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One of the most important goals of the Ship Structure Committee is the improvement of methods for... more One of the most important goals of the Ship Structure Committee is the improvement of methods for design structures. This report is the third in Structure Committee reports on a project ment of an accurate, but less expensive, analysis method. and analysis of ship hull a sequence of four Ship directed toward developcomputer aided structural This report contains the User's Manual for the transverse strength analysis portion of the program.
Journal of ship production, Feb 1, 2000
During the past several years the US Navy and the shipbuilding indust~have been working together ... more During the past several years the US Navy and the shipbuilding indust~have been working together to develop a cost estimating tool that is sensitive to manufacturing proce.wes and techniques. The Product-Oriented Design and Construction Cost Model (PODA C) Project's charter is to develop a product-based, production driven cost e.rtimating tool that wi[l be used by shipbuilders and the Navy to assess the cost of innovated and advanced technologies proposed for naval application. This paper will highlight the progress of the modei development and the future direction of the project. Additionally, the PODA C Integrated Product Team (lP~has been installing and implementing the PODAC Cost model atfive major U.S. shipyards and within the Naval Sea Systems Command (NA VSEA) over the last twe[ve months. A structured evaluation of the model has taken place at several shipyards. The evaluation process was conducted in terms of technical or engineering trade-o ffstudies. The findings and recommendations of one of these studie.q are discussed.
Journal of ship production and design, May 1, 2016
(AT&L) recently presented analyses of cost and schedule growth on Major Defense Acquisition Progr... more (AT&L) recently presented analyses of cost and schedule growth on Major Defense Acquisition Programs (MDAPs) over the last 20 years (2013, 2014). For naval ships, AT&L (2013) concluded that contract work content growth (not capability growth) dominates total cost growth statistically. In addition, costs-over-target are significant and reflect poor cost estimation or faulty framing assumptions. AT&L (2014) also concluded prices on fixed-price contracts are only "fixed" if the contractual work content remains fixed, but this is often not the case. We show that under-sizing the ship during concept design studies increases ship outfit density and adds complexities to the design. These early-stage design decisions on sizing the ship are a major contributor to unnecessary work content growth later in Detail Design and Construction (DD&C) that cannot be eliminated no matter how productive the shipbuilder. However, new ship design methods are being developed and integrated with legacy physicsbased design and analysis tools into a Rapid Ship Design Environment (RSDE) that will enable a more rational process for initially sizing ships. We also identify the need for early-stage design measures of complexity and ship costing tools that are more sensitive to these measures, and propose solutions that will aid decision-makers in reducing DD&C work content by making cost-effective design decisions in early-stage naval ship design.
This paper presents new approaches to the structural analysis of tankers. For the longitudinal st... more This paper presents new approaches to the structural analysis of tankers. For the longitudinal strength studies, the ship's hull is treated as a grillage. Solutions obtained by this method converge with those obtained by conventional simple beam theories if the transverses are regarded as perfectly rigid. This new technique, however, further provides information about the shear loads on the longitudinal bulkheads and side shells. For the transverse strength analysis, the application of finite elements is employed but with a new twist, for the currently used coarse-mesh macro analysis is eliminated A set of variable transformations allows stresses of the transverse to be calculated directly from a three- dimensional structure which may include several cargo holds. The degrees of freedom can be thus increased by an order of magnitude with an accompanying reduction in computer time of 50 to 85 percent. The calculated results correlate very well with full-scale tests and with standard methods.
Abstract : The report, second in a sequence of four Ship Structure Committee Reports on a method ... more Abstract : The report, second in a sequence of four Ship Structure Committee Reports on a method for performing structural analysis of a tanker hull, contains the User's Manual and Computer Program for the longitudinal strength analysis portion of the program. The program is written in FORTRAN 4 for the UNIVAC 1108 and CDC 6600 computers. (Author)
This document has been approved for public release and sale; its distribution is unlimited.
Marine Technology and Sname News, 2005
This paper describes the concept design of a high-speed trimaran roll-on/roll-off (RO/RO) designe... more This paper describes the concept design of a high-speed trimaran roll-on/roll-off (RO/RO) designed for commercial cargo but readily convertible to military use. It is designed for a coastal express service, such as Port Canaveral, Florida, to Wilmington, Delaware, so the emphasis is on speed, simplicity, and reliability. All the RO/RO cargo is carried on the main deck, and there is room for a limited number of passengers to accompany their cargos.
: WORK-PAC, Work Planning and Control System, is a complete computer software package designed to... more : WORK-PAC, Work Planning and Control System, is a complete computer software package designed to improve shipyard labor planning and to monitor labor charges against planned estimates, measure job progress and give notice to both real and potential labor over-runs and schedule slippages. WORK-PAC permits a ship repair/conversion or new construction project to be broken down into discrete work orders, which can be classified under any given set of work cost account categories: steel work; piping, electrical and machinery systems; outfit; design/drawing; and yard support services. To further facilitate labor scheduling and control, WORK-PAC allows these work orders to be assignable to specific ship zones and shop work centers. The input of planned manhours (with or without trade estimate detail) and scheduled start and finish dates and the actual manhours from timecards as applied to these work orders completes the planning feedback cycle that is tailored to shipyard operations. WORK...
[
: The authors describe the need for fully integrating all aspects of shipbuilding so that current... more : The authors describe the need for fully integrating all aspects of shipbuilding so that current resources can be utilized in the most effective and cost-efficient way possible. The integration of manpower, scheduling, and material control using mini-computer planning, and cost/ schedule control systems have proved to be extremely beneficial to small and medium sized shipyards. These systems have given management an added insight into areas that have been troublesome. Now, corrective action can be applied and the results measured quickly, directly, and accurately. By integrating all efforts of the shipyard plan, relative merits of new production techniques can be measured and evaluated. This extension of management visibility and control permits the shipyard to implement new technologies with far more confidence than possible before.
During the past several years the US Navy and the shipbuilding industry have been working togethe... more During the past several years the US Navy and the shipbuilding industry have been working together to develop a cost estimating tool that is sensitive to manufacturing processes and techniques. The Product-Oriented Design and Construction Cost Model (PODA C) Project's charter is to develop a product-based, production driven cost estimating tool that will be used by shipbuilders and the Navy to assess the cost of innovated and advanced technologies proposed for naval application. This paper will highlight the progress of the model development and the future direction of the project. Additionally, the PODAC Integrated Product Team (IPT) has been installing and implementing the PODAC Cost model at five major U.S. shipyards and within the Naval Sea Systems Command (NA VSEA) over the last twelve months. A structured evaluation of the model has taken place at several shipyards. The evaluation process was conducted in terms of technical or engineering trade-off studies. The findings an...
Journal of Ship Production and Design, 2016
The Office of the Under Secretary of Defense, Acquisition, Technology, and Logistics (AT&... more The Office of the Under Secretary of Defense, Acquisition, Technology, and Logistics (AT&L) recently presented analyses of cost and schedule growth on Major Defense Acquisition Programs (MDAPs) over the last 20 years (2013, 2014). For naval ships, AT&L (2013) concluded that contract work content growth (not capability growth) dominates total cost growth statistically. In addition, costs-over-target are significant and reflect poor cost estimation or faulty framing assumptions. AT&L (2014) also concluded prices on fixed-price contracts are only "fixed" if the contractual work content remains fixed, but this is often not the case. We show that under-sizing the ship during concept design studies increases ship outfit density and adds complexities to the design. These early-stage design decisions on sizing the ship are a major contributor to unnecessary work content growth later in Detail Design and Construction (DD&C) that cannot be eliminated no matter how productive the shipbuilder. However, new ship design methods are being developed and integrated with legacy physicsbased design and analysis tools into a Rapid Ship Design Environment (RSDE) that will enable a more rational process for initially sizing ships. We also identify the need for early-stage design measures of complexity and ship costing tools that are more sensitive to these measures, and propose solutions that will aid decision-makers in reducing DD&C work content by making cost-effective design decisions in early-stage naval ship design.
Outfit density is an indication of how much of a ship's design volume is consumed by machinery, e... more Outfit density is an indication of how much of a ship's design volume is consumed by machinery, equipment components and the many different outfit systems. Highly dense spaces are often too difficult to gain easy access for equipment/system installations, operation, maintenance and potential upgrades. Highly dense spaces often require tortured and expensive routings of distributed systems to avoid interferences between competing systems.
One of the most important goals of the Ship Structure Committee is the improvement of methods for... more One of the most important goals of the Ship Structure Committee is the improvement of methods for design structures. This report is the third in Structure Committee reports on a project ment of an accurate, but less expensive, analysis method. and analysis of ship hull a sequence of four Ship directed toward developcomputer aided structural This report contains the User's Manual for the transverse strength analysis portion of the program.
Journal of ship production, Feb 1, 2000
During the past several years the US Navy and the shipbuilding indust~have been working together ... more During the past several years the US Navy and the shipbuilding indust~have been working together to develop a cost estimating tool that is sensitive to manufacturing proce.wes and techniques. The Product-Oriented Design and Construction Cost Model (PODA C) Project's charter is to develop a product-based, production driven cost e.rtimating tool that wi[l be used by shipbuilders and the Navy to assess the cost of innovated and advanced technologies proposed for naval application. This paper will highlight the progress of the modei development and the future direction of the project. Additionally, the PODA C Integrated Product Team (lP~has been installing and implementing the PODAC Cost model atfive major U.S. shipyards and within the Naval Sea Systems Command (NA VSEA) over the last twe[ve months. A structured evaluation of the model has taken place at several shipyards. The evaluation process was conducted in terms of technical or engineering trade-o ffstudies. The findings and recommendations of one of these studie.q are discussed.
Journal of ship production and design, May 1, 2016
(AT&L) recently presented analyses of cost and schedule growth on Major Defense Acquisition Progr... more (AT&L) recently presented analyses of cost and schedule growth on Major Defense Acquisition Programs (MDAPs) over the last 20 years (2013, 2014). For naval ships, AT&L (2013) concluded that contract work content growth (not capability growth) dominates total cost growth statistically. In addition, costs-over-target are significant and reflect poor cost estimation or faulty framing assumptions. AT&L (2014) also concluded prices on fixed-price contracts are only "fixed" if the contractual work content remains fixed, but this is often not the case. We show that under-sizing the ship during concept design studies increases ship outfit density and adds complexities to the design. These early-stage design decisions on sizing the ship are a major contributor to unnecessary work content growth later in Detail Design and Construction (DD&C) that cannot be eliminated no matter how productive the shipbuilder. However, new ship design methods are being developed and integrated with legacy physicsbased design and analysis tools into a Rapid Ship Design Environment (RSDE) that will enable a more rational process for initially sizing ships. We also identify the need for early-stage design measures of complexity and ship costing tools that are more sensitive to these measures, and propose solutions that will aid decision-makers in reducing DD&C work content by making cost-effective design decisions in early-stage naval ship design.
This paper presents new approaches to the structural analysis of tankers. For the longitudinal st... more This paper presents new approaches to the structural analysis of tankers. For the longitudinal strength studies, the ship's hull is treated as a grillage. Solutions obtained by this method converge with those obtained by conventional simple beam theories if the transverses are regarded as perfectly rigid. This new technique, however, further provides information about the shear loads on the longitudinal bulkheads and side shells. For the transverse strength analysis, the application of finite elements is employed but with a new twist, for the currently used coarse-mesh macro analysis is eliminated A set of variable transformations allows stresses of the transverse to be calculated directly from a three- dimensional structure which may include several cargo holds. The degrees of freedom can be thus increased by an order of magnitude with an accompanying reduction in computer time of 50 to 85 percent. The calculated results correlate very well with full-scale tests and with standard methods.
Abstract : The report, second in a sequence of four Ship Structure Committee Reports on a method ... more Abstract : The report, second in a sequence of four Ship Structure Committee Reports on a method for performing structural analysis of a tanker hull, contains the User's Manual and Computer Program for the longitudinal strength analysis portion of the program. The program is written in FORTRAN 4 for the UNIVAC 1108 and CDC 6600 computers. (Author)
This document has been approved for public release and sale; its distribution is unlimited.
Marine Technology and Sname News, 2005
This paper describes the concept design of a high-speed trimaran roll-on/roll-off (RO/RO) designe... more This paper describes the concept design of a high-speed trimaran roll-on/roll-off (RO/RO) designed for commercial cargo but readily convertible to military use. It is designed for a coastal express service, such as Port Canaveral, Florida, to Wilmington, Delaware, so the emphasis is on speed, simplicity, and reliability. All the RO/RO cargo is carried on the main deck, and there is room for a limited number of passengers to accompany their cargos.
: WORK-PAC, Work Planning and Control System, is a complete computer software package designed to... more : WORK-PAC, Work Planning and Control System, is a complete computer software package designed to improve shipyard labor planning and to monitor labor charges against planned estimates, measure job progress and give notice to both real and potential labor over-runs and schedule slippages. WORK-PAC permits a ship repair/conversion or new construction project to be broken down into discrete work orders, which can be classified under any given set of work cost account categories: steel work; piping, electrical and machinery systems; outfit; design/drawing; and yard support services. To further facilitate labor scheduling and control, WORK-PAC allows these work orders to be assignable to specific ship zones and shop work centers. The input of planned manhours (with or without trade estimate detail) and scheduled start and finish dates and the actual manhours from timecards as applied to these work orders completes the planning feedback cycle that is tailored to shipyard operations. WORK...
[
: The authors describe the need for fully integrating all aspects of shipbuilding so that current... more : The authors describe the need for fully integrating all aspects of shipbuilding so that current resources can be utilized in the most effective and cost-efficient way possible. The integration of manpower, scheduling, and material control using mini-computer planning, and cost/ schedule control systems have proved to be extremely beneficial to small and medium sized shipyards. These systems have given management an added insight into areas that have been troublesome. Now, corrective action can be applied and the results measured quickly, directly, and accurately. By integrating all efforts of the shipyard plan, relative merits of new production techniques can be measured and evaluated. This extension of management visibility and control permits the shipyard to implement new technologies with far more confidence than possible before.
During the past several years the US Navy and the shipbuilding industry have been working togethe... more During the past several years the US Navy and the shipbuilding industry have been working together to develop a cost estimating tool that is sensitive to manufacturing processes and techniques. The Product-Oriented Design and Construction Cost Model (PODA C) Project's charter is to develop a product-based, production driven cost estimating tool that will be used by shipbuilders and the Navy to assess the cost of innovated and advanced technologies proposed for naval application. This paper will highlight the progress of the model development and the future direction of the project. Additionally, the PODAC Integrated Product Team (IPT) has been installing and implementing the PODAC Cost model at five major U.S. shipyards and within the Naval Sea Systems Command (NA VSEA) over the last twelve months. A structured evaluation of the model has taken place at several shipyards. The evaluation process was conducted in terms of technical or engineering trade-off studies. The findings an...
Journal of Ship Production and Design, 2016
The Office of the Under Secretary of Defense, Acquisition, Technology, and Logistics (AT&... more The Office of the Under Secretary of Defense, Acquisition, Technology, and Logistics (AT&L) recently presented analyses of cost and schedule growth on Major Defense Acquisition Programs (MDAPs) over the last 20 years (2013, 2014). For naval ships, AT&L (2013) concluded that contract work content growth (not capability growth) dominates total cost growth statistically. In addition, costs-over-target are significant and reflect poor cost estimation or faulty framing assumptions. AT&L (2014) also concluded prices on fixed-price contracts are only "fixed" if the contractual work content remains fixed, but this is often not the case. We show that under-sizing the ship during concept design studies increases ship outfit density and adds complexities to the design. These early-stage design decisions on sizing the ship are a major contributor to unnecessary work content growth later in Detail Design and Construction (DD&C) that cannot be eliminated no matter how productive the shipbuilder. However, new ship design methods are being developed and integrated with legacy physicsbased design and analysis tools into a Rapid Ship Design Environment (RSDE) that will enable a more rational process for initially sizing ships. We also identify the need for early-stage design measures of complexity and ship costing tools that are more sensitive to these measures, and propose solutions that will aid decision-makers in reducing DD&C work content by making cost-effective design decisions in early-stage naval ship design.
Outfit density is an indication of how much of a ship's design volume is consumed by machinery, e... more Outfit density is an indication of how much of a ship's design volume is consumed by machinery, equipment components and the many different outfit systems. Highly dense spaces are often too difficult to gain easy access for equipment/system installations, operation, maintenance and potential upgrades. Highly dense spaces often require tortured and expensive routings of distributed systems to avoid interferences between competing systems.