bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical Transmission Systems for Arctic Tankers
Authors: Koch R. L.
Published: January 2021

Propulsion plants for arctic tankers must have characteristics not normally required for other large ships. These special requirements make electric transmission systems particularly attractive. The paper examines four candidate electric transmission systems for this application. The performance of two of these, the ac variable-frequency system and the ac—rectified—dc system, are reported in detail, and the analog computer program used to simulate the operation of the ac—rectified—dc system is described. Discussers A. C. Brown G. A. Johnson C. E. Heil Jack Lewis D. B. Hoover S. S. Morse
Naval Force Levels: Theory and Practice, with Naval Engineering Challenges for the 1990s
Authors: Hope Jan Paul
Published: January 2021

This paper outlines the theory and practice of how naval force levels are created and sustained. A forcelevel equation is shown and the factors of this equation are discussed from the contrasting perspectives of vision and reality. The naval recovery program of the 1980s is discussed in the context of naval forcelevel theory and practice. The second part of the paper discusses naval engineering challenges for the1990s as the United States seeks to maintain strong naval forces. Several different ship types, namely, battle force combatants, aircraft carriers, amphibious ships, and underway replenishment ships are addressed along with the capability for sealift, ocean surveillance, and protection of shipping. Potential innovations, production opportunities, and trends are highlighted. Using the prospective innovations and the theories of force levels developed in the first part of the paper, alternative force structures are shown that are of interest to naval engineers and naval warriors.
Coast Guard Requirements for Marine Vapor Control Systems
Authors: Fitch Robert H. , Marsh Gordon D.
Published: January 2021

The paper describes the U.S. Coast Guard's efforts to establish regulations for marine vapor control systems that will maintain the safe operation of tankships, tank barges, and waterfront facilities when the more stringent air-quality standards are implemented by the Environmental Protection Agency. The reasons for the new standards are given. Marine vapor control systems are described, along with their attendant hazards. The development and nature of the Coast Guard's regulations are described and, finally, international efforts in the area are briefly reviewed.
U.S. Coast Guard Regulation of Passenger-Carrying Submersibles
Authors: Johnson Steve , Salerno Brian
Published: January 2021

Passenger-carrying submersibles have been certified by the Coast Guard for operations in the United States Virgin Islands, Hawaii, and Guam. Although subject to the Coast Guard small passenger vessel regulations, 46 CFR Subchapter T, submersibles are not specifically addressed in the regulations. The Coast Guard does have a background in submersible safety based on past efforts to regulate industrial and research submersibles and interaction with the American Bureau of Shipping (ABS), which has been classing submersibles for many years and has classed all passenger submersibles to date. The certification process developed for these unique vessels evolved during the certification of Atlantis III, the first U.S. passenger submersible. Several designers, builders, and operators have entered the market and the business is steadily expanding into new areas of operation worldwide. The Coast Guard has initiated two major studies by the Department of Transportation and the National Research Council to ensure that this new maritime business is carefully analyzed for the safety of passengers and crew.
Dynamic Stability of Planing Boats
Authors: Blount Donald L. , Codega Louis T.
Published: January 2021

High-speed craft have been known to lose stability while underway even though they possess adequate static stability. Dynamic instabilities have been reported in roll, pitch and yaw, and include porpoising, chine walking, loss in running trim (diving), bow steering, progressive heeling to port or starboard, or a combination of motions. Instabilities can result in structural damage, loss of control, and crew injury. The problem is not well understood and accepted guidelines do not exist which will ensure adequate dynamic stability. The authors report data for boats which exhibit nonoscillatory dynamic instabilities and suggest quantitative criteria which may result in development of dynamically stable planing boats. Experimental procedures are presented to indicate the potential for nonoscillatory instabilities for expected operating conditions.
Effect of Stern Flaps on Powering Performance of the FFG-7 Class
Authors: Cave William L. , Cusanelli Dominic S.
Published: January 2021

The effect of a stern flap on the powering performance and annual fuel consumption of an FFG-7 Oliver Hazard Perry Class Guided Missile Frigate is presented. Analytical analysis using free surface potential flow theory was conducted to evaluate the flow on the afterbody of the ship. Model tests were conducted to determine the optimum geometrical characteristics of the stern flap. Based on the analytical and model test results, a stern flap was retrofitted to an FFG-7 Class frigate, and full-scale results on powering performance were collected. Results of model powering experiments showed that the flap, set at 10 deg trailing edge down, decreased the delivered power by 8.4 percent at 26 knots, and provided for a 3.8 percent decrease in annual fuel consumption. This decrease in annual fuel consumption places the payback period on the cost of the flap installation at only 10 months. The full-scale comparison of the flap's effectiveness was marred by adverse weather conditions and differences in the pre-and post-flap ship configurations. However, observations of the full-scale stern wave system, before and after the installation of the stern flap, lead the authors to conclude that the flap will produce a larger decrease in delivered power at full scale than shown by the model experiments.
Feasibility Studies for an Ice-Capable Oceanographic Survey Ship FY92 T-AGS Ocean (ICE)
Authors: Strasel Erik S. , Bebar Mark R. , Lee Hung-Chi
Published: January 2021

In recent years, interest in the oceanography of the subarctic ocean area has lead to increased activity in the Marginal Ice Zone (MIZ) in terms of bathymetric and hydrographic data collection with an associated increase in damage reports. The hazards of the MIZ include floating ice, topside icing, cold weather and heavy seas, each of which calls for special attention in design. The Oceanographer of the Navy's requirement for data from this region has led him to specify that the FY92 T-AGS Ocean be capable of operation in the MIZ. This paper describes the design process followed to meet this requirement. The oceanographic, hydrographic, programmatic and environmental requirements placed on the design effort are discussed. The resulting design is presented and the impacts of meeting all the requirements in terms of hull-mounted systems, topside arrangement, ship powering, stability and hull form are discussed.
Shipbuilding’s Supplier Base: Outlook for the ’90s and Beyond
Authors: Stabler D. Scott
Published: January 2021

A review of the outlook for American shipbuilding and its supplier base as both enter the '90s is presented. The inexorable link between demand at shipbuilder level and revenue for suppliers mandates analysis of both macro and micro economic conditions. Included is a review of the shipbuilding industry, factors determining contracting levels and direction as well as the resultant impact upon domestic suppliers. As a focus for future action, the current status of the supplier base is presented, including projection of what fallout can be anticipated in light of the anticipated reduction in funding levels for naval shipbuilding. Recommendations for mitigating these impacts, including philosophical change in DOD contractor management strategies, development of a more commercially-oriented Navy and a revised focus for U.S. trade policy on shipbuilding, are presented. The paper concludes that the Government must work directly with shipbuilders and their suppliers to ensure that America maintains her capability to produce the warships necessary for defense and reestablishes her ability to maintain economic well-being via production of her own link to worldwide commerce.
Advanced Bridge Automation
Authors: Denham Edward
Published: January 2021

The past thirty years have seen great advances in many areas of the technologies used in naval vessels. Propulsion systems, machinery automation, and information management systems have all undergone revolutionary changes. The bridges of these ships have similarly seen the advent of many new sources of navigational and environmental data. The process of correlating and interpreting all of this information has until now remained very labor-intensive, subject to human error at many stages of the process. In response to this challenge, a suite of new equipment has been developed for distributing, displaying, correlating, and logging shipboard data. This equipment automates most of the low-level, routine tasks involved in navigating a vessel at sea, significantly reducing the stress and workload of bridge personnel. This gives the humans on the bridge more time for doing the job that they do so much better than machines: making decisions. This paper focuses on the key technologies that are used in these new products and the advances in bridge design and automation they make possible. The benefits of these new capabilities to system designers, to shipbuilders, and to ship operators are also explored.
Recent Research and Development in the Design of an Oceanographic Research Vessel
Authors: Washio Yushu , Miyoshi Masao , Takekuma Katsuyoshi , Yamada Kenji , Kobayashi Kazuo
Published: January 2021

Requirements for characteristics of a large oceanographic research vessel are extended over various fields of its design. General-purpose running work such as retrieving various kinds of fundamental data about the ocean, extensive on-board scientific research, and worldwide exploration, including the polar regions, are described. Recent developments in acoustic measurements and instrumentation, such as the multi-narrow beam, require noise abatement in the design because of both airborne and waterborne noise caused by the vessel itself. The design features and R&D achievements of such vessels are described, especially with respect to general arrangement, type of power plant, hull form, maneuvering, seakeeping, noise abatement by choice of propellers, mounting of machinery and structure, and also design and building schedule. The example case used is the Hakuho Maru, the newest and most sophisticated research vessel for the Ocean Research Institute of the University of Tokyo.
The Design and Construction of the Floating Golf Green
Authors: Hurley William L. , Funston Craig
Published: January 2021

This paper relates the evolution of a design and construction project of interest to the engineering community, that of a floating golf green. It also presents technical details on the unique aspects of this project and elucidates the design development process by explaining the evolution of technical criteria and their application to the facility design. A patented technique for construction of a large rigid pontoon from small prefabricated modules is described and final design and construction details are summarized. Numerous naval architecture and engineering tasks covering various disciplines were involved, including: design of steel, concrete, and composite structures; climatology assessment; determination of structural wave loads and mooring loads; design of fixed and adjustable mooring systems; provision of aesthetic design: design of piping systems; and development of weight assessment tools.
Some Naval Architectural Problems in Underwater Coal Mining
Authors: Bilen Branislav , Bilen-Katic Branka , Zerjal Marko
Published: January 2021

This paper presents a solution for a propulsion system that provides perfect speed control and maneuverability for a survey launch used in the process of underwater coal mining. First, mining aspects of coal exploitation are explained. There is also a brief technical description of a cutting wheel suction dredger, including specifications for dredging equipment. The important role of the survey launch in underwater mining procedures is outlined and technical specifications of an installed indirect diesel-hydraulic drive are given. A qualitative comparison between the diesel-hydraulic and the other conventional propulsion systems is made. Finally, some operating parameters of the diesel-hydraulic propulsion system are given through a number of diagrams recorded during trials.
Maneuvering Information for the Pilot/Navigator: Its Source Value and Limitations
Authors: Knierim Thomas G.
Published: January 2021

In 1987 a ship struck a bridge in the Brunswick River in Georgia. The NTSB (National Transportation Safety Board) investigation after the accident determined that the ship's pilot had not studied the ship's maneuvering information, but if he had, would not have understood the terms "advance" and "transfer." He also did not appreciate the effects of trim or bottom clearance on a ship's maneuverability. By inference NTSB suggested this ignorance of terms and hydraulic effects may be widespread, and apply to a large percentage of pilots. Also, the courts have determined that a vessel may be considered unseaworthy and a navigator/pilot possibly liable should he not understand and use all navigation aids (ARPA, charts, maneuvering information, etc.). This paper attempts to explain the many different forms of maneuvering information developed by naval architects, how they are derived, and the strengths and weaknesses of the information exhibited on the bridge. The paper is written for the navigator/pilot involved in piloting, to close the loop between that navigator/ pilot and the naval architect through writing and dialogue. It intends to make the navigator aware of the information that is available and also to develop an avenue for the naval architect to appreciate the needs of a navigator/pilot, and through the various regulatory bodies tailor maneuvering information to meet those needs. There is also discussion of the efforts of Japanese pilots to rate and keep records of actual ship maneuverability. The hope is that through knowledge will come safer and more economical pilotage.
Log Boom Drag Measurement at Sea
Authors: Green Sheldon I. , Garfitt John R. , Young G. Glenn
Published: January 2021

Measurements of the drag on a typical (52-section) log boom were made under calm conditions at sea. The drag coefficient based on planform area is essentially independent of Reynolds number over typical operating conditions, cD = 0.0083 + 0.0006. Engineering calculations suggest that the log boom drag is caused primarily by skin friction drag and that wake drag is slightly less important; wave drag is entirely insignificant. A small-scale (4-section) log boom was constructed to test the influence of log arrangement within the boom on boom drag. Neither aligning the front row of bundles transversely nor covering boom sections with an underwater shroud had a significant impact on the boom drag.
Improving Mariner/Ship Interaction
Authors: Lowry Ian J.
Published: January 2021

This paper focuses on mariner-ship interaction from the practical end of the design spectrum. Statistical data on marine collisions, rammings and groundings attribute a considerable percentage of marine casualties to poor ship controllability. A vessel's controllability is of a dichotomous nature, constrained not only by its inherent controllability characteristics, fixed by the naval architect, but also by the skill and the expertise of the shiphandler in initiating a conclusive control strategy. The results of an international survey of naval architects and shiphandlers are presented. The techniques of frequency distribution and factor analysis were used to identify the key ship controllability effectors. This survey highlights where improvements in terms of interface design can be made. The survey identifies the key controllability effectors of naval architects and ship-handlers for effective mariner-ship interaction. A case study is presented which identifies the applicability of part-task ship simulation to improve confidence levels in practical ship control. For effective mariner/ship interaction, the designers of ships must use the various codes of practice for a ship's bridge in order to improve the bridge as a control station, and marine licensing authorities have to realize the potential benefits that training with computerized ship simulation can bring the industry.
Development of a Diesel-Powered, Heavy Lift, Amphibious Air Cushion Lighter System for the U.S. Army
Authors: Noble Peter , McMillan David , Dabell Mark
Published: January 2021

In order to provide additional over-the-shore logistics for U.S. troops, the U.S. Army recently solicited a proposal for the design and construction of a new Lighter Amphibious-Heavy (LAMP-H) vehicle. The vehicle had to be capable of carrying 100 short tons of deck cargo at 10 knots and be fully amphibious. Kvaerner Masa Marine (KMM) was retained by Bollinger Machine Shop & Shipyard in Lockport, Louisiana, to develop a new concept in military heavy-lift, amphibious vehicles, based on earlier work on diesel-powered air cushion vehicles. Existing air cushion military transport vehicles, such as the U.S. Army LACV-30 and the U.S. Navy L-CAC, represent what may be best described as "low technology aircraft" with lightweight, aluminum structures and gas turbine prime movers. The Kvaerner/Bollinger approach has been to develop a "high technology marine craft" with combination steel/aluminum structure and diesel engines. The project evolved through concept design and model testing into a contract design package from which a shipyard bid proposal was developed. The resultant design gives an innovative solution to the over-the-shore logistics problem.
The New America’s Cup Rule—A Search for the Performance Edge
Authors: Antrim James K.
Published: January 2021

America's Cup races held in May 1992 featured a new type of monohull sailboat. Characteristics of the new breed of yacht are examined, as determined by the new International America's Cup Class Rule, and as evidenced by the first year's contestants. Limitations and "loopholes" of the rule are discussed, with special emphasis on hull shape and proportions, keel and rudder geometries, and hull structure.
Design Validation Using Computer Models in Lieu of Full-Scale Mockups
Authors: Tatum S. A. , Byrum J. C. , Rourke P. W.
Published: January 2021

For many years the complexity of submarine design has required the construction of full-scale mockups to integrate the system designs, plan the construction, and verify the operability. In the late 1980's, computer technology evolved to allow ship design to be accomplished by developing comprehensive mathematical models of the ship's arrangement. Imaging of these models creates a virtual reality of the ship's interior. This paper explores the features of this technology that emulate the function of the physical mockup, discusses experience to date in the SEAWOLF design at Newport News Shipbuilding in applying CAD technology as a mockup alternative, and looks to the opportunities that are available in the near term.
Shaft Alignment Monitoring Using 3D-Coordinate Measurement on the Heavy Icebreaker CCGS Louis S. St. Laurent
Authors: Welke Met
Published: January 2021

A detailed description of 3D-coordinate measurement for shaft alignment monitoring is presented. The method was used at Halifax-Dartmouth Industries Ltd. (HDIL) during mid-life modernization and refit of a heavy icebreaker, CCGS Louis S. St. Laurent. The vessel was undergoing substantial repairs of its steel structure, a significant part of which was concentrated in way of the propeller stern tubes and shaft line foundations. The application of an electronic theodolite allows measurement of the exact position of nine points along each of the three shafts within half an hour.
Multicriteria Optimization Model for a Containership Design
Authors: Ray Tapabrata , Sha Om Prakash
Published: January 2021

This paper describes a multicriteria optimization approach to ship design. The method incorporates accepted naval architectural estimation methods, a decision system handler and a nonlinear optimization tool. It allows the designer to identify different objectives, define prescribed limits on the design variables or define constraints on the design. The decision system identifies the weightages corresponding to different objectives based on the relative importance of the objectives using multi-attribute decision-making methods. The advantage of using optimization techniques along with a decision system handler allows the designer to develop new designs, while considering various interactions within the system, in a shorter time span. The proposed approach is illustrated by its application to a containership design. The effect of the weightages associated with the different objectives on the overall design is shown in the case studies.
An Introduction to Ethnotechnology for Naval Architects: Sea Kayak Design of Yesterday and Tomorrow
Authors: Noble Peter , Wadden Michael , Bourke Timothy , Williams David , Nordbo Knut
Published: January 2021

The skin-covered kayaks and baidarkas of the Inuit and Aleut peoples are elegant examples of naval architectural technology developed over centuries of experimental refinement. This paper describes the ethnotechnology which lies behind the design of modern sea kayaks and discusses the development of the DeCourcy Duet, a two-hole kayak, which utilizes numerical lines fairing, extensive computer stability calculations and full-scale towing tank testing as part of its design development.
Ship Operational and Safety Aspects of Ballast Water Exchange at Sea
Authors: Woodward John B. , Parsons Michael G. , Troesch Armin W.
Published: January 2021

A dry bulk carrier, a tanker, and a containership—taken as typical of ships trading to U.S. ports—are analyzed for possible hazards caused by emptying and refilling ballast tanks at sea. Using hydrostatic data furnished by the shipowners, hull bending moments and stabilities are investigated to find the tank-emptying operations that produce the greatest changes in those parameters. As should be expected, bending moment changes do not exceed allowable stillwater values. Changes in GM are insignificant. The worst hydrostatic cases serve as a guide to conditions that should be analyzed in rough water. The University of Michigan SHIPMO program shows that in waves of 10-ft significant height wave-induced bending moments and shears are far below the design values published by the American Bureau of Shipping. On the other hand, in waves of 20-ft significant height, the maximum wave heights that occur occasionally can cause moments or shears that exceed design values. For the 20-ft case, both linear and nonlinear versions of SHIPMO are used.
Improved Passage Planning Using Weather Forecasting, Maneuvering Guidance, and Instrumentation Feedback
Authors: Lacey Peter , Chen Henry
Published: January 2021

ARCO Marine currently operates ten tankers which move crude oil from Valdez, Alaska to West Coast ports of the United States. These tankers range in size from 70 000 to 265 000 dwt and operate throughout the year in the harsh environment of the North Pacific Ocean. All of the ships have experienced fatigue and slamming related structural damage. Fatigue damage of structural details occurs from cyclic loading as the ship hull girder flexes in response to the seaway. Damage to local bow structure results from slamming, which is a high magnitude impulse load that induces a high frequency response in the hull girder. Because of this high frequency response, slamming also contributes significantly to fatigue damage. With the goal of minimizing this structural damage, ARCO Marine initiated the Hull Monitoring Program with Ocean Systems Inc. in mid-1992 to develop an onboard computer-based Decision Support System (DSS) that conveys information to the shipmaster to aid in avoiding encounters with ship damaging seas. There are three basic sources of information to the DSS: weather forecasting, analytic and empirical seakeeping computations, and instrumentation feedback. An instrumentation package was installed on the ARCO California and continuously recorded ship motion and hull girder responses throughout its five 1992/93 winter voyages. Analysis of the recorded data resulted in several significant findings that validate the need for an onboard DSS. The Hull Monitoring Program built on the success of the 1990 ARCO Tanker Slamming Study [1] and has resulted in the conceptual design of a prototype DSS ready for implementation during the 1993/94 winter voyages. This paper describes the 1992/93 instrumentation package and data acquisition process, presents many of the significant findings, introduces the concept of improved passage planning, and discusses plans for the onboard implementation of the prototype system.
Tanker Structure Behavior During Collision and Grounding
Authors: Daidola John C.
Published: January 2021

Recent accidents and the Oil Pollution Act of 1990 have precipitated a renewed interest in the behavior of tanker structure in collision and grounding. The nature of collision and grounding is reviewed and analysis techniques are identified from the literature. Existing and proposed structural arrangements for modern tankers are considered in light of their ability to provide environmental and cargo protection during collision and grounding. Critical structural details which may reduce the protective characteristics of the structure are identified. Sample calculations and results are provided for various structural arrangements and details.
Design Concept of Marine GenSet Engines
Authors: Schnohr O.
Published: January 2021

Experience gained from the MAN B&W Holeby heavy fuel burning marine GenSets is described. This is the most widely used diesel generator engine for marine applications within its power range. The combustion process is based on design parameters and features which enable operating and maintenance costs to be kept low even when the cheapest types of heavy fuel are used. The paper outlines how the design concept also results in very low emission figures, which will permit ship-owners to observe prospective NOx regulations at no extra expense. The Uni-concept, which features the combined installation of the two-stroke low speed propulsion engine and the generating sets, sharing a common fuel system (Uni-fuel Concept), common simplified cooling water systems, starting air installation, etc., is explained. This concept enables the shipyard to select the simplest and most cost-efficient engine installation for the vessel. The technology used for the unrestricted low load operation of the engine is presented, and an outline is given of the special operational conditions, and of the great electrical load fluctations that prevail, for instance during the loading and unloading of the vessel by means of its own cargo-handling equipment.
Passenger Vessel Design and the ADA—Americans with Disabilities Act
Authors: Chapman David S.
Published: January 2021

The marine industry faces a challenge in making passenger vessels accessible to persons with disabilities. With the passage of the Americans with Disabilities Act, freedom of access has become the law of the land. Accessibility issues pertaining to vessel design include embarking and disembarking the vessel, paths of travel aboard the vessel (doorways, thresholds, aisles), multideck access, accessible bathrooms and other services, and emergency evacuation. Accessibility extends beyond the wheelchair user to include the blind and visually impaired, the deaf, and others. The design community, working with the passenger vessel owners and persons with disabilities, has an opportunity to develop creative solutions to the numerous problems of vessel accessibility.
Design and Development of the M.S.-5: 5000 Cubic Yard, Split-Hull Dump Barge
Authors: Edgar John L. R. , Hurley William L.
Published: January 2021

Fig. 01Launch of the J.D.-6(sister to the M.S.-5), July 15, 1995 (courtesy Gunderson Marine Inc.)This paper presents an overview of the design and development process leading to the construction of the M.S.-5, the first in a class of 5000 cubic yard, split-hull dump barges for the Dutra Construction Company, San Rafael, California. This design process incorporates current dredging industry practice, regulatory body criteria and specific owner requirements into engineering procedures to develop and assess the stability, longitudinal strength and structural details for this unique class of barge.
A Model for an Engineering Education
Authors: Lamley Rachel A.
Published: January 2021

College students have the impression that education stops at the door of the classroom. However, in today's technically based society it is difficult for a student to master all the skills required of their profession in the classroom. Valuable experience can be gained outside the classroom through various work study programs. These programs allow students to work on realistic projects rather than on simplified classroom problems. This paper looks at various naval architecture and marine engineering related work study programs and a case example.
Tests on Yacht Hull Plating
Authors: Brown K. C. , Joubert P. N. , Yan Ping
Published: January 2021

Static pressure tests on sections of yacht hulls, manufactured to copy the structure of certain yachts which failed in service due to slamming loads, are reported. The materials of construction were aluminum, steel, plywood and fiberglass. The failure modes and pressures are discussed. In addition, some tests in which mild steel plates, corresponding in construction to the mild steel hull tested under static pressure, were loaded impulsively by the shock wave from an explosive charge detonated in air. The design of hull plating should take into account the impulsive nature of the loading, and the actual mode of failure. Neither the design impulse, however, nor the means for predicting the hull plating response to it are available from the current literature. If resort is to be made to the design of plating for simple static pressure, then a design pressure of at least 350 kPa(51 psi) is suggested for the bottom plating of yachts of about 13 m (43 ft) length overall. This is about five times the pressure required by the ABS Guide.
The Defense of the Great Lakes Against the Invasion of Nonindigenous Species in Ballast Water
Authors: Weathers Katherine , Reeves Eric
Published: January 2021

The Great Lakes is the first place where the United States has established a defense against the introduction of nonindigenous species carried in ballast water. U.S. regulations controlling the discharge of ballast from all vessels entering from outside the Exclusive Economic Zone into the Great Lakes went into effect in early 1993 and are enforced by the United States Coast Guard, with active assistance from the Canadians and the Seaway authorities. The Great Lakes are a unique, valuable, and sensitive resource which have already suffered significant damage from nonindigenous species and are under continuing threat from new invasions. The Great Lakes also have some unique defensive advantages because vessel traffic can be controlled at the Saint Lawrence Seaway and open ocean exchange with salt water can be used as a verifiable, reasonably cheap, and safe method for impeding the invasion of new freshwater species. However, more effective defenses are needed in order to prevent new invasions over the long term. Development of these new defenses will probably require engineering changes in ballast systems in all vessels engaged in transoceanic trade, whether going to fresh or saltwater ports.
Marine Safety Regulation in Transport Canada: The Winds of Change
Authors: Grinstead John
Published: January 2021

The paper traces the history of marine regulation in Canada from pre-Confederation days to the present. It addresses a number of the external forces which have impacted the regulatory scene over the past few years and outlines in some detail the recent organizational changes which have taken place within the Canadian Coast Guard with respect to marine regulation. The paper concludes with a few comments concerning future directions.
SSIIS -The Ship Structural Integrity Information System
Authors: Schulte-Strathaus Rolf , Bea Robert
Published: January 2021

The availability of advanced database systems in conjunction with increased computer storage and performance capabilities makes it possible to improve vessel design, maintenance and operations through the use of integrated database systems. This paper describes the development of a Ship Structural Integrity Information System (SSIIS). The general need for ship information systems is outlined. Existing database systems are summarized and evaluated. The information needs of various vessel analysis software have been reviewed to determine the necessary data structure for SSIIS. The initial development and implementation focused on the representation of vessel inspection results and are described in this paper.
Impact of Simulation-Based Design on Today's Shipbuilders
Authors: Polini Michael A. , Wooley Daniel J. , Butler James D.
Published: January 2021

The Advanced Research Projects Agency (ARPA) sponsored the development of a prototype of the n rt-generation ship design system. The results of the project, titled Simulation-Based Design (SBD), were demonstrated in June of 1994. Based on its success and on the benefits it offers over today's systems, ARPA has initiated a new program to full)' develop SBD. The goal is to create a virtual environment in which a ship can be totally designed, manufactured, operated, and evaluated before a single plate is cut, part is ordered, or piece of equipment is purchased. The ramifications of such a tool are widespread across both the commercial and naval shipbuilding markets, and SBD will, undoubtedly, lead to changes in the way we do business. Newport News Shipbuilding (NNS) was a partner on one of the teams responsible for developing one of the two prototypes considered by ARPA. As such, they have had an opportunity to weigh the impact of such a system in today's marketplace. This paper discusses some of the capabilities that SBD will provide to shipbuilders of the future, especially in the areas of concurrent design, coupled analyses (e.g., seakeeping and structural analysis), digital mockups, and manufacturing simulation.
Ocean Scout: Conversion to a Multi-Service Vessel
Authors: Ambrose B. D. , Randall R. E. , Luke J.
Published: January 2021

In today's offshore market some older, smaller, and obsolete semisubmersible drilling rigs are finding a new place in the offshore industry as multi-service vessels capable of an array of tasks. During the spring academic semester at Texas A&M University, College Station, Texas, the ocean engineering senior design class of 22 students, working with industry and faculty advisors, produced a preliminary design for the conversion of the semisubmersible "Ocean Scout" to a multiservice vessel for operation in the Gulf of Mexico. This report explains the major topics of the project addressed by the class which include vessel additions to create a variable deck load of 3000 long tons, a dynamic positioning system capable of stationkeeping in a one-year, nonhurricane storm event, and an economic analysis of the conversion for a five year project life producing a 38 month payback period.
Rudder Winglets on Sailing Yachts
Authors: Sclavounos Paul D. , Huang Yifeng
Published: January 2021

During the defender round robins of the 1995 America's Cup, the yacht Young America featured a pair of rudder winglets. Their raison d'etre was to improve the vessel rough water performance, and in particular reduce her added resistance in waves. This article presents the background analysis which leads to the conclusion that rudder winglets may improve appreciably the seakeeping performance of a sailing yacht. The seakeeping method used to study the rough water performance of America3 in 1992 and Young America in 1995 is reviewed along with the fluid dynamics governing the generation of thrust by oscillating wingswings. The effect of winglets upon the yacht seakeeping is considered, the mechanisms contributing to the reduction of the yacht added resistance are identified and the effect of rudder, bulb and bow winglets is studied.
Comparative Study on Collision Resistance of Side Structure
Authors: Kitamura Ou
Published: January 2021

In the second phase of ASIS 's 7-year research project for improved tanker safety against collision and grounding supported by Ministry of Transport, a series of numerical simulations of side damage due to collision was carried out adopting ASIS's methodology based on the customized explicit FEM simulation system in order to demonstrate its potential power in the field of practical application Assuming the simplified rigid bow of a 150K DWT colliding ship, the energy absorption capacity of the various side double hull design options for a VLCC, such as increased number of side stringers, double side structure with top side tank in conjunction with hopper tank, and unidirectional girder stiffening system, was studied The contribution of each structural component, -side shell, inner hull, transverse web, side stringer, etc. -was also investigated in detail. Based on the results of both the numerical study and the 1/2-scale collision experiments, a new conceptual design of a VLCC side structure was developed Further study on crushable bow structure against collision and enhanced design of bottom structure against grounding is now in progress.
Residual Strength Assessment of Ships after Collision Grounding
Authors: Paik Jeom Kee , Thayamballi Anil K. , Yang Soo Hong
Published: January 2021

The aim of this study is to develop a fast and reasonably accurate method for assessing collapse of the hull girder in the damaged condition. Location and amount of collision and grounding damage are prescribed. The possibility of hull collapse is explored by a comparison of the applied extreme bending moment and the ultimate hull strength which are estimated using design oriented methods and formulas• Two types of residual strength index, namely the section modulus based residual strength index and the ultimate bending strength based residual strength index, are defined. The method developed in this paper should be useful for preliminary structural design of a ship hull in accidental situations• It should also be potentially useful as one element of a decision making process related to salvage and rescue.
Weight Control and Monitoring in Fiberglass Yacht Construction
Authors: Miner Jay N.
Published: January 2021

Weight considerations are common to all ship and boatbuilding, but fiberglass yachts have particular propensities for weight growth. The dynamics which exist among the designer, builder, vessel owner and naval architect require attention to specific areas to ensure a successful conclusion to the project.
Roll Stabilization for Small Fishing Vessels Using Paravanes and Anti-Roll Tanks
Authors: Bass D.W.
Published: January 2021

Excessive roll is a constant source of discomfort and danger for small fishing vessels. The paper describes two methods of reducing roll: paravane stabilizers and passive stabilization tanks. In particular an analysis is presented of the possible hazards of paravane use in severe seas, based on the capsize of a small fishing vessel after the loss of one paravane. Anti-roll tanks, as an alternative to paravanes for some small vessels, have been proposed and successfully tested on three boats. The design and testing at model and full scale of such a system is described. Full scale tests were carried out on three sister vessels, two with tank systems and the third with paravanes.
A Conceptual Design of an Underwater Drilling Rig
Authors: Ross Carl T. F. , Laffoley-Lane G.
Published: January 2021

The paper presents a design concept for an underwater drilling rig which can operate up to a depth of 5000 m below sea level. The proposed main hull of the drilling rig is in the form of a thick-walled toroidal shell, although other possible forms are considered. The proposed primary method of power generation is via a pressurised water nuclear reactor. Considerations are made as to the health and safety of the crew and also to the transport of the retrieved oil.
Buying the Boat -Choosing a Ship for the Sealift Conversion Program
Authors: Busch Ian
Published: January 2021

One of the first steps in any ship conversion program is determining which ship to convert. The Strategic Sealift Programs offered an opportunity to develop a tool for selecting the ship, and then put that tool to use for an actual conversion program. A preference based, measure of merit system was used based on the Governments technical requirements for the converted ship. The selection tool served to narrow the choice set of candidate hulls such that ship owners could be pursued and a class of ships finally selected. The system used to review each of the candidates will be reviewed, as well as some of the particulars of the candidates. The factors that resulted in selecting the class that was converted will also be discussed.
TRICAT High Speed Ferry -Redesign for the U.S. Market
Authors: Wood William A. , Hunter John A.
Published: January 2021

Ferries are making a comeback in the U.S. because they are a cost-effective alternative for traffic-weary commuters and travelers. The U.S. gave up most of its ferries by the 1960's in favor of bridges and tunnels because we could afford them. Most of the rest of the world continued to operate and improve on the much lower cost ferry system. The U.S. marine industry was, therefore, not a major participant in the development of modern high speed ferries. Now, with the resurgence of ferries, especially high speed passenger ferries, many U.S. entrepreneurs are looking for proven foreign designs. This paper discusses some of the design issues including the IMO High Speed Craft Code, classification and problems encountered when the British-designed 318 passenger, 45 knot TRICAT ferry was Americanized for construction and operation in the U.S.
The Future of Minimal Manning and Its Effects on the Acquisition and Life-Cycle Costs of Major Coast Guard Cutters
Authors: Green Matthew A.
Published: January 2021

Since the 1970's, the world's merchant fleets have been pursuing crew reductions as a way to cut costs: however, the United States military has been slow to adopt this trend. In the current age of tight budgets and defense cutbacks, the Coast Guard and Navy can no longer afford to continue in this manner. Both services have now initiated research and acquisition projects which address minimal manning. These projects must be carried out and minimal manning practices implemented if our sea going services are expected to maintain their edge as world leaders. This paper presents a study designed to research the quest for minimally manned crews and its applicability to military vessels. It is meant to provide guidance to the United States Coast Guard and other interested parties on future surface combatant acquisition projects including but not limited to the Coast Guard Deepwater Program. Emphasis is placed on the theory behind automation and the organizational impacts associated with minimal manning.
Preliminary Ship Design Using One and Two-Dimensional Models
Authors: Mackney Michael D. A. , Ross Carl T. F.
Published: January 2021

Computational studies of hull-superstructure interaction were carried out using one-, two-and three-dimensional finite element analyses. Simplification of the original three-dimensional cases to one- and two-dimensional ones was undertaken to reduce the data preparation and computer solution times in an extensive parametric study. Both the one- and two-dimensional models were evaluated from numerical and experimental studies of the three-dimensional arrangements of hull and superstructure. One-dimensional analysis used a simple beam finite element with appropriately changed sections properties at stations where superstructures existed. Two-dimensional analysis used a four node, first order quadrilateral, isoparametric plane elasticity finite element, with a corresponding increase in the grid domain where the superstructure existed. Changes in the thickness property reflected deck stiffness. This model was essentially a multi-flanged beam with the shear webs representing the hull and superstructure sides, and the flanges representing the decks One-dimensional models consistently and uniformly underestimated the three-dimensional behaviour, but were fast to create and run. Two-dimensional models were also consistent in their assessment, and considerably closer in predicting the actual behaviours. These models took longer to create than the one-dimensional, but ran in very much less time than the refined three-dimensional finite element models Parametric insights were accomplished quickly and effectively with the simplest model and processor, but two-dimensional analyses achieved closer absolute measure of the displacement behaviours. Although only static analysis with simple loading and support conditions were presented, it is believed that similar benefits would be found for other loadings and support conditions. Other engineering components and structures may benefit from similarly judged simplification using one- and two-dimensional models to reduce the time and cost of preliminary design.
Shaping Ship Safety: The Face of the Future
Authors: Vassalos Dracos
Published: January 2021

This paper intends to demonstrate that ship safety is currently at the center of intense international activities, undergoing a process of evaluation and change that is likely to yield a new face that bears little resemblance to the past. It is most heartening that changes take place in desirable directions but the need for vigilance is now greater than ever. In exploring this process of change the paper stresses the areas where attention is needed the most and attempts to provide evidence in support of a key argument concerning a gap in the way safety has always been approached. More specifically, it is contended that the largest single factor contributing to the unsatisfactory state of affairs as regards ship safety is the compulsion to deal with it through rule development and legislation. This route is becoming progressively more impractical as evolutionary changes happen faster than experience is gained, thus depriving the rule making process of its basic ingredient. As an alternative, a proposal is put forward allowing safety to be brought to the heart of ship design, and integrated within the design process through a suitable generic formalization that ensures inherently safe and costeffective ship designs.
Shaft Alignment Using Strain Gages: Case Studies
Authors: Cowper Bruce , DaCosta Al , Bobyn Stephen
Published: January 2021

Two case studies are presented in which measurement and modeling programs were undertaken to assess the installed shaft alignment condition on marine vessels. One on the CCGS Earl Grey, and the other on the HMCS Huron. In both cases catastrophic damages had previously occurred to shaftline components, which were suspected to be a result of shaft mis-alignment. The damaged components were repaired, and the shaftlines were re-aligned using traditional methods (optical/laser). To assess the alignment condition of the installed shaftlines, measurements were taken by using the strain gage technique. In one case the shaft was realigned according to the strain gage measurements. Mathematical modeling was also conducted to assess the implications of the alignment measurements, and to provide the means to estimate the offsets of the installed bearings from their prescribed positions.