bluuebunny/crossref_metadata_2025 huggingface dataset:
The International Load Line Convention: Crossroad to the Future
Authors: Alman Philip , Cleary William A. , Dyer Michael G. , Paulling J. Randolph , Salvesen Nils
Published: January 2021

The 1966 Load Line Convention (ICLL 66) has been in existence for 26 years and was preceded by the first Load LineConvention in 1930. For many years, there has been a ecognized need to reassess the technical provisions of ICLL 66.With the passage of time, development of new technology, and the introduction of novel ship designs, many of the inherent strengths and weaknesses of the document have become apparent. A wide panorama of design concepts never envisioned 30 years ago were steadily introduced into the marine industry. These new types of ships present problems for direct application of the Convention in the assignment of safe free-boards. There has been an increasing trend to utilize analytical seakeeping studies coupled with model tests as a means to assess deck wetness on novel ship designs. The recent ability to conduct analytical seakeeping studies verified by model test programs has expanded the horizon of potential application to load line assignment, and it is the key to understanding the level of safety inherent in ICLL 1966.
Probabilistic Ship Structural Analysis: An Incorrect Way to Compute the Probability of Failure
Authors: Psaraftis Harilaos N.
Published: January 2021

There has been a recent paper in the probabilistic ship structural analysis literature that describes an incorrect way of calculating the probability of failure. This short technical note points out this fallacy and suggests the correct way to calculate this probability.
Solo-Stack Containership Hold Design
Authors: Grey Vincent G.
Published: January 2021

This paper suggests a departure in traditional containership cellular hold design. The proposal deals with the ability of the marine carrier to transport the growing variety of container lengths, widths and heights that are appearing in the United States and Europe. The idea is this: Below-deck stowage of the (currently evolving) new families of containers (having dissimilar physical dimensions) can be achieved aboard a cellular containership by supporting containers individually rather than by stacking them. By the solo-stack technique described here, no container will bear on the one below or against those adjacent to it.
The Anatomy of Tanker Grounding
Authors: Wierzbicki T. , Peer D. B. , Rady E.
Published: January 2021

The destructive effects of the Exxon Valdez grounding achieved worldwide notice. Yet, few tools exist for the ship designer or classification societies to assess or improve the survival of ships and cargo in catastrophic grounding situations. Two models have been developed which provide new insight into the grounding of longitudinally framed tankers. Several typical failure modes have been identified and calculations support the observed failure pattern in recent tanker groundings. The extent of damage to the bottom has been calculated and related to the kinetic energy of the ship, the geometry of the impacting rock, and matedal and structural characteristics of the ship.
The Design of an Eight-Oared Rowing Shell
Authors: Scragg Carl A. , Nelson Bruce D.
Published: January 2021

Rules governing the design of rowing shells do not restrict basic hull parameters. In designing a new eight-oared rowing shell for international ard Olympic competition, the authors sought a high speed, minimum drag hull form, subject only to the constraints on minimum displacement and roll stability. An investigation of optimum hull parameters using analytically determined resistance curves was made. Optimum hull parameters for both deep and shallow water racing are presented. Using the hull parameters determined for minimum resistance at racing speeds in shallow water, several new hull forms were created and analyzed in both deep and shallow water. Two promising final design candidates were proposed for model-scale testing. Results of both steady and unsteady towing tests are presented.
ARCO Tanker Slamming Study
Authors: Lacey Peter , Edwards Rod
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. Some of these ships have experienced bow structural damage, presumably due to slamming in heavy weather conditions. In late 1990 ARCO initiated a program with Arctec Offshore Inc. and Ocean Systems Inc. to investigate slamming of ARCO tankers. This ongoing effort focuses on three issues: the frequency of occurrence and intensity of impacts; the relationship between the impact characteristics, sea conditions, and ship motions; and the development of an onboard slam monitoring and warning system. During the winter of 1991 data were collected aboard two ARCO 190 000 dwt San Diego Class tankers. This paper describes the data acquisition program, including the problems encountered, the preliminary interpretation of the collected data, and plans for continuation of the program.
Design and Operational Experience of the SWATH Ship Navatek I
Authors: Seidl Ludwig H. , Clifford William F. , Cummings James P.
Published: January 2021

A presentation is attempted linking the historical development, general design considerations for Small Waterplane Area, Twin-Hull (SWATH) hull shapes, the design of a particular SWATH, the Navatek/, and her operational experience. The "carrier vessel" concept on which the Navatek I is based is introduced. Principal dimensions and general arrangements are shown. A parametric study of twin-strut SWATH hull forms for a hull of constant displacement is presented in some detail. Stability and ship motion are discussed and actual data for the Navatek I presented. The overall structural analysis is briefly presented, including the method of analysis for the Navatek I. The SWATH captain's operational experience with the Navatek I during her extensive journeys is related to quite some extent.
An Application of Oil Spill Recovery Technology to Response Vessel Design—The Burrard Cleaner No. 9
Authors: Lerch D. W.
Published: January 2021

Part 1 examines the fate of crude oil spilled at sea and develops the design philosophy for the response recovery vessel. Part 2 describes the model testing, design details and construction of a 75-foot tractor design, modern oil recovery vessel for open water and coastal operation. Part 3 reviews the underwater appendage design, the problems and solutions.
Vapor Recovery on Tankers from Design to Operation
Authors: Clement Chris
Published: January 2021

Vapor control legislation has presented the vessel operator with a multitude of factors that must be given consideration during the retrofitting of a vessel vapor control system. This paper discusses notable aspects concerning the integration of various facets of vapor control as they relate to vessel installations from conceptual design through operation. While complete vessel collection and processing systems are permitted by the Regulations, discussions in this paper are limited to vessel collection systems because, for the most part, industry has adopted the concept of limiting vessels to the collection of vapors only, with subsequent transfer to shoreside facilities for processing. Discussions are based on experience gained during development of vapor collection systems for two different classes of inerted, multi-grade cargo product tankers. Accordingly, some topics are not applicable or can be simplified when considering installations on board tank vessels carrying single cargoes or on non-inerted tank vessels.
Reliable Performance Prediction: Techniques Using a Personal Computer
Authors: MacPherson Donald M.
Published: January 2021

Much of the literature available for the computerized prediction of ship performance is devoted to the equations and formula that mathematically represent model test results. It is not the intent of this paper to reiterate this body of work, but rather to provide background and guidance to designers regarding the confident application of these numerical methods through the use of commercially or individually developed personal computer software. The paper covers these issues by reviewing basic methodologies for the prediction of resistance and propulsive coefficients; by introducing various numerical formula and data; by describing techniques to correlate predicted results with known performance; and by presenting a systematic approach to predicting the various aspects of a vessel's performance with personal computer software.
Benefits of Quality Control Techniques in Series Ship Construction by Computer Integrated Manufacturing
Authors: Bernhard Bryant S.
Published: January 2021

The application of quality control theory to shipyard practices is described. The work is facilitated from the project engineering level on a contract applying a construction process which includes state-of-the-art technology employed by shipyards and other manufacturing industries throughout the world. The paper explains the benefits to be derived by using quality control methods in the production processes. The system is enhanced further when designs are configured to recognize production factors. The quality control techniques described herein have proved effective in bringing the process under control and maintaining the dimensional integrity of the subject series of vessels.
Shipboard Acoustics Investigation—with Specific Application to Conversion of a Cargo Vessel into the Maritime Schoolship TS Empire State
Authors: Tanwar Ravinder K.
Published: January 2021

Shipboard noise control has received attention in naval vessels, while in commercial shipbuilding it has remained in the background of engineering considerations to a very limited extent by either barely meeting the existing rules and regulations or satisfying them to the owner's satisfaction by use of alternative methods. Passenger vessels demanding customer satisfaction have been the exception and require more sophisticated prediction techniques for stringent noise control. This paper while briefly discussing the availability of noise level prediction and control techniques presently used in new ship construction, stresses the importance of the equally simple methods of applying these techniques in identifying critical noise areas and analyzing the effects of methods used in controlling and reducing the noise levels in existing vessels. Through improvements to existing vessels or conversion to different type of vessel service, benefits are obtained which increase human comforts and work efficiency without costly studies and expensive experimental modeling or statistical analysis data collection techniques. TS Empire State, formerly the break-bulk carrier SS Mormactide
Buckling Analysis of Sandwich Shell Structures Subjected to Hydrostatic Load
Authors: Chryssostomidis C. , Papadakis N.A.
Published: January 2021

This paper examines the buckling phenomenon of sandwich cylindrical shell structures subjected to hydrostatic pressure. Global bifurcation buckling is considered, and the effect of discrete ring stiffeners on the critical pressure is analyzed. The local buckling problem is discussed, including the influence of the shape and the thickness of the core stiffeners on the critical load. Finally, the paper treats the sensitivity of local and global buckling on the thickness distribution between the inner and outer shells of the sandwich structure.
A Survey of Classical and New Response Methods for Marine Oil Spill Cleanup
Authors: Tsocalis Emilio A. , Kowenhoven Thomas W. , Perakis Anastassios N.
Published: January 2021

Both classical and new marine oil spill cleanup response methods and techniques are discussed. The intention is mainly to answer the fundamental questions of when, where, and how to apply the different methods. A brief review of the stages of the oil spill response problem is first presented, followed by the factors that influence the different methods. This is followed by an analysis of some new cleanup methods and improvements to existing methods, specifically: bioremediation, the use of more efficient ships for skimming, the use of fishing nets for heavy oil recovery, and new materials and designs of sorbents. Some cases are also analyzed to evaluate the performance of some methods under real conditions.
Implications of OPA 90 in General and Its Effect on the T-AO 187 Class Oilers in Particular
Authors: Hofmann Hans , Kapsilis George , Smith Eric , Wasalaski Robert
Published: January 2021

The Oil Pollution Act of 1990 has mandated that by the year 2015 all oil tankers operating in waters subject to jurisdiction of the United States must have double hulls. This paper examines the Act and the status of regulatory initiatives it has generated. Guidance for new hull construction and retrofit of existing vessels is outlined, and both IMO (International Maritime Organization) and U.S. Coast Guard requirements are discussed. Finally, the structural changes necessary to convert the U.S. Navy's T-AO Class oil tankers to meet the requirements of the Act are specified and illustrated.
The MIT Marine Hydrodynamics Water Tunnel—A 53rd Anniversary Celebration
Authors: Kerwin Justin E.
Published: January 2021

Fifty-three years ago, Professor Frank M. Lewis presented a paper entitled "Propeller Testing Tunnel at the Massachusetts Institute of Technology," at the spring meeting of SNAME. The tunnel is still there, although its name is changed, and its appearance2 is very different. However, the goals of the laboratory are still very much the same—to conduct innovative experiments designed to learn more about the fundamentals of the flow around propellers and other objects of interest to ocean engineers. This paper presents a historical review of many of the varied experiments conducted since the tunnel was completed, with emphasis on several recent projects. This will include an account of the application of the Laser Doppler Velocimeter to map the flow around propellers, underwater vehicles and cavitating foil sections, as well as the development of an apparatus to study the response of a two-dimensional foil to high-frequency gusts. The combination of experiments and theory is discussed, and some thoughts on future experiments are presented.
Reverse Osmosis Desalination
Authors: Abdella Dana L.
Published: January 2021

Reverse osmosis (RO) desalination is a method of producing fresh water from seawater by a process similar to filtration, rather than by traditional evaporative distillation. A semipermeable membrane allows water molecules to pass through while blocking the passage of most other ions. The qualities of RO which make it attractive for naval and marine applications are its ability to operate on electric power alone, requiring no heat source; its comparatively low system weight to other methods of freshwater production at sea; and its ability to operate automatically, requiring minimal operator attention. RO's high operational reliability has contributed to its gain in popularity in recent years. RO is used for freshwater production in commercial industry and surface ship applications worldwide. The following research paper discusses RO desalination and presents RO as an alternative to conventional distillation for naval and marine use.
Mine Countermeasure Support Platform Conversion Ship Design
Authors: Proctor Barry , Nutting Marianne
Published: January 2021

U.S. Navy experience gained from the mine countermeasures (MCM) operations against the mines planted by Iraq during Operation Desert Storm highlighted the need for a centralized platform for support of MCM operations. This centralized Mine Countermeasures Support (MCS) platform would meet two critical needs: it would enable the employment of integrated MCM forces and it would allow the MCM Group Commander to be deployed with those MCM forces. Full integration of all MCM forces by the MCM Commander is the key to effective MCM operations. The MCM forces comprised Airborne Mine Countermeasures (AMCM), Surface Mine Countermeasures (SMCM) and Explosive Ordnance Disposal Mine Countermeasures (EODMCM). The strengths of each must be captured and coordinated by the MCM Commander. AMCM assets are capable of rapidly deploying to conduct reconnaissance, precursor and clearance MCM operations. SMCM assets are more capable of sustained large area mine clearance and possess an organic ability to neutralize located mines. EODMCM assets are specialized EOD detachments that are also capable of rapidly deploying to support AMCM and SMCM minehunting and mechanical sweeping operations by identifying, neutralizing or countercharging, recovering, exploiting and disposing of sea mines. USS Inchon (LPH-12) has been selected by the U.S. Navy as the most cost-effective platform to provide a near-term solution which will meet the requirements discussed above. After a brief discussion of MCM operations, other candidate MCS platforms studied, and the far-term (new construction) MCS(X), the remainder of the paper will focus on the conversion of the LPH-12 to operate as the centralized platform for MCM operations
Implementation of Free-Fall Lifeboats on Ships
Authors: Nelson James K. , Regan Nancy B. , Khandpur Rajiv , Landsburg Alexander C. , Markle Robert L.
Published: January 2021

The free-fall lifeboat is quickly becoming a common lifesaving appliance on ships and offshore facilities. Although a free-fall lifeboat has never been launched from a vessel in distress, free-fall lifeboats were successfully launched and recovered in a seaway during two separate maritime rescues. Discussed in this paper are the basic behavior of free-fall lifeboats, considerations when using free-fall lifeboats on ships, the relative economics of free-fall lifeboat systems compared with conventional davit-launched lifeboat systems, and anticipated improvements in safety afforded by free-fall lifeboats during an emergency.
Large Amplitude Rolling Motion of an Ocean Survey Vessel
Authors: Falzarano Jeffrey , Ul Mulk Mohammad Taz
Published: January 2021

This paper describes some recently completed research at the University of New Orleans into the nonlinear and coupled aspects of large amplitude ship rolling motion, including capsizing, at all heading angles. The study analyzes the roll motion of a vessel which experienced large amplitude motions. By studying the nonlinear and coupled aspects of the critical roll motion, insight into the important parameters affecting the roll was obtained. The roll was found to be multivalued and highly coupled to the sway and the yaw motion. Additional work has been completed and more work is in progress to investigate additional aspects of the subject vessel's motion.
The International Sailing Canoe: A Technical Review
Authors: Miller Paul H. , Dillon David L.
Published: January 2021

The unique features of the International Sailing Canoe have intrigued naval architects and sailors for years. This paper highlights the historical design development, describes current trends, and presents results from finite element analyses of three popular construction methods: cold-molded cedar, fiberglass, and carbon/epoxy. Comparisons are presented of the bending and torsional stiffness, pitch gyradius, and factors of safety. In general, the carbon/epoxy exhibited the best characteristics, followed by the cold-molded cedar and the fiberglass. The Tsai-Wu quadratic failure criterion developed for laminated plates was used in the factor-of-safety calculations. Factors of safety correlated closely to empirical development.
Design, Construction, and Operation of Niagara River Icebreakers
Authors: McMillan Dave
Published: January 2021

This paper describes the design and construction of two small icebreakers for operation exclusively in the fast-flowing Niagara River above the celebrated falls. Special features of these purpose-built craft—which due to their dangerous operating environment include many redundant systems—are presented. Results of maneuvering trials and model tests are given, along with a comparison between hull forms of the two vessels—Ontario Hydro's Niagara Queen II and the William H. Latham, operated by the New York Power Authority.
Scale and Roughness Effects in Ship Performance from the Designer’s Viewpoint
Authors: Mishkevich Victor
Published: January 2021

Evaluation of the scale effect in the absence of flow separation is usually based on two independent calculation procedures for the drag and lifting forces. Prediction of the full-scale drag forces is based on modeling of the viscous part of the resistance in accordance with the difference in Reynolds numbers. As a rule, a lifting force coefficient for full-scale bodies is treated as a lift coefficient for a model having the same Froude number. The proposed method is based on the idea that an initiation of the lifting force is associated with the viscous effects in the boundary layer. According to this approach, an estimation of the scale effect is based on a calculation of potential, boundary layer and wake flows with viscous/nonviscous interaction for given Froude and Reynolds numbers. The roughness of a surface is taken into account due to the use of special velocity profile parameters. These parameters depend on type and height roughness (casting, milling grooves, polishing, paint, fouling, acid deposit, etc.). As a result, the effects of viscosity (Reynolds number) and surface roughness are determined as the difference between the drag and lift forces calculated for the model and full-scale conditions. The magnitude of the scale effect may reach 50% to 70% for the drag and 10% to 20% for the lift forces. The unusually large scale effect for the lift may play a significant role in engineering applications. Results of the systematic calculations and experimental evaluations are reported for a broad range of ship types and propellers.
Shipboard Controlled Atmosphere Plants: Selection, Installation, and Operation
Authors: Levin Martin D.
Published: January 2021

The increasing demand for marine transportation of agricultural produce under controlled atmosphere (CA) conditions is leading owners of refrigerated ships to provide permanently installed on-board nitrogen generating plants and atmosphere control systems. The selection of the shipboard CA gas generating plant must take into account the vessel type, the cargoes to be carried, and the range of controlled atmosphere conditions to be achieved for different commodities. The shipboard CA gas generating plant can be situated on the ship's weather deck, installed in the vessel's main or auxiliary machinery spaces, located in a separate CA compartment, or a combination of these options. Ventilation of all spaces containing CA generating equipment and pipelines, combined with atmosphere monitoring and alarms, and safety training of all concerned personnel, provides an acceptable level of safety. Experience with installation and operation of shipboard CA systems demonstrates that, with careful attention to sealing of the cargo spaces, proper equipment selection and installation in accordance with classification society guidelines, a successful shipboard CA installation can be achieved.
An Update on the Oil Pollution Act of 1990
Authors: Lamb Barbara L. , Bovet David M.
Published: January 2021

The Oil Pollution Act of 1990 (OPA 90) is significantly impacting the business of U.S. and international tanker owners engaged in the U.S. trades. This paper delineates the affected segments of the oil shipping industry, the salient regulatory elements stemming from OPA 90, the financial and operational impacts that result, and the strategic implications for the shipowner. Regulatory areas addressed include liability and compensation, financial responsibility, new ships, existing vessels, and vessel response plans. Originally presented in April, 1993, this paper has been updated for publication two years later.
Comments on the Structural Design of High Speed Craft
Authors: Koelbel Joseph G.
Published: January 2021

A brief discussion of materials used in the construction of small high speed craft is given along with a history of the calculation of hydrodynamic bottom loads. Calculation methods currently in use are reviewed, including those for added drag in waves, vertical accelerations in rough water, total bottom load, load on each structural member, and the required structural properties of the member. In particular, a discussion of the uncertainty inherent in these methods is presented, as well as a recommendation for a somewhat simpler approach which removes some of the uncertainty, and additional recommendations for the improvement of several details of the procedure.
MSRC Responders: Construction and Operation of Sixteen Oil Spill Response Vessels
Authors: Cowardin William H. , Dowell George W , Rodi Richard C.
Published: January 2021

The Marine Spill Response Corporation (MSRC) was established to provide catastrophic spill response capabilities to its client companies as required by the Oil Pollution Act of 1990 (OPA 90). The MSRC fleet consists of 16 oil spill response vessels (OSRVs), 16 boom support boats, 17 oil barges, and numerous small craft totaling 273 vessels, 185 of which are U.S. Coast Guard certificated. This paper provides an overview of these vessels, their capabilities, and their roles in oil spill response. Particular emphasis is placed on the design, acquisition, and operation of the 200 ft oceangoing OSRVs and the technical issues which had to be resolved in the extremely short time frame mandated by the OPA 90. The authors also discuss some of the problems encountered in assembling this fleet and the lessons learned.
Z-Drive Escort Tug Operating Modes
Authors: Jukola Hannu , Castleman Gregory E.
Published: January 2021

The suitability of various types of tugs to perform indirect towing has been a lively subject of debate, mainly in the international arena, and increasingly in North America. In the United States, this is the result of the enactment of well-meaning laws to improve the safety of seaborne oil transportation in environmentally sensitive areas such as Puget Sound and San Francisco Bay. Escort by means of a tug tethered to the stern of a tanker to permit rapid response to loss of propulsion or steering is often promoted as being the best way to accomplish the goal of such legislation. The development of indirect towing has made it possible to satisfy the desire to combine environmental safety with reasonable transit speeds. Indirect towing uses steerable propulsion to present the profile of the hull to the direction of advance of the tanker. Simultaneous braking and steering forces result. At elevated speeds, extremely high line pulls can be achieved, but with some risk to the towing vessel as it is in a girthing situation at all times. Research conducted by Aquamaster-Rauma Ltd. reveals that vessels equipped with independently controlled steerable propulsion systems (i.e., Z-drives) are capable of other means of producing arresting and steering forces with reduced risk of placing the escorting tug in a potentially dangerous situation. In this paper, these methods are discussed with comments on the situations where each mode applies.
SM Racer: Design and Operation of One of the World’s Fastest Monohulls
Authors: Acampora Brunello
Published: January 2021

Powerboat racing goes back to the beginning of the century, but offshore racing as we know it today started in the 1950's. The natural evolution of the sport led in 1990 to the birth of the Endurance class, intended for extended races on long offshore routes. This paper introduces Endurance racing and describes the design and practical operation of a powerboat, the SM Racer, expressly built for this kind of competition.
A Comparison of Alternative Bow Configurations
Authors: Stromgren Chel
Published: January 2021

Newport News Shipbuilding (NNS) has been preparing for a reentry into the commercial shipbuilding market for several years. Those preparations resulted in the signing of a contract in October of 1994 with Eletson Corporation for the construction of two (with an option for an additional two)46500 dwt product carriers. This is the first contract for a U.S. shipyard to build commercial ships for a foreign owner in 37 years. In developing the hull form for the standard product carrier Double Eagle, NNS performed studies to determine the economic and hydrodynamic effects of alternative bow configurations on a representative modern, high-block tanker. The objectives of the study were to update the NNS commercial ship speed-power database, investigate the application of state of the art computer software, and create a bow design which strikes a balance between hydrodynamic performance and producibility. To achieve these goals, NNS worked with SAIC to use the computational fluid dynamics (CFD) SLAW software to mathematically analyze several candidate bows. These designs were then model tested at the Swedish State Model Basin in Gothenburg to validate the results of the CFD codes. Construction costs were then estimated for each design and finally, the bow forms were compared on an overall economic basis.
Examination of Shipboard Ground Detectors with Recommendations for Covering Their Limitations
Authors: Dengel Joseph J.
Published: January 2021

Vessels with ungrounded electrical systems monitor the isolation with a USCG-specified ground detector. The required detector is suitable for most grounding cases but is deficient with some reactive faults and faults not at phase potential. In these instances, the detector provides confusing indications and may seriously misrepresent the isolation integrity. In this paper detector performance is examined in detail using both analytic and computer models. The advantages and limitations of the detector are explored while sample ground-fault cases are reviewed. Finally, a test procedure is proposed which supplements the detector and confirms that the required isolation is present.
Design of a Catamaran Sounding Vessel for Operation in the St. Lawrence
Authors: Davidson A. , Benckhuysen J. , Francoeur G.
Published: January 2021

CCG Laurentian Region currently operates three vessels whose primary function is the sounding of dredged navigation channels in the St. Lawrence from Montreal to Gap Gribane, 15 km downstream from lle d'Orleans. The vessels also provide services as far out as Rimouski and into the Saguenay. These vessels sound, on an annual basis, some 120 km2 of surface area. Due to its association with Seaway dredging in which some 0.3 million m3 of material is removed annually, this sounding activity has to be carried out with an accuracy greater than that normally associated with hydrographic charting. CCG Laurentian Region specialists have brought together current off-the-shelf sounding and position-keeping equipment which comprise a sounding mission system capable of onboard real-time data processing compatible with significantly higher sounding speeds than the 10 knots of the existing fleet. The existing fleet, which comprises two 18 m catamaran vessels and the shipping channel maintenance vessel Nicolet, is now approaching the end of its economic life and is scheduled for replacement. The replacement program comprises two catamaran vessels designed to sound at 18 knots, thus providing full area coverage in the 8-month operating season from mid-April to mid-November. This paper presents some of the challenges represented by the mission requirement and the engineering solutions incorporated into the vessel design.
The Contribution of Maritime Economics to the Revitalization of the U.S. Marine Industry
Authors: Zeien Jennifer J. , Hillmann J. F.
Published: January 2021

A thorough understanding of the role of economics in the various sectors of the maritime industry is vital to success in increasingly global markets. In this paper, the authors discuss the importance of economics in the maritime industry and the consequences of ignoring the effect of economic factors. The authors explore the effect that economics has on the industry's organization, including its structure, behavior, and performance. They examine the relationship between maritime economics and transportation economics, and explore implications of modeling the demand for shipping and shipbuilding services as a derivative of the demand for international trade and commerce. In this regard, the authors present the U.S. maritime industry and chart significant milestones in its development. This factors into a discussion of the impact of the globalization of commercial shipping. The authors also consider the history of government involvement and the military role of the maritime industry. The central thesis of this discussion is that the markets for ships and shipping are becoming increasingly more competitive, and less susceptible to outside constraint. The authors then illustrate their thesis by presenting case studies capturing the two main segments of the maritime industry: international shipping and international shipbuilding. The authors prescribe the need for a market-driven industry receiving minimal intervention by government. Finally, the authors discuss the role of SNAME's Panel 0–36, "Maritime Economics," in relation to the concerns of maritime economics that embrace far-reaching issues with significant application to shipping and shipbuilding in the United States.
A Probabilistic Study of the Simultaneous Effect of Ship Motions on the Cargo Shifting Onboard
Authors: Hua Jianbo
Published: January 2021

Cargo movement aboard ship can occur even in waves that produce only moderate rolling motion. It is caused when the simultaneous effect of vertical acceleration, horizontal acceleration and roll motion on the cargo onboard—defined as the equivalent roll angle—becomes sufficiently large for the problem to develop. In this paper, an analytical expression is derived for the probabilistic calculation of the equivalent roll angle, which has a nonlinear characteristic. Also, a so-called indirect time-domain simulation method is described for calculating the problem. Both methods are based on motion transfer functions calculated according to strip theory. The calculations presented here show both methods to be in good agreement. A probabilistic calculation of the equivalent roll angle of a roll-on/roll-off (RO/RO) ship is carried out using the two methods and focusing on parameters such as significant wave height, mean wave period, ship speed, and relative course angle. It is proved from the point of view of probability that the nonlinearity of equivalent roll angle results in a magnifying effect on its extreme value. The calculation shows also that in severe wave conditions large peak values of equivalent roll greater than 35 deg can be experienced by the studied RO/RO ship.
Feasibility Study and Preliminary Design of a Channel Buoy Mounted Oil Sensor System
Authors: Lake Matthew William
Published: January 2021

Due to high vessel traffic and the presence of industry, oil pollution is often an overwhelming menace. Oil spills potentially may remain undetected for long periods of time, despite routine surveillance by the Coat Guard and other environmental agencies. A Channel Buoy Mounted Oil Sensor System capable of warning oil spill response units of the presence of oil immediately after a spill occurs would greatly increase the effectiveness of cleanup efforts. The Channel Buoy Mounted Oil Sensor System (CBMOSS) has been designed to detect oil spills and subsequently send an alarm via a VHF-FM transmitter. This alarm could be received by a centralized monitoring station. The CBMOSS consists of an infrared oil monitor, logic circuit, VHF transmitter, power unit, and an antenna. The system is designed to be mounted and powered by existing U.S. Coast Guard lighted buoys. The system is fairly low powered and capable of running off existing power sources aboard lighted buoys. Due to the utilization of off-the-shelf components and low cost electrical gear, this system is relatively inexpensive. Though the Channel Buoy Mounted Oil Sensor System is intended to be used on buoys throughout a body of water at locations where there is a high probability of an oil spill, the system has the potential for use as an oil spill sensing platform in other applications as well.
Cargo Oil Heating Requirements for an FSO Vessel Conversion
Authors: Chen Bill C. M.
Published: January 2021

Highly viscous crude oil stored in a floating-storage-and-offloading (FSO) vessel can provoke cargo pumping and remain-on-board (ROB) problems. Cargo oil heating in the vessel to reduce the viscosity and minimize the problems is studied in this paper as well as heating requirements. An operating scenario is introduced for a vessel of 300 kdwt with assumed data. Heat dissipation from warm cargo to ambient, heat addition to incoming cold cargo, and heat depletion during cargo offloading are analyzed for the vessel. A simplified but robust heat loss analysis for the vessel is presented. Using the readily available product crude as the boiler fuel to heat cargo is a logical decision. Fuel consumption is estimated for the vessel. Boiler loads for heating steam generation and heating devices are discussed. The cargo offloading configurations between the vessel and shuttle tanker are investigated for heated and unheated cargo to determine its deliverability. The configuration dictates the length of offloading hoses from the vessel to the tanker. High pressure losses within long hoses may prevent unheated cargo from being delivered at the design rate to the tanker. Alternatives to cargo heating are postulated. Addition of heating coils to an ultra-large crude carrier (ULCC) built in the 1970's or 1980's is considered during the vessel conversion. The cost estimates of addition and conversion for cargo heating are assessed. The transportational considerations are discussed. Conclusions and recommendations are presented.
Patrol Boats: A World Market Overview
Authors: Underwood Mark J.
Published: January 2021

This is a brief discussion of "patrol boats" from a marketing analysis viewpoint. The methodology of analyzing a foreign navy's current fleet and projected acquisitions is described. The factors affecting the purchase of ships or systems are given. There is a detailed discussion of "definition," including the parameters that are used in defining classes of ships. Examples of representative ships that fall into a given definition are shown. The importance of properly defining a ship, especially in the patrol boat class, is discussed. The world market in patrol boats is then presented. The data are broken down with numbers and value of existing ships plotted by vessel type and region. Finally, future projections for the patrol boat market are given
Application and Advantages of Catamarans for Coastal Patrol Vessels
Authors: Allan Robert G.
Published: January 2021

Although the catamaran hull has been, for the past decade, the predominant choice for ferry designs of increasingly larger dimensions, as well as other applications, its adoption for small patrol craft has been limited. This paper describes the advantages and applicability of the catamaran for typical patrol boat missions, assesses its capital and operating costs versus those of a monohull of equivalent performance, and reviews the experience of a standard series of catamaran patrol boats operating in offshore British Columbia waters by the Royal Canadian Mounted Police. RCMP Commissioner class patrol vessels at speed
Marine Vapor Control System for the Valdez Marine Terminal
Authors: Rein David C.
Published: January 2021

The Clean Air Act Amendment of 1990 will require many marine terminals in the United States to provide a means to control hydrocarbon emissions during loading of marine vessels. The Valdez Marine Terminal in Alaska is the largest domestic crude oil loading terminal and it will be affected by new regulations for vapor control. Engineering design is in progress for systems to control vapor emissions during loading of marine vessels. The paper addresses the basic system design considerations, special requirements, and unique features of the Valdez Marine Terminal Vapor Control project.
RO/RO Passenger Ferry Safety: A Perspective from the Canadian West Coast
Authors: Schauer Todd , Noble P. , Martin H. , Hatfield P.S. , Davies Ken , Roddan G. , Stensgaard G.
Published: January 2021

This paper discusses actions which the British Columbia Ferry Corporation has undertaken subsequent to the catastrophic 1994 Estonia capsize accident in the Baltic Sea that resulted in the loss of 912 lives. The corporation sets as its highest goal the provision of a "safe, efficient and effective ferry system," and therefore the actions described form part of a continuum of safety improvement which is central to the BCFC operating philosophy. Recommendations with respect to both rough water, northern route vessels and to the southern route, more sheltered water fleet are outlined. In addition, the improvement of safety on the northern routes vessels by the fitting of improved supporting and closing devices on the bow visors, by improving the bow ramp securing arrangements and by installation of inner weathertight doors is described in detail. Some recent model testing undertaken to investigate the potential for "bow scooping," and which has provided valuable input to the International Maritime Organization's Panel of Experts in determining the limits of application of proposed bow flooding criteria, is reviewed.
Sailing Ship Intact Stability Criteria
Authors: Cleary Chris , Daidola John C. , Reyling Christopher J.
Published: January 2021

The comeback in recent years to the world's oceans of large displacement sailing vessels has increased the interest in design requirements. At the same time, there have been a number of accidents and capsizings of sailing vessels that investigators have attributed to a lack of adequate intact stability. In an attempt to identify improved stability criteria for large sailing vessels, using the U.S. Coast Guard training barque Eagle as a model, the authors have conducted a worldwide search of the literature and other sources to gather a body of criteria for comparison with each other and then with the existing standards for the Eagle. The results of this research are presented and illustrated, including the domain of interaction between ship motion and sail forces. The methods presented herein could be a useful contribution to the safe design and operation of large sailing vessels.
Cracks and Structural Redundancy
Authors: Stenseng Arne
Published: January 2021

This paper proposes a way to use finite element models to determine the effect of fatigue cracks in ship structures. Cracks of different lengths are modeled and the maximum nodal stress at the crack tip is used to estimate the stress intensity level. The calculated stress intensity factor is substituted into fracture mechanics equations to calculate the rate of crack growth and the critical crack length. The main advantage to calculating the stress intensity factor from an appropriate finite element model is that load redistribution effects are included. Since the ship structure is redundant, load shedding and multiple load paths can significantly reduce the propagation rate and thereby improve the safety of the structure. Including the crack in the finite element model also makes it possible to study the crack's impact on the stress levels in surrounding structure. The method is independent of the cause of structural failure, hence this kind of analysis can be used to investigate the effects of cracks created by fatigue, collision, or grounding damage.
Bulk Carrier Safety
Authors: Frystock Karen , Spencer Jack
Published: January 2021

During the past ten years, more than 700 crewmen have died as a result of Bulk Carrier casualties. Following a rash of 25 Bulk Carrier losses in 1990 and 1991, The American Bureau of Shipping (ABS), The International Association of Classification Societies (IACS), and various other segments of the marine industry initiated measures in an attempt to correct this situation. During the next several years another 11 Bulk Carrier losses (resulting in the death of 174 crewmen), indicated that these measures, although improving the situation, did not go far enough to solve the problem. A close examination of the vessels involved indicated that the overwhelming majority of the bulk carriers were in excess of 15 years old. While inadequate maintenance and improper loading have been likely contributory factors, it is apparent that present BulkCarrier designs have not matched expectations as these vessels age. At ABS a study to investigate the response of the Bulk Carrier hull structure was undertaken in an attempt to understand the causes of the structural weaknesses which may have contributed to these losses. In applying a first principles approach of using representative and realistic dynamic loads, the critical areas, including hold frames and end brackets, corrugated transverse bulkheads, cross deck structures and fore end structures were studied. This study resulted in the development of a new complete, flexible, and integrated strength criteria for design and assessment of Bulk Carrier hull structures. The approach encompasses:the loading criteria,the strength criteria for minimum scantling requirements, andthe strength assessment procedures incorporating failure criteria dealing with material yielding, buckling/ultimate strength and fatigue.

In this paper, an overview of this new strength standard is presented and the procedures to rectify problem areas unique to bulk carriers are discussed.
A Seakeeping Study of the UBC Series
Authors: Calisal Sander M. , Howard David , Mikkelsen Jon
Published: January 2021

The University of British Columbia (UBC) and the British Columbia Research Incorporated (BCRI) collaborated to design a fishing vessel suitable for use on the west coast of Canada. This vessel, called the UBC Series parent hull form, was designed to have a large aft deck area and a volumetric coefficient comparable to those of modern Canadian fishing vessels. The resistance characteristics of this hull were improved without compromising on functionality and usable space. A resistance algorithm developed from the results for a systematic series of low-L/B displacement-type vessels, the UBC Series, was previously published (Calisal&McGreer, 1993). However, during the design process, the seakeeping performance of the vessel was never addressed. This paper describes the seakeeping performance of the UBC series in head seas. An algorithm, developed from the results of the model tests, can be used to calculate the seakeeping response of similar low L/B vessels. To calibrate the seakeeping measurement procedure, tank instrumentation, and data collection system, the ITTC Standard Seakeeping hull form (the S-175 hull form) was tested and the results were compared against published results for this hull form. The same techniques used for the standard hull form were then used to measure the seakeeping performance of the UBC Series. Possible application of the algorithm for non-UBC Series forms is also discussed.