bluuebunny/crossref_metadata_2025 huggingface dataset:
The Reproduction of the Godspeed
Authors: Stewart Duncan , Boze William
Published: January 2021

The authors, and designers, of the reproduction of the 17th century Godspeed present the criteria used to design, build, launch, and sea trial the 1984 reproduction. Foul weather notwithstanding, the reproduced Godspeed reenacted the Atlantic crossing in 1985 and is now homebased at Jamestown, Virginia.
The Influence of Hierarchical Decisions on Ship Design
Authors: Smith Warren F. , Kamal Saiyid , Mistree Farrokh
Published: January 2021

The design of engineering systems involves the design of dependent subsystems and the integration of these into a whole. A typical system has the characteristics of being multileveled, multidimensional, and multidisciplined in nature. It is this complexity which causes problems for the designer in making well-founded decisions. A decision support technique has been developed which offers a structured facility for the design of the subsystems and for the modeling of the interaction which is present between subsystems. The method, employing optimization procedures, allows all aspects of the system design to be considered concurrently, to produce the "best" solution, as defined by the specifications. This is in contrast to the traditional design method, which is iterative and cyclic in nature, involving sequential reevaluation and refinement. In this paper, the effectiveness and efficiency of the decision support problem approach is demonstrated using the hierarchical characteristics of a design for a barge. The barge problem, though basic in form, is comprehensive in concept and tutorial in nature. As a formulation for "system" optimization, it uses a computer-based method for solution and illustrates the virtues of a multilevel/multidisciplinary approach to design and decision-making. It also exhibits the same characteristics and provides valuable insight into the solution of the more complex problems encountered in practical ship design.
A Case Study of Dynamic Instability in a Planing Hull
Authors: Codega Louis , Lewis James
Published: January 2021

Soon after introduction into service, a class of high-speed planing boats began to exhibit a dynamic instability that manifested itself in the craft trimming by the bow, rolling to a large angle of heel to port, and broaching violently to starboard, all within five seconds. This behavior, which occurred within the craft's normal operating envelope, could not be attributed to operator causes and resulted in unacceptable operating restrictions being placed on the craft. After a number of unsuccessful attempts to remedy the problem, an investigation to research possible causes was undertaken. Concurrently, a test boat was instrumented to quantify its behavior and, most importantly, to record the hydrodynamic bottom pressures acting while this phenomenon occurs. The craft is described and initial attempts at solving the problem are outlined. The results of research on this type of phenomena in both planing craft and flying boats are presented. The instrumentation system, complex for this size craft, is detailed and the test procedure described. The results of the full-scale tests are given, along with qualitative comparisons with other craft that display a similar problem and model tests that would indicate the possibility of such instabilities. The cause of the instability is described and recommendations are made to avoid similar problems in future craft.
Renovation of the Floating White House
Authors: Gow Paul A. , Waterhouse John W.
Published: January 2021

Built in 1934 as a cutter for the U.S. Coast Guard, the Potomac achieved its notoriety while serving for ten years as a yacht for the President of the United States, Franklin D. Roosevelt. Through 50 years of changing technology, marine regulations, and fashion, this 165-ft (50.30 m) vessel has made its sometimes halting way, escaping the scrapping yard, and is today sitting in Oakland, California awaiting renovation. The goal of the owner, the Port of Oakland, is to use the Potomac as a floating museum carrying passengers on an excursion into the late 1930's. In the fall of 1984 the Association for the Preservation of the Presidential Yacht Potomac (APPYP), managers of the Potomac, contracted with Nickum & Spaulding Associates, Inc. (N&SA) for engineering services. N&SA was to generate a shipyard bid package that would produce a restored vessel acceptable to the U.S. Coast Guard as a Subchapter H passenger ship. This paper reviews the vessel's history and examines some of the design compromises necessary to make the Potomac as historically accurate as possible while meeting the current marine regulations and museum function requirements.
Practical Bollard-Pull Estimation
Authors: Isin Y. A.
Published: January 2021

During the preliminary design of a tugboat, the use of minicomputers can permit the designer to give a very quick estimate of propeller characteristics such as pitch-diameter ratio, expanded area ratio, revolutions per second, and the thrust and delivered horsepower for the bollard-pull condition. These estimates can be made by the use of charts derived from polynomial expressions of experimental propeller series data, for example, the Wageningen B-Screw Series.
Enhanced Piping System Reliability with Heat Recoverable Couplings
Authors: Honeywell William
Published: January 2021

Heat recoverable couplings (HRC's) have been used to join pipe on U.S. Navy ships since 1978. They are designed to meet demanding performance requirements and have been extensively tested. HRC's are manufactured from a nickel-titanium alloy called Tinel® and their design centers around a property of this material called "shape memory." The design of the couplings, their use history, and the function of shape memory are reviewed. The test performance of HRC's is then discussed and compared with conventional pipe joining techniques. They are shown to provide a higher overall reliability than either braze joints or socket welds.
High-Performance Rudders—with Particular Reference to the Schilling Rudder
Authors: Bingham V. P. , Mackey Thomas P.
Published: January 2021

The evolution of the rudder as a means of steering or maneuvering ships has not kept up with other progress in ship machinery and propulsion systems. During the past decade, however, several significant advances in ship maneuvering have been made based on the principle of diverting the propulsive thrust rather than simply steering the hull. One of these innovations is the Schilling rudder, which offers, at a relatively economical cost, greatly improved maneuverability even at very slow speeds. The Schilling rudder can be rotated 75 deg to either side without stalling, which provides stern thrust capability to the ship as the main engine thrust can be diverted at an angle of 90 deg to the hull. A twin Schilling Rudder system, with independently controllable rudders, has the additional features of allowing vectored reversal of ahead thrust, eliminating the need for a reversing gear or controllable-pitch propeller, and, when coupled with a suitable bow thrust device, can even provide a level of dynamic positioning capability to the ship. Both the single and double Schilling rudder systems have now been proven in service and their applicability extended to most types of vessels with no limit on size.
On the Flow-Induced Structural Noise of a Ship’s Sonar Dome
Authors: Rao V. Bhujanga
Published: January 2021

A detailed study on the importance of flow-induced structural noise of a ship's sonar dome and its relative contribution to ship's sonar self-noise is presented. Flow-induced dome wall vibration statistics subjected to a turbulent boundary-layer flow are computed using a suitable mathematical model describing the turbulent boundary-layer pressure fluctuations. Various noise and vibration sources contributing to sonar self-noise are experimentally analyzed. The measured hull vibration amplitudes are compared with calculated dome wall vibration amplitudes in order to ascertain the importance of flow-induced dome wall vibration as a contributor to flow-induced structural noise.
The Design and Operation of Pumps Furnished for Marine Cargo Service: Part I—Centrifugal Cargo Pumps
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. (Because this paper is too large for publication in a single issue, Part II, on other types of cargo pumps, will appear in the next issue of MT, April 1988.)
Classification Systems for Ship Items: A Formal Approach and Its Application
Authors: Birbanescu-Biran Adrian
Published: January 2021

Calculation of masses and moments of ship items is carried out mainly to establish the main ship dimensions, to assess intact and damage stability and to estimate cost. The mass properties of ship items can be systematically summed over subgroups, groups, and main groups of items if these are classified according to a hierarchical system. The process can be facilitated and eventually automated by assigning each item a classification number that induces the desired hierarchic system. Formal definitions and conventions are presented for constructing such numbers. Accepted classification systems such as SWBS, MARAD, and SFI were analyzed briefly in the light of the proposed formalism and corrections were proposed for the MARAD system. The results of this analysis were used to develop a program for summing mass properties at the level of detail specified by the user, that is, at the level of subgroups, groups, or main groups of ship items. This program was written as part of a computer-aided design system integrated around a relational database. The availability of the program also enabled a significant reduction of the redundancy of stored data.
Current Practices and Future Trends in Marine Propeller Design and Manufacture
Authors: Norton John A. , Elliott James W.
Published: January 2021

The demand for propellers of greatly increased efficiency that maximize fuel savings while minimizing both cavitation and propeller-excited vibrations has been driving the development of sophisticated computer programs for current application as well as into the 1990's and beyond. These programs enable the designer to evaluate the effects of geometry details without the necessity for—or at least greatly reduced reliance upon—costly and time-consuming model tests. This paper looks at these new propeller hydrodynamic design processes and examines the challenges faced by manufacturers to produce many different types of propellers that all meet highly exacting tolerance, materials, and performance criteria.
CCGS Louis S. St. Laurent Mid-Life Modernization Design Studies
Authors: Kendrick A. , Carter J.
Published: January 2021

The CCGS Louis S. St. Laurent has been in service since 1969, and is the largest and most powerful unit in the Canadian Coast Guard fleet. She is now approaching a major mid-life modernization, intended to give her at least a further 15 years' useful life. This modernization will provide the opportunity to greatly improve the performance of the ship, notably its icebreaking capability and its fuel economy, by applying technology and knowledge developed in the 20 years since the ship was designed. This paper describes the series of studies, tests, and trials commissioned by the Coast Guard to develop a clear picture of the improvements which it will be feasible and cost-effective to implement.
Drogues: A Study to Improve the Safety of Sailing Yachts
Authors: Hervey Carol L. , Jordan Donald J.
Published: January 2021

Sailing yachts, in particular those less than 45 ft in length, face the potential hazard of breaking wave capsize when sailing offshore. A study was conducted using both model and full-scale tests to investigate the use of a drogue to alleviate the potential of capsize. In addition, a mathematical model was prepared which simulates the motion of a boat and drogue in regular waves and in a breaking wave strike. The results have shown that this technique offers the promise of a large improvement in safety, and it can be readily applied to the current fleet of sailing yachts with only minor modifications to existing hardware.
Contingency Planning for Oil Spills: An Update Based on Experience Gained from the Port Angeles Spill
Authors: Levine Robert A.
Published: January 2021

Although the best method for handling an oil spill is to prevent its occurrence, the risk of a significant oil spill, from either a tank or other vessel, is always present. When a spill does occur, a good spill contingency plan will help to limit the adverse effects of the spill. This paper discusses the contents and development of Spill Contingency Plans, with emphasis on experience gained during the cleanup of the Port Angeles spill. Information pertinent to and details from ARCO Marine Inc.'s Spill Contingency Plan have been included to aid interested parties in their endeavors to develop suitable contingency plans.
Shortening Afloat of a Very Large Crude Carrier
Authors: Podenzana-Bonvino Carlo , Tedeschi Rodolfo , Boote Dario , Ferrando Marco
Published: January 2021

A method for shortening afloat a very large crude carrier by means of a watertight transverse cofferdam is described. The method permits completely dry operations both when cutting the ship into three parts (while disconnecting the bottom plates and stiffeners) and when joining together the end sections (welding of the underwater structures). During the initial approach to the problem it became obvious, on the basis of theoretical calculations, that it would be impossible to eliminate the shear force and bending moment acting on the two sections to be cut; therefore, a series of linking means was designed to bear the residual shear and bending stresses which, to the authors' knowledge, were unavoidable in view of the uncertainties existing as to the longitudinal weight distribution. In order to ensure correct loading of these linking means, proper ballast transfers were arranged so that the ship was maintained in a slightly hogging condition while the bottom was being cut, and then in a slightly sagging condition while the deck was being cut. These linking devices were equipped with strain gages, so that they worked as actual load cells.
U.S. Maritime Assistance in Perspective
Authors: Lowry Robert , Zeien Jennifer
Published: January 2021

This paper describes government assistance to the U.S. merchant marine and shipbuilders by providing both an historical perspective and an assessment of the present status of these industries. The paper then describes over 50 merchant marine/shipbuilding aid strategies proposed over the past 25 years. Strategies are grouped according to their contribution in the areas of ship operation, ship construction, and cargo preference.
Industrial Photogrammetry—Its Application to Shipbuilding
Authors: Gunn Michael J. , Hicks Ronald S.
Published: January 2021

Photogrammetry is the science of acquiring and interpreting three-dimensional data of physical objects by measuring and analyzing their images on photographic plates. The development of this technology since the mid-seventies has increased its credibility for application to industrial and shipbuilding use. Analytical photogrammetry is now routinely employed in shipbuilding for tasks as diverse as predicting the fit-up of structural steel assemblies prior to their joining, verifying the circularity of submarine hulls, and checking the alignment of catapult trough components on aircraft carriers. The authors address the practical applications of photogrammetric technology, and identify the reliability, versatility, and productivity of photogrammetric surveying when applied to shipbuilding.
Some Guidance for Hull Form Selection for SWATH Ships
Authors: Lamb G. Robed
Published: January 2021

Even though in 1987 there were only a dozen SWATH (smali-waterplane-area twin-hull) craft and ships afloat around the world, word of their markedly superior seakeeping performance is spreading rapidly. The number of SWATH vessels is likely to double within five years. As in many other areas of technology, the United States and Japan are the acknowledged leaders in the development and practical application of the SWATH concept. This paper reviews the characteristics of existing SWATH craft and ships from the standpoint of the stated seakeeping objective. Hull form differences between four SWATH craft and ships, including the Navy's SSP Kairnalino, are analyzed and interpreted. Important considerations for the early-stage design of a SWATH ship are discussed. Differences in the range of feasible hull form geometries for coastal areas and unrestricted ocean operations, and for low-speed versus moderately high-speed applications, are pointed out.
A Decision Support System for Containership Stowage Planning
Authors: Saginaw D. J. , Perakis A. N.
Published: January 2021

The results of a project intending to design and develop a microcomputer-based, interactive graphics decision support system for containership stowage planning are presented. The objective was to create a working prototype that would automate data management tasks and provide computational capabilities to allow the stowage planner to continuously assess vessel trim, stability, and strength characteristics. The paper provides a complete description of the decision support system developed to meet this objective, including a definition of the containership stowage problem, and details on the design and development of the Automated Stowage Plan Generation Routine (ASPGR). The paper concludes with a discussion of issues relevant to the implementation of the system in the maritime industry.
Simulation in Marine Transportation System
Authors: Chowdhury Khabirul Haque
Published: January 2021

This paper describes a computer simulation model as an essential technique to examine alternative marine transportation systems. A two-port system with a two-deck roll-on/roll-off (RO/RO) ship has been taken for the study to represent a short sea transportation system. All operating variables, including those which exhibit random variation in the RO/RO transportation system, have been incorporated. Productivity data for varying number of tugmasters and for alternative internal access options have been obtained partly from physical observation and partly from the output of a simplified mathematical model. A simple economic model has been incorporated to enable the total model to produce the relevant output for the alternatives. The model also produces as output various histograms for some of the operational indices of interest. In the absence of enough real-life data for comparison, some of the results have been verified through the opinion of experts. It was found that such simulation studies are useful and indeed practical tools for the analysis of complex marine transportation systems.
Jet-Propelled Remote-Operated Underwater Vehicles Guided by Tilting Nozzles
Authors: Gangadharan Sathya N. , Krein Heinz L.
Published: January 2021

This paper is a study and experimental analysis of a forced jet propulsion system with tilting-type nozzles for slow-moving remotely operated underwater vehicles (ROV's). A test setup simulating the motion of the underwater vehicle was fabricated to investigate the effect of nozzle configurations on the propulsion of such vehicles. Plexiglass nozzles of different conical contraction angles (θ = 4 to 28 deg), different conical expansion angles (θ = 3 to 9 deg), and a straight cylindrical section were used in the study. Tests were carried out underwater, and the parameters measured include thrust, flow rate, angular velocity, and total head. Different circular disk type drag plates were used to simulate the drag of the vehicle underwater. Efficiency of propulsion is the criterion for comparing the performance of each nozzle. An expression for the optimum efficiency was derived neglecting the effect of inlet head recovery, which can be assumed for slow-moving vehicles. The energy loss and loss coefficients in submerged propulsion nozzles were found both theoretically and experimentally. A proposal for the fabrication and testing of an innovative design of a jet-propelled ROV guided by tilting nozzles is presented. The design uses a stepper motor for tilting the nozzles. A comparison is made between stationary and swivel-type configurations. The nozzles were tested for optimum area ratio. The propulsion system and the ROV was designed and checked for stability. The study revealed that for a range of flow rates, one particular nozzle was the most efficient compared to other nozzles.
Roll Damping on Two New England Trawlers: An Experimental Study
Authors: Goudey Clifford A. , Venugopal Madan
Published: January 2021

An experimental study on three types of roll damping devices—bilge keels, passive bilge fins, and paravanes—is described. These tests were conducted in the MIT Ship Model Towing Tank using scale models of a 76-ft single-chine trawler and a 119-ft double-chine trawler. The models were fitted with each damping device and excited in roll by a hull-mounted moment generator. Roll motions were measured at zero speed and at trawling and steaming speeds. Nondimensional damping ratios have been calculated and the effects on roll damping of each device are compared. The relationship of bilge keel and bilge fin area and aspect ratio to damping ratio are studied and some design considerations are presented. Practical aspects of each device type are also discussed.
Sailing Vessel Stability—with Particular Reference to the Pride of Baltimore Casualty
Authors: Chatterton Howard A. , Maxham John C.
Published: January 2021

Stability is a critical element in the design and safe operation of sailing vessels. This paper discusses U.S. Coast Guard requirements for the intact stability of sailing vessels with emphasis on wind heel and dynamic stability criteria for passenger and sailing school vessels. The effects of deck edge immersion, downflooding angle, range of stability and intended route are examined in detail. The righting energy and wind velocity relationship of the U.S. Navy's small craft criteria is analyzed and applied. The Pride of Baltimore casualty is reviewed as an example of wind effects on a sailing vessel under various conditions of sail.
Nature’s Dynamometer: Hull Performance Profiles and Dynamic Resistance for Sailboat Hulls
Authors: Selness Jerry N.
Published: January 2021

A new method for predicting full-scale sailboat hull resistance from full-scale coasting tests is presented. A way to minimize the influence of the ship's own wave is based on the creation of a "dynamic resistance" curve from several tests. Experimental results from tests conducted on an International Offshore Rule type sailboat are presented. The results show promise for future practical applications.
People to People International (P/P) SNAME China Trip Report
Authors: Lowry Robert , Serim Feridun K.
Published: January 2021

This is a report on a 21-day trip made to the Peoples Republic of China in 1986 by twelve SNAME delegates at the invitation of the China Society of Naval Architects and Marine Engineers (CSNAME) under the auspices of People to People International. The delegates visited four universities, five ship design organizations, three regional shipbuilding management organizations, seven shipyards, three shipping service organizations and three port areas. The tour visited Beijing, Dalian, Shanghai, Guangzhou, and Hong Kong.
System Safety Engineering as Applied to Ship Design
Authors: Halebsky Max
Published: January 2021

This paper describes the application of System Safety Engineering (SSE) during the design development phase of a ship program. The major objective is to incorporate safety into the initial ship design, including consideration of maintenance and operating safety. Accomplishment is by safety analyses which identify potential safety hazards and recommend specific actions to eliminate or minimize the hazards. The principal types of analyses performed are the preliminary hazard analysis, the subsystem hazard analysis, the system hazard analysis, the operating hazard analysis, and the fault tree analysis. Hazards are classified from Category I (catastrophic) to Category IV (negligible). Corrective action follows an order of precedence in which the preferred approach is to eliminate or control the hazard by means of the basic design, and the least desirable approach is to attempt to avoid the hazard by means of operating procedures
A New Cruise Ship Concept for Hawaii
Authors: Boylston John W.
Published: January 2021

The Hawaiian interisland cruise trade is presently served by two U.S. flag Vessels, the Constitution and the Independence. These vessels, in their 35th year, are approaching the end of their useful life and the only proposed replacement is the conversion of another existing vessel, the Monterey, which will enter the trade in 1988. As a Jones Act trade, any new replacement vessel must be built in the United States. The existing vessels employ U.S. crews and older, inefficient steam plants, but have a near zero capital cost. Any new competing vessel therefore suffers from its high initial capital (construction) cost and must provide savings in operating costs and enhanced passenger amenities to compete. In this paper, the present cruise trade is examined, and a new concept design is proposed that will meet the needs of the growing Hawaiian cruise trade, provide a superior cruise atmosphere, reduce U.S. construction costs and, perhaps, provide a competitive service. The reduction of construction cost would be obtained by a unique vessel arrangement and method of construction, whereby the base hull and machinery are built in the U.S., but the accommodation is built outside the shipyard and transported in a unique fashion to the construction site. This method would be consistent with Jones Act requirements. The concept design has been taken to sufficient detail to be compared with another new, conventionally arranged, proposed Hawaiian cruise ship.
Computer Representation of Numerical Expertise for Preliminary Ship Design
Authors: Duffy A. H. B. , MacCallum K. J.
Published: January 2021

In the early stages of ship design a considerable amount of experience and knowledge is used to build and evaluate empirical models with known design relationships. However, computer-based systems which aim to assist this stage have tended to concentrate on the analytical aspects of the process and have not been successful in integrating with this expertise and benefitting from it. This paper presents some of the results of a program of research into methods and representing knowledge of empirical numerical relationships used in these early stages of the design process. The work is based on an experimental system, DESIGNER, described in earlier papers. The DESIGNER system is used to carry out a series of evaluations of design sessions, using a warship design model. By examining the progress toward a set of design goals and the classes of interactions used, an improved understanding of the requirements of an interactive numerical design system is developed. As a consequence, methods have been developed to handle approximate values and relationships, to include design margins, and to represent explicitly in the system the definition and use of goals, or design requirements. Using a design model representing a bulk carrier, the paper then presents a worked example to illustrate the use of the new numerical knowledge techniques. It is concluded that the techniques could make a useful contribution to any interactive numerical design system which aims to provide improved use of expertise.
Product Liability Goes to Sea: A Survey of the Legal Liability of Sellers and Manufacturers in the Marine Industry
Authors: Davies David G.
Published: January 2021

United States law imposes potential liability on sellers and manufacturers of maritime products that prove to be defective in design or production. The degree of their vulnerability depends on the nature of the damage that results from the defect and their legal relationship with the person who suffers the damage. When the defect results in death or bodily injury, the potentially liable party cannot act be-forehand to limit the persons to whom he is liable or the amount of his liability. Common issues in such cases are causation, often based on expert testimony or government reports, hindsight determination of design defects or failures to warn adequately of unavoidable hazards, and foreseeable human errors. If damages are "economic," however, the seller's or manufacturer's liability may be limited to those with whom he had contracted directly, and the contract can further limit the amount of liability to those persons and the methods by which they can enforce what rights they have.
Static Pressure Distributions Over 2D Mast/Sail Geometries
Authors: Wilkinson Stuart
Published: January 2021

A variable-camber aerofoil with integral pressure tappings has been built to investigate the nature of the flows around two-dimensional, highly cambered, sail-like aerofoil sections with circular masts. Data have been obtained in the form of static pressure distributions over representative ranges of Reynolds number, camber ratio, incidence angle, mast diameter/chord ratio and mast angle. Two sail shapes—based on the NACA a = 0.8 and NACA 63 mean-line camber distributions—were involved in the test program. All flow regimes present have been identified and related to the salient model and flow parameters.
A Preliminary Design Method for the Prediction of Squat in Shallow Water
Authors: Millward A.
Published: January 2021

The variation of squat with speed in shallow water has been shown to be important with the sinking of the ferry Herald of Free Enterprise, yet it is not easily predictable, particularly at higher speeds. The squat characteristics of a number of ship models have been analyzed and an empirical method of predicting the squat at subcritical speeds has been devised. This method has been compared with data from the model tests of the Herald of Free Enterprise and has shown good agreement.
Ship Operator's Problems in Today's Environment
Authors: Leback Warren G.
Published: January 2021

This article is a speech presented to the Philadelphia Section by one of the maritime industry's leading spokesmen. Although it is not in the format of a formal technical paper, it is judged to be a timely presentation on a subject of general interest to SNAME's members and is therefore published in Marine Technology to provide wide distribution.
Shaft Alignment in Ship Repair: Three Case Studies
Authors: Jackson Paul C.
Published: January 2021

In ship repair, there are many times when the propulsion shaft has to be realigned after repairs have been completed. This paper looks at some of the theoretical approaches to shaft alignment and some of the techniques for alignment. Three different cases are examined to demonstrate how the principles work in the dock and some of the problems incurred. The three cases involve vastly different shaft systems with different repair and alignment problems.
Corrosion Protection for Ballast Tanks of Arctic Offshore Structures
Authors: Kwan George H. H.
Published: January 2021

Protecting the ballast tanks of Arctic offshore structures from salt-water corrosion is a time-consuming and costly process involving usually the application of such anti-corrosives as coal tar epoxy. This paper points out the drawbacks of relying on these coatings alone, among them the prohibitive cost and difficulty of dry-docking huge Arctic offshore structures for repainting when the original coating deteriorates or fails. A solution to the problem—cathodic protection via the attachment of aluminum anodes to tank surfaces coated with only a light primer—is described along with the results of a full-scale application on a submersible barge in the U.S. Beaufort Sea.
Operation and Cost of High-Speed Craft
Authors: Wright Christopher
Published: January 2021

The various types of high-speed craft (HSC)—air supported, foil supported, displacement hull, planing hull—are briefly described and their suitability for certain passenger routes in different operating environments is analyzed. The transport and commercial efficiencies of a number of existing craft of mixed sizes and services are graded and graphically compared. The paper concludes with a discussion on the economics of HSC service and the many factors that bear upon optimum craft selection for a particular route and operating environment.
An Analysis of Marine Total Losses Worldwide and for Selected Flags
Authors: Ponce Paul V.
Published: January 2021

The results of a detailed analysis of marine vessel total losses in relation to selected vessel population characteristics are presented. The casualty and vessel characteristics data used in the analysis are those published by Lloyd's of London in their quarterly casualty returns and in their yearly statistical tables [1,2].2 The data used for the analysis include the six-year period from 1980 through 1985, the data from 1980 through 1983 being the most complete. The casualty and population data were processed into tables which provided frequency data for total losses worldwide and vessel population worldwide by age classes. Similar tables were constructed for selected flags.
Gentlemen, Choose Your Weapons—The Race Conditions for the America’s Cup
Authors: Kirkman Karl L.
Published: January 2021

It is probable that no competitor has entered the America's Cup competition without holding some expectation of winning, and a dominant factor in doing so is the equipment used. Yacht racing is an equipment sport, and except for a small minority of so-called one-designs, no serious observer considers the equipment to be equal for the various competitors. Because of the great variety of conditions under which races are conducted, and the statistically small samples used to select an America's Cup winner, the variation in equipment takes on supreme importance. Indeed, the competition has sometimes been won2 before the preparatory gun for the first race; thoughtful equipment choices made the racing itself a sail-over. On the other hand, public opinion seems to eschew a mismatch. A paradox seems to exist in that part of the competition is understood and agreed to involve the "contest before the contest"—placing oneself at advantage by means of clever equipment choices—while at the same time observers claim to want a fair race series, which directly contradicts the acceptance of equipment advantage. In short, the public wants a victory but not a rout. In light of recent controversy regarding equipment rules in the 1983, 1987 and recently in the 1988 series, the paper recounts the historical context of equipment choices to assist in the understanding of an apparently chaotic situation.
U.S. Commercial Ships for Tomorrow
Authors: Landsburg Alexander C. , Gabler Eric , Levine George , Sonnenschein Richard , Simmons Earl
Published: January 2021

Foreign "ship of the future" research programs, recent design work, and other studies are the background for this paper, which addresses the interaction between innovation and competitiveness; trends in economics; advances in technology; effective manning; social needs; and design constraints. The paper then provides a discussion of attractive innovations and avenues toward U.S. competitiveness in the maritime industries of tomorrow.
Fatigue Crack Propagation in an HSLA Steel (MF-80) in Air and in Salt Water
Authors: Gill S. J. , Crooker T. W.
Published: January 2021

Fatigue crack propagation was studied in MF-80 HSLA steel in ambient room air and in 3.5 percent sodium chloride salt water. Region II fatigue crack growth rate (da/dN) data were obtained at two load ratios, R = 0.10 and R = 0.67. da/dN values were found to be affected by both load ratio and environment, with the greatest effect being caused by the combination of high load ratio and salt-water environment. Overall, the results of this study suggest that MF-80 HSLA steel may have slightly less Region II fatigue crack propagation resistance than other high-strength steels of comparable strength.
The Relocation of the SSDC/MAT in 1987
Authors: Jolles W. H.
Published: January 2021

The Canmar SSDC/MAT drilling unit was relocated in the U.S. Beaufort Sea in the fall of 1987. The relocation plan consisted of the initial breakout phase, the lift before the tow, the tow to the new drilling location, and the setdown on the new location. This paper discusses some of the experiences gained during the relocation. The main concerns for relocation of a bottom-founded drilling unit are the soil suction and adhesion effects, the time required for lifting free of the seabed, the stability during breakout, the control that can be exercised over the unit when it breaks free of the seabed, and the positioning and ballasting accuracy that can be achieved during setdown. This relocation has shown that lift-off in adverse or soft cohesive soil conditions is not limited by the suction breaking capability of the unit. The relocation also showed that high horizontal position accuracies were achieved during setdown. Comparisons are made between the target procedures developed in the planning stage and the actual procedures monitored during the relocation. A brief description is given of the equipment installed on board as used for the control and monitoring of the operation. The design operating requirements of the unit are highlighted.
Status of Deepwater Production Systems
Authors: Horton Edward E.
Published: January 2021

As oil exploration and production moves farther offshore, innovative technology is required to exploit energy resources in ever deeper waters. This paper covers two areas of deepwater production: offshore Brazil and the Gulf of Mexico. The types of wells and their capacity are described as well as the alternative platform designs, both fixed and semisubmersible, being used to recover both oil and gas from depths greater than 1500 ft. The paper outlines why these deepwater regions are of interest now and describes developments that are expected in the near future.
Designing the Future U.S. Naval Surface Fleet for Effectiveness and Producibility
Authors: Graham Clark , Bosworth Michael
Published: January 2021

David Taylor Research Center is just commencing investigations into a new manner of defining future fleet architectures. The cost of current performance-driven ship designs has increased at a rapid rate. While it is true that a warship designed with insufficient performance is of meager utility, it is also true that the best performing warship design is of no utility if never built. Both performance and affordability are required if sufficient numbers of ships are to be built to counter the threat. By designing a future fleet architecture with producibility as a major requirement from the start, we hope to impact the acquisition cost significantly. One battle force concept titled "Distribute, Disperse, Disguise and Sustain" suggests two fundamental surface ship types; the Carrier of Large Objects (CLO) and the Scout Fighter. A CLO feasibility design in progress, Carrier Dock Multimission, is outlined to inform shipbuilding researchers of an initiative that promises to have significant impact on naval ship procurement and provide increased visibility within the U.S. Navy on producibility issues. Before an attempt is made to conceptualize a future U.S. naval surface fleet, to help create a vision of the U.S. Navy for the year 2030 and beyond, the shortcomings of the current surface Navy must be addressed first. An honest assessment of where we are now is a must for us to determine where we need to be in the future and how to get there.
Explosive Ordnance Disposal SWATH Ship Design
Authors: Schaffer R. L. , Kupersmith J. A. , Wilson R. , Valsi T. J.
Published: January 2021

This paper describes the technical details, design management and procurement status of a 70-ton SWATH (small waterplane area twin hull) designed to support underwater Explosive Ordnance Disposal (EOD) forces. There are several objectives of this paper, including:to contribute to the limited database of small SWATH design information;to describe a practical approach to planning and scheduling constrained small craft design efforts; andto present some general lessons learned regarding the design of new or innovative craft or systems.
The Weight of Concrete Barge and Pontoon Hulls
Authors: Harrington K. E. , Hansen R. , Marshall A. L. , Hubert M.
Published: January 2021

Increased structural weight has always been a major disadvantage and probably the main objection to using concrete hulls. Postwar development in materials and construction techniques has led to claims that it is now possible to achieve structural weights equalling or closely approaching those of equivalent steel hulls. After reviewing the postwar material and construction technique developments, this paper compares the structural weight of existing and equivalent steel and concrete barge and pontoon hull designs. It is found that increased structural weight is a dual factor advantageous in some applications but disadvantageous in others, and that despite the postwar developments concrete barges and pontoons are still heavier than equivalent steel hulls.
Several Recent Rammings Investigated by the National Transportation Safety Board
Authors: Johnson Ralph E. , Katcharian Leon Z.
Published: January 2021

This paper discusses several recent rammings investigated by the National Transportation Safety Board:the ramming of the U.S. fishing vessel Chickadee by the guided-missile frigate USS Richard L. Page (FFG-5) in the Atlantic Ocean near Virginia Beach, Virginia on April 21,1987;the ramming of the Sidney Lanier Bridge by the Polish bulk carrier Ziemia Bialostocka at Brunswick, Georgia on May 3, 1987;the ramming of the Spanish bulk carrier Urduliz by the aircraft carrier USS Dwight D. Eisenhower (CVN 69) at Hampton Roads, Virginia on August 29, 1988; andthe ramming of the French tankship Camargue by the Swedish auto carrier Figaro in the Gulf of Mexico near Galveston, Texas on November 10, 1988.

The paper addresses both crew and ship performance which contributed to these accidents. In addition, the paper discusses the role of the Safety Board in accident investigations, and the safety recommendations issued by the Safety Board as a result of these investigations.
Weight Definition and Control for Fast Craft
Authors: Daidola John C. , Reyling Christopher J.
Published: January 2021

A standard for weight definition and an approach to weight control is presented for modern motor yachts and other craft. This includes a definition of weight and loading conditions for these vessels which can be related to attainable vessel speeds. The weight control plan addresses concept though detail design, construction, delivery and service life. The procedure is adaptable to all types of hull structural material. Weight curves developed from regression of previous vessel data are included and cover a variety of pleasure and commercial craft. Examples of the effect of weight control on speed are given. Recommendations for application of the procedures are offered.
The Design and Installation of Efficient Deepwater Permanent Moorings
Authors: D'Souza Richard , Dove Peter G. S. , Hervey Donald G. , Hardin Donald J.
Published: January 2021

Industry interest in floating production systems in the Gulf of Mexico and elsewhere is increasingly pointing toward deeper water depths ranging to 10000 ft. In these waters, the moorings are an increasingly significant factor in the overall system cost. This paper presents important design considerations for deepwater mooring systems for permanently moored floating platforms. The engineering of feasible and cost-effective deepwater moorings requires substantive departures from conventional design and installation techniques. These include rethinking commonly accepted design criteria, the use of synthetic materials, alternatives to conventional catenary systems, increasing use of deeply submerged buoys, and innovative ideas for system installation. Issues addressed include: design criteria; the use of lightweight, high-strength materials such as aramid fiber rope in lieu of wire rope; analysis methods and procedures indicating the importance of quasistatic, dynamic, fatigue and probabilistic analyses; installation options and the benefits of maximizing deployment vessel options; the use of alternatives to a conventional chain/ wire catenary system; and design considerations and construction options of large-buoyancy, deeply submerged buoys.
Ship Topside Integration and Electromagnetic Interference Control
Authors: Juras Joseph , Cebulski Donald
Published: January 2021

Electromagnetic Interference (EMI) is rapidly becoming one of the major contributors to mission degradation in the U.S. Fleet today. Topside design and integration efforts have been used to reduce EMI, but this is not the total solution to the problem. A program of total ship and system EMI control must be implemented that will span battle groups and be effective during joint operations before optimum combat system effectiveness can be realized. This paper gives examples of some of the major EMI problems in the fleet today. It discusses both intraship and intership EMI problems, how these problems arose, and how they might have been prevented through the use of techniques such as frequency management, equipment design, better element placement and improved cable shielding. It describes the current topside design process, electromagnetic compatibility (EMC) improvements being made and traces the history of EMC requirements and their application to date. It also describes a developing program for managing ship topside arrangement configuration. The authors project where the challenges lie for future topside and EM engineering designers and describe how the equipment acquisition process must improve in order to meet the challenge of effective EMI control.
SEAWOLF Design for Modular Construction
Authors: Bevins S. E. , Clemens C. F. , King D. E. , Koger T. H. , Pollock R. R.
Published: January 2021

There has been much discussion on designing for producibility, new and innovative construction techniques, changing traditional relationships between engineering design and construction planning, and the requirement for new design products providing information beyond the class design system viewpoint to support the construction of interim products. The purpose of this paper is to continue this dialogue and provide some insight into how the design process has changed by offering for discussion, information, or use the specific process that the SEAWOLF design agent is using today in the development of sectional construction drawings.