bluuebunny/crossref_metadata_2025 huggingface dataset:
Problems of Dry Docking Unusual Ships
Authors: Crandall Paul S.
Published: January 2021

The development of many new ship designs, both commercial and naval, having very unusual hull shapes and projections has greatly increased the problems of dry docking. This paper was presented to the New England Section of SHAME in October 1965 to emphasize the existence of the problems and to offer some solutions that had been successfully used to overcome the problems. Because timber blocking has been an important structural material to fit between ships and dry docks and because this timber is usually loaded in side grain compression, tests were carried out to ascertain the compression behavior of five domestic timbers. Attention is given to the importance of ship load distribution on blocks and the important effect of undercutting of the hulls to the blocking load. Recommendations are also made concerning the limitation of crushing of blocks to avoid damage to ships' hulls.
Development and Experience With a Supercharged Steam-Generating System
Authors: Fritz W. A. , Tursi T. P.
Published: January 2021

This paper describes the supercharged steam-generating cycle as currently employed in the U. S. Navy. In this cycle gas pressure in the boiler varies with load to a design peak of five atmospheres. The boiler receives its air for combustion from an air compressor which is powered by boiler exhaust gases expanding through a gas turbine. A historical background of the cycle and its components follows. Since a number of systems of the supercharged type have been and are being subjected to test at the Naval Boiler and Turbine Laboratory, the components of the systems, with particular emphasis on the boilers, are described. Advantages and disadvantages of the system are detailed and evaluated. The conclusion is that advantages are significant and that suspected problems or disadvantages do not need to exist if it is understood that the supercharged steam generator is regarded as not just another boiler, but rather as a precision piece of equipment. The test program at the Naval Boiler and Turbine Laboratory is defined as to scope and objectives. Test results are discussed and modifications required as a result of tests are described. Finally, there is a short review of shipboard operating experience to the present time. A major point developed is that the introduction of a new type boiler to the Navy's Fleet required an RDT&E effort, a full-scale test program, a new appreciation of the art of boiler design and manufacture, and a realistic and well-defined training program, plus the development of new ancillary equipment. The most important of the other equipments required is, of course, a compact and reliable supercharger set (air compressor and gas turbine) to provide air for combustion. The successful design of a compact supercharger set is the key to the use of the supercharged steam cycle.
Centralized Machinery Control on Sun Ship Cargo Vessels Built for U. S. Lines (C4-S-64a)
Authors: McNeal J. K.
Published: January 2021

The application of centralized control should begin with a review of the machinery systems in order to integrate the functions, simplify the arrangement, and coordinate the requirements for control with the selection and performance of the control equipment. These vessels were modified in their machinery systems as the delivery schedule would permit. Then the centralized control system was designed around the modified plant. The control system comprises the equipment necessary to fulfill the functions of controlling the throttle, logging data, displaying information on readout devices, monitoring and alarming for off-normal conditions, and controlling various motors and valves. The status of this system in the hierarchy of control requires an adequate control engineering capability on the part of the shipbuilder that crosses over traditional lines of engineering disciplines. A high degree of functional integration is required to optimize the ship as a vehicle of transportation.
Simulated Service Evaluation of Marine Coatings
Authors: Devoluy R. P. , Nowacki L. J. , Fink F. W.
Published: January 2021

There is a strong demand for faster, and yet reliable, methods of evaluating new protective coatings for underwater marine service. Many of the new materials are so durable that it is impractical to await the outcome of the traditional methods of testing panels in tropical waters. Furthermore, stationary panel exposures in sheltered waters often omit the service conditions that are the controlling causes of failure. For underwater coatings these variables may include exposure to electrical currents (cathodic protection),abrasion, impact, impingement, cavitation, and other velocity effects. Coatings tests applied to ships are costly to install. They are also prone to accidental damage, and subject to carelessness or overly protective attention. Moreover, it is difficult to control surface preparation, application, and climatic variables well enough to make a fair comparison between coating systems. Finally, they take so long that more promising materials are often available before the program is completed. This paper describes some of the proven techniques for simulating marine service and suggests their use to parallel more closely actual conditions that coatings encounter in marine service. The criterion for a good test is that it predict the order of performance of a number of coatings in the service for which they are intended. Proposed simulated service evaluation techniques must first be checked with coatings of known performance for that service. It is important that the coatings fail in laboratory studies in the same way as in actual service. Thus, the performance of new coatings can be related to the performance of the known coatings.
Cargo Pumping in Modern Tankers and Bulk Carriers
Authors: Feck A. W. , Sommerhalder J. O.
Published: January 2021

Cargo pumping in mammoth tankers and bulk carriers demands attention in regard to needed international unity pump safety and test standards. The suggested cargo system model tests are a negligible added investment to reduce the risk of cargo system problems. Pump design features, requirements imposed by the system, choice of pumps and drivers, and automation aspects are described to review their influence on the application of modern pumping systems. The use of the Vac-Strip3 system to utilize the main cargo units as high-capacity stripping pumps, the advantage of being able to eliminate conventional stripping systems with their fittings and fixtures, and a new method of clean ballast pumping are discussed in this paper.
Fire Protection in Future Passenger Ships
Authors: Price Robert I.
Published: January 2021

A first report to the Society of Naval Architects and Marine Engineers of the results of an intensive series of technical meetings on Fire Protection of Passenger Ships just concluded in the intergovernmental Maritime Consultative Organization. The author is the U. S. Representative to the IMCO Subcommittee on Fire Protection. The paper explains the background of the discussion, setting in proper time frame the sequence of meetings and the shipboard fire casualties which have been prominent in the news. It touches upon the improvements in the international fire safety requirements adopted for existing ships, overcoming the "grandfather clause." The bulk of the paper examines the scope and effect on future ships of the text of revisions of the SOLAS Convention, now pending acceptance.
Floating-Type Offshore Drilling Vessels
Authors: Seymour D. J. , McCardell C. R.
Published: January 2021

After two decades of oil exploration on the world's continental shelf, various design types of mobile drilling rigs have evolved, namely the submersible, the jack-up, and the floater. The authors consider that the current stage of development of these rigs has sufficiently established design patterns which are worthy of investigation and review. The authors have selected the floater type for discussion and presentation as being of germane interest to the naval architect and marine engineer. Section 1 of the paper reviews the design aspects of floating drilling vessels by considering them in two groups: "surface hull" type and "column stabilized" type. Functional design requirements are discussed, including some fundamentals on rotary oil drilling to familiarize the naval architect with its basic techniques. Requirements and recommendations for deck areas and volumes are given, together with representative weights for drilling equipment and vessel weight summaries. Hydrostatic, stability, and motion characteristics are compared between the two types. Structural design, safety features, and logistic support systems are reviewed. Section 2 describes the offshore drilling vessel Reforma as typical of one of the large surface-hull-type rigs incorporating the latest drilling techniques and marine systems. The rig, one of a fleet of three, is owned and operated by Perforadora Mexico, S. A., a private drilling contractor under contract to Petroleos Mexicanos, off the east coast of Mexico.
Sea Spectra Simplified
Authors: Michel Walter H.
Published: January 2021

A dissertation on the simple wave elements that make up the complex sea, this paper is intended to give the practicing naval architect a clearer view of how regular waves combine into an irregular pattern and how the consequent irregular behavior of a vessel at sea can be predicted on the basis of recent statistical formulations.
The Challenges of Ocean Engineering of the Future
Authors: Keil A. H.
Published: January 2021

The paper discusses steps necessary to identify and develop future ocean engineering. It points out the need to establish broad objectives for advances of ocean-engineering capabilities on the basis not only of present technology but especially of projected technology. The interrelation of the engineering aspects of foreseeable ocean-engineering efforts is studied. Conclusions are drawn on how ocean engineering can be advanced in a systematic manner. The needs for systematic technological developments in selected areas, for selected focus projects, and for development of professional resources are reviewed.
Preliminary Design of a Catamaran Submarine Rescue Ship (ASR)
Authors: Meier Herbert A.
Published: January 2021

The submarine rescue ship has as its primary mission the handling and support of a new design of rescue submersible. The catamaran appeared to be ideally suited to handling large heavy weights and hence was investigated as a suitable configuration for this ship. It was found that, in addition to simplifying the hoisting problem, the catamaran has superior low-speed maneuverability, and, when compared to a single hull of approximately the same displacement, had a 40-percent increase in deck area. These advantages were felt to justify the extensive model testing necessary to ensure a structurally and hydrodynamically sound final design. Both symmetrical and asymmetrical hulls with varying hull spacing were tested, resulting in the selection of the asymmetrical hulls with the spacing selected solely on the basis of handling requirements. Resistance as found to be insensitive to hull spacing over the practical range of spacing. Strain-gage instrumented models were run in waves, and it was determined that the maximum loading on the bridging structure, from the point of view of vertical shear and moment loads, occurs in beam seas at zero speeds and, for torsional loads, at zero speeds in quarter head seas.
A New Concept of Electric Ship Propulsion
Authors: Harvey L. M. , Fulmer R. D.
Published: January 2021

Based on a principle established by Faraday in the nineteenth century, acyclic machines produce a true direct current. They are smaller, lighter in weight, and higher in efficiency than commutator-type dc motors and generators. By using the eutectic alloy of sodium and potassium as the current-carrying medium, acyclics eliminate the need for carbon brushes and the maintenance associated with them, thus leaving only the bearings and auxiliaries subject to normal maintenance. The authors point out the applicability of acyclics to ship propulsion by showing a schematic of the control system and listing the benefits of acyclic machinery for this application.
On the Seakeeping of Planing Hulls
Authors: Savitsky Daniel
Published: January 2021

An analysis is made of available data on the seakeeping behavior of planing hulls in order to define and categorize those hydrodynamic problems associated with various speeds of operation in a seaway. It is found that seakeeping behavior at speed-length ratios less than 2.50 is distinctly different than the behavior at larger speed-length ratios. Analysis is made of the rough-water resistance increment; the pitch-and-heave motions; and the impact accelerations for both speed regions in head and following seas. The effect of hull trim and hull section form on these rough-water hydrodynamic characteristics is discussed.
Special Design Features, OSS 01 Oceanographer and OSS 02 Discoverer
Authors: Powell A. L. , Stover H. B.
Published: January 2021

Special construction features required by oceanographic research ships are described in this paper. They are grouped into categories relating to the following: atmosphere, surface, mid-water, bottom, subbottom, and general. Other overall construction features which assist the ships in their performance in the foregoing activity fields are also described. These features are position fixing, position holding and control, operations control center, stability, open deck, antiroll tank, oceanographic laboratory, data acquisition system, and electric power generation. The new Coast and Geodetic Survey Ships Oceanographer and Discoverer are used as the basis for discussion. A technical description of each of the ships is given in the Appendix.
Selection of Power Plants for Yachts
Authors: Wyland G. Gilbert
Published: January 2021

Considerations governing selection of power plants for yachts include determination of power for speed and performance desired. This, in turn, requires determination of the best compromise on shaft revolutions compatible with limitations of propeller diameter and possible effects of cavitation. The problem as to whether to use diesel or gasoline engines is also investigated. Curves are given which give general criteria for estimating power over a large range of speeds. Accessories including reverse gears, reduction gears, and their mode of control are discussed. Propeller design in reference to engine rating is investigated, it being pointed out that on many current engines a propeller sized for maximum power and revolutions will be much too small for the horsepower available at a continuous rating.
Size Determinants in Destroyer Design
Authors: Oakley Owen H.
Published: January 2021

The increasing size and cost of warships is a matter of concern to the Navy and the Department of Defense. This paper presents the results of an attempt to determine the factorsthat "drive" ship size. The analysis showed that the weights of structure, auxiliary systems, and a large part of equipment and outfit vary as a function of hull volume. Thus the weights are largely controlled by volume requirements; i.e., the ships are "volume critical."Analysis of volumes showed that the spaces required for payload, people, machinery, and so on, are tightly dictated by the function and design standards. The influence of new, lighter and more sophisticated machinery, the demand for topside space by weapons and electronics, and the need for more complete system integration, particularly with regard to ordnance and ship systems, are discussed as factors that will have increasing influence on the size, cost, and effectiveness of warships. The impact of Concept Formulation/Contract Definition on the design process is also briefly discussed.
Legal Responsibilities and Liabilities of the Small Boat Designer and Manufacturer
Authors: Greene Raymond T.
Published: January 2021

This paper presents an analysis of the evolution in the legal field of "product liability" and how it applies to the naval architect and the manufacturer in the rapidly expanding small boat industry. Consideration is given to the standards and controls to be developed by the industry.
Why Not Ferro-Cement?
Authors: Norris C. F.
Published: January 2021

Two methods of building a hull in ferro-cement are described. The history of ferro-cement construction, the properties of this material, and design considerations in its use are discussed. Cost comparisons are made with the more common materials employed in the construction of small craft.
The Maritime Administration Maintenance and Repair Data Processing and Evaluation System
Authors: Karlson Edward S. , Davis John J.
Published: January 2021

An operational system for providing processed maintenance and repair information for vessels is described. Content includes description of a detailed coding system for reducing raw data to composite code numbers suitable for automatic data processing. Objectives of the system and constraints thereon are discussed. The Marad data system has been operational for four years. Scope of data processed and its utilization are presented. Seven current studies concerning vessels as a whole and specific shipboard equipments are included.
Welding Problems in Shipbuilding
Authors: Masubuch Koichi
Published: January 2021

During the past 30 years, many new welding processes have been applied to the fabrication of various metal structures. However, these processes have largely been ignored by the shipbuilding industry, and modern ships continue to be fabricated primarily by a manual arc-welding process that is more than fifty years old. This paper discusses some of the problems related to welding ship structures, focusing mainly upon two important subject areas:new welding processes, andnotch toughness of weld metal.

The author reviews briefly developments in the technology and, emphasizing the technical problems, indicates how research can improve the state of the art.
New Concepts Applied to Research Ship Design
Authors: Reed Sherman C. , Sarchin Theodore H. , Leiby Jonathan
Published: January 2021

When the Navy's AGOR-3 class of research ships could no longer be modified to meet changing oceanographic requirements, a new design, the AGOR-14 class, was developed. A number of new concepts were incorporated into this design. They included a major step forward in the position keeping and maneuverability of research ships by employment of cycloidal propellers, and an improved compromise between a standardized class design and an individualized design by inclusion of options to customize the research payload. Important aspects of the preliminary design to meet diverse and changing research requirements are presented.
Economic Considerations in Shipboard Design Trade-off Studies
Authors: Harrington R. L.
Published: January 2021

The economic aspects of shipboard design trade-off studies are given a comprehensive analysis. The net present value criterion is employed in developing a procedure which can practicably be used to assess the economic merits of design alternatives. Examples, which illustrate the procedure developed, are given.
The Emerging Shape of Policies for the Acquisition of Major Systems
Authors: Frosch Robert A.
Published: January 2021

This paper is the transcript of an address by The Honorable Robert A. Frosch, Assistant Secretary of the Navy (Research and Development), given at the Association of Senior Engineers Annual Technical Symposium Banquet, Washington, D.C., March 28, 1969. The same ideas were delivered in substantially the same form before the Institute of Electrical and Electronics Engineers, Inc., on March 26, 1969.
Protection and Securing of Deck-Stowed Containers
Authors: Cushing Charles R.
Published: January 2021

The great benefits and economies attained through containerization have been offset somewhat by damage to deck-stowed containers. This paper outlines considerations to be examined in designing systems for securing and protecting containers stowed on the weather deck. The general lack of agreement about the minimum requirements of an adequate securing system is due in part to the absence of an accurate method for calculating ship motions and inertia forces acting on the containers. The paper discusses the stress-strain relationships between lashing wires and the container structures, and points out the necessity for adequate safety factors.
Stability and the Stowage of Bulk Grain in Ships: Activities of the Intergovernmental Maritime Consultative Organization
Authors: Price R. I. , Middleton E. H.
Published: January 2021

Six years of study and research into the behavior of grain stowed in bulk in dry cargo ships were carried to an effective conclusion by the Intergovernmental Maritime Consultative Organization (IMCO) during sessions in January and February 1969. The Organization's Subcommittees on Subdivision and Stability and on Containers and Cargoes gave the last touches to a draft of a complete revision of the present Chapter VI, Grain Regulations, of the 1960 Safety of Life at Sea (SOLAS) Convention. A final consideration by the governing technical body of the Organization, the Maritime Safety Committee, was accomplished in February. The agreed-upon text was sent for adoption by the IMCO Assembly, at its October 1969 session, with the recommendation that member governments use the revised regulations as an equivalent to the existing Chapter VI.
A Ship Design Procedure
Authors: Lamb T.
Published: January 2021

The small number of published articles on the subject of practical ship design suggests that naval architects are reluctant to discuss this most important part of the overall ship production sequence. It is felt that constant discussion of all aspects of ship design would enable progress to be made in what, at the moment, is an empirical art. A ship design procedure is therefore presented in the hope that it will provide a basis for discussion. Each stage in the procedure is discussed in detail in separate sections and both standard forms and data are given. An example is included to illustrate the use of the forms and data.
Main Reduction Gears for Contrarotation
Authors: Budd W. I. H.
Published: January 2021

The trend to high-power marine propulsion plants can be satisfied by machinery suppliers with existing design techniques, experience, and manufacturing facilities. The naval architect's task of utilizing this increased power efficiently leads to consideration of contrarotating propellers, particularly in vessels where the draft is limited. The major portion of the paper is devoted to discussion of gear designs for contrarotation. The special characteristics and problems attendant to the application of epicyclics in first and second reductions are discussed. The advantages of conventional fixed-axis gearing for contrarotation together with suitable arrangements are described. Finally, areas are indicated where additional research is desirable.
Predicted and Measured Performance of a Daysailing Catamaran
Authors: Bradfield W. S.
Published: January 2021

A simplified theory is given for predicting the performance of light displacement craft sailing at small heel angles. The theory predicts and experiment confirms that the ratio of boat speed to true wind speed is virtually independent of true wind speed for all headings to the true wind for this type of boat. Only two additional dimensionless parameters and the aerodynamic drag angle are required to completely specify the performance within the approximations set forth. Performance tests of a 14-ft catamaran substantiate the theory to within the experimental uncertainty of the investigation. A simple, direct method used for experimental performance evaluation is described.
The Economics of the Containership Subsystem
Authors: Miller Dave S.
Published: January 2021

The effects of a container operation on a traditional steamship company are discussed, and the need for planning emphasized. The "optimum" containership is defined, and the naval architect's role in its determination is outlined. The two basic approaches to optimizing a system are described, and the limitations of each approach stipulated. An algorithm which estimates both capital and operating costs for containerships is presented, together with relationships for capacities, weights, and dimensions. (The computer program is appended.) A typical algorithm output is presented, and its application to two basic types of optimization studies is described.
Anomalous Behavior of Merchant Ship Steering Systems
Authors: Taggart Robert
Published: January 2021

An unusual combination of circumstances occurring during an Atlantic crossing of a highspeed containership created a situation where the rudder, acting in response to automatic steering control demands, caused excessive ship rolling. Further investigation revealed the existence of an unstable condition due to a combination of asymmetrical hydrodynamic and mechanical characteristics and the interrelationship of ship motion and control actuation. Similar response has been noted on other high-speed vessels and is a cause for major concern in future containership operations. The elements involved in creating these conditions have been examined in detail and a plausible explanation has been evolved as to how they can combine to produce the observed results. With an understanding of the causes of this anomalous behavior it is possible to devise means for preventing its occurrence in future designs.
Managing Complex Ship Overhauls
Authors: Ballou L. D. , Freakes W.
Published: January 2021

The management of complex ship overhauls is a subject which has received little attention in the technical press. In fact, this statement can be applied to the overhaul and repair business in general. This paper is intended to serve as a section of a bridge designed to span the information gap which has developed in this important segment of the industry. The authors discuss various aspects of overhaul planning and make recommendations for improving performance. They next present an organizational arrangement for conducting complex overhauls, including a suggestion to counter the adverse effects of specialization. Finally, they make a plea to collect and analyze statistical data to the end that correlation will show the way to improvements.
On the Design of Offshore Supply Vessels
Authors: Mok Yingkei
Published: January 2021

The offshore supply vessel came into being in 1954 to meet the demands of a rapidly growing offshore oil industry. The authors give a brief history of this development and present the arrangement and profile of a typical supply vessel as well as a complete table of characteristics on a number of vessels. It is shown how the demand to carry large quantities of cargo on deck resulted in a hull form that is unique in some respects. Two particular areas of design are stressed: stability and powering. The question of stability is examined in detail, including development of the current U. S. Coast Guard stability criteria. The difficulty in estimating power requirements for the low speed/length ratios associated with supply vessels is discussed. Data for estimating power requirements are presented.
The New Catamaran Submarine Rescue Ships: ASR 21 Class
Authors: Christensen J. F. , Brown A. C. , Mancill G. W.
Published: January 2021

The loss of the USS Thresher in 1963 focussed attention on the need for new and modern submarine rescue facilities. The Navy's Deep Submergence Systems Project organization (DSSP) was created to explore and develop systems for search, rescue, salvage and associated undersea research programs. Among the systems developed by this organization were the Deep Submergence Rescue Vehicle (DSRV) and a deep-diving system employing saturation diving techniques. A new type of ship was required to support these systems, having characteristics quite different from existing submarine rescue ships (ASR's). In 1965 the Navy began preliminary design of the ASR 21 class of vessel, whose primary mission will be to support the rescue of personnel from sunken submarines. In order to perform this mission, the ship has to have the capabilities of transporting and handling two deep-submergence rescue vehicles; conducting deep-diving operations, including support of associated man-in-the-sea maneuvers; conducting search operations; and performing other miscellaneous tasks associated with its primary mission. The paper describes the principal features of this unique catamaran ship and outlines some of the design control aids and construction highlights.
Ship Design and the Computer
Authors: Nowacki Horst
Published: January 2021

The paper discusses current trends in computer-aided ship design, and the effects computer use may have on the scope and style of ship design.
Propulsion Machinery Considerations for Contrarotating Propeller Systems
Authors: Steele T. W.
Published: January 2021

Contrarotating (CR) propellers offer one attractive solution to meeting the needs for higher power, more efficient ship propulsion. A planetary second-reduction gear system is proposed to provide the CR energy to a pair of propellers from a conventional turbine power source. The concentric line shafts, bearings, and lubrication system are discussed as vital components to a CR system. Some favorable full-scale operating experience has been obtained on all components except a high-power second-reduction planetary gear operating in the CR mode. The use of a CR propeller system should have a significant economic impact on the powering of ships.
Measures of Merit for Ship Design
Authors: Benford Harry
Published: January 2021

My purpose in writing this paper is to explain the role of engineering economy in ship design and to discuss the relative virtues and shortcomings of the several measures of merit in current use. In particular, I want to compare the two criteria most popular with United States business managers today: net present value and discounted cash flow rate of return, or yield. I also want to make the point that, under some conditions, the required freight rate criterion may be preferable to either of those two. All valid criteria have the characteristic of flat laxity. Therefore, finding an exactly optimal design is not as important as establishing the range of designs that promises close to the maximum level of profitability. Applying the different criteria to a typical speed-optimization study demonstrates that, when properly used, each valid criterion will indicate a design that is within the reasonable range indicated by the others. The effects of taxes as well as bank loans are covered in some detail, with illustrative examples from a feasibility study. These demonstrate that taxes have great influence in weighing the economic merit of new technologies but that bank loans do not. A brief discussion of inflation concludes that technical decisions need be little affected by expected changes in the value of the dollar.
Pollution of the World's Harbors, Docks and Inland Waterways, with Particular Reference to Ships
Authors: Stokes John H.
Published: January 2021

The paper stresses the damaging effect upon our waterways of excessive or continuing pollution loads, with particular reference to that arising from ships or pleasure craft traversing inland waterways or berthed in our docks and harbors. The suitability of various solutions is examined in some detail. These are considered against the background of unskilled handling on board ship and of the tightening requirements of the law. Difficulties of law enforcement are also considered where standards for sewage effluents exist or are proposed for future legislation. A set of criteria is suggested and a method of overcoming the problem by the elimination of overboard discharge in restricted waters is described in some detail. The author concludes by making the point that future standards must be international, realistic, and likely to secure the full cooperation of shipowners, captains, and crews. Its enforcement must be simple and not demanding of an army of enforcement and sampling officers. In short, he maintains that "containment" alone can ensure the peace of mind of all the parties concerned.
The Transportation of Refrigerated Anhydrous Ammonia on the Inland Waterways
Authors: Creelman William A.
Published: January 2021

The carriage of refrigerated anhydrous ammonia by barge is a relatively new technique and has grown rapidly in the past several years. As the movement has grown many problems have been identified and solved, but others remain to be worked out. This paper attempts to trace the development of ammonia barging, presents an operating profile of a typical ammonia movement and identifies remaining problems. Discusser A. H. Schwendtner
On the Dynamics of Cables with Application to Marine Use
Authors: Alexandrov Michail
Published: January 2021

Cables play an important role in ship operations, whether in anchoring, docking, towing, or in passing through locks. The frequent casualties that result from cable failure attest to the need for a better understanding of cable dynamics. This paper explains analytical techniques that can be used to assess the adequacy of cables of all types. The classical methods for treating static conditions are reviewed. Then dynamic conditions are analyzed in recognition of transient loads applied to cables (e.g., the surging of a ship at anchor). Water resistance and cable elasticity are also recognized. The paper concludes with a numerical example showing how the foregoing principles can be applied to a typical situation of a ship at anchor.
Observations on the Effect of Vessel Speed on Bow Thruster Performance
Authors: Ridley Donald E.
Published: January 2021

The paper explores the effect of vessel speed on thruster performance by comparing fullscale data to model test data. The steering effect of the thruster alone, and in combination with the rudder, is considered. A limited amount of full-scale data on the steering effect of a bow thruster, with the vessel proceeding astern, is presented.
Explosion-Bonded Metals for Marine Structural Applications
Authors: McKenney Charles R. , Banker John G.
Published: January 2021

The application of explosion-bonded aluminum-to-steel welding transition joints on marine vessels is discussed. Evaluation of this material's suitability for joining aluminum superstructures to steel decks is reviewed in detail. Galvanic corrosion is demonstrated to be negligible, thereby providing significant savings on maintenance costs when compared to mechanical connections. It is shown that mechanical properties, design adaptability, and installation costs meet marine-industry requirements.
Ship Design Aspects of Oil Pollution Abatement
Authors: Dillon E. Scott
Published: January 2021

The paper presents an overview of measures which can be taken in basic designs of ships to facilitate elimination of intentional oil discharges and minimize accidental oil spills in the event of collision or stranding. The author discusses economic impacts of alternative solutions for coping with oily ballast and oily wash water disposal. In like manner, various tanker compartmentations contribute to reduction of probable oil outflow from collision or grounding injury. Certain arrangements yield dual benefits of protection against accidental spills as well as clean-ballast capacity to partially or completely eliminate the oily-water disposal problem.
On the Behavior of the ASR Catamaran in Waves
Authors: Wahab Rama , Pritchett Clark , Ruth Lawrence C.
Published: January 2021

A review is given of the results of the experiments carried out to investigate the behavior of the ASR Catamaran in a seaway. These investigations were focused on:Motions in waves, including the effects of wave direction and hull separation. Some predictions are made of the prototype motions.Wave-induced forces and moments acting on the bridging structure in waves of various directions for several hull separations.Hydrodynamic impacts on the lower part of the bridging structure.
The DDH 280 Class Design
Authors: Farrell K. P. , MacLaren R. E. , Bennett C. L. , Reilley J. D. S. , Redman K. L. , Partridge A. E.
Published: January 2021

The first part of this paper presents an outline of the studies and decisions which preceded the DDH 280 design. Accordingly, it begins with the development of the concept, the design plan, the procurement plan, and the drawing processes. The second part of the paper discusses the principal systems which are incorporated into the ship. Emphasis is given to special features such as the bridge-controlled gas turbine propulsion plant, the integrated weapons system, and the helicopter aviation facilities, all of which have been developed in Canada to satisfy Canadian defence requirements.
Some Considerations in the Design of Polar Icebreakers
Authors: German J. Gordon , Collins C. F. , Webster A. R.
Published: January 2021

This paper highlights some primary considerations in the design of polar icebreakers. Factors affecting determination of power-displacement relationships and the propulsion horsepower are discussed, as is the importance of clearly defining the manner in which the various ice conditions are to be handled. The authors deal briefly with hull construction aspects, outlining the general requirements for polar-class icebreakers, choice of parameters, and the principal hull design features of a proposed new Canadian polar icebreaker. Propulsion machinery options are discussed, including medium-speed diesel engines, aircraft and industrlal-type gas turbines, and combination systems.
IMCO Activities Updated
Authors: Goddu L. W.
Published: January 2021

The activities of the Intergovernmental Maritime Consultative Organization (IMCO), a United Nations specialized agency dealing with maritime safety, have been covered in previous issues of Marine Technology. It is felt appropriate to update past information with recent activities. In addition to its regular work program, IMCO has placed special emphasis on marine pollution and cargo containers. This paper highlights briefly recent developments in these two areas of concern.
LNG and the U. S. Coast Guard
Authors: Jansky Charles
Published: January 2021

A good deal of confusion appears to exist currently as to the role of the United States Coast Guard (USCG) in regulating the marine transport of liquefied natural gas (LNG). The purpose of this paper is to clarify some of this confusion.
Analysis of Ship Structural Loading in a Seaway
Authors: Hoffman Dan
Published: January 2021

The recent advent of the large tanker and bulk carrier has promoted the requirements for more detailed structural analysis of a ship and the reevaluation of theories for calculating the static, quasistatic and dynamic loads. The paper begins with discussion of the methods available to determine the various types of loads expected, their phase relationship, and ways of superimposing them. It then proceeds to the treatment of sea loads based on theoretical and experimental data, and techniques of determining the ship response in a seaway are discussed. The response to regular waves is reviewed with special reference to the determination of pressure distribution on the hull. Statistical ship response, immediate and cumulative over the life of the ship, is demonstrated in relation to the prediction of long-term bending moment trends, and the distribution of the extremes is discussed. Special loading conditions are described with special emphasis on the transverse pressure distribution, dynamic effects due to motion of liquid cargo in tanks, shipping of green water, wave-induced vibrations, slamming pressures and whipping stresses due to various causes. The paper treats the above subjects in a broad manner and no attempt to illustrate the theory in detail is made.
Notes on the Buckling and Postbuckling Behavior of Deep Web Frames
Authors: Payer Hans Georg
Published: January 2021

The paper deals with web plates of deep web frames loaded below and above the buckling load. Emphasis is given to the influence of initial deflections, which commonly are encountered in welded constructions, on the response of the plate. The process of solving this nonlinear plate problem is outlined and results for several plate configurations are discussed. Contour plots illustrate the character of the deflection and stress distribution for two typical cases. Good correlation is found between the theory and results from full-scale experiments on a tanker. Design curves for a square and a rectangular plate panel loaded by shear are included in the results.
Longitudinal Strength Analysis of the Grounded Barge Carrying Independent Cargo Tanks
Authors: Michelsen Finn C. , Kilgore Uilmann
Published: January 2021

The problem has been treated of determining deflections and bending moments of the barge hull and independent cargo tanks combination as these occur in Class I and Class II barges during grounding. The method of solution is that of the initial parameters, which is here developed by means of operational calculus. The solution is closed and exact within the limitations of the Euler-Bernoulli beam theory.
Analysis of Slamming Stresses on SS Wolverine State
Authors: Maclean Walter , Lewis Edward V.
Published: January 2021

A study has been made of slam-induced midship hull stresses on a general cargo ship in North Atlantic service. The slam-induced stresses superimposed on wave stresses were treated statistically for different Beaufort numbers in the range of 4–10. It was found that although the percentage of records with slamming increases with Beaufort number, the overall frequency of slamming first increases and then decreases with Beaufort number. This is because the higher Beaufort numbers occur less often than lower numbers. As for the magnitude of slamming stresses, it was found that the statistics are relatively insensitive to Beaufort number and hence to sea condition. It is shown that this finding is accounted for by the reduction in speed and/or change of course that is normally adopted by the master as weather becomes more severe
The Prediction of Shipyard Costs
Authors: Summers Lewis S.
Published: January 2021

This paper presents the function, operating methods, a few problems, and suggested solutions for the estimator of a shipbuilding or ship repairing firm. Specifications and their effect on estimating are discussed. The advantages to operator and yard alike that may be obtained by using clear, simple, and unambiguous specifications are mentioned. The possibilities of standardized terminology to assist in achieving these advantages are also reviewed.
Offshore Nuclear Power Plants
Authors: Kehnemuyi Muzaffer , Lochbaum Robert E.
Published: January 2021

Historically the demand for electric energy has approximately doubled every decade since the 1930's, and projections indicate this trend is expected to continue into the mid-80's. Although the rate may then be expected to decrease slightly, the absolute growth in kilowatts will continue to be very large. The electric utility industry is faced with the problem of supplying this growth in a manner consistent with the preservation of the environment and, at the same time, overcoming present problems of siting, licensing, public awareness, construction, and financing. The offshore nuclear power plant is a concept which goes far toward solving many of these problems. This paper describes the floating nuclear plant concept with specific reference to the Atlantic No. 1 and No. 2 units being manufactured for Public Service Electric & Gas Company by Offshore Power Systems. Site description and selection criteria, the shore support facilities, the breakwater required to protect the plants, the floating nuclear power plants, the manufacturing facility for the plants, and supporting studies being conducted are discussed.
Heavy-Duty Gas Turbines-A Viable Marine Propulsion Option
Authors: Woodruff R. Bruce
Published: January 2021

Heavy-duty industrial gas turbines are suggested as an alternative propulsion plant to consider for ships, particularly ships of large displacement that are not volume limited. This paper examines the use of such a plant in a naval auxiliary, the Fast Combat Support Ship (AOE-1, Sacramento Class). The cycle discussed is of the combined gas turbine and steam cycle. The inlet to the compressor is supercharged and then intercooled, allowing the gas turbine to perform at significantly higher than rated power levels. Two controllable-pitch propellers at 50,000 shp each are used to drive the ship. Exhaust from the turbine is used to generate steam in an unfired waste-heat boiler. Reliability, maintainability, life-cycle costs and manning are addressed for comparison with the presently installed steam plant.
Segregated Ballast VLCCs: An Economic and Pollution Abatement Analysis
Authors: Kimon Peter M. , Kiss Ronald K. , Porricelli Joseph D.
Published: January 2021

This paper presents the results of a study of very large crude carriers (VLCCs) to determine the cost and effectiveness of variations in the capacity of segregated ballast and variations in arrangement expected to reduce oil pollution due to operational and accidental causes. The arrangements considered include double bottoms, double sides, double skin, and alternating cargo and ballast wing tanks. The paper concentrates on a series of 250,000-dwt tankers, but does consider the influence of size by including results for tankers of 120,000 dwt and 477,000 dwt. The degree of effectiveness is estimated for both operational and accidental pollution based on the best available data. Sensitivity studies are provided to check general conclusions. Finally, estimates of the cost of preventing one cubic meter of oil pollution with each design are presented. A discussion of operating factors subject to a reduction in performance as a result of design features is given.
Sea Trials: Some Recommended Practices
Authors: Jack Robert L.
Published: January 2021

The paper discusses some of the common errors committed in conducting sea trials on commercial vessels. Precautions that are covered in the T&R Bulletin C2, Code for Sea Trials, soon to be published by the Society, have been purposely omitted. The author has attempted to call attention to many accepted practices that can, and often do, produce inaccurate trial results. In addition, there are discussions and recommendations on several long-standing controversies associated with sea trials such as the necessity for shaft calibrations and the allowable factors used in the correction of fuel rates and turbine water rates.
An Owner’s Experience with Barge-Carrying Ships
Authors: Thayer Stuart W.
Published: January 2021

Radical new cargo handling concepts, such as those found on the Lykes SEABEE design which lifts two fully loaded 1000-ton barges on an elevator located at the stern of the vessel, invariably bring about some interesting and unforeseen problems. This paper gives a review of the many items that must be considered during the construction and operation of a new system concept as well as pointing out some of the specific difficulties encountered. The required pre-planning for operations, procedures during guarantee, and the effect of outside influences on the system are also presented.
Design and Model Evaluation of a Highly Skewed Propeller for a Cargo Ship
Authors: Boswell Robert J. , Cox Geoffrey G.
Published: January 2021

This paper presents the design process and model evaluation of a highly skewed propeller for a modern cargo ship. The design process is discussed in detail including considerations of cavitation, mean and fatigue strength, and propeller-excited vibratory forces. Model experimental results are presented which confirm the validity of the design process and show that the highly skewed propeller possesses propulsion performance comparable to the propeller now fitted to the ship, has less tendency towards cavitation erosion than this propeller, and possesses adequate strength for ahead and steady astern operation. Theoretical calculations indicate that the highly skewed propeller will produce lower vibration excitation forces than the propeller currently fitted to the ship.