Understanding to Support Program Development in Naval Architecture and Marine Engineering between the United States Naval Sea Systems Command and the University of Michigan. It has been funded by an Office of Naval Research Grant (Number N00014-90-J-1404).
Multiskilled Work Teams at Finnish Shipyards
Authors: Nallikari Matti
Published: January 2021

This paper presents the results of a study jointly conducted by the Finnish shipyards in 1992–93. The study surveyed the possibilities of applying group work at the zonal outfitting of ships. Six zones of two sister ships, multipurpose icebreakers, were outfitted using both conventional and work group technology. The study revealed that there is a great potential to shorten the throughput time and increase productivity. When multiskilled independent work groups are implemented correctly, a decrease of 50% in throughput time and an increase of 20% in productivity can be expected. Synchronization and management problems can also be decreased
The Netherlands’ Shipbuilding Industry: Own Solutions to Competitiveness
Authors: Goldan Michael
Published: January 2021

Shipyards in the Netherlands rely on a flexible infrastructure of subcontractors, colleague yards, and manpower pools to temporarily increase their capacity. In addition, the industry has developed some unique concepts with respect to marketing, and to facilitating enterprises for design and engineering, partial work preparation, parts fabrication, hull erection, and outfitting. This paper addresses the subject of competitiveness in shipbuilding and the factors which determine the strategic competitive position of shipyards. The applicability of various simple models, which can be used to describe shipyards' strategic market positions, are discussed. In particular, a model addressing a ship's life-cycle is detailed. The paper further focuses on solutions generated by the shipbuilding industry in the Netherlands in its drive to achieve and maintain a competitive position in domestic and world markets.
Shipbuilding Robotics and Economics
Authors: Reeve Ronald C. , Rongo Robert
Published: January 2021

Commercial shipbuilding is surviving and prospering in mature high-labor-cost countries even under intense competition from low-labor-cost countries. Prospering shipyards are investing in robotic automation to increase productivity and worker added value. Robot welders are producing higher quality ships for as little as $1 per hour. It is projected that U.S. shipyards must also use robots in order to successfully compete in commercial world markets. This paper describes how the Technology Reinvestment Project (TRP) on Shipbuilding Robotics is leveraging advanced robotic technology to provide low-cost robotics for U.S. shipyard automation. The TRP is described, economic analysis methods for robot welding are presented, and factors for successful implementation of robotics are discussed. A case study of a successful shipyard gantry robot implementation is reported.
The Product Model as a Central Information Source in a Shipbuilding Environment
Authors: Johansson Kaj
Published: January 2021

In a shipbuilding CAD/CAM system a product model is successively built up during the design process, with geometric as well as nongeometric information. In parallel with the design process, the model is further extended with work preparation (in some countries called production engineering) information, e.g., definition of building strategy and definition of the assembly structure. Information needed for part fabrication can be derived from the model, such as drawings, parts lists and information for numerically controlled (NC) equipment. When work preparation definitions are combined with a product model, the information needed for assembly parts lists, assembly drawings, etc. can be derived from the product model instead of being created manually. Use of the product model concept, systems based upon it and procedures implementing it in an organization will allow a reduction of costs and an increase in productivity and competitiveness
Techno-Economic Optimization of an LNG Carrier with Multicriteria in the Preliminary Design Stage
Authors: Lee Dongkon , Kim Soo-Young
Published: January 2021

When economic optimization is considered in the preliminary design of a ship, required freight rate (RFR) is usually taken as the objective function because it is related to the building and the operating costs of a ship, reflecting the interest of both the shipyard and the shipowner. However, the choice of RFR as the objective function sometimes has an adverse effect on the designer. For example, to analyze the effect on the objective function of change of the building and operating costs, a sensitivity analysis is required for each item. That is, the relative importance of the two costs, when constructing a design model, is not obvious as they are combined together. In order to overcome the limitation of single objective optimization, a multicriteria optimization method has been used. To solve the multicriteria optimization problem with efficiency, a hybrid optimization solver is developed by coupling the genetic algorithm and the direct search method. Furthermore, to accelerate the searching speed of the solver in the design space, an Al (artificial intelligence) technique is applied to the hybrid optimization solver. It is applied to the optimum design of a liquified natural gas (LNG) carrier in the preliminary design stage. Through application to the ship design, the relative importance between the operating and building cost in the economic analysis of the ship design was manifested.
A Production Control System Based on Earned Value Concepts
Authors: de la Fuente Ramon , Manzanares Ernesto
Published: January 2021

In the past four years, Astilleros Espafioles S.A. (AESA) has completed the implementation of its shipbuilding industrial model, based on the use of a product work breakdown structure (PWBS) for each new construction shipyard. As a logical development of this model, a new production control system has been built using earned value techniques. This paper describes the state of the implementation of this production control system. First, the basic structures of the shipbuilding model are defined as the product work breakdown structure of each ship under construction, the process breakdown structure of the shipyard, and the organizational breakdown structure. Also described is how these structures are reflected in the basic logical concepts of the production control system: product, process, organization, control accounts and control points (by product, process or organization), work packages and work orders. The functional description of the production control system is explained. Some examples of outputs are presented, stressing the method of result analysis prepared for each responsibility level of the shipyard general manager, production manager, and shop and production unit managers. Next, the development of the implementation phase in one test corporate shipyard is described, as well as the main problems found and the way in which they have been solved. Finally, some conclusions about the production control system are presented, together with several future planned developments for the system.
Stress in Bonded Adherends for Single Lap Joints
Authors: Bezine G. , Roy A. , Vinet A.
Published: January 2021

A finite-element technique is used to predict the shear stress and normal stress distribution in adherends for polycarbonate/polycarbonate single lap joints subjected to axial loads. Numerical and photoelastic results are compared so that a validation of the numerical model is obtained. The influences on stresses of the overlap length and the shape of the adherends are studied.
Naval Shipyard Base Realignment and Closure: The Environmental Remediation Effort
Authors: Pieper Rodney K.
Published: January 2021

Mare Island Naval Shipyard was placed on the "Fast Track" toward military base closure as of October 1993. All ship projects will end by April 1995. The base will close in April 1996. This paper discussesthe cooperative efforts of the Federal, state and local authorities, and the shipyard, to quickly turn over the yard for effective civilian reuse; andthe shipyard effort to train and utilize the existing workforce as a major element in the environmental remediation effort—to both prepare the facility for reuse and to prepare the workforce for reemployment.
Search for a Model of Effective Ship Production Management
Authors: Sladoljev Želimir
Published: January 2021

The objective of the paper is to explain problems and offer a simple model of the production management in shipyards with an uneven production. Shipyards with flexible and different building programs frequently meet disturbances in their production caused by changes in designs and workshop drawings; these changes are due to owners' demands, overloading of capacity, and many other reasons. Such shipyards are constrained to consider it as their normal way of building ships. In order to stay competitive they have to organize the work-preparing process with integrated production engineering activities and an effective coordination of all participants in the building process. Essential scopes as well as the basic structure of the production management of a flexible shipyard are explained.
A Revolution in Warship Design: Navy-Industry Integrated Product Teams
Authors: Keane Robert G. , Tibbitts Barry F.
Published: January 2021

The authors advocate the adoption of joint Navy-Industry Integrated Product Teams (IPTs) throughout the whole acquisition process for a new warship, including detail design and construction of the lead ship. This paper describes how the use of joint Navy-Industry IPTs is revolutionizing warship design during the early design stages, and identifies both the benefits and some of the critical obstacles for the use of such IPTs after contract award. The purpose of this paper is not to offer "textbook" solutions, but rather to stimulate discussion and to initiate dialog. The authors contend that the use of IPTs is essential to quality design and timely acquisition of effective, balanced, and affordable warships. The experience that U.S. shipbuilders gain from the application of Integrated Product and Process Development (IPPD) principles to the design and construction of world-class warships can be directly transferred to the world-class development of commercial ships for the international market.
Shipbuilding Competitiveness: The Marketing Overview
Authors: Stott Paul , Kattan M. R.
Published: January 2021

The analysis of competitiveness is to the fore in shipbuilding at present, in particular in the United States as shipyards position and benchmark themselves against international competition in the commercial sector. The impending Organization for Economic Cooperation and Development agreement has also focused attention in this direction. This analysis is normally primarily based on a comparison of productivity, comparing labor utilization with output. This is only one aspect of the competitive equation, however, and competitiveness is above all a matter of economics. The aim of this paper is to examine all aspects of competitiveness, both technical and economic, and to show how they fit together in the competitive equation, drawing conclusions for the U.S. industry.
A Study on the Prediction of Deformations of Plates Due to Line Heating Using a Simplified Thermal Elasto-Plastic Analysis
Authors: Jang Chang Doo , Seo Seung II
Published: January 2021

The line heating process has long been used in plate forming of hull surfaces and it has depended on skillful workers. Since reduction of production cost is a major concern of shipbuilding companies, line heating work must be improved for higher productivity. In this paper, as a first step to automatic hull forming, a method is proposed to predict deformations due to line heating. It includes a simplified thermal elasto-plastic analysis to increase computing efficiency and to enable real-time visualization of deformed shapes. The simplified thermal elasto-plastic analysis method shortens the thermal elasto-plastic process and introduces inherent strains. Predicted deformations for line heated plates show good agreement with experimental results. For the prediction of deformation, a method to estimate heat flux of the torch is also introduced. The proposed method can be used in control and simulation of the line heating process with simplicity and efficiency.
Kinematic Analysis of the Process Planning for Compounding Ship Hull Plates
Authors: Shin Jong Gye , Kim Won Don
Published: January 2021

The formation of compound-curved structures, or compounding, is a process which applies permanent bending and in-plane strains to flat plates. The process includes roller bending for forming single-curved plates, followed by line heating for complete compound-curved ones. Currently, the process is carried out by skilled workers, and is based on their experience and intuition. To improve accuracy and to prepare new workers in this field, quantitative and mechanics-based approaches will be required. In this paper, a kinematic analysis to determine the bending and in-plane strain distributions of compound-curved shells with reference to the flat plates and to the roller-bent shell plates is presented. These strains are important parameters for forming processes. The approach employed is in accord with the currently used sequential process of roller bending and line heating. In addition, it utilizes offset data provided with flat plates. Numerical solutions are presented with real data. The distribution of strains will aid shipyard experts in determining the forming parameters, such as rolling direction, radius, heating power, path, and related issues. Also, this approach will be useful in establishing a database for future computerized forming processes.