bluuebunny/crossref_metadata_2025 huggingface dataset:
Full-Scale Measurements and Statistical Analyses of Ship Motions in a Navigation Channel
Authors: Wang Shen
Published: January 2021

Due to the trend toward large dry and liquid bulk carrier construction in recent years, safe navigation in ports and channels has become a major concern to both governmental regulatory agencies and the maritime industry. This paper presents the results of a study on motions of deep-draft vessels in a navigation channel. The objective of this study was, through measurements and analysis of the vessel motions, to validate the design assumptions for a specific channel as well as to establish the general design information on channel width and depth requirements with respect to the ship characteristics and channel environment. Full-scale measurements of motion characteristics for 29 vessel transits through the Columbia River Entrance Channel have been conducted. The measurements include pitch, heave and roll motions, vessel heading angles and position tracks. Analyses of the measured data have been conducted with the objective of deriving both short-term and long-term statistics. For short-term correlations, all the motion variations have been assumed stationary, and comparisons of the histograms of motion amplitudes with the theoretical Rayleigh distribution have been conducted and found satisfactory. As to the long-term statistics, it is found that the measured data can be very well represented by the log-normal distributions.
A Simplified Stability Letter for Offshore Supply Vessels
Authors: Meyer Richard B. , Feeney Kevin V.
Published: January 2021

This paper presents a simplified method for the preparation of stability information for offshore supply vessels. The paper reviews the current methods used by the Eighth Coast Guard District Merchant Marine Technical Office for preparation of stability information and compares these with the proposed "simplified" method. The simplified stability letter incorporates a loading diagram which will make it easier for the vessel operator to use. The recommended letter will allow designers to obtain a higher maximum amount of deck cargo, provide more flexibility in the manner in which cargoes are carried, allow operators to exchange consumables for additional below-deck cargo, and simplify the calculations necessary for preparation of the stability information. It should be cautioned that the method presented is only the opinion of the authors. Approval should be obtained from the cognizant Coast Guard technical office before employing this or any other proposed method. It should also be noted that the stability criteria presented in Appendix I are not yet included in regulations and are subject to change.
Parcel Chemical Carriers: Characteristics and Operation
Authors: Symon R. S.
Published: January 2021

Parcel chemical carriers are a type of tank ship purpose-built to carry a variety of bulk liquids requiring specialized cargo handling and cargo containments. The ships are designed and built to provide exceptional flexibility of cargo tank use and cargo stowage over a wide range of liquid cargo characteristics. The paper describes the salient and more unique characteristics of this ship type. The manner in which cargo tank configuration design is dependent upon trade routes, regulatory requirements for dangerous cargo, and other special requirements are described. Cargo handling flexibility is reviewed. Operational points particular to this ship type are discussed.
Calculating the Cross-Curves of Stability Using the Hand-Held Programmable Calculator and Printer
Authors: Cromer Paul B.
Published: January 2021

This paper describes a three-part program the author has written for the Texas Instruments 59 Programmable Calculator and PC-100A Printer for calculating the cross-curves of stability for a vessel at inclinations of 15, 30, 45 and 60 deg from its offsets. The intended application of this program is in preliminary design studies. The program is based on the following assumptions, discussed in the "Basic Ideas" section of the paper: The intersection of the draft and inclined waterlines at each station can be treated as the origin (0) of an x-y coordinate system; the areas of the immersed and emerged wedges can be approximated by the sums of areas of triangles; the centroid of each of these triangles can be located by calculating the point of intersection of two of its medians; the areas of the two wedges can be made equal by moving the origin a certain direction and distance along the draft waterline; and the vessel's vertical center of gravity lies at the bottom of the keel. The three parts of the program are explained in the paper's "Program" section; they are Offset Encoding, Wedge Equalization and Moment Calculation, and Righting-Arm (GZ) Calculation. "Using the Program" discusses program restrictions and describes how the program is used to compute cross-curves. The "Conclusions" section of the paper describes the advantages to the program user: No wedge or layer corrections are required, the actual or assumed KG is taken into account when the GZ is calculated, program operation is semi-automatic, and no large-scale full-body is required. In addition, the author has included an improved version of his curves-of-form program as an Appendix.
Testing of Automated Systems from the Safety Point of View
Authors: Vitkauskas John D. , Peters John R.
Published: January 2021

The Coast Guard NVIC 1–69 has provided guidelines for the design of automated systems so that human surveillance can be reduced without jeopardizing the vessel. An integral part of these guidelines is the preparation of a Test Procedure which periodically tests the vital safety systems to increase the probability that they will function properly when called on. However, the Test Procedure guidelines are general and subject to wide interpretation. This paper attempts to provide some insight into what needs to be periodically tested, why the testing is required, and what techniques are acceptable, at the same time stressing the need for efficient testing. Some examples are also provided of testing procedures that have been found to be efficient and sufficiently comprehensive.
The U.S. Coast Guard Academy Circulating Water Channel
Authors: Colburn Warren , Simpson William , Phelps Vernon
Published: January 2021

In 1974 it was determined that the Marine and Ocean Engineering programs at the Coast Guard Academy were suffering from the lack of a facility to allow students to do experimental work in the area of fluid mechanics and ship hydrodynamics. A study was conducted to develop and evaluate the options, and this resulted in the design and construction of a free-surface circulating water channel (CWC) with the associated instrumentation. This CWC has a test section 2 ft deep by 4 ft wide by 12 ft long and a maximum velocity in excess of 8 ft/sec (Froude No. >1). The technique of using a vertical loop circulation with a 3-to-1 compression section prior to water entry into the test section and the use of turning vanes to inhibit separation of the flow stream have resulted in a uniform velocity profile quite suitable for the experimental work by the Academy and the Research and Development Center.
Optimum Freeboard: A Critical Reassessment of the Balanced-Ship Concept
Authors: Bales Nathan K.
Published: January 2021

The minimum freeboard requirements needed to obviate performance limitations due to deck wetness, that is, to "balance the ship," are taken as an idealized standard. Ship performance using these freeboards is assessed and compared with performance at lower freeboards. The comparative results are used to derive a measure of the performance degradation caused by using less than the ideal, minimum required free-boards. It is found that, under some circumstances, freeboards significantly less than the idealized minimum requirements can be used with only a minor penalty in ship performance. These results provide a rational basis for optimizing freeboard in tradeoff against conflicting design requirements.
The Economics of Oil Spill Cleanup
Authors: Bianchi R. A.
Published: January 2021

The cleanup costs of large oil spills since the Torrey Canyon grounding amount to over 250 million dollars. Other costs associated with these spills increase the total cost to at least one billion dollars. The equipment and technologies that are commercially available to reduce the damage and resulting costs from these spills, and a strategy for implementing a coastal defense system, are economically justified. A new M.I.T. Sea Grant College Program which was initiated in July 1979 is described. The industry-and government-sponsored project entitled "Oil Spill Cleanup Economic and Regulatory Models" promises to provide a more complete and comprehensive study of the oil spill cleanup problem.
Spill Containment and Cleanup—Research and Development
Authors: Leigh James T.
Published: January 2021

Current and past Coast Guard research and development interest in oil spill containment and cleanup can generally be categorized as concerned with severe environmental conditions and rather large spill volumes. Problem areas receiving attention at this time include recovery of oil in fast currents, pollution response in ice-infested regions, open-ocean pollution response, disposal, and pollution prevention. Each of these problems is at a different stage of development. The scope of the problem and the nature of USCG efforts vary substantially, and this note briefly outlines its interest and activities.
Bulk Cargo Inventory Costs and Their Effect on the Design of Ships and Terminals
Authors: Benford Harry
Published: January 2021

Conventional approaches to marine transport economics consider only the shipowner's interests; the cargo owner's interests are usually ignored. The intent of this paper is to recognize both interests so that shipowner and cargo owner, by acting in unison, can minimize the costs of physical distribution. Taking this wider-angle view involves, as a start, a recognition of the inventory value of the goods in transit. But, it should also recognize the costs of stockpiling the goods at each end of the voyage. This paper shows how traditional ship economic criteria can be modified to recognize these incremental factors. A case study is used to illustrate the application of the economic principles proposed.
Steering Gear Requirements: Changes on the International and Domestic Scene
Authors: Maxham John C.
Published: January 2021

Steering gear is vital to the safety of a ship, its personnel, and the marine environment. Because of recent major casualties involving steering gear, considerable effort has been directed toward improving national and international standards for steering gear, particularly for tankers. Much of this effort has been conducted by the Intergovernmental Maritime Consultative Organization. This paper discusses basic U.S. CoastGuard and international requirements for steering gear and outlines changes resulting from such agreements as Resolution A.325(IX), the Tanker Safety and Pollution Prevention Conference, and the most recent amendments to SOLAS 74, which are ready for adoption during the 12th IMCO Assembly in November1981. U.S. and international requirements are compared and a probable timetable for implementing new requirements is presented.
T-AO ‘Commercial’ Fleet Oiler
Authors: Davis Clayton W. , Ince John F. , Gessow I. David
Published: January 2021

Three point designs and 15 tradeoff studies for a commercial fleet oiler were completed and price estimates prepared for them. Based on the results, two concept designs and four more tradeoffs were completed and price estimates prepared. This paper presents the results of these studies, and documents design guidelines, approach, and technical details.
Modeling of Propeller Cavitation on Merchant Vessels
Authors: Gray Leslie M. , Greeley David S.
Published: January 2021

The time-varying cavitation on a marine propeller, which excites hull vibrations, is calculated. The analytical model is exercised to guide propeller design and operation in order to minimize this type of hull excitation. This model, as well as a more elaborate model under development at Massachusetts Institute of Technology, is compared with recent full-scale observations of propeller cavitation. The paper illustrates the importance of both accurate input data on scaled vessel wake velocities and the inclusion, in analytical models, of tip vortex cavitation.
Potential Impact of Twenty Year Hindcast Wind and Wave Climatology on Ship Design
Authors: Bales Susan L. , Cummins William E. , Comstock Edward N.
Published: January 2021

This paper highlights some features of the Navy's new climatology which appear to extend the designer's capability to realistically assess ship performance. The climatology provides global wave and wind parameter statistics, identifies the occurrence and persistence of some heavy weather conditions, and promises to permit a substantial upgrading of wave directionality and spectral shape models. Effects of these features are summarized in terms of predicted performance of several naval combatants.
Subdivision of Crude Oil and Product Tankships
Authors: Daidola John C. , Graham Douglas A. , Jovino Victor W. , Hogg William A. G.
Published: January 2021

In light of the new U.S. Federal regulations aimed at reducing oil pollution from most tank vessels of 20 000 dwt and above through the use of segregated ballast, side and bottom protective area, and crude oil wash, it is necessary for ship designers to reconsider the overall subdivision scheme of certain tankships. Using cargo carrying capacity considerations, various subdivision schemes of crude oil and product tankships ranging in size from 20 000 to 260 000 dwt are scrutinized. Both new and existing vessels are considered. The schemes differ primarily in number and locations of the longitudinal bulkheads and the presence or absence of double bottoms. In addition, current requirements are summarized in a tabular format, and various existing designs, developed before and after the new regulations came into force, are compared.
Mathematical Ship Lines and Surfaces
Authors: Munchmeyer Frederick
Published: January 2021

A mathematical spline, with mathematical ducks, is proposed for naval architecture as an alternative to the familiar draftsman's spline with its lead ducks. These mathematical tools are handled in virtually the same way that their traditional counterparts are used, as the hull form is developed line by line. A visual study of the curvature graph of the new spline substitutes for the naval architect's touch when testing for fairness. After the lines have been laid down and faired in, a mathematical surface is constructed automatically. Next, another new tool is applied: a graphic display of the Gaussian curvature of the whole hull is drawn at the designer's computer terminal. This display permits a visual evaluation of surface curvature, which is comparable to a model maker's test of surface fairness. Examples are given of lines laid down with mathematical splines and of the Gaussian curvature display.
Subdivision, Stability, Liability
Authors: Cleary William A.
Published: January 2021

This paper attempts to show that a balance of responsibility exists for casualty prevention, mitigation and recovery and it is jointly shared by the designer, the administration and the operator. Each of these is partially responsible for the ship's safety and continues to have some responsibility throughout the lifetime of the vessel. In order to plan a safe marine operation, the designer, with accurate information from the operator, is professionally responsible for reviewing all proposed operations for the indicated lifetime of the ship and must examine each to define its potential for disaster. The master needs to know the threshold of motion, force, buoyancy, roll, and seaway steepness over which the safety of the ship is beyond his skill and becomes a matter of providence. This knowledge will help him act in a timely fashion to save the lives of those on board when it is known that the ship cannot be saved. The regulatory administration must follow a similar path and select milestones on the designer's path which become the minimum federal standard for regulatory acceptability.
Acoustic Emission/Rupture Load Characterizations of Double-Braided Nylon Rope
Authors: Williams James H. , Lee Samson S.
Published: January 2021

Acoustic emission (AE) nondestructive evaluation characterizations have been obtained from new Samson double-braided 2-in-1, 0.635-cm-diameter (¼ in.) nylon rope in the dry condition at room temperature. A parameter called the "AE load delay" has been defined as the tensile load required to produce a specified low baseline level of AE activity. It has been observed that the AE load delay can be correlated with the ultimate rupture load of the rope with cut core yarns and with a variety of stress-concentrating knots.
Fundamentals and Applications of the Finite-Element Method in Analyzing Structural and Nonstructural Marine Problems
Authors: Liu Donald , Chen Yung-Kuang
Published: January 2021

The finite-element method has become a popular and effective tool not only for structural analysis, but also for a wide range of physical problems which are of particular interest to the marine industry. A brief review of the finite-element formulation for structural and nonstructural problems is presented. Applications to marine structures, including static and dynamic analysis and fracture mechanics, are given. Nonstructural applications to heat transfer and ship hydrodynamic problems are also demonstrated. Recent developments in the coupled fluid-structural interaction problem using the boundary integral method, which is considered as an extension of the finite-element method, are also described.
Optimal Preliminary Selection of Mobile Offshore Drilling Units
Authors: Zumwalt Crane E.
Published: January 2021

A comprehensive, systematic method tor selecting a mobile offshore drilling unit is presented. Going beyond the normal, simplistic cost analysis, the procedure includes the unit's performance capabilities and operating time as criteria. The analysis evaluates the suitability of the broad classes of units and/or specific units for the intended operating program. At key points in the analysis subjective decisions are made by the evaluator in keeping with his specific perspective and drilling program needs. Thus the selection utilizes both the quantitative information available on the units and planned drilling program as well as the qualitative decision-making ability of the evaluator. As an example, an evaluation of a general series of units for a multiple-location, multiple-well North Sea drilling program is presented.
Ship-Model Correlation of Powering Performance on USS Oliver Hazard Perry, FFG-7 Class
Authors: Woo Everett L. , Karafiath Gabor , Borda Gary
Published: January 2021

Standardization trials were conducted on USS Oliver Hazard Perry (FFG-7) in May 1978. From the results of the trial data and the post-trial model correlation experiments which simulated the trial conditions, the powering correlation allowance of 0.00045 was obtained for the FFG-7. It should be noted that the pretrial model tests used the design correlation allowance of 0.0005 to predict full-scale powering performance. In addition, the powering performance was predicted using the "1978 ITTC Performance Prediction Method for Single Screw Ships."
Experience with an Unmanned Vehicle-Based Recovery System
Authors: Wernli Robed L.
Published: January 2021

The Naval Ocean Systems Center (NOSC) has been in the forefront of undersea vehicle and manipulator development since the early 1960's. Through extensive at-sea and laboratory test programs, methods have been developed to optimize these remote systems. NOSC's technological background is presented here with particular emphasis on the optimization of undersea manipulator and work systems. Methods of increasing system efficiency while keeping complexity to a minimum are also presented.
Design and Operation of a Highly Maneuverable Great Lakes Self-Unloader
Authors: Bassett Noel L. , Kline Roger G. , Miller Robert H.
Published: January 2021

The motor vessel American Republic is a Great Lakes self-unloading dry bulk carrier designed and built for operation between Lorain, Ohio and the head of navigation on the Cuyahoga River in Cleveland, Ohio. In order to safely navigate the Cuyahoga River on a regular basis, the vessel was designed with twin screws, Kort nozzles, four flanking rudders, four steering rudders and bow and stern thrusters to enhance maneuverability. In addition, a novel pilothouse arrangement was incorporated into the design to optimize visibility and vessel control. The design of the propulsion and steering system is discussed and an evaluation of the vessel's operation is presented.
Diesel Reduction Gear Design and System Considerations from a Torsional Vibration Viewpoint
Authors: Mowers Gary P.
Published: January 2021

Ships propulsion systems consisting of diesel engines and reduction gears are popular due to the ability of the internal combustion engine to operate on the less-expensive heavy fuels. This paper highlights system torsional design considerations that heretofore may not have been appreciated or recognized. Diesel engine misfiring and torsional coupling stiffness variables are addressed to show these effects on shaft stresses and gear overload. The role of the computer in monitoring and recording actual torsional vibration data is presented.
An Analysis of the Ultimate Strength of Deck Structures Under In-Plane Loads
Authors: Shapir Ygal , White Gregory J.
Published: January 2021

A step-by-step procedure for determining the mode of failure and the ultimate strength of ship deck structures under in-plane compressive loads is developed. A comparison of several analytical theories for the buckling strength of deck structures in the elastic and inelastic zones is presented and the reason for the approach taken at each step is explained. The final result is a simple flow chart for this procedure and an algorithm which is easily adapted to most computer systems. The procedure is compared with experimental results and a method for determining reasonable size factors of safety (or correction factors) to account for initial deflections, residual stresses, etc., is presented. An example coding in FORTRAN IV for use as a subroutine in larger programs, or as a simple program itself, is given. An example structure is solved to explain each of the steps of the procedure.
Wind Loads on a 1:115 Model of a Semisubmersible
Authors: Troesch A. W. , VanGunst R. W. , Lee S.
Published: January 2021

A series of experiments involving the wind loads on a 1:115 scale model of a semisubmersible is described. The effects of the boundary-layer profile and Reynolds number in the force and moment coefficients are noted. The contributions to the total drag that various hull components made were measured. The model was placed in a highly viscous fluid to aid in heel and pitch angle changes. This type of testing technique is discussed. The experimental drag and height coefficients are presented and compared with calculated values.
A New Approach to Vessel Weather Routing and Performance Analysis
Authors: Petrie George L. , Bongort Kenneth J. , Maclean Walter M.
Published: January 2021

The concept of ship weather routing has long held forth the promise of improved efficiency and more economical operation of ships at sea. A new approach to ship weather routing has recently culminated in the development of an algorithm which combines presently available technologies in the areas of weather and wave forecasting with vessel seakeeping and speedkeeping, in conjunction with a comprehensive vessel operating cost model. The resulting model, when solved by a dynamic programming technique, will identify the optimum vessel routing consistent with prevailing weather and operational constraints, as well as related economic factors. The application of the Optimal Ship Routing Algorithm in the analysis of several actual vessel routings is described. Actual vessel performance and projected voyage costs, for ships sailing with and without weather routine advisories, are compared with those expected along the route selected by the Optimal Ship Routing Algorithm and also with the route selected by commercial weather routing services. The potential for substantial improvements in on-time performance and reductions in cost is amply demonstrated, for operations in both moderate and severe weather conditions. In addition, the algorithm can be used for post-voyage performance evaluation, vessel operability analyses, and preparation of vessel performance data for scheduling decisions.
Drilling and Production Platforms for Arctic Offshore Development
Authors: Gerwick Ben C.
Published: January 2021

Rapidly expanding development is taking place in the Arctic and sub-Arctic seas of Alaska and Canada, driven by the discovery of immense resources of oil and gas and favorable geophysical conditions in adjoining areas. The Arctic regions are dominated by sea ice, from the central polar pack to the pressure ridges and rubble piles that form in the shear zone along the periphery. In the east, adjoining Labrador and Newfoundland, icebergs are encountered. Storm waves and surges during the summer, strong seismicity in certain areas, and weak and construction-difficult soils in many areas combine to make the design and construction of platforms abnormally difficult. Existing platforms for offshore exploration include sand and gravel islands in shallow-water areas, floating drillships accompanied by icebreakers, a concrete-caisson-retained island in the Canadian Beaufort Sea, and a converted VLCC, grounded on a prepared embankment and given additional protection by artificially constructed ice rubble. At the present time, two steel caissons, designed to be filled with sand after founding, and one floating drilling structure are under construction. In the design and planning stage are a number of new concepts for caissons, mostly constructed of prestressed lightweight concrete, designed to resist global forces in the range of 150 000 kips or more and local concentrated forces of 800 to 1000 psi over small areas. Prestressed lightweight concrete appears well suited to the demands of Arctic service. The towing, deployment, founding, and subsequent removal of exploratory platforms demands consideration of a wide variety of naval architectural aspects. One of the more critical areas facing designers is how to determine the forces and displacements caused by impact from a large ice floe or berg. The compliance of the structure and the hydrodynamic dissipation of kinetic energy need to be considered, as well as the crushing of the ice. The successful development of the Arctic demands consideration not only of a wide range of engineering and naval architectural aspects but also their integration with ecological, social, political and economic considerations.
Recent Experience in Model-Scale Simulation of Tension Leg Platforms
Authors: Dillingham Jeffrey T.
Published: January 2021

Several recent model tests of tension leg platforms (TLP's) are described. Some new and challenging design problems which are unique to tension leg platforms have become the focal points of these tests. These have required the development of new modeling techniques and methods of data processing. A general review of TLP characteristics and modeling requirements is presented along with a description of recent test programs and modeling techniques. Research areas of particular interest in the recent tests are described and some recommendations for future research are made.
Lightweight Materials for Mooring Lines of Deepwater Tension Leg Platforms
Authors: Salama Mamdouh M.
Published: January 2021

The design of a mooring system for tension leg platforms (TLPs) becomes more complicated as water depth increases. The use of steel mooring lines requires complicated tensioning, handling, and flotation systems. This paper discusses the basic design requirements for the TLP mooring system and identifies several advanced fiber-reinforced lightweight materials as alternatives to steel. High-modulus carbon fiber/KevlarcircleR fiber hybrid composites and Kevlar ropes appear to offer the optimum mooring systems for TLPs used in the development of large and medium-size reservoirs, respectively.
American Bureau of Shipping Activities on Behalf of the United States Coast Guard
Authors: Reiter John W.
Published: January 2021

The American Bureau of Shipping and the U.S. Coast Guard have enjoyed an excellent working relationship for a long period of time. This paper gives a brief description of both organizations, describes some of the past cooperative arrangements, and details the latest agreement concerning commercial vessel plan review and inspection.
Design, Construction, and Operation of a 36 250-ST Self-Unloading Collier with a Coal-Fired Steam Plant
Authors: Baseler Robert W.
Published: January 2021

The Energy Independence, first coal-fired collier built in America in over 30 years, was delivered to the New England Collier Company on August 6, 1983. In her first year of operation she has brought nearly 2½ million tons of coal from the coal fields surrounding Chesapeake Bay to New England power plants at Salem and Brayton Point. This innovative vessel embodies advanced technology in both its power generation and cargo systems, and, as its name implies, represents an important new resource to the New England power consumer. This paper reviews the initial design requirements, the design development, and the trial and post-delivery performance of Energy Independence.
Recent Research on Dynamic Behavior of Large Great Lakes Bulk Carriers
Authors: Stiansen Stanley G.
Published: January 2021

This paper reviews several research projects undertaken by the American Bureau of Shipping in the recent past which are of particular interest to Great Lakes vessels. These projects cover five areas of research, namely, linear springing prediction, analytical and experimental investigation of nonlinearity in springing, pressure correlation, ship vibrations, and fatigue behavior.
Effects of Nonlinearities on Hull Springing
Authors: Troesch Armin W.
Published: January 2021

The wave-induced vibration of the main hull girder, commonly called springing, is discussed. When the frequency of the wave excitation force matches the natural frequency of ship's hull, large bending stresses can result. Through the use of experimental and theoretical results, the effect of springing on a Great Lakes bulk carrier's midship bending moment is estimated. Both the linear and nonlinear excitations are considered. The numerical examples given show that the total response is critically dependent upon the vessel's natural frequency and speed in addition to the shape of the sea spectrum that the vessel is operating in. In some instances, the nonlinearities can account for one third of the total response.
Containership Stowage: A Computer-Aided Preplanning System
Authors: Shields Jonathan J.
Published: January 2021

It is well known that the advent of cargo containerization has revolutionized the art of ship stowage by greatly increasing cargo handling efficiency. However, in order to take full advantage of this capability, and to optimize the use of the containership itself, the physical distribution of containers on board the vessel must be carefully planned. In this paper, a computer software system designed to aid in this planning process is described. First, the particular difficulties of containership stowage are discussed and a set of stowage objectives is developed. The solution algorithm, employing a combination of simulation and a Monte Carlo technique, is described. Finally, the implementation of the system by a major U.S. shipping line is discussed.
An Investigation into the Loss of the Mobile Offshore Drilling Unit Ocean Ranger
Authors: Johnson Ralph E. , Cojeen H. Paul
Published: January 2021

The loss of all 84 persons aboard the mobile offshore drilling unit (MODU) Ocean Ranger on February 15, 1982 and 123 of the 212 persons aboard the MODU Alexander L. Kielland on March 27, 1980 are dramatic examples of MODU accidents. One of the purposes of this paper is to describe the investigative process undertaken by the National Transportation Safety Board (NTSB), the U.S. Coast Guard and the Canadian Royal Commission to determine the cause of the capsizing and sinking of the Ocean Ranger. In that regard, the NTSB analysis and findings are presented. A number of other MODU casualties are summarized in order to put this casualty into perspective. The responsibility for the safe operations of these complex and expensive platforms must be shared among regulators, vessel owners, drilling contractors, operators and labor organizations. The paper examines the national and international rules and regulations that are in place relating to design, construction and operation of MODU's. The NTSB recommendations are put into this shared-responsibility framework.
The Shipbuilder's Choice: Fitness for Service, or the Medicine Man?
Authors: Morrison Samuel G.
Published: January 2021

Hundreds of thousands of dollars are spent on needless weld repairs on every major ship built in the United States. This results from the use of irrational weld acceptance standards whose source can be traced to the conviction, developed among shipbuilders and operating agencies during World War II, that all welds must be completely sound. Forty years of research have demonstrated that adherence to traditional workmanship standards costs vast sums and contributes little to real quality. It is possible to develop fitness-for-purpose standards, based on principles of fracture mechanics, which will improve quality and reduce cost at the same time.
The Impact of Extensive Automation: A Hopper Dredge Case Study
Authors: Soland James G. , Lowell William A.
Published: January 2021

In recent years there has been a great emphasis on reducing ship operating costs, especially in light of the overall decline of the marine industry. This paper discusses the impact of extensive automation of a dredge, with special emphasis on reliability, maintainability, and overall manning requirements. More extensively automated systems are studied, along with the impact of designing machinery to be operated at reduced manning levels to satisfy American Bureau of Shipping rules, and actual manning required by the U.S. Coast Guard.
Development of Rigid Inflatable Boats for U.S. Navy Shipboard Use
Authors: Amick David W. , Hamilton Robert , Shields Curtis E.
Published: January 2021

The Rigid Inflatable Boat (RIB) was originally developed as a gasoline outboard powered craft for surf zone rescue use by the Royal National Lifeboat Institution in the United Kingdom. The objectives were to provide a craft with extremely good stability characteristics to operate in steep onshore breaking waves without capsizing, and to improve the safety of operations alongside other vessels. Open ocean rescue and boarding applications were of interest to the U.S. Coast Guard because of the inherent stability and alongside safety of the RIB. Subsequent feasibility studies by the U.S. Navy indicated that the RIB would be superior in performance to the present 26-ft motor whaleboat, and could also reduce topside weight. The Navy opted for diesel inboard power for the RIB's designated to be carried aboard combatant ships. A diesel-powered RIB was procured for concept evaluation by the U.S. Navy, and has undergone a series of trials and tests to establish smooth-and rough-water performance characteristics. The data acquired confirmed the theoretical performance predicted during the feasibility studies. This first RIB was deployed on a U.S. Navy DDG-993 Class ship utilizing an existing single-point davit. During that deployment, the RIB was launched and retrieved successfully at ship's speeds up to 12 knots. Early indications are that this development program will result in a new ship's boat and an accompanying davit system which will provide the Fleet with a safe, high-performance craft which will greatly enhance operational capability and safety, and substantially reduce topside weight. The enthusiasm of test and Fleet personnel who have operated the RIB attests to its superior performance and to a high degree of probability for success of the program.
A Systems Engineering Approach to Support Design of the Navy’s SL-7/T-AKR Fast Logistics Support Ship Conversions
Authors: Russon Larry , Streifer Stephen
Published: January 2021

This paper describes the systems engineering approach that was used by National Steel and Shipbuilding Company (NASSCO) in performing tradeoff analyses associated with the design for conversion of SL-7 containerships to T-AKR Fast Logistics Support Ships for the U.S. Navy. This design effort involved the development, from a baseline set of minimum performance requirements, of an initial design to maximize the ship's mission capabilities within a firm cost constraint. A series of tradeoffs among various design features was performed to arrive at the most capable, cost-effective solution. Tradeoffs had to rationally consider the competing requirements of difficult-to-quantify mission criteria—such as cargo capacity, capability to load/unload within specified times, and endurance—as well as cost. NASSCO, with consulting support from Booz, Allen & Hamilton, developed a formal systems engineering model as a consistent means for validating rational design decisions, based on the collective experience and engineering judgments of the team members. The model ensured a common focus on the multiple attributes of mission capability within the overall cost constraint. The approach was based on concepts and techniques of system requirements analysis, multi-attribute utility analysis, pairwise comparison of attributes, and analytic hierarchy modeling blended into a practical systems engineering application. The NASSCO design approach, including support provided by systems engineering, led to development of a highly capable T-AKR design. The systems engineering approach that was used has broad applicability to the design of Navy ships where cost is only one of many criteria for evaluating the attractiveness of design alternatives.
The Estimating and Administration of Commercial Shipbuilding Contracts
Authors: Byington J. A.
Published: January 2021

The author condenses his many years of experience as chief estimator of a large shipyard. He explains the organization of commercial shipbuilding contracts in the United States, and presents current cost data applicable to tugs, barges, product tankers and ferries. Cost information on general shipyard functions, voyage repairs and change orders is also presented. The guidelines for planning, preparing the estimate, and administrating are useful to anyone dealing with shipbuilding contracts.
The Small Passenger Vessel
Authors: Cashman Robert M.
Published: January 2021

This paper opens with a brief historical review and then discusses design and construction of self-propelled U.S.-flag passenger vessels from 50 to 200 ft in length. Technical topics include hydrodynamics, hull form, structure, weights, trim, subdivision, stability and machinery. A discussion of regulatory standards and the effect of the regulatory process on the industry is included.
Effects of Stress Concentration and Reinforcement on the Fatigue Strength of Rectangular Openings
Authors: Chang Pin Yu
Published: January 2021

Large rectangular openings on the strength deck are a major concern of the designers of commercial and military ships. Currently used methods are inaccurate for the prediction of stress concentration factor (SCF). There is no commonly accepted criterion for the maximum stress. The current design method cannot be used to explain the behaviors of the structure when the stress at a small area is calculated as greater than the ultimate strength of the metal. Nor can it explain the failures that occur at relatively low nominal stress. All these problems can be better explained and analyzed by the concept of fatigue strength and fatigue life. This paper proposes some new methods for the prediction of SCF, approximate methods for the prediction of fatigue strength reduction factor due to stress concentration, and fatigue life of openings. Validation of the new method is also included.
Stability of Large Sailing Vessels: A Case Study
Authors: Tsai N. T. , Haciski E. C.
Published: January 2021

The U.S. Coast Guard training barque Eagle (WIX 327), built in 1936 as the Horst Wessel by Blohm & Voss in Germany, has recently been renovated to improve her performance. As part of the renovation, the stability of large sailing vessels in general and Eagle in particular were studied. Changes in the subdivision, ballast and tankages were made to satisfy the criteria of two-compartment damage stability. Extensive renovation in the areas of machinery, structure, navigation and habitability were also made during the same period while maintaining her scheduled training cruises each year.
Features of Maneuverability of Ships with Steering Nozzles
Authors: Asinovsky Volf
Published: January 2021

The hydrodynamics of a steering nozzle is different from the hydrodynamics of a rudder installed behind a propeller. These two steering devices react differently to a change of kinematics of ship motion and propeller loading. The influence of the propeller work regime on the side force value is much more significant in the case of the nozzle. The side force, created by the nozzle at all regimes, except the motion by inertia and at low rpm, is higher than that provided by the rudder in comparative conditions. This paper considers the specific features of maneuverability of ships equipped with steering nozzles. The analysis of these features is used for the development of practical recommendations for designers, taking into account the specifics of the nozzle as a steering device.
The Usefulness of Response Monitoring for Estimation of Bow
Authors: Petrie George L. , Maclean Walter M. , Cojeen H. Paul , Schudel Gregg
Published: January 2021

During the 1970's, the Maritime Administration, as part of its Exploratory Research Program, supported the development of shipboard instrumentation systems for the sensing of ship motions and structural responses and the prediction of response changes to be expected when a ship's course or speed is altered. Two systems were installed, one on the SS LASH Italia operating in the Atlantic/Mediterranean service and the other on the USNS Furman operating in trans-Pacific service. These systems were operated for several years during which time significant data were obtained on midship bending, bow accelerations, bow side frame stresses and rolling. Filtering allowed identification of slamming and green water events. SNAME Panel HS-2 (Impact Loads and Responses), long in need of full-scale data on heavy-weather transient loadings of the hull, wished to determine whether these data, collected for other purposes, could be useful for predicting the frequency and magnitude of loads on the bow flare structure due to slamming and green water events. This paper presents the results of the investigation that was carried out and suggests some implications regarding the establishment of criteria for bow structure design in regard to loadings of this type.
Response of Submarine Power Cables During Laying Operations in Deep Waters
Authors: Vega Luis A. , Nihous Gérard C.
Published: January 2021

This paper reports the results of an analytical study performed for the Hawaii Deep Water Cable Program to determine the feasibility of transmitting electric power via cable in waters up to 7000 ft in depth and over a distance greater than 150 miles. The computer-aided methodology described herein sought principally to determine the cable loads and motions as functions of environmental, vessel and cable parameters.
Cargo Mechanics (Application of Seakeeping--Revisited)
Authors: Hutchison Bruce L.
Published: January 2021

The basic concepts of modern risk and reliability theory are reviewed. Application of these concepts to topics arising in the analysis of ship motions, cargo sea-fastening design and voyage risk studies is explored. The role of risk analysis in decision theory is briefly discussed and the paper concludes with a suggested program of analysis for marine activities and enterprises subject to sea-action induced risk.
12-Meter Design: State of the Art in 1986
Authors: Van Hemmen Rik F.
Published: January 2021

A number of factors have contributed to renewed efforts in using engineering methods to design 12-Meter yachts. This paper describes the wide range of engineering methods used during the design and development of 12-Meter yachts, and clarifies how the data resulting from the use of these tools can contribute to better performance. The strengths and weaknesses of each tool are identified, and it is shown that, next to hard engineering numbers, an artist's touch and experience are still required for designing an outstanding 12-Meter.
Application of 1985 SSPC Surface Preparation Specifications to the Marine Industry
Authors: Miller Neil M.
Published: January 2021

The Steel Structures Painting Council's Surface Preparation Specifications most used by the marine industry, SSPC-5, 6, 7 and 10, were revised in 1985. SNAME's T&R Panel 0–23 (Ship's Paints) believes those concerned with all phases of ship coatings in the industry should be aware of the changes, additions, and limitations of the new specification wording in order to take full advantage of what is included, as well as be aware of what is not mentioned.
Aircraft/Deck Interface Dynamics for Destroyers
Authors: O'Reilly Peter J. F.
Published: January 2021

The interface between vertical takeoff and landing (VTOL) aircraft and destroyer and frigate-type warships involves a great many factors. This paper discusses a computer analytical technique which permits dynamic analysis of the aircraft landing or taking off from a moving deck or being handled or stowed on the ship. A condensed explanation of how the synthetic time histories are generated is contained in the Appendix. Two examples of how the technique has been used are included: first, a Recovery Assist and Secure System (RAS) analysis, and second, a pilot landing aid system, the Landing Period Designator (LPD) research program.
Damage to Ship Plating Due to Ice Impact Loads
Authors: Wiernicki Christopher J.
Published: January 2021

This paper presents a simple yet rational analytical approach for assessing the damage of an entire stiffened ship panel which arises from the inelastic behavior due to laterally applied ice forces. Included in this approach is an improved method for the determination of plating thickness for either icebreaking or icetransiting hulls. By allowing an acceptable amount of plastic deformation in the stiffened panel, significant weight savings can be realized. A design method is presented that relates permanent set in the stiffened panel to the panel loading pressure and gives a measure of the reserve strength afforded by the selection of any given structural parameter.
Implementation of Fiber Optic Technology in Naval Combatants
Authors: Morais Robert M.
Published: January 2021

This paper provides a summary of activities and developments that directly impacted the implementation of fiber optics on naval combatants. The paper concludes that the benefits are clear, that the technology has matured, and that implementation as a system element in ship design and construction is accelerating. The paper also includes a short tutorial on the basic elements of a fiber optic link as well as the advantages, disadvantages, and applications of fiber optics.
The Salvage of MV Essi Silje and Lloyd's Arbitration Hearing
Authors: Chan Edwin S.
Published: January 2021

In 1982 the chemical tanker MV Essi Silje caught fire and was abandoned in the North Atlantic. The Canadian naval supply ship, HMCS Protecteur, undertook the salvage operation before the arrival of the salvage tugs. The vessel was eventually salvaged. For the subsequent Lloyd's Arbitration Hearing in London, the author was tasked by the Department of Justice of Canada to provide evidence for presentation at the hearing. This paper presents a brief account of the incident, the technical investigation, the technical disputes, and provides recommendations for future salvage operations.