bluuebunny/crossref_metadata_2025 huggingface dataset:
Container System Design Developments Over Two Decades
Authors: Harlander L. A.
Published: January 2021

This paper reviews the progress made over the past 20 years in the design and handling of containers. Factors influencing present container dimensions and strength criteria are discussed, as well as the crucial activity to establish container standardization. The container itself—"the common denominator"—is addressed from the viewpoint of its fittings, design loads and construction materials; and the containership from the viewpoint of arrangements, size, speed, stability, stowage and economics. The author offers several conclusions following the last two sections of the paper, which cover the remaining components of the system, namely, the shoreside gantry cranes and terminal facilities.
Reducing Fuel Consumption for Liquid Cargo Heating Systems
Authors: Ponton George E.
Published: January 2021

Cargo vessels carrying heavy liquid petroleum products, such as No. 6 fuel oil or asphalt, traditionally have an extensive heating system. This system consists of thousands of feet of 1,2 or 2-in. pipe arranged in the bottom of the cargo tanks through which a heat-transfer fluid is passed. A heater is used to raise the temperature of the heating fluid, which is forced through the coils. This maintains the cargo at a temperature suitable for off-loading by centrifugal cargo pumps. This heat source (heater) for the fluid is fuel fired usually with diesel oil. With the costs of fuel spiraling upward, an approach that would reduce fuel consumption should be attractive to the owner/operator of such a vessel. This paper presents the results of an analysis to determine potential savings in heating systems for No. 6 fuel oil cargos. Since positive-displacement pumps can handle much more viscous fluids than centrifugal pumps, they were studied for off-loading instead of using traditional vertical deep-well mixed-flow pumps. Two types of petroleum cargo vessels were analyzed, including an oceangoing 180 000-bbl Tank Vessel and a river tow consisting of eight tank barges with a combined capacity of 160 000 bbl. The analysis indicates that a significant reduction in fuel consumption could be realized with the new cargo pump type by reducing the size of the heaters. Additionally, the quantity of heating coils could be reduced. This would reduce construction costs and save substantial operating costs if incorporated into petroleum cargo vessel design
Experience with Real-Time Motion Monitoring on the Barge Foss 245
Authors: Hutchison Bruce L. , Nichol Robert E.
Published: January 2021

The shipment by barge of a 240-ton retired steam generating unit from the Surry, Virginia nuclear power plant in the spring of 1980 provided an opportunity to apply modern state-of-the-art motion monitoring and damage-avoidance techniques to a towed ocean barge. This paper reports onthe project background, including prevoyage risk analysis which resulted in the recommendation that real-time motion monitoring be provided;the design and installation of the motion monitoring system; andthe tug master's experience during the voyage with the real-time motion feedback.

The paper concludes by comparing selected motion records from the motion monitoring system to motion predictions based on logbook and hindcast sea-state data. It is concluded that the real-time motion monitoring worked well on the subject barge shipment and achieved the primary objective of providing useful feedback to the tug master concerning the effects of his actions on the barge and cargo. It is suggested that the technique is sufficiently promising to warrant wider use by the offshore tug/barge industry. All sciences are vain and full of errors that are not born of experience, mother of all certainty, and that are not tested by experience…Leonardo
A Different Method to Evaluate the Intact Stability of Floating Structures
Authors: Radwan Abobakr M
Published: January 2021

A mathematical formulation of a computer-based method to evaluate the intact stability of floating structures is presented. The technique depends on describing the surface of the structure in terms of many small finite elements, which allows the analysis of complicated hull geometry, determining the hydrostatic pressure on each element for a known heel angle, and integrating the pressure forces to find the magnitude, direction, and line of action of the buoyant force. This will result in the correct location of the metacenter for small, as well as large, angles of heel. For structures of variable cross section, the position of the heeled vessel in equilibrium is defined such that the weight is balanced by the buoyant force, and only a pure righting moment associated with the heeling angle is evaluated. Formulation for the wind heeling moment is also presented. Assessment of the stability of the vessel is made from the righting and heeling moment curves in light of regulatory body rules.
Marine Coal-Fired Boilers—State of the Art
Authors: Hedges Robert B.
Published: January 2021

Owing to economic considerations, there has been renewed interest in the use of coal as a shipboard fuel. To utilize coal aboard ship again required only the application of technology developed and proven ashore over the past 30 years since coal was last used extensively at sea. The development of a modern coal-fired marine boiler was thus possible in a relatively short time. The paper discusses the state of the art of marine coal-fired boilers, including economics, alternative firing systems, boiler performance, design philosophy, and system design.
A Survey of Shipboard Piping Design and Fabrication
Authors: Williams L. E. , Oglesby R. S.
Published: January 2021

Domestic and foreign practices relative to shipboard piping design, fabrication, and installation are discussed. The emphasis is on commercial shipbuilding practices. Individually defined phases of piping design, fabrication, and installation are discussed as well as various "integrated" approaches to each of these activities. Material presented is based largely upon on-site surveys by the authors of 21 domestic facilities, including 13 shipyards, four design agents, two piping fabrication equipment manufacturers and two piping fabricators. Material from on-site surveys by the authors of four Western European shipyards is also presented.
Influence of Ship Design and Fabrication on Underwater Maintenance and Repair
Authors: McCord Ray Scott
Published: January 2021

By increasing the scope of diver operations and decreasing the time to accomplish these tasks, it is possible to lengthen the time between normally scheduled drydockings, minimize the time a ship needs to remain pierside for repairs (when the underwater task is the critical event in readying the ship for sea), and decrease the frequency of emergency drydockings. The method of approach used is to identify many of the common underwater tasks performed on ships and the problems associated in performing these tasks. Proposals are then offered that may alleviate these problems. This can be done by making the tasks less complicated, improving the tools used by the diver, or eliminating the task altogether. The discussion presents the basic format of how the operations are performed and how the designer and fabricator may interface with these operations.
Dustpan Dredging—A Unique Concept
Authors: Butler James P. , Lockwood Richard C.
Published: January 2021

Dustpan dredging is a unique method which has been in use since 1893 and, until recently, exclusive to the U.S. Army Corps of Engineers. The Corps' Marine Design Center is presently involved with the design of a new dustpan dredge, its first new dustpan design since 1934. The application of state-of-the-art technology to this old dredging concept has posed some interesting problems and solutions. This paper presents an overview of the 88-year history of dustpan dredges and discusses in some detail several of their more interesting design aspects, past and present.
Analysis and Preliminary Design of a Sailboat with Self-Trimming Wing Sail
Authors: Newman B. G. , Fekete G. I.
Published: January 2021

A theoretical analysis has been made of the static and dynamic stability of a self-trimming rigid wing sail for use on a sailboat without sheets or halyards. The effects of camber or flap deflection and the position of the trimming plane are considered. A satisfactory design incorporates an uncambered main wing of medium aspect ratio and a trimming tail plane. Wind tunnel tests on a model of this design confirmed the stability of the sail and indicated adequate damping. The measured lift and drag coefficients were in good agreement with existing data at a similar Reynolds number.
Noise Control on Diesel Tugs—A Sequel
Authors: Dyer Thomas R. , Lundgaard Bertel
Published: January 2021

This paper is a sequel to "Noise Control on Diesel Tugs" published in the October 1973 Marine Technology. It reviews fundamental principles of tugboat noise control, including new construction specifications. Noise levels on four classes of new or repowered tugs are presented, including comparison of vessels with and without main engine isolation. The problem of backfitting noise control measures to existing vessels is discussed in detail. An experiment is reported in which consecutive measures were fitted in six steps to evaluate the effectiveness of each measure. The problem of deck noise and noise standards being considered by the U. S. Coast Guard is discussed. The paper is illustrated with tables of noise levels and shows typical vessel arrangements. A short bibliography is included.
Marine Epoxy Resin Chocks
Authors: Wilson J. Murray
Published: January 2021

Epoxy resin chocks originally answered a ship repair need for a diesel engine rechocking method that eliminated foundation and bedplate machining. Service experience quickly showed that resin chocking was not only faster and cheaper, but also superior to steel or cast iron. Adoption for new construction came slowly, but today resin chocking is standard procedure for many shipyards. The same resins have numerous other uses, notably for sterntube and strut bearing installation. Increasing adoption by the United States Navy will probably give the final seal of respectability to these underutilized materials.
Structural Design of River Tank Barges
Authors: Billingsley Daniel W.
Published: January 2021

Tank barge size has increased substantially over the past two decades. Existing rules and regulations are based largely on the design of shorter barges and are concerned primarily with the ability of tank boundary structure and hull structure to withstand local loads. The designer of a long barge, a barge which will not be uniformly loaded, a barge which is to carry high-density cargoes, or a barge which is to carry products with appreciable vapor pressures is well advised to conduct a rational analysis of the loading and strength of his barge. This paper provides guidelines, based on studies of barge loading and strength, for conducting such an analysis.
Deflections of Great Lakes Ore Carrier Hull Structure by Finite-Element Analysis
Authors: Kaldjian Movses J. , Woodward John B. , Reid William R.
Published: January 2021

Calculation of hull deflections in way of machinery spaces of two Great Lakes bulk carriers is presented. Methods of modeling and analysis by the finite-element method are discussed, and some results are given. Calculated results are compared with measured results. Calculation of shaft bearing influence coefficients with hull flexibility included is discussed. Finally, an application is presented in which a proposed alteration to an existing ship was analyzed.
Economic and Technical Feasibility of Copper-Nickel Sheathing of Ship Hulls
Authors: Czimmek D. W. , Sandor L. W.
Published: January 2021

This paper is an objective evaluation of the feasibility of copper-nickel (Cu-Ni) sheathing as a protection against biofouling for ship hulls. The first part of the paper covers the economic feasibility of Cu-Ni sheathing. An economic analysis was performed for trade-off purposes using the life-cycle method. Three different antifouling systems were analyzed for this purpose: conventional antifouling paint, self-polishing copolymer, and Cu-Ni sheathing. In this analysis two ship types were considered, a medium-speed roll-on/rolloff vessel and a slow-speed crude oil carrier. In the second part of the paper the technical feasibility of Cu-Ni sheathing is evaluated. The current technology is discussed for the physical application of Cu-Ni sheathing to the hull, including several methods of attaching the sheathing. Current test results on the Cu-Ni sheathing test panels installed on the tanker Arco Texas are presented and new cost-effective welding techniques for Cu-Ni sheathing of ship hulls are proposed.
Low-Grade Fuel Engines in the United States
Authors: Gupta S. K.
Published: January 2021

All major low-speed and many medium-speed engines now have the capability of operating and maneuvering on low-grade fuel oil (Bunker C). Low-grade fuel engines have recently been appearing in U.S.-flag ships. The economic reasons which influence owners to order these engines are surveyed here. The increased price of diesel oil and the improved efficiency of low-grade fuel engines have been major factors for their implementation. Improved equipment design for reliability and maintainability has decreased downtime due to repairs. Many ships operate auxiliary engines on low-grade fuel. Maritime schools have followed this trend by adding or expanding diesel courses to provide hands-on training and advanced techniques such as engine room simulators to teach problem handling. The low-grade fuel engine, with its superior fuel efficiency, is expected to become the dominant propulsion mode in U.S. merchant ships, as it already is in the rest of the world.
Economic Power Generation at Sea: The Waste Heat Recovery Plant/Constant-Speed Shaft-Driven Generator Combination
Authors: Corrado Charles N.
Published: January 2021

This paper presents an alternative method of generating electrical power onboard motor ships at sea. Consisting of a waste heat recovery plant and turbogenerator supplemented by a constant-speed shaft-driven generator, the generating plant offers significant potential fuel savings. Details of the plant, together with the results of several different case studies, are presented. Each case study consists of a selected set of operating conditions for the waste heat recovery plant, an estimate of the cost of the entire plant, and a preliminary economic analysis. Although the paper emphasizes the application of the proposed plant to a low-speed diesel installation, both the plant and the method of analysis are easily adaptable to medium-speed diesel and gas turbine installations.
Arrangement of Navigating Bridge with Emphasis on Bridge Visibility
Authors: Fay Christopher , Henry Robert W. , Holler Eugene J.
Published: January 2021

This paper examines the influences that help to determine merchant vessel bridge arrangement; in particular, it focuses on navigating bridge visibility. The efforts to develop bridge visibility guidelines both nationally (U.S. Coast Guard/Maritime Administration) and internationally (International Maritime Organization) are discussed. The paper concludes with a practical approach on integrating bridge visibility criteria into a ves-sel's conceptual design.
Investigation of Design Power Margin and Correlation Allowance for Surface Ships
Authors: Hagen Grant R. , Comstock Edward N. , Slager John J.
Published: January 2021

This paper follows two earlier papers, published by the Society in 1962 and 1979, dealing with correlation allowance and design power margin. For some time it has been perceived that a need exists for changes in the numerical quantities which have been specified by the U.S. Navy for correlation allowance coefficients and design power margins. This perception results from the recognition of a growing body of experimental data, both from model experiments and from ship standardization trials, that provide the basis for both correlation and margin policies. In response to this need, an exhaustive investigation was undertaken to establish a sound basis for a revised correlation allowance policy and to evaluate its impact on design power margin policy. The investigation, which led to proposed revisions in both policies, provided the material for this paper. Presented herein are:a review of the state of the art in the areas of correlation allowance and speed-power margin;an updated database derived primarily from model experiments and standardization trials of U.S. Navy ships;an assessment and interpretation of the database;a proposed alternative to the current correlation allowance policy;an evaluation of the impact of applying the proposed policy in determining required speed-power margins for U.S. Navy ships; anda proposed alternative to the current design power margin policy for new U.S. Navy ships.
A New Monohull Form Development as Applied to an Offshore Drilling Unit
Authors: Michael Farid Y. , Waller David B.
Published: January 2021

A new monohull form has been developed specifically in an attempt to combine certain advantages of the semisubmersible and conventional ship shape drilling vessel into a vessel of unique design. The new hull form represents a well-balanced workable design particularly suited to ships where seakeeplng, environmental operability and overall cost-effectiveness are the primary requirements. The basic advantages of the new monohull form when applied to a drillship are as follows:excellent motion characteristics (motions approach those of a comparable semisubmersible);economical advantages in hull fabrication due to the use of straight line framing and developable surfaces;high payload-to-displacement ratio compared with a semisubmersible;large usable deck area compared with a conventional drillship;safety—substantially improved intact stability characteristics, thus incorporating a major advantage of a semisubmersible; anda hull configuration that provides good structural integrity when compared with a semisubmersible.
The Lockheed Space Shuttle Rocket Retrieval Ship
Authors: Lamb Thomas , Loudon Alex M. , Van Slyke Robert J.
Published: January 2021

This paper describes the design and construction of a 200-ft rocket retrieval ship for West Coast space shuttle operations. The ship, MV Independence, is designed to retrieve the reusable solid rocket booster casings from each launch of the space shuttle. Construction design and technical management of the project are outlined and a typical rocket retrieval mission is described. Updated information on builder's trials and mission performance is appended.
Systems Engineering in the Fishing Industry
Authors: Hamlin Cyrus
Published: January 2021

The fishing industry is probably one of the most complex and indeterminate of mankind's occupations. Traditionally it has been fragmented into small enterprises, each expert in its own specialty. But modern fishing methods have forced the adoption of the integrated concept, that is, management of the industry from seabed to consumer by single corporate entities or by regulatory agencies. Integration of the fishing industry depends upon long-term and broad-based planning and decision-making. The best, possibly only, methodology for this is the orderly and rational techniques of systems engineering. The author's company has used systems engineering since 1967 for solving fisheries problems as well as for other marine issues. This paper outlines the difficulties facing the fishing industry decision-makers, and illustrates the use of systems engineering in their resolution. Specific examples are cited, and a short program for the estimation of fishing vessel size and cost is given.
Carbon Fiber Sailboat Hulls: How to Optimize the Use of an Expensive Material
Authors: Sponberg Eric W.
Published: January 2021

Carbon fiber is a very strong and stiff material that is ideally suited to sailboat hull construction. However, it is often poorly engineered or misused. At best, this results in an inefficient use of an expensive material. At worst, it can lead to serious unexpected failures. This paper discusses basic sailboat hull engineering and the results of flexural and impact tests conducted by the author on five sandwich laminates which have differing lay-ups of S-2 glass, carbon fiber, and core materials. The results show that a sandwich laminate using some carbon fiber in conjunction with S-2 glass placed in equal thicknesses either side of the core has significant advantages over sandwich laminates where the carbon fiber is placed on one side of the core only, or where carbon fiber alone is used. These latter cases represent common current practices, and, therefore, they are probably not the best.
The MV Robert LeMeur Ice/Propeller Interaction Project: Full-Scale Data
Authors: Laskow V. , Spencer P. A. , Bayly I. M.
Published: January 2021

An experimental program was conducted in which ice/propeller interaction data were collected on a twin-shaft shrouded controllable pitch propeller vessel with 3500 kW per shaft line. The tests were conducted in late June 1984 in the seasonal ice of the Canadian Beaufort Sea. Collected data illustrate the phenomena occurring in the Kort nozzle. A number of observations were made: interaction forces during nozzle blockage are of the same magnitude as during ice-blade impact; the maximum ice-induced blade force is not a function of ship speed; maximum ice-induced blade force occurs near relative radius 0.8. Ice interactions cause significant movement of the shaft relative to the shaft bearing; in ahead mode the blade is bent forward during ice interactions. Ice-induced shaft torque transients reached twice nominal and ice-induced shaft thrust transients reached four times nominal value. The largest blade impact forces are associated with the short-duration impacts.
The Emerging Domestic Cruise Industry
Authors: Leeper John H. , Boylston John W.
Published: January 2021

The U.S. market, with its high per-capita income, generous leisure time availability, and open market entry, has become the world's most lucrative market for ocen cruising. Cruise ships sailing from the United States serve six distinct markets: the Bahamas, Bermuda, the Caribbean, Alaska, Mexico, and inland/coastal. With the exception of the Alaska and inland/coastal markets, the trade is served almost exclusively by foreign-flag vessels. The Jones Act, which restricts passenger service between consecutive U.S. ports to U.S.-flag vessels, together with the increased popularity for ocean cruising, has created a demand for U.S.-built/U.S.-manned cruise vessels that can operate in the inland/coastal market. Also, legislation allowing tax deductions for business conventions held aboard U.S.-flag vessels, coupled with a soft market for U.S. new construction and U.S. seagoing labor, has culminated in the potential for an internationally competitive U.S.-flag cruise industry. This paper reviews the current status of the U.S.-flag cruise industry, its operating environment, the rules and regulations that govern its operation, and its probable future.
Conversion of San Clemente Class Tankers to Hospital Ships for the U.S. Navy
Authors: Reid Alan R. , Huff David S. , Cameron John C.
Published: January 2021

This paper describes a program—unique in the history of U.S. Navy ship procurement—to convert two 90 000-dwt crude oil carriers into hospital ships. The San Clemente class tankers, of 894 ft length overall, proved ideally suited to the conversion because (1) the long, parallel midbody design offered large, open spaces for the installation of modularized hospital and habitability units; (2) the ships' hydrostatic characteristics were favorable to the addition of new upper deck structures; and (3) the ships' hydrodynamic characteristics provided excellent seakeeping qualities with reduced ship motions critical during casualty reception and underway medical operations. Under the programmatic direction of Naval Sea Systems Command, the conversions were accomplished by National Steel and Shipbuilding to meet U.S. Coast Guard and American Bureau of Shipping regulatory requirements for passenger ships. The ships will be operated by the Military Sealift Command in support of authorized medical missions.
Microcomputer Software for Computer-Aided Ship Design
Authors: Parsons Michael G. , Beier Klaus-Peter
Published: January 2021

The rapid evolution of the microcomputer has changed the software needs of today's naval architects. The Department of Naval Architecture and Marine Engineering at The University of Michigan has been a leader in the application of computers in ship design education. The computer environment readily available to the department's students has changed dramatically in the past few years with the evolution of the Computer-Aided Marine Design Laboratory within the department and the creation of the Computer Aided Engineering Network (CAEN) within the College of Engineering. The microcomputer facilities available to the students are briefly described. To fully integrate this capability into the department's curriculum, a coordinated suite of computer-aided ship design software has been developed for use on the Macintosh and IBM-PC/XT/AT microcomputers provided for the students. To support the use of this and other software on a wide range of computers, a portable, device-independent computer graphics subprogram package M-PLOT has been developed. The educational philosophy behind this design software and its scope, capabilities, and use in ship design education are described. Examples of the use of selected programs are presented to illustrate these capabilities. Plans for further work are outlined. The effort is well toward the goal of a complete, microcomputer-based ship design software environment.
Machine Management of Marine Operations
Authors: Biancardi C. G. , Dellwo D. R.
Published: January 2021

Marine operations traditionally have been managed by professional mariners whose years of experience and training have prepared them for that responsibility. The science of artificial intelligence (Al) has made possible the development of computer programs used in monitoring, controlling and simulating the behavior of fully automated vessels. The advent of such programs means that, in the future, ships will be operated by a combination of human and machine intelligence. This paper is intended as a brief review of the subject of expert systems (ES), a branch of Al technology, and as a survey of its current maritime applications.
The Use of CAD in Ship Design
Authors: Van Devender W. W.
Published: January 2021

This paper outlines the methods of implementation for computer-aided design (CAD) and manufacturing within the shipbuilding industry. It is intended to show the most productive methods of computer-aided design and manufacturing based on logical research and development within a major shipyard. The differences between conventional methods and 3-D modeling are examined. Each topic is explained briefly to the extent that it is possible to derive positive results from the implementation of 3-D modeling; illustrations stress the point. The results described herein are achievable using current application packages presently available as a result of a commitment of progressive upper-level management to achieve the maximum productivity from the latest technology available.
The Design and Operation of Pumps Furnished for Marine Cargo Service: Part II
Authors: Sembler William J.
Published: January 2021

To a pump manufacturer, marine cargo service represents one of the most demanding applications for which he can design and furnish equipment. In addition to being subjected to the stresses encountered in a shipboard environment, cargo pumps must often perform over a wide range of operating conditions and handle multiple fluids with different viscosities, vapor pressures, specific gravities, temperatures, and material requirements. In this paper the author reviews characteristics of the different types of pumps used for marine cargo service, with an emphasis on the special features that should be incorporated into their design for this rigorous duty. Different types of automatic self-priming/stripping systems available for use with these cargo pumps are also examined. Pump operation is discussed, including the significant impact that system design has on proper pump performance.
Continuously Distributed Fiber Optic Monitoring System for Shipboard Applications
Authors: Griffiths Richard W. , Chatterton Herbert I.
Published: January 2021

This paper suggests several areas of applicability wherein continuously monitored fiber optic cables of composite construction will improve the sensing ability of locating and reporting the conditions extant on ships of various types. By using continuous fiber cables strategically located throughout the ship that are compositely clad with different coatings to detect temperature, pressure and strain, an optically attenuated profile can be continuously monitored on a cyclical basis to report the specific conditions on a real-time basis. Preliminary bench test results of prototype jacketed fiber optic cable indicate that strains of 0.0004 to 0.003 in./in. can be detected as well as pressure changes of similar sensitivity. Currently, tests are being run to determine temperature sensitivity, and it is expected that comparable results will be achieved. With the development of the systems and improvement in jacketing materials, further refinements and expansion of capabilities are expected.
Three-Dimensional Sloshing of Water on Decks
Authors: Pantazopoulos Michael S.
Published: January 2021

A methodology is proposed to solve the problem of the three-dimensional flow of water sloshing on the deck of a vessel, and to calculate the resulting forces and moments at the center of gravity. The Eulerian equations of motion of the water particle for incompressible inviscid shallow water flow are formulated with respect to a system attached to the oscillating vessel. The system of the nonlinear hyperbolic equations of motion is solved numerically using Glimm's method (random-choice method). Complex flow patterns consisting of oblique bores and "swirling" motions of the water on deck were revealed, for a vessel oscillating in roll and pitch motions, for a wide range of excitation frequencies. Large accumulation of water occurs at the corners while parts of the deck become dry. Significant rolling moments due to sloshing are exerted on the vessel. These must be taken into account when the dynamic response of the vessel is studied.
Effects of Length on Frigate and Destroyer Performance and Cost
Authors: Colwell J.L.
Published: January 2021

The major effects of hull length on frigate and destroyer performance and cost are examined by comparing design candidates with common design requirements, but with different lengths. Three hull forms are considered; one is representative of contemporary NATO practice, one is relatively long, and one is relatively short. In some cases, the long hull form provides the least expensive design solution, as it can satisfy common design requirements with lower installed propulsion power. When comparing ships with the same propulsion system, the platform acquisition cost of the longer hull form is generally slightly higher than the contemporary and shorter hull forms (within 1 percent); however, in some cases both the long and contemporary hull forms have lower platform acquisition cost than the short one. Comparison of design candidates indicates that, even when the longer ship has higher platform acquisition cost, it has sufficient performance, arrangement and future cost advantages to justify the higher initial expense.
Diaphragm Couplings Versus Gear Couplings for Marine Applications
Authors: Mancuso Jon R. , Paluh James H.
Published: January 2021

The gear coupling has been in existence for over 50 years. As advances in marine propulsion have occurred, so have advances in gear couplings. There are many variables in gear couplings that can affect their characteristics, including tooth design, materials, and lubrication methods. All couplings react on connected equipment. A system designer must consider these reactions when designing a system. If a gear coupling is chosen, there are many characteristics which are difficult to predict; therefore, one must conservatively estimate the maximum forces and moments that can be anticipated. This usually will make the system rather large and heavier than may be required. The diaphragm coupling usually has more predictable coupling characteristics, which can make a designer's life easier. This paper compares the characteristics of diaphragm couplings versus the gear (dental) type couplings in marine applications. Applications of couplings for main propulsion and auxiliary equipment are discussed. The methods used to analyze the design and calculate the forces and moments generated by both the gear coupling and the diaphragm coupling are also provided. These analyses are used to show that the forces and moments generated by a diaphragm coupling are not only predictable, but are usually lower than those of a gear coupling. The paper shows that a diaphragm coupling can provide a more predictable, reliable alternative to the gear coupling for advanced marine applications.
Small Vessel Hull Form Optimization for Heave and Pitch Performance
Authors: Zborowski Andrew , Sainsbury Simon R.
Published: January 2021

The Ship Motion Program (SMP) originally written for a mainframe computer system has been adapted for use on the IBM PC microcomputer family and subsequently applied to study ship seakeeping performance. The converted program, referred to as the Ship Seakeeping Characteristics Program (SSCP), was utilized for a parametric study on the influence of the main form parameters on heave and pitch performance for the British Ship Research Association (BSRA) trawler series of geometrically related forms. From the results of this study an optimum form has been indicated and its geometrical features defined.
An Empirical Review of the Design and Performance of Icebreakers
Authors: Dick R. A. , Laframboise J. E.
Published: January 2021

This paper utilizes available data on existing icebreaking ships to compile a review of the design features that influence ship performance. The data were extracted from a recently completed review of the state of the art of Arctic ship technology and include icebreaking ships from Argentina, Canada, Denmark, Finland, Japan, Sweden, the United Kingdom, the Soviet Union, the United States, and West Germany. It is the aim of this paper to offer guidance in the initial stages of icebreaker design and thereby give confidence to the designer in the selection of dimensions, hull shape and propulsion.
A New Usable Propeller Series
Authors: Denny Stephen B. , Puckette Larry T. , Hubble E. Nadine , Smith Susan K. , Najarian Richard F.
Published: January 2021

The Combatant Craft Engineering Department began, in the early 1980's, to evaluate a systematic series of propellers representing those available in the commercial market. The primary goal of the program was to generate "open-water" equivalent thrust and torque data, from full-scale trials, to improve propeller selection techniques for small craft and small ships, particularly at high speeds. The first phase of the program investigated three-bladed propellers with systematic variations in pitch ratio as well as propeller blade "cupping." Cupping has been a long-practiced, but ill-defined, art for fine-tuning propeller performance. The second phase, in 1987, expanded the series to include four-bladed propellers. In addition, the propulsion system of the test craft has been changed to achieve higher speeds, and therefore lower cavitation numbers.
Experimental Performance of a Trochoidal Propeller with High-Aspect-Ratio Blades
Authors: Bose Neil , Lai Peter S. K.
Published: January 2021

Open-water experiments were done on a model of a cycloidal-type propeller with a trochoidal blade motion. This propeller had three blades with an aspect ratio of 10. These experiments included the measurement of thrust and torque of the propeller over a range of advance ratios. Tests were done for forward and reverse operation, and at zero speed (the bollard pull condition). Results from these tests are presented and compared with: a multiple stream-tube theoretical prediction of the performance of the propeller; and a prediction of the performance of a single blade of the propeller, oscillating in heave and pitch, using unsteady small-amplitude hydrofoil theory with corrections for finite amplitude motion, finite span, and frictional drag. At present, neither of these theories gives a completely accurate prediction of propeller performance over the whole range of advance ratios, but a combination of these approaches, with an allowance for dynamic stall of the blades, should lead to a reliable simple theory for overall performance prediction. Application of a propeller of this type to a small ship is discussed. The aim of the design is to produce a lightly loaded propeller with a high efficiency of propulsion.
Dynamic Positioning of a Floating OTEC Plant Using Current-Derived Forces
Authors: Bucher Warren E.
Published: January 2021

A study is performed to determine whether Ocean Thermal Energy Conversion (OTEC) platforms can be dynamically positioned by the use of forces derived from ocean currents. The dynamic positioning characteristics of a 40-MWe spar buoy configured plant are simulated by computer solution of the equations of motion. The dynamic positioning system consists of two large vertical vanes attached to the plant's cold-water pipe. The vanes act as underwater sails and, where the current has a vertical speed gradient, may be operated such that the resulting hydrodynamic force and plant velocity have components directed upstream to the surface current. Forces on and motions of the plant are determined for operations in Hawaiian currents and in the Gulf Stream. The dynamic positioning method is shown to be theoretically feasible.
Design and Hydrodynamic Performance of Sailboat Keels
Authors: Greeley David S. , Cross-Whiter John H.
Published: January 2021

Computational techniques for sailing yacht keel design and analysis are presented and their application in the design process is discussed by means of examples for several different types of yacht keels. Comparisons of computed results and experimental data are made where possible to show the usefulness of the computational procedures presented, as well as their shortcomings. The emphasis of the paper is on the development of insight into the physical variables influencing keel hydrodynamic behavior, rather than optimization procedures for specific configurations. The computational techniques presented were developed and utilized by the authors during the 1987 America's Cup campaign, and have been used subsequently for both cruising and racing yacht keel design work.
Intact Stability Standards for Containerships
Authors: Tagg Robert D. , Michel R. Keith
Published: January 2021

U.S. flag containerships operate under the United States Coast Guard's wind heel criteria while the remainder of the international fleet operates under a wide disparity of stability requirements. This paper gives some background and history on the development of the various types of stability criteria. The current national and international criteria are presented and nine sample containerships are evaluated. The concept of "wave adjusted" criteria is discussed and sample calculations are presented. Recommendations for modifications to the Coast Guard's existing criteria and direction for further development of a comprehensive stability criteria are also presented.
Overview of Coast Guard Plan Review for High-Tech Ship Design
Authors: Watson James A. , Hayden William M.
Published: January 2021

The competitive nature of the marine industry has compelled ship and drill rig owners to expect vessel designs which operate more efficiently and are less expensive to build. Designers have abandoned the "old reliable" rule based designs of the 1960's and 1970's in favor of state-of-the-art, high-tech approaches to reduce design unknowns. Analysis techniques include six-degree-of-freedom motion simulation, finite-element structural analysis, fatigue and fracture mechanics techniques, structural and component reliabilities, and electronic on-board monitoring systems. At the Coast Guard Marine Safety Center, where construction plans are reviewed and approved, evaluating the safety of these designs is not an easy task! Unlike the rule-based designs, there are no "cookbook" formulas for double-checking the designer's calculations. An acceptable level of safety must be established and the design approach must be proven for its application to be accepted. Unfortunately, the level of safety that is built into "the rules" is not completely clear, so "acceptable" becomes difficult to establish. This paper discusses the requirements and capabilities of the Coast Guard commercial vessel plan review program and proposes an alternative plan submittal procedure for nonstandard designs.
Reliability Analysis of Great Lakes Marine Diesels: State of the Art and Current Modeling
Authors: Perakis Anastassios N. , Inozu Bahadir
Published: January 2021

Some essential steps for the application of reliability, availability, and maintainability (RAM) techniques to marine diesel engines are presented. The paper begins with a summary of the basic concepts of reliability engineering, followed by a survey of the relevant literature on RAM applications to the marine industry and to marine diesel engines in particular. Next, the results of an informal survey of the reliability, maintenance, and replacement practices of Great Lakes operators are presented. Finally, the first two steps for a RAM application, failure modes and effects analysis and fault tree analysis, are introduced and applied for a prototype Colt-Pielstick marine diesel engine.
An Appraisal of Unconventional Aftbody Configurations and Propulsion Devices
Authors: Blaurock J.
Published: January 2021

Recently, several additional devices and unconventional aftbody shapes have been applied to improve the overall efficiency of ship propulsion. These are Grothues spoilers, wake ducts, vane wheels, and asymmetric aftbody shapes. The paper describes the different physical mechanisms and specific features of the devices and configurations. Furthermore, theoretical and experimental data are presented regarding the gain in efficiency, based on calculations and model tests. Finally, experience with full-scale applications is reported.
Prediction of Craft Turning Characteristics
Authors: Denny Stephen B. , Hubble E. Nadine
Published: January 2021

A procedure is presented for predicting steady turning radius and turning rate of planing and displacement craft equipped with conventional propeller and rudder arrangements. The procedure enables prediction of turning characteristics for various rudder angles and approach speeds. Predictions of steady turning radii are compared with actual trial data for craft up to 110 ft in length. General graphs are presented which can be used by designers and craft operators to estimate approximate steady turning radius and turn rate when a minimum of craft information is available.
Use of Antipitch Hydrofoil to Reduce Added Resistance of a Yacht in Waves
Authors: Avis John
Published: January 2021

The use of a horizontal antipitch hydrofoil for the purpose of reducing the vertical motions and added resistance of a sailing yacht is investigated. The difficulties, limitations and assumptions inherent in studying yachts in waves are discussed. A mathematical model is presented in an attempt to predict the effect of an antipitch foil on the motions and added resistance of the 12-Meter Canada II. Scale model experiments were conducted and the results are presented and compared with the theoretical results. Experimental results show that the antipitch foil is indeed very effective in reducing the motions and added resistance of the model. At resonance, pitch is reduced by 22 percent, heave by 15 percent and added resistance by 40 percent. Theoretical results do not agree quantitatively with experiment. However, they do show good qualitative agreement with respect to the percentage reduction in motions and added resistance that can be expected through the addition of the foil and therefore could be useful as a preliminary design tool.
SHIPCOST: Vessel and Voyage Costing Model
Authors: Arnold John , Panagakos George
Published: January 2021

The paper describes SHIPCOST, a computer-based method developed first in 1984 by the World Bank, and subsequently refined, to evaluate vessel and voyage costs. The economics of vessel ownership and operation are examined and examples given of typical fleet voyage and trade costs, including a comparison between the use of newbuildings and secondhand ships. The separate fleet, ship and voyage modules included in the SHIPCOST model are discussed and typical applications given.
The Effect of Defects in Glass-Reinforced Plastic (GRP)
Authors: Cable Christopher W.
Published: January 2021

A rational basis for developing acceptance standards for glass-reinforced plastic structures hulls is presented. Using existing models and a fracture mechanics analysis, the effects of key defects are quantified. Cracks in the edges of penetrations are shown to be potentially critical defects. Additionally, an equivalency between key defects is demonstrated. This equivalency allows correct proportioning of efforts to control and correct defects.
Floating Body Equilibrium by Potential-Energy Minimization
Authors: Campanile Antonio
Published: January 2021

The paper presents a computer-based approach aiming to solve the equilibrium equations of a floating body by means of potential-energy minimization. After a brief and general discussion, the principle that the potential energy of the system must be at a minimum is adopted as the condition for identifying the stable equilibrium positions of a marine vehicle. A consistent mathematical formulation is then developed. The problem is solved, therefore, by searching for the minimum of a function of three variables using a simple and efficient iterative method. This makes it possible for the equilibrium positions to be determined directly, unlike the classic methods-that is, without any previously constructed table of hydrostatic data and regardless of the magnitude of waterplane rotation compared with the initial orientation. No restriction is stipulated on hull form. Some study cases relating to a prismatic barge and a jacket-type platform are presented and analyzed. Relevant numerical results allow the procedure to be optimized so as to improve convergence. Finally, peculiar features of the proposed method are discussed, with particular reference to jacket-type offshore platforms, and further valuable applications are indicated.
Ship Maneuverability Analysis Using Steady-State Techniques
Authors: Asinovsky Volf , Huang Kiang-Ning , Oakes Mark C.
Published: January 2021

This paper discusses the application of steady-state techniques to maneuverability, position-keeping and track-keeping analyses in the ship design process. A two-step method of calculating the diagram of steering is described. The first step gives an approximate solution based on a preliminary analysis of the relationship between the drift angle and the angular velocity of ship in the steady turn. The second step solves the nonlinear equations of motion using an iterative process. In the second step of the solution, the hull's hydrodynamic characteristics are introduced into the equations of motion directly in numerical form without a preliminary approximation by analytical functions. Assumptions about the kinematic parameters of motion are not used. This results in increased accuracy of the calculations. The hydrodynamic characteristics of the hull, rudder and appendages, and their interaction are considered separately. Position and track-keeping analysis using an approach similar to that used for the calculation of the diagram of steering is discussed.