bluuebunny/crossref_metadata_2025 huggingface dataset:
The Outlook for Lighter Structures in High-Performance Marine Vehicles
Authors: Heller S. R. , Clark Dennis J.
Published: January 2021

Structural weights of existing high-performance marine vehicles, principally hydrofoil craft, are examined to determine the design or geometric parameters that have significant effect. For total structural weight, vehicle density and structural density are shown to be governing. Similarly, the governing parameters for individual weight groups are identified. These governing parameters and the loads which determine scantlings, where known, are compared to develop measures of efficient use of structural material. These figures of merit are applied to a number of existing high-performance marine vehicles, and projections of what might be attainable in the future are made.
A New Dimension in River Towboats: 10,500 shp
Authors: van Mook Cornelis , Courtsal Donald P.
Published: January 2021

In the spring of 1974 the first 10,500-shp towboat went into service on the lower Mississippi River. This event raised the level of horsepower in river towboats to a new high—approximately 50 percent greater than that which existed only four years earlier. The design of these new vessels made use of service-tested features wherever possible, but the dramatic increase in horsepower dictated that many design parameters be extrapolated and not based on anything that had been done previously. This paper describes the design of one of the boats in this class which the authors believe is typical. It includes the basis for the design and many of the factors that were considered in arriving at the specific features included.
Thruster Design for Acoustic Positioning Systems
Authors: Brown Neal A. , Norton John A.
Published: January 2021

The cavitation noise of ducted transverse thrusters threatens to interfere with the operation of acoustic positioning or navigation systems as employed on ocean drilling ships, mining ships, and other work or scientific vessels so equipped. The design of an acoustically and hydrodynamically sophisticated transverse thruster is described in terms of its gross parameters and reasons for their selection. The design of the CRP propeller blades, which are of highly unorthodox form, is discussed in detail along with its conceptual basis. Model tests show that a large improvement in cavitation performance has been achieved while also maintaining efficiency. Measurements of the acoustic baffle effectiveness of the thruster duct, and engineering means to realize it, are described and applied to estimation of the interference noise levels expected to be sensed through the vessel's positioning system hydrophones.
Arrangement of Shipboard Piping by Digital Computer
Authors: Woodward John B.
Published: January 2021

A method of computerized arrangement of piping is described. It will choose a path for a pipe, including branches, if geometrical data specifying terminals, obstructing objects, and compartment boundaries are given to the computer. The main path chosen typically follows a vertical route to a horizontal layer in which a minimum-length path can be run, followed by a vertical leg to the destination. The routing within the horizontal layer is accomplished by a dynamic programming adaptation. The routing of branches follows the same procedure as the main pipe, after a trial-and-error selection of branch origins that are expected to give a near-minimum branch length. The paper outlines the method, describes some of the key techniques, and gives brief descriptions of the computer routines required, but complete description of the programming is not provided. Although the method is working on a developmental basis, it is judged to be unready for use in practical design.
The Steerbear System at Sun Ship
Authors: Schorsch Eugene
Published: January 2021

The Steerbear System is a comprehensive computer-based design and steel processing system in production use at Sun Ship. The paper reviews Sun Ship's decision to switch to numerically controlled burning, its choice and development of the Steerbear System, and its present state of use. Future developments are indicated.
The Construction and Testing of a 33,000-Ton (M) Lift Floating Dry Dock
Authors: Warnke Helmut J.
Published: January 2021

The constantly increasing volume of world trade necessitates continuous enlargement of international merchant fleets. The number and size of new ships have risen sharply in recent years. In order to keep up with the demand for new ships, the world's shipyards have had to invest large sums of money, and will be forced to continue to do so. These developments lead in their turn to the necessity for greater service and repair capacities. This paper describes the way in which the installation of a new 33,000-ton floating dock enabled Jacksonville Shipyards, Inc. of Jacksonville, Florida greatly to enlarge their service and repair capacity.
Recent Developments in Shipyard Welding
Authors: Brayton W. C.
Published: January 2021

The paper presents results of the research and development program which was initiated by the members of the Ship Production Committee of The Society of Naval Architects and Marine Engineers and financed largely by government funds through a cost sharing contract between the Maritime Administration and Bethlehem Steel Corporation. The effort of this project was directed to the development of improved methods and hardware applicable to shipyard welding in an effort to improve productivity and reduce shipbuilding costs in U. S. shipyards.
Structural Design of Aluminum Crewboats
Authors: Spencer John S
Published: January 2021

This paper is a commentary on the design of crewboats and similar deep-vee-hulled planing boats constructed of aluminum. It includes a description of current design practices and significant problems encountered in the design process. It suggests techniques that can be used to avoid deficiencies in the strength and integrity of the hull. Mathematical expressions that will enable the naval architect to estimate design loads over any portion of the hull bottom have been developed from the latest research efforts, and it is hoped that future full-scale testing will refine even further the methods of predicting slamming loads. Recommended design loads for other parts of a vessel, and allowable design stresses, are also given. A worked example has been included to demonstrate the design process for a typical Gulf of Mexico crewboat,
General Considerations Regarding the Structural Design of High-Performance Ships
Authors: Sorkin G. , Pohler C. H. , Stavovy A. B. , Borriello F. F.
Published: January 2021

Reliability of structures is an overriding consideration in the design of high-performance, weight-critical ships which require design with new materials having high strength-to-weight ratios. These high-strength materials can be susceptible to catastrophic failure in the presence of small flaws, such that the initiation and propagation of cracks by cyclic loading of the structure is of the utmost concern. Techniques for dealing with these problems, as they relate to structural reliability, are discussed, and the close relationship between problems of high-performance ships and aircraft is examined. The current need to rely on large-scale validation testing of vehicle structure and structural details is examined, with particular attention to the requirements for high-performance ship structures."Air Cushion Vehicles have an inherent over-the-beach capability that makes them extremely well suited for amphibious assault or possibly Arctic over-the-ice roles." Rear Admiral N. Sonenshein, former Commander, Naval Ship Systems Command [1].5"Hydrofoils are best suited for high-speed, all-weather missions, such as patrol and interdiction. The demonstrated ability of PCH and the PGH's (Patrol Craft Hydrofoil and Patrol Gunboat Hydrofoil) to maintain speed in extremely high sea states is a proven accomplishment." [1]."To go to the SES (surface effect ship, with rigid sidewalls), the exact mission for these have not been defined because this is new technology" [1]. However, Admiral Elmo R. Zumwalt, former Chief of Naval Operations, has proposed the hard sidewall surface effects vessel that can travel at 80 knots to serve as a small aircraft carrier. A small (2000 ton) SES also offers a platform which could be developed in greater numbers to perform a portion of the ASW surveillance mission [2]. The PURPOSE of this paper is to review the fatigue and fracture aspects of today's ship, submarine, and aircraft structures and, through lessons learned, project the technical needs from these experiences to the design of future high-performance surface ships. The paper synthesizes the overall technical considerations of fatigue and fracture requirements for ships and aircraft structures for the benefit of designers and research managers, and suggests to research scientists areas needing additional research effort. Major attention is given to the application of submarine and aircraft materials and structures technologies to advanced high-performance ships. These structural performance requirements are consolidated in terms of a ‘hull-subsystem’ to (a) relate the structural subsystems to total system program managers, (b) acquaint these system managers with the structural validation tests necessary to assure design of reliable ships for the new types of service called upon by today's commercial and military demands, and (c) make them better aware of available technology and facility resources relevant to validation of structural performance.
Reduction Gear Damages Related to External Influences
Authors: Volcy Guy C. , Budd W. I. H.
Published: January 2021

Increases in the tonnage of tankers, LNG carriers, and container vessels accompanied by increases in the powers of propulsion plants have led to incompatibility between the deflections of the hull and the lineshafting stiffness. This incompatibility is at the origin of the harmful influences exerted on main gears by external effects, including: deformability of the hull girder and double-bottom structure; flexibility of thrust foundations and rocking of thrust bearings; improper shafting and turbine alignment; and thermal expansion. Strain-gage, displacement, and vibration measurements on the journals of shafting and gears have given evidence of the existence of these harmful external influences. The solutions adopted for different types of gearing and thrust bearing designs have produced positive results. Previous experience together with modern finite-element calculation techniques on speedy computers has made it possible to proceed with preliminary calculations that furnish the alignment data for satisfactory installation of main gears and shafting. These modern calculation methods have served to explain some phenomena recently encountered on gears and shafting of VLCC vessels which were caused by the influence of ship's structure.
The Guidance Manual for Loading Great Lakes Bulk Carriers
Authors: Foss Bruce E.
Published: January 2021

This paper explains the need for a guidance manual for loading Great Lakes bulk carriers. The guidance manual is concerned with limiting the stillwater bending moment to the design value. Topics covered herein are the effect of stillwater bending moment on deflection, historical stillwater bending moment as a function of ship parameters, light ship weight distribution, and items commonly included in the guidance manual.
The Trans-Alaska Gas Project Site Selection and System Optimization
Authors: Schmitt Ivan W.
Published: January 2021

This paper focuses on problems associated with two major issues of fundamental concern to the marine transportation of LNG, and it presents the approach used in solving these problems. The first issue centers on the selection of the plant and marine terminal sites; the second, on the development of optimum systems designs based upon the sites selected.
Water Impact Loads
Authors: Sellars F. H.
Published: January 2021

This paper covers an analysis of different types of slamming experiments with account taken of different model structural characteristics and the effect of air entrapped in the water. Model data for peak impact pressure are found to correlate on the basis of an absolute pressure ratio and a velocity ratio that accounts for inertial effects. Scaling laws for slamming are identified. Impact pressure data from full-scale trials are compared with model data on the basis of the scaling laws identified from model data to demonstrate that the model data and the scaling laws are applicable to full-scale ships. Scale effects which may cause errors when extrapolating model results for impact pressure to the full scale are also discussed. A proposed basis for estimation of peak pressures for water impacts by use of model results is shown to result in conservative predictions when compared with full-scale measurements.
Damage Stability Requirements for Tankships, Chemical Ships, and Gas Ships
Authors: Kime J. W. , Johnson R. E. , Rabe W. D.
Published: January 2021

This paper reviews the various U. S. regulations, international conventions and IMCO codes which contain damage stability requirements for tankships, chemical ships, and gas ships. A brief history of damage stability standards and background on the development of the 1973 Pollution Convention, the IMCO Chemical Code, and the IMCO Gas Code are presented. The similarities and differences among the various damage stability criteria and requirements, with emphasis on the determining philosophies and assumptions, are shown. Finally, the type of information to be presented in stability booklets and the extent of calculations required to develop that information are discussed and illustrative examples given. Discussers Angelo P. Ritola Harry D. Johnson R. W. Baseler and T. G. Ogrodnik Merville Willis Tom F. Robinson Larry L. Goldberg W. Michael Walsh William Garzke James B. Robertson Eric Linsner
Developments in Ocean Facilities Engineering
Authors: Gill Henry L.
Published: January 2021

There has been only limited capability to design, implant, and maintain facilities attached to the seafloor in deep water to support Naval operations in the open sea. Equipment and techniques are being developed for use to water depths as great as 20,000 ft. For example, anchors that are shot from a gun into the sea-floor have been built and tested. These have exceeded their design goal of 20,000-lb holding capacity in any direction, including uplift, and in any seafloor material from soft clay to basalt at those water depths. A similar but larger anchor for use in water of moderate depth has held more than 200,000 lb in uplift. Also, design guidelines have been formulated for concrete hulls for underwater structures. A 10-ft-dia, 20-ft-long, one-atmosphere, reinforced concrete structure was placed on the seafloor for eleven months and performed satisfactorily. The work is now directed toward massive concrete structures, and periodic observations of several spherical hulls moored at the seafloor to depths of 5000 ft are continuing to study long-term implosion resistance and water infiltration. Procedures for increasing the safety and effectiveness of ocean implantment operations have been developed and tested in full-scale seafloor construction experiments. In addition, techniques and equipment are being developed to salvage objects weighing several thousand pounds from the seafloor in 20,000 ft of water. These and other advancements related to fixed-ocean facilities are described.
Development of Very High Pressure Water-jet for Cleaning Naval Boiler Tubes
Authors: Tursi T. P. , DeLecce R. J.
Published: January 2021

Mechanical brushing has been the standard method for removing soft deposits from the watersides of steam generating tubes in U. S. Naval boilers. Problems with that method such as limited deposit removal, equipment breakage and jamming of brushes in tubes led to a program to develop more rapid, effective, and trouble-free methods of soft deposit removal. The use of very high pressure water evolved out of that program. This paper describes the research and development conducted to improve water-jetting and apply it to naval boiler tube cleaning. It describes the development of optimum pressures, flow rates, nozzle and flexible lance configurations, control methods, degree of deposit removal, cleaning procedures, safety considerations and many other aspects, including the Navy-wide adoption of this method. Also mentioned are other potential applications of water-jetting for cleaning, removal of tight deposits and coatings, and for machining and surface finishing operations.
Performance and Stability of Wind-Referenced Autopilots for Sailing Vessels
Authors: Letcher John S.
Published: January 2021

A linearized model is developed for the motions of a vessel steered by a windvane servomechanism. By neglect of several fast-time-scale effects, and assumption of linear hydrodynamics and mechanism, a second-order linear equation governing slow oscillations is derived, System dynamic stability is found to depend on certain vessel hydrodynamic coefficients, operating conditions, geometry, proportions and linkage ratios of the control system; this dependance is explored for several different vane and control combinations.
Procedures for Hydrodynamic Evaluation of Planing Hulls in Smooth and Rough Water
Authors: Savitsky Daniel , Brown P. Ward
Published: January 2021

Recent Davidson Laboratory basic studies of planing hull hydrodynamics have produced a wealth of technology which is not generally available to the small-boat design profession. Included are studies related to the preplaning resistance of transom-stern hulls, the effectiveness of trim control flaps, the effect of bottom warp on planing efficiency, the influence of reentrant transom forms, and the seakeeping of planing hulls. The present paper consolidates these results in a form suitable for design purposes and illustrates their application in predicting planing performance in smooth and rough water.
A Steering Nozzle for a Great Lakes Bulk Carrier
Authors: Johnston R. C.
Published: January 2021

This paper describes some of the model testing and full-scale results arising from the decision to fit a Kort steering nozzle to the Great Lakes bulk carrier MV Ralph Misener. Because the nozzle was the largest in the world at the time, and has been relatively trouble-free for eight years, the results are of interest. The enhanced maneuverability of the vessel is important in the confined channels and locks of the St. Lawrence Seaway System and is sufficient justification for fitting a Kort steering nozzle.
Ship Rolling, Its Prediction and Reduction Using Roll Stabilization
Authors: Barr Roderick A. , Ankudinov Vladimir
Published: January 2021

This paper is designed to provide the ship designer with a description of the phenomenon of ship rolling, its prediction using available theoretical methods, and its reduction using available roll stabilization systems. A critical review of a number of available, predictive methods is provided. It is concluded that roll motions without stabilizers can be satisfactorily predicted using available methods and that it is necessary, in predicting rolling motions, to consider coupled roll-sway motions. The use of passive and active antiroll tanks and active fin stabilizers is discussed, and the size, performance, advantages, and disadvantages of each type are considered. Finally, the need for model tests to validate predicted roll stabilizer performance and the need for additional research in the area of roll motions are considered.
The U. S. Petroleum Transportation Dilemma
Authors: Duncan R. Scott , Lutkus Anthony J.
Published: January 2021

An economic evaluation of the merits of a deepwater tanker terminal was conducted based on the reduction in transportation costs it would return. A single tanker economic model was used to generate a fleet transporting oil from five exporting regions. U. S. energy demand was predicted based on linear regression analysis. A linear programming approach was used to determine the tanker fleet size and transportation costs. Results indicated the reduction in transportation costs made a clustered monobuoy system economically attractive. However, the high capital investment required to construct an artificial island could not be justified with this approach.
Building and Operating Experience of Spherical-Tank LNG Carriers
Authors: Howard James L. , Kvamsdal Rolf S. , Naesheim Kjeld
Published: January 2021

A summary of the analytical and experimental bases of the spherical-tank LNG carriers of the Kvaerner-Moss design is given. Primary attention is paid to a complete description of the experience from building spherical tanks in both 9 percent nickel steel and aluminum, including such critical areas as welding, nondestructive testing, maintenance of tolerances, and repairs of defects. The results of stress and temperature measurements made on the cargo tanks under test are compared with earlier predictions from analytical studies. Operating experience with the cargo system is reported.
Design of On-Deck Container Securing Systems
Authors: Liu King-Tao , Michel R. Keith
Published: January 2021

Elements of marine freight container strength which form an integral part of on-deck container lashing systems are evaluated. Actual test results for these strength elements are presented and compared with current international standards. Proposed strength criteria are established for both containers and securing hardware that offer optimum balance between the two. Forces and motions affecting stowed containers are discussed, and a procedure to analyze container lashing systems is presented. A brief comparison between typical lashing configurations is also included.
Development of the Ship Channel Between Montreal and Deep Sea
Authors: McDonald R. M.
Published: January 2021

The dredged channel of the St. Lawrence River between Montreal and lle aux Coudres forms part of one of the largest inland navigation systems in the world. From the Gulf, ships can travel almost 2000 miles to the head of the Lakes. The various stages of development of the channel to obtain a controlling depth of 35 ft between Montreal and Quebec City and a sufficient depth for a draft of 48 ft—with the aid of the tide— from Quebec City eastward are discussed in this paper.
Determination of Stability Derivatives by Impulse-Response Techniques
Authors: Scragg Carl A.
Published: January 2021

This paper presents a new method of experimentally determining the stability derivatives of a ship. Using a linearized set of the equations of motion which allows for the presence of a memory effect, the response of the ship to impulsive motions is examined. This new technique is compared with the traditional method of regular-motion tests and experimental results are presented for both methods.
Sewage Pollution Control: A Practical Guide for the Shipowner and Designer
Authors: Isaacson Alfred D.
Published: January 2021

This paper is presented to the reader as an aid in understanding the local and federal regulations and as a guide for selecting and installing a sewage treatment system as it pertains to his specific requirements. The present regulations regarding the disposal of sewage generated on board vessel compels the industry to modify existing vessels, and design into new vessels the capability of complying with such regulations by 1980. Many operators have already installed systems, some of which have fallen short of expectations. Included is an investigation of the types of sewage collection systems and flushes and a discussion of the merits of the various types of commercial systems available.
Prospects for Shipping of Liquefied Natural Gas
Authors: Stiehl George L.
Published: January 2021

Natural gas comprises approximately 20 percent of the more than 200 quadrillion Btu's of energy consumed annually in the free world today. This paper examines energy requirements of major energy-consuming areas such as the United States, Western Europe and Japan, indicating the probable demand for natural gas through 1985. Implications of this demand in terms of importation of liquefied natural gas are measured to determine probable future requirements for LNG carriers.
Operational Experience with Floating Breakwaters
Authors: Adee Bruce H.
Published: January 2021

In the past few years floating breakwaters used for the protection of marina facilities have found increasing application. They provide a cost-effective solution at many potential sites and alleviate the environmental damage associated with more traditional breakwater construction. Operational experience has shown that these devices are effective in reducing incident wave heights where they are not subjected to long-period ocean waves. Experience also indicates suitable construction materials. Problems have developed in providing satisfactory connections between segments, but the large anchoring forces that were originally expected have not materialized in field measurements.
The Speed of the SS United States
Authors: Kane John R.
Published: January 2021

Following the maiden voyage of the passenger vessel SS United States in July 1952, on which she easily bettered by four knots the existing transatlantic speed records from Ambrose Light to Bishop Rock and return, the curiosity of the marine world was aroused to know the maximum speed capability of the phenomonal vessel. William Francis Gibbs, the architect of the United States, had other ideas, however, and the top speed performance of the vessel, and the details as to how it was attained, remain today a well kept secret. Since the ship is now retired from the United States Lines, and is no longer viewed as a potential naval auxiliary in case of an emergency, security has been lifted and such information can now be released. This information, although historic, is to some degree timely nonetheless, since it represents a yardstick with which to measure the performance and potential of the large fast cellular-type containerships which are beginning to rival in size and approach in speed that attained in 1952 by the SS United States..
An Evaluation of Intact Stability Criteria
Authors: Nickum George C.
Published: January 2021

Coast Guard and Navy intact stability criteria which were in existence in 1952 are described. The evolution of the IMCO criteria for fishing vessels and for all other vessels under 100 m (328 ft) in length and of the Coast Guard criteria for offshore supply vessels and towing vessels is described. The conclusion is reached that these criteria properly applied are adequate to ensure stability for seagoing vessels.
The National Shipbuilding Research Program: Report of the Ship Production Committee
Authors: Peterson Ellsworth L.
Published: January 2021

The paper reviews the progress of the title program, a six-year-old cooperative effort by Government and industry to improve U. S. ship production methods. Appended are Ship Production Committee status reports, in tabular form, on the four major research and development projects ongoing under the program: welding; ship producibility; outfit and production aids; and surface preparation and coatings. A status report is given also for the Research and Engineering for Automation and Productivity in Shipbuilding (REAPS) Program.
Update on Self-Unloading Dry Bulk Vessels
Authors: Vaughan W. R.
Published: January 2021

This paper deals with the high-capacity gravity-type self-discharging vessel which has become the dominant means for handling dry bulk cargoes on the Great Lakes of North America. Other forms of self-unloading vessels, such as the geared bulker with its deck-mounted grabs and the specialized carriers for products such as bulk cement, are not discussed since they are capable of only low discharge rates. The purpose of this paper is to provide the reader with an update in the design of the self-unloader since 1969. The period between 1969 and 1976 has seen many changes in the unloading equipment aboard these vessels, and the self-unloading fleet has grown to become the common means of transporting bulk on the Lakes. In addition, these vessels are growing in their importance in the St. Lawrence traffic, as well as in some deep-sea trade route areas.
Propulsion Systems for RO/RO Containerships, with Particular Reference to the Controllable-Pitch Propeller
Authors: Tani M. , Okamoto H. , Hirabayashi K. , Koyama M.
Published: January 2021

The authors' company has had long and extensive experience with controliable-pitch (CP) propellers and marine geared diesel plants. In 1974, on the basis of this experience, the company built the world's largest CP propeller [46 000 hp (34 300 kW)]. This paper describes the design features of the propeller, its operating experience, the reasons for adopting a CP propeller, and the historical background of the merchant ship in which the propeller was installed.
Fatigue Considerations for Semisubmersible Structures
Authors: Riggs Robert P.
Published: January 2021

This paper contains a summary of methods and the quality of results obtainable with various fatigue analysis approaches to marine structures. The discussion is directed toward semisubmersibles, but is broadly applicable to many other structures. Areas of the analysis sequence that are not commonly found in existing marine literature are discussed in more detail than the standard naval architecture calculations. Adequate references are given for the technique to be independently developed with a relatively small engineering effort. The method has been applied to numerous structures with excellent results being provided for relative fatigue susceptibility.
Efficient Steam Generators for Modern Marine Cycles
Authors: Ciavarella Robert J.
Published: January 2021

An urgent demand has developed throughout the marine industry for more efficient steam plants to reduce the impact of high fuel costs. The Maritime Administration has undertaken with ship designers a number of studies of ways to reduce fuel consumption. Ship operators are studying their present plants and looking for more efficient new cycles to reduce their operating costs. However, they are approaching the new cycles cautiously in a desire to avoid higher maintenance costs, traditionally associated with lower flue gas temperatures and higher steam temperatures, when burning low-grade oils. These varied interests are looking to the major propulsion plant equipment manufacturers to provide the technology for meeting the industry's new needs. Manufacturers of steam-generating equipment are cooperating to provide many advancements to maximize efficiency, reduce fuel consumption, improve reliability, and reduce maintenance costs. This paper discusses boilers and the related equipment required for the improved cycles.
Least-Energy Operation of River Shipping
Authors: Marbury Fendall
Published: January 2021

This investigation covers the line-haul phase of river shipping. Methods have been derived for determining the best speeds at which to operate river shipping equipment in order to minimize fuel consumption per mile (or per barge-mile, or per ton-mile) or to minimize line-haul cost per mile, etc. These best speeds depend on equipment propulsive performance and costs, whether bound upstream or downstream, swiftness of current, and depth of water. This methodology will prescribe a best speed for each reach of a river, given the equipment used, its fuel rates and costs. Introduction and scope
The Navy’s First Ocean Construction Platform, SEACON: Design and Operation
Authors: Agdern Fredric A. , Sherwood Wilbur G.
Published: January 2021

The SEACON is the Navy's first ocean construction platform. Converted from a 260-ft (79.2 m) YFNB-type seagoing barge, the SEACON was designed to be a self-sufficient, dynamically positioned platform. Specialized navigation, control and underwater systems permit the vessel to locate, recover, and install structures on the ocean bottom. Additional capabilities include: laying and shore-ending cable, diving operations, and deep ocean lifts of 50 tons. Designed for versatility, the large deck space and center well are intended to support various specialized equipments utilized during each particular operation. This paper discusses the design requirements and criteria for the conversion, method of construction, general arrangement, and propulsion machinery. The dynamic positioning control, navigation and underwater systems are described. The vessel's first major operation is discussed along with comments on its design and performance.
Acoustic Analysis of Quiet Ball Bearing Failure Modes
Authors: Rutter Thomas A.
Published: January 2021

Qualitative analysis of rotating machinery structureborne noise and vibration can identity ball bearing installation problems. Indications of improper lubrication and impending bearing failures are identified. The problem of nonuniform motion of ball bearing components in determining expected bearing frequencies is noted together with the effects of grease deterioration. The philosophy of structureborne noise versus vibration measurements and an appreciation of several analysis techniques in the context of determining maintenance requirements and evaluating subsequent repair are discussed.
Formulation of the U. S. Navy Ship Design Speed-Power Margin Policy
Authors: Slager John J. , Tomassoni Carlos A. , Covich Philip M.
Published: January 2021

This paper describes the analyses used in deriving data which are applicable to formulation of the U. S. Navy's speed-power margin policy. Corrections made to the powering predictions and trials data for the ships in the data base, in order to achieve equitable comparisons of predicted powering performance and powering performance actually measured during full-scale trials, are described; the power margins derived from these comparisons are presented. In addition, a statistical analysis of this newly derived power margin data is described and the results are presented. It is shown that the statistically derived margin values provide an appropriate basis for a speed-power margin policy and that small changes to the current interim NAVSEC speed-power margin policy may be desirable.
On the Installation Planning of a Self-Floating Offshore Platform
Authors: Metcalf Michael F. , Praught Michael W. , MacDonell Wayne O.
Published: January 2021

This paper describes the installation planning for a major self-floating offshore platform that recently has been installed in the North Sea. Attention is given to the naval architectural aspects of the installation planning with particular emphasis on three phases: analysis and design, scale-model testing, and field activity preceding and during the actual installation operation. The paper describes the state-of-the-art in the installation planning of major self-floating offshore platforms of the kind being designed and built worldwide, and demonstrates the close coordination of many diverse disciplines in planning such installation operations.
Current and Proposed USCG and IMCO Regulations for Communications and Navigation Equipment for Vessels Over 1600 Gross Tons
Authors: Bizub E. J.
Published: January 2021

Shipowners and operators are continually faced with the responsibility of complying with regulatory body requirements. In the United States, the Coast Guard and the Federal Communications Commission are the agencies that issue and administer the regulations that apply to communications and navigation equipment. Many of the current and proposed regulations of these agencies resulted from IMCO proceedings and were implemented as required by international treaty. A basic understanding of these regulations is essential. Proposed changes should be of concern and should be thoroughly analyzed to determine their operational and financial impact. This paper discusses the rules and regulations in effect on 1 January 1979. A discussion of special requirements for Maritime, Administration subsidized new construction is also presented. A discussion of each of the following proposed or recently enacted changes is also presented:Port Safety and Tank Vessel Act of 1978,USCG requirements for Loran C,changes due to the 1974 Safety of Life At Sea Convention,a proposed Class С Emergency Position Indicating Radio Beacon,VHF requirements for vessel traffic systems,oil transfer communication requirements, andproposed changes for main/reserve antennas.
Professional Liability as it Relates to the Naval Engineer Architect/Marine (and Other Maritime Professionals)
Authors: Chandler George F.
Published: January 2021

Dramatic changes in product and professional liability are reaching the maritime sector. This paper reviews the present state of the law as it effects the naval architect/marine engineer. Among the topics to be considered are a practical explanation of what professional liability entails, reasons for the increase of lawsuits • in this area, differences in liability with reference to commercial versus consumer cases and property damage versus personal-injury cases, and leading cases affecting the professional with examples of how they might relate to common problems found in naval architecture/marine engineering. Typical defenses available to defendants are also presented, along with the dangers inherent in these lawsuits such as large expenses, both legal and expert, and disruption of business activities. Insurance coverage as to types and availability, including alternatives, categories of monetary damages, limitation and indemnity clauses, and protection of assets are topics also reviewed, and, finally, recommendations are made for the evaluation of business practices from the standpoint of liability. It is hoped that, by improving his or her understanding of all the facets of professional liability, the naval architect/marine engineer can avoid at least some of the more extreme problems present in this area.
Noise and Vibration Control Techniques for the U. S. Navy 3000-LT Surface-Effect Ship
Authors: Fox Gary L.
Published: January 2021

The Navy 3000-LT Surface-Effect Ship (3KSES) Program has provided a major advance in the development of high-performance ship technology in many areas. One such area is noise and vibration control techniques applicable to lightweight/high-power vehicles. New analytical methods have been evolved and substantial testing accomplished to support certain theoretical aspects of the analysis or to provide the necessary empirical data. This paper presents a summary of the technical approach used in the 3KSES Noise and Vibration Analysis, a description of the systems installed to achieve the desired acoustical control, and comparison of the predicted ship noise and vibration environment with the Navy specification. The noise sources considered are those related to the major machinery, that is, the gas turbine engines, the large lift fans, and the waterjet propulsors.
The Ubiquitous Barge: Some Trends in Barge Design and Construction in British Columbia
Authors: Ward Thomas C.
Published: January 2021

This paper briefly reviews barge construction in British Columbia, Canada in the 1970's. Changes in the material handling systems for barges serving the forest products industry are outlined. The design of the fore end structure of unmanned barges to withstand slamming forces in heavy seaways is discussed. Progress in the design of the bow form and skeg configuration of larger barges and specific resistance characteristics of a wide variety of barges are examined. The practical effect of the application of some aspects of the 1966 Load Line Convention to unmanned barges and the possible effect of recently promulgated Canadian Interim Stability Standards for this type of vessel are discussed. Finally, trends in the use of radio-controlled remote operation of anchors and ballasting pumping systems, emergency/pickup gear, and paint coating systems favored by the Canadian West Coast tug and barge industry are outlined.
Concept Developments for Offshore Thermal Energy Conversion Platforms
Authors: Scott Robert J. , Giannotti Julio , McClure Alan C. , Dunning Fred
Published: January 2021

This paper discusses studies leading to the concept design of two platforms to support the Department of Energy's Offshore Thermal Energy Conversion (OTEC) mission in the 1980's. The first part of the paper discusses the technical and economic factors evaluated in the selection of optimum plant size and configuration. Variables included a range of capacities from 50 to 500 MW, six hull-form options and three deployment sites. Parameteric trends in platform size and weight as a function of payload and hull shape are evaluated. A methodology for evaluating the various platform options is presented, based upon consideration of cost, schedule and risk, leading to recommendations for an optimum plant. The second part of the paper describes the development of the conceptual design of two selected commercial plant candidates, a ship and a semisubmersible, each of 400-MW net output, to be deployed off Hawaii. Initial tradeoff studies are described and selected platform characteristics are provided. Methods of plant fabrication and deployment are proposed, with emphasis on cost/schedule relationships. Finally, concepts are presented for a demonstration plant which will prove the technical and economic feasibility of OTEC before commitment to the prototype commercial plant.
Estimating for a Changing Technology
Authors: Ramsden Harold D.
Published: January 2021

Over the years, estimators have been challenged to predict the costs of jobs to which they could relate by similar experience. To the estimator this is a comfortable situation. Now, with increasing frequency, the estimator must deal with new elements and new environments for which there are little or no historical data. In these instances the estimator must rely on his experience and judgment to develop his cost estimates. Estimating for a changing technology is no different from established estimating practices except that more care is required in data preparation. Each item of a new requirement must be broken into elements which can be compared with similar elements for which there is an experience record.
The National Transportation Safety Board’s Role in Marine Safety
Authors: Johnson Ralph E. , Swann Benjamin R.
Published: January 2021

The Transportation Safety Act of 1974 has significantly increased the responsibilities of the National Transportation Safety Board (NTSB) in the investigation of marine accidents. Major marine accidents and certain accidents involving public vessels are investigated in accordance with joint regulations between the U.S. Coast Guard and NTSB. The Safety Board is required to determine the cause of those accidents and to make safety recommendations. The paper discusses how NTSB's role in marine safety evolved, the investigation of marine accidents, and the processing of safety recommendations. Some selected accidents and safety recommendations are discussed.
Assessing Intact Stability
Authors: Henrickson William A.
Published: January 2021

This paper was originally prepared to provide discussion material for a proposed senior-level course in advanced stability considerations at the University of Michigan. The author has since revised and restructured the paper. The theory and history underlying existing intact stability criteria based on initial GM, righting moment balance and righting energy balance are discussed. Application of these assessment methods is shown and the critical weaknesses of each are addressed. Examples are drawn from current U.S. Coast Guard and IMCO requirements.
Photogrammetric Surveys of the COGNAC Jacket Structure
Authors: Kenefick John F. , Huete David A.
Published: January 2021

The three sections of the jacket for Shell Oil Company's "COGNAC" drilling platform, when mated together, stand nearly as high as the Empire State Building. Because of the size of the sections, fabrication schedules, and the schedule for lowering the sections into place in the Gulf of Mexico, it was not possible to physically test the fit between sections beforehand. To assure that the sections would properly mate underwater, a vigorous surveying and mathematical analysis program was undertaken as an integral part of the construction process. Analytic photogrammetric triangulation was one of three survey techniques employed. Photographs of the jacket sections were taken from a helicopter, from an inflatable raft and from the ground. Measurements made on these photographs were computer-processed through photogrammetric programs to produce as-built plan dimensions and elevations of the structure's legs at their mating faces with a tolerance of about ±3/16 in. These data, along with data produced by other surveys, were used by Shell engineers to aid prediction of the fit between the jacket sections. In the final analysis it was found that any one of the survey methods would have given satisfactory results. However, the photogrammetric survey required the least amount of on-site preparation and caused relatively little interference with other ongoing work. Also, the photogrammetric survey produced additional data which could not be readily obtained by the other methods.
Design of Steering Gears, Rudders, Rudderstocks, and Propeller Protection for Canadian Arctic Class Vessels
Authors: Laskey N. V.
Published: January 2021

Transport Canada's Arctic Shipping Pollution Prevention Regulations table rules for design and construction of Arctic Class vessels. As Arctic shipping projects have remained moribund for years, some items of equipment described in these rules have not been developed or tested. This paper deals with those items, which are listed in the title, and endeavours to establish their significance and the type of hardware to be developed to implement them. An Appendix is included listing the precise regulations pertaining to the equipment. First 28 000-dwt Arctic Class 2 bulk carrier built to Canadian Arctic Shipping Pollution Prevention Regulations
An Updated Analysis of Fuel Consumption: Steam and Diesel
Authors: Stott C.W. , Casey J.P.
Published: January 2021

Each element of the total fuel consumption of typical steam plants is presented, starting with the turbine propulsion cycle performance, then building up to the standard all-purpose fuel consumption rate normally reported. The method of presentation illustrates the contribution of each element to the whole, including consideration of transmission loss, boiler efficiency, fluid pumping power, electrical load, etc. Similarly, diesel plant performance is represented in as duplicate a format as possible, starting with the test-bed performance of the engine and then considering in-service fuel, lube oil, electrical load, etc. By presenting both plants in the manner described, from approximately 40 to 100 percent power, the point is made that the disparity between steam and diesel plant performance is less than normally assumed, and, in certain applications, nonexistent. As a corollary, the part-load performance of the two plants is shown to be remarkably similar. The paper is divided into four parts for ease of reference:summary and conclusions,steam plant,diesel plant, andcomparisons.