bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Study of Containment Boom Behavior in Waves
Authors: Bruno Michael S. , Van Dyck Robert L.
Published: January 2021

An effort to assess containment boom performance in waves is described. New model testing instruments and procedures have been developed to provide a direct measure of boom heave response to wave excitation at several points along the boom. Measurements have been made in reproducible regular, irregular and breaking waves for various generic model boom configurations over a range of wave characteristics, boom buoyancy/weight ratios, and towing speeds. A model scale of 1/8 allows for tests in regular waves up to 12 ft high full scale at 12:1 length/height ratio and irregular waves with significant heights of up to 8 ft full scale. Breaking waves equivalent to over 6 ft height above mean water level are also generated. Measurements include total towing force and heave motion at four locations along each boom. The results of tests of three different size models all scaled to the same 4 ft high prototype boom show no significant scale effects on heave response to the various types of waves. Drag differences found among the models are attributable to differences in full scale lengths, as well as buoyancy/weight ratios. A buoyancy/weight ratio of 10 or greater was found to improve heave conformance with waves at optimum towing speeds of about 0.5 knot. Short wavelength waves, requiring the highest frequency response, are shown to be the most difficult conformance problem. Of particular concern is the fact that a catenary tow shape focuses waves near the vertex, thereby amplifying the wave height and causing excessive motions near the center of the boom. For this reason, light weight, highly flexible booms with maximum buoyancy/weight ratio and sufficient freeboard are recommended for open sea operations.
Cross Section of Experience in SafeHull Applications
Authors: Rynn Philip G. , Morlan Christopher E.
Published: January 2021

This paper provides information regarding the use of the ABS SafeHull program/criteria for review of tanker and bulk carrier structures. It focuses on the submittal and review processes as carried out by the classification society in an effort to address the needs of the client. Detailed examples are provided which illustrate the necessary information to be submitted and the results of a typical review. The paper demonstrates lessons learned from the reviews which have been performed to date. The paper also includes a brief discussion of future program developments.
Titanic Defended
Authors: Woodward John B.
Published: January 2021

Authors of popular books on the Titanic tragedy often criticize the design of the ship, e.g., writing that it was deficient in that it lacked watertight decks and longitudinal subdivision. On the other hand, experts in ship design spoke quite differently in the public evaluations of the ship that followed, particularly in the Board of Trade investigation of 1912, and in the SOLAS conferences of 1914 and 1929. Pertinent excerpts from their findings and rule-makings are quoted, and discussed with respect to their posthumous application to the Titanic. With one exception, this process supports the present author's assertion that the Titanic was neither an unsafe nor poorly designed ship.
SWATH Golf Club Hull Flow Studies
Authors: Ratcliffe Toby , Kenneil Colen
Published: January 2021

Analytical and experimental results" are presented from an exploratory investigation of the flow phenomena encountered with golf club SWATH designs. The focus of this work is testing done on three closely related SWATH models with common hulls and strut waterplane shapes. The models are constructed to allow testing of the hulls in three athwartship positions: a full golf club, a conventional SWATH, and an intermediate partial golf club. Traditional measured data augmented by flow visualization information are used to identify flow phenomena present. In addition to the test program, supporting calculations were made with advanced hydrodynamic flow codes to assess these analytic tools and provide insight into flow phenomena encountered.
Diving Support Vessel Concept Design
Authors: Morrissey George R. , Stone Michael C.
Published: January 2021

This paper describes the preliminary process for designing a 250 ft dynamically positioned, Diving Support Vessel. This is to serve the offshore oil industry as a platform for underwater intervention. Enlisting the use of the latest technological advances, the vessel will support both remotely operated vehicles and human divers. We will trace the development of this design with a well-defined agenda. Beginning with an analysis of the existing fleet, a practical hull form is created, which leads to solid estimations for hydrostatics, stability, resistance, powering and preliminary arrangements. We will also discuss the steps that will follow over the next several months.
A Cost-Effective Approach to Penetrating Ship Structure
Authors: Rivinius Geoff , Tedesco Matthew
Published: January 2021

During the design of the first Sealift Conversion at the National Steel and Shipbuilding Co., it became apparent that existing standards related to penetrating ship structure would result in a costly system layout. The decision was made to develop an improved strategy for follow-on Sealift ships. This paper describes a structural study and approach to maximizing penetration sizes with the least compensation required. The strategic reasons for performing the study, the technical study itself, and the resulting implementation through revised standards are discussed.
Stability of Capsized Fishing Vessels During Dive Rescue Operations
Authors: Hall Terrence A.
Published: January 2021

With numerous capsizings of smaller vessels (primarily fishing vessels) each year along the west coast of Canada and the inherent risk to rescue divers who must enter these inverted hulls to extract victims, Transport Canada initiated an investigation to determine whether the relative stability of capsized vessels could be gauged by first response personnel, thereby assisting them in determining whether supplementary buoyancy or other stabilizing measures be taken prior to committing a diver to the hull. This paper addresses the findings of the investigation, including criteria for gauging a capsized vessel's stability, the effectiveness of various stabilizing methods and recommended procedures for first response personnel and divers when undertaking a rescue involving a capsized vessel.
Tests on Conventional and Novel Model Ro-Ro Ferries
Authors: Ross Carl T. E , Roberts Hywel V. , Tighe Richard
Published: January 2021

The paper presents a brief history of roll-on/roll-off ferries'and their problems, together with a novel design based on a perforated vehicle deck. Two I/woth scale models of the Herald of Free Enterprise were manufactured in glass reinforced plastic. These two models were tested dynamically in a tank, and the results showed that the modified novel design was considerably superior to the conventional design. The novel design does not affect the roll on/roll off concept of the ro-ro ferry. Additionally, it should be possible to retrofit it into existing vessels and thus meet SOLAS requirements.
Measurement and Analysis of Shipboard Vibrations
Authors: Frank DeBord , William Hennessy , Joseph McDonald
Published: January 2021

Excessive shipboard vibrations can cause structural and machinery failures, crew discomfort and fatigue, and increased maintenance requirements for shipboard systems. In many cases ship construction specifications require the shipyard to demonstrate "acceptable " levels of vibration using measurements completed during sea trials. This paper provides an overview of standards for these measurements and modern techniques used to collect and analyze the specified vibration data. A brief discussion of the types of vibrations found on ships and their causes is followed by a review of codes, guides and standards for vibration measurement. Instrumentation suitable for measurement of each type of vibration response is described and the design of a typical trial measurement system is presented. Techniques for analyzing and presenting trial results are reviewed and compared with analysis methods specified by SNAME, ISO and NAVSEA. Finally, a discussion of potential problems faced by an owner and shipyard in developing and meeting a vibration measurement specification is offered.
Reliability Data Collection for Ship Machinery
Authors: lnozu Bahadir , Schaedel Peter G. , Molinari Veronique , Roy Philippe , Johns Robert
Published: January 2021

An industry-wide international network is needed to collect Reliability, Availability and Maintainability (RAM) data on shipboard machinery and share this data at different levels by linking vessel chief engineers, ship operators-managers, regulatory agencies, equipment manufacturers, and shipyards/designers. This network should facilitate the efficient collection and flow of RAM information between these entities with industry-wide continuous improvement in safety and cost-effectiveness. This paper describes the implementation of a worldwide information network, called RAM/SHIPNET to support the optimization of safety, reliability and cost effectiveness throughout all stages of a vessel's life cycle. Development of this network was started with seed funding from SNAME and continued under the umbrella of the Ship Operations Cooperative Program with primary funding from the Gulf Coast Region Maritime Technology Center at the University of New Orleans. First generation data collection and processing tools have been completed and, pilot validation and testing has been performed in the USA. The project is now moving into the second implementation stage enabling full scale testing, validation and roll-out on a global scale. A call is made to the industry for suggestions on improvement to meet emerging needs.
Design Trends in High-Speed Transport
Authors: Kennell Colen
Published: January 2021

This paper presents a method for analyzing transport properties of competing ship types of interest for high speed commercial transport. Simple parametric relationships link requirements (speed, range, and cargo weight) to design characteristics (installed power, ship weight, and fuel weight) for conventional and unconventional hull designs. These design trends are supported by data for a variety of ship types (monohull, catamaran, SES, hydrofoil, airship, ekranoplan) either currently or formerly in service. While the method is inherently general, the data selected is focused on large ships capable of transporting heavy cargos over trans-oceanic distances at speeds of 40–100 knots.
High-Speed Sealift Technology
Authors: Kennell Colen , Lavis David R. , Templeman Michael T.
Published: January 2021

This paper describes a process that is currently being used within DoD and industry to examine the possibilities offered by technology to enhance the transport performance of high-speed commercial and military sealift. Technology projections are presented for both the near-term and the far-term. The impact of technology projections on transport performance properties is assessed both quantitatively and qualitatively. These assessments provide significant insight into the overall transport performance potential of hullforms and other technologies of interest, considerably in advance of detailed design studies. The quantitative assessment uses a derivation of the empirical method published by Kennell[1]4, which provides simple parametric relationships between mission requirements, expressed in terms of speed, range and payload, and design characteristics, expressed in terms of displacement, installed power and fuel weight, to compare the various hullforms and other technologies of interest. The qualitative assessment applies an established decision-making method to ascertain the relative capabilities and relative risks of hullforms and other technologies of interest for significant aspects of sea transport, other than speed, range and payload. While the methods used are generic, the data selected and results presented are aimed at ships capable of rapidly transporting heavy cargo over long distances.
Helical Turbines for the Gulf Stream: Conceptual Approach to Design of a Large-Scale Floating Power Farm
Authors: Gorlov Alexander M.
Published: January 2021

This paper describes the helical turbine as an efficient new instrument for converting the kinetic energy of hydro streams into electric or other mechanical energy. A multi-megawatt project is proposed, conceived as an ocean power farm equipped with a number of helical turbines, along with a floating factory for in situ production of hydrogen fuel by means of electrolyzing ocean waters. Besides mega hydro-power farms, mini-power stations with helical turbines of a few kilowatts each are also proposed as possibilities for small communities or even individual households located near tidal shorelines or river banks with strong water currents. No construction of hydro dams is necessary for such applications.
A New Preservation Protocol for Seawater Ballast Tanks in Naval Applications
Authors: Kikuta Miles Y.
Published: January 2021

The reality that a smaller force must continue to meet heavy overseas commitments clearly indicates that high maintenance, manpower intensive, and costly repair processes must continue to be improved. One of the most significant maintenance problems identified by the Fleet was the continual and costly requirement to overhaul the coating system in seawater ballast tanks. This paper reports on the research conducted in conjunction with the Naval Sea Systems Command (NAVSEA) to develop a seawater ballast tank preservation protocol which extends the current 5 to 7 year coating service life to one that is expected to last 20 years. The approach to develop the new preservation protocol is discussed, the critical elements of the new preservation protocol are described, and methodologies for the design of sacrificial cathodic protection system for seawater ballast tanks and for the detection of surface contamination are provided.
SQIS: A Framework for the Development and Implementation of an Industry-Wide Ship Quality Information System
Authors: Reeve Henry P. , Bea Robert G.
Published: January 2021

The Ship Structural Integrity Information System Phase III (SSIIS III) Project presents the framework for the development of an Industry-Wide Ship Quality Information System (SQIS) for use in the United States oil tanker trade. This full-scope, life-cycle, industry-wide information system provides the basis for the development of risk based inspection, maintenance, and repair (IMR) activity management tools, intended to supplement those in development by industry members. The SQIS combines information concerning structures, machinery, and operations, and provides analysis of the links between all facets of vessel management. The cooperation of all sectors of the marine community is paramount to the successful implementation of a Industry-Wide SQIS. The recommendations and requirements of interested parties have been incorporated into the development of the SQIS framework. The organizational requirements for the development and implementation of the full scale Industry-Wide SQIS have been identified.
Subdivision of RO/RO Ships for Enhanced Safety in the Damaged Condition
Authors: Pawlowski Maciej
Published: January 2021

The paper shows that ROZRO ships can be as safe in the damaged condition as other ship types without restricting their design features, i.e., with no transverse and/or horizontal subdivision within the cargo space liable to damage, if there are provisions for reserve buoyancy above the vehicle deck—the first deck above the deepest waterline. For this purpose, these ships should embody a double hull over the entire length of the cargo part of the ship, terminated at the second deck above the waterline and, in addition, double decks at least the first deck above the waterline, preferably inclined upwards in the longitudinal direction. The double hull and double decks should be sufficiently densely subdivided by watertight bulkheads into watertight compartments, the former preferably cross-connected and of a breadth less than BZ5. Cargo spaces below the double decks should be provided with efficient air escapes for removing air cushions from the undersides of the decks. A deck (or decks) if any, below the first deck above the waterline, along with this deck should be designed as opened to the passage of flooding water, incorporating efficient down-flooding arrangements.
Discussion on Kitamura: "Comparative Study on Collision Resistance of Side Structure"
Authors: Woisin Gerhard
Published: January 2021

Dr. Kitamura presented some data on the collision damage experienced by seven different designs of the sidewall of a VLCC the instant before rupture is initiated in the outer, and then, inner side shell. The data were gathered by FEM calculations assuming a deformable sidewall and a rigid bulbous bow. However, the transferability of the published FEM results to real ships, and thus also the validity of the comparisons, does not appear to be reliable. This discussion outlines my reasoning and offers a solution for similar projects in the future.
The Harmonization of Polar Shipping Requirements
Authors: Kendrick Andrew
Published: January 2021

An unprecedented international initiative is underway to develop a comprehensive system to enhance the safety of all aspects of ship operations in polar waters. This involves a working group of the International Maritime Organization (IMO), and another from the International Association of Classification Societies(IACS), developing IMO Guidelines and a parallel set of classification society Unified Requirements. This paper presents an overview of the process, and describes some of the key issues for the various countries, industries, and other players involved in the process.
Optimized Alignment of a USCG Polar Class Icebreaker Wing Shaft Using a Distributed Bearing Finite-Element Model
Authors: Reeves John D. , Vlahopoulos Nickolas
Published: January 2021

There are indications that new analytical techniques must be employed for determining and optimizing the shaft alignment of the wing shafts of the U.S. Coast Guard's Polar Class icebreakers. These indications include failing shaft coupling bolts and excessive stress concentration factors in the shaft. Current design practices dictate the use of point bearing loads for both design and realignment analysis of propulsion shafts. In this work, a general purpose finite-element code is utilized for modeling the shaft. The bearings are modeled as flexible distributed supports. A public domain optimization routine is coupled to the analysis for determining the optimum shaft alignment. The new process is validated, and then utilized for analyzing the USCG Polar Class ice-breaker wing shafts. Results are presented and discussed.
The Prediction, Measurement, and Analysis of Wake Wash from Marine Vessels
Authors: Stumbo Stan , Fox Kenneth , Dvorak Frank , Elliot Larry
Published: January 2021

In the marine environment, wake wash from passing vessels can be detrimental to a shoreline environment, damage shoreline property and disturb or damage other marine operations. Slowdowns to prevent such impact can hamper or curtail high-speed vessel operations that depend on speed for successful service. To prevent this failure, low-wash vessel designs are needed and success must be assured before significant dollar investments are made. This paper describes establishment of "no harm" wash criteria, prediction of wash using computational fluid dynamics for various speeds of high-speed aluminum catamarans, techniques of measurement and analysis of the wash from actual vessels, and agreement between wash predictions and wash measurements. This paper documents a successful program which Washington State Ferries used to procure new, high-speed environmentally friendly passenger ferries for operation on Puget Sound.
Hazard and Risk in the New England Fishing Fleet
Authors: Dyer Michael G.
Published: January 2021

The United States Coast Guard and the Volpe National Transportation Systems Center studied the 102 serious fishing vessel accidents (1993–1997) in Coast Guard District 1 (New England and Long Island, New York), U.S. national fleet accident data, and international fishing vessel safety programs for the purpose of establishing risk factors and formulating options for future action by the Coast Guard to enhance fleet safety. The 102 regional accidents involved total vessel losses and/or death(s), excluding strictly occupational cases. Each accident was studied in detail to determine causality among human and organizational, fishery and operational, and preventive safety factors. Causality in each case was assigned among the factors, summing to 1.0 and weighted according to the outcome of the accident, i.e., numbers of deaths and injuries. The results quantify (1) the aggregate "significance" of the causal factors; (2) the average weighted outcome of accidents by type (e.g., capsize, collision); and (3) the sensitivity of (1) and (2) to varied relative weightings of vessel losses and deaths.
Damage Stability Characteristics of Model RO/RO Ferries
Authors: Ross Carl T. F. , Stothard Simon , Slaney Andrew
Published: January 2021

The paper reports on experimental investigations which have been made on four model RO/RO ferries. One of these was based on a 1/100th scale model of the Herald of Free Enterprise. Two of the other models were modified versions of the Herald of Free Enterprise, which were so modified that they did not decrease the efficient concept of the vehicle throughput of a conventional vessel. The tests revealed that the capsize times of these modified RO/RO vessels were increased by 350% for one vessel and 500% for the other vessel. The modified vessels should meet SOLAS 90 + 50 regulations. A fourth model was fitted with two equally spaced transverse bulkheads. This model also had good damage stability characteristics. The paper also summarizes the history of some of the past RO/RO ferry disasters.
Discussion on Ross et al: “Damage Stability Characteristics of Model RO/RO Ferries”
Authors: Bjödrkman Anders
Published: January 2021

I have read this paper with great interest. The following observations may be of interest. It is correct that the Estonia sank in about 40 minutes, but if it was caused by water collected on top of the car deck as suggested in [1] is not certain. Reference [1] actually says that water started to come in on the car deck at 01.14 hours, when the ramp was dislodged by the loose visor, and that small amounts of water started to enter, resulting in a 3-dug list. Then it is suggested that the visor fell off at about 01.15 hours, pulling the ramp fully open and allegedly larger amounts of water came in--250 tons/minute--resulting in a sudden 15-deg list. Then the water inflow stopped--the list was constant for several minutes--which enabled about 300 persons inside to evacuate the ship to open deck no. 7. Finally, more water allegedly started again to enter on top of the car deck so that the list increased, but the vessel never capsized, which you would have expected. With 2000 tons of water on the car deck you would have expected that the ship would have turned turtle and floated upside down. The inflow rate is not clear in [1]. One calculation (supplement no. 522) says it took 28 minutes for 2000 tons to enter, another (supplement no. 523) that it should have taken 2 minutes--in both cases the ship capsizes.
Design of a 33-Knot Aluminum Catamaran Ferry
Authors: Latorre R. G. , Herrington P. D.
Published: January 2021

This paper presents the results of an investigation on the suitability of using hull panels with alternating fixed and floating frames for a 30–40 knot aluminum catamaran ferry. A prototype 4.6 m × 1.8 m bottom hull panel with alternating frames is analyzed numerically and physically tested. The corresponding finite-element analyses and test results are in good agreement. The results show that the floating frame hull panel design is a feasible structure for an aluminum catamaran. The floating frame structure was then used for a 33-knot, 250-passenger aluminum catamaran ferry designed to meet the ABS High Speed Craft rules. A midship section of the catamaran hull was analyzed using the finite-element method. Catamaran weight estimates, heave and pitch motions, and powering estimates are also provided. The results show that the alternating floating frame structure was within the ABS rules stress allowables.
A Concept of the Triple-Hull Frigate
Authors: Dubrovskiy Victor A.
Published: January 2021

Ships with outriggers, such as multihull vessels, are defined and their advantages and disadvantages described. The general feasibility of a hull with a small waterplane area is considered as a method for development of an outriggered frigate design. The main dimensions, general arrangement, and hull structure of this design are offered along with calculations of initial transverse stability, longitudinal bending moment in waves, wetted area, residual resistance coefficient of the single hull, as well as the hydrodynamic interaction of the main hull with the outriggers.
Dynamic Instability of a High-Speed Planing Boat Model
Authors: Thornhill Eric , Veitch Brian , Bose Neil
Published: January 2021

A series of bare-hull resistance and self-propulsion tests were carried out on a 1/8 scale model of a 11.8 m long, waterjet-propelled planing hull in the clear water towing tank at the National Research Council of Canada's Institute for Marine Dynamics. The bare-hull resistance tests, performed with the waterjet inlets closed, spanned a range of eight model velocities and nine ballast conditions consisting of three displacements each with three positions of the longitudinal center of gravity. The hull was then fitted with two model waterjet thrusters and tested over the same speeds and ballast conditions. Dynamic instability, or porpoising, was seen during certain high-speed tests. A discussion of this behavior and its relation to published dynamic stability limits is given.
The Cogito Project: Design and Development of an International C-Class Catamaran and Her Successful Challenge to Regain the Little America’s Cup
Authors: MacLane Duncan T.
Published: January 2021

In January 1996, Cogito, the U.S. challenger, defeated the Australian defender, Yellow Pages Edge, by the score of 4–0 in the 22nd running of the International Catamaran Challenge Trophy. This brought the trophy, better known as the Little America's Cup, back to the United States after an eleven-year stay in Australia. The Cogito project was three years in length and encompassed the design/construction phase, initial sailing and tuning at her home, the Bristol Yacht Club in Bristol, Rhode Island, and the final training and competition at the race venue, McCrae Yacht Club on Port Philip Bay south of Melbourne, Australia. This paper will cover all phases of the project from the design through the racing.
Drawbacks of the Present System of Unified Requirements for Ship Hull Global Strength and Potential Ways to Rectify Them
Authors: Boitsov G. V. , Koudrin M. A.
Published: January 2021

This paper considers inadequacies in the formulas for ship global hull strength currently approved by members of the International Associations of Classification Societies (IACS). Citing the results of several experimental and numerical studies, the author proposes modifications to the Rules formulas on ship hull vertical bending moments. Wave loading on the hull under steady wave conditions is studied for long-term ship operations, and the existing fatigue strength standards for hull longitudinals are also examined.
The U.S. Navy Afloat Solid Waste Management Challenge
Authors: Markle Stephen P. , Gill Sean E. , McGraw Peter S.
Published: January 2021

The U.S Navy has developed and implemented a comprehensive Solid Waste Management Program to comply with "Act to Prevent Pollution from Ships" (Title 33 United States Code Chapter 33), as amended, which ratified "International Convention for the Prevention of Pollution from Ships" (MARPOL 73/78). Through this program, the U.S. Navy is backfitting its surface fleet with plastic waste processors, pulpers, and shredders to manage nonhazardous solid waste by 31 December 2000. Future Navy ship designs are building upon the lessons learned from the fleet modernization process and are pushing technology to achieve the Chief of Naval Operations, Director Environmental Protection, Safety and Occupational Health (CNO N45) vision for the environmentally sound ship of the 21st century. Evolutionary development of waste transport systems and thermal destruction technologies are essential for realizing this vision. This paper provides an overview of the program and a glimpse of future expectations for management of solid waste through the Navy Integrated Waste Management System. The cornerstone of this system is a compact Plasma Arc Waste Destruction System capable of destroying solid waste, liquid waste, oily waste, and medical waste.
Complex Comparison of Seakeeping: Method and Example
Authors: Dubrovskiy V. A.
Published: January 2021

A method of seakeeping comparison, proposed originally by author in 1978, offers the possibility of taking into account all limitations of speed in waves and other ship characteristics, including motion amplitudes, accelerations at any point, slamming, deck wetness and bending moments for every type of ship. General characteristics of seakeeping are presented as one number for needed sea or for average conditions of the world's oceans. An example of the comparison is presented for two small-sized ships: a catamaran and a twin-hulled ship of small waterplane area (SWATH). Results of systematic calculations for naval ships in the North Atlantic are also presented.
Further Discussions on Ross et al: “Damage Stability Characteristics of Model RO/RO Ferries”
Authors: Turner James E. , Harris F. J.
Published: January 2021

I have read, with interest, the proposals put forward in this paper for reducing the probability of a RO/RO ship capsizing in the event of flooding of the vehicle deck. The results of the model tests in which the underdeck tank was subdivided by longitudinal bulkheads showed that, compared with the " conventional ship," flooding of any combination of compartments produced a considerable reduction in list angle for a greater ingress of water. Such results are much as expected since the reduction in free-surface effect associated with the subdivision of a tank by longitudinal bulkheads is well known. However, these experiments did highlight the problems associated with the flooding of wing compartments. For both the six- and nine-compartment models, flooding of wing compartment No. 1 alone produced very large list angles. Thus, the idea of the authors to fit quick-acting high-capacity pumps in each compartment is seen to be essential.
Seventh International Conference on the Stability of Ships and Ocean Vehicles (STAB’ 2000)—A Review
Authors: Belenky Vadim L.
Published: January 2021

A brief review is given of the papers presented at the 7th International Conference on the Stability of Ships and Ocean Vehicles, held 7–12 February 2000 in Launceston, Australia. The review covers the following stability-related subjects: human factors, stability standards, operational aspects, influence of water on deck, damage stability, stability in following and quartering seas, stability of high-speed craft and sailing yachts, nonlinear dynamics of ships, test procedures, roll stabilization and cargo shift, waves and the environment, rolling in beam seas and stability of particular types of ships.
On the Nature of the Transport Factor Component TFship
Authors: Kennell Colen
Published: January 2021

This paper presents a revised empirical model for TFship, the Transport Factor component related to empty ship weight. Empty ship weight is shown to be dependent on a ship volume parameter, "deadweight density," that relates the sum of cargo and fuel weight to the sum of cargo and fuel volume. The revised model is compatible with Transport Factor analyses that assess transport properties of ship types of interest for high-speed sealift. Applicability is limited to displacement and semi-displacement monohulls and catamarans.
An Approximate Method for Cross Curves of Cargo Vessels
Authors: Yilmaz Huseyin , Giiner Mesut
Published: January 2021

In this study, a formula is presented to estimate cross curves of cargo vessels and to predict statical stability at the preliminary design stage of the vessel. The predictive technique is obtained by regression analysis of systematically varied cargo vessel series data. In order to achieve this procedure, some cargo vessel forms are generated using Series-60. The mathematical model in this predictive technique is constructed as a function of design parameters such as length, beam, depth, draft, and block coefficient. The prediction method developed in this work can also be used to determine the effect of specific hull form parameters and the load conditions on stability of cargo vessels. The present method is applied to a cargo vessel and then the results of the actual ship are compared with those of regression values.
Selection of the Power Plant for an Alaskan RO/RO Ship
Authors: Boylston John , Brooks Michael
Published: January 2021

In 1996 TOTE began a Maritech project with NASSCO aimed at looking at replacement tonnage for their existing fleet of steamships. The Maritech study started with a single-screw, slow-speed diesel ship that in essence would have been a lengthened Pfeiffer containership. Between the capacity and speed requirements of the trade, it became evident that a twin-screw ship was required with greater beam than the Pfeiffer. It was also clear that the short run of the ships heightened the relationship between port time and sea speed, and that from a cargo load and discharge time, certain machinery arrangements were more favorable than others. The original 17 power plant options were reduced to four options that were studied in detail. This paper endeavors to document the decision process and the economic and operational comparisons that were made.
Estimate of the Ultimate Load on Structural Members Subjected to Lateral Loads
Authors: Belenkiy L. , Raskin Y.
Published: January 2021

This paper examines plastic behavior of typical ship structures, specifically beams, grillages, and plates subjected to predominantly lateral loads. The ultimate loads, determined on the basis of the theorems of limit analysis [1,2], are evaluated using nonlinear finite-element plastic analysis. The relationships between analytical and finite-element models for prediction of ultimate loads of beams, stiffened panels, and grillages are illustrated. It has been shown that the ultimate loads, obtained from the theorems of limit analysis, can be successfully used for strength assessment of stiffened ship structures subjected to lateral loads. The effect of shear force on ultimate load is analyzed using the finite-element method. This paper confirms that in the case of beams and grillages under lateral loading, the ultimate load may characterize the threshold of the load at which a stiffened ship's structure fails by the development of excessive deflections. For plate elements, on the other hand, the plastic deflections represent the permissible limit of external load better than the ultimate limit load.
SWATH Research Vessel Hull Strength Upgrade
Authors: Van Slyke Robert J. , Morgan Justin M. , Leach Timothy S. , Etchemendy Stephen A.
Published: January 2021

The Monterey Bay Aquarium Research Institute (MBARI) owns and operates the SWATH oceanographic research vessel RV Western Flyer. This vessel is of aluminum construction and was designed and built (as reported in Ref 1) to handle MBARI's remotely operated vehicle (ROV) Tiburon in the Eastern Pacific. Western Flyer was delivered in 1996 and shortly thereafter experienced significant cracking when exposed to relatively moderate seas. This paper outlines the steps that were taken to assess the causes of the cracks and the process used to determine the necessary modifications. The vessel was redelivered in the summer of 1999 and has returned to scientific missions.
Risk-Based Technology Method for the Safety Assessment of Marine Compressed Natural Gas Fuel Systems
Authors: Wilcox Robb , Burrows Mark , Ghosh Sujit , Ayyub Bilal M.
Published: January 2021

The introduction of alternative fuels (other than diesel oil or gasoline) for some commercially operated marine vessels presents a problem to marine regulators and designers since accepted standards and U.S. Coast Guard policy have not been established. Establishing safe design criteria is a common problem with the introduction of new technologies, novel concepts, and complex systems. In order to determine design safety for novel marine concepts such as compressed natural gas (CNG) fuel, a formal system safety approach may be used. Risk-based technologies (RBT) provide techniques to facilitate the proactive evaluation of system safety through risk assessment, risk control, risk management, and risk communication. The proposed outfitting of a CNG fuel system on the Kings Pointer training vessel is discussed as a specific marine application of CNG fuel and an appropriate situation for applying system safety techniques.
Control of VOC Emissions from Crude Oil Tankers
Authors: Martens Otto M. , Oldervik Ole , Neeraas Bengt Olav , Strom Terje
Published: January 2021

Results from a preliminary study on some concepts for the prevention of VOC emissions from crude oil tankers are presented, with special reference to shuttle tankers and floating production units. The evaporation rate of the individual volatile hydrocarbon components as well as gas volume flow and gas composition during loading and discharging of crude oil cargo are modeled and computed by means of a comprehensive simulation program. Emission is controlled through a series of optional combinations of control techniques, including depression of evaporation at the outset through sequential transfer of tank atmosphere (STTA), condensation of oil vapor, and absorption of oil vapor in the cargo oil.
An Efficient Single-Screw 11 000 TEU Containership: The Suez Max SS
Authors: Rosello B. J. , Perakis A. N.
Published: January 2021

The ability to transport containers with the least cost at currently required service speeds of approximately 25 knots to maintain a regular operating schedule is the goal of every post-panamax containership operator. The desire to carry more containers is driven by several economies of scale and their implications, which allow for significant savings. A single-screw containership, the Suez Max SS, is designed and evaluated against existing designs that include the P & O Nedlloyd Southhampton, Maersk S-Class, and the twin-screw Suez Max, which is a concept vessel. The containerships are compared using several different ratios and a cost per 20-ft equivalent unit (TEU) evaluation. The design of the Suez Max SS was built to the maximum draft currently allowed by the Suez Canal Authority. An initial stability analysis is performed that utilizes five different container loading conditions. A cost analysis that involves capital, operating, port, and fuel costs and Suez Canal fees is also completed. The four vessels are evaluated on a round-trip schedule between the ports of Rotterdam and Singapore with the same voyage characteristics and conditions. The Suez Max SS is found to be a more economical design with savings of approximately 25% over the existing vessels and a 15% savings over the concept vessel evaluated in the cost analysis. The Suez Max SS utilizes its economies of scale and the advantages of a two-port schedule that allow it to be such a cost-efficient design.
Torsional Vibration of a Damped Shaft System Using the Analytical-and-Numerical-Combined Method
Authors: Wu Jong-Shyong , Hsieh Mang
Published: January 2021

Torsional vibration analysis of the propulsive shaft system of a marine engine—one of the most important tasks in preliminary ship design—is carried out today by either the Holzer method, the transfer matrix method (TMM), or the finite-element method (FEM). Of the three methods, Holzer is the most popular and is adopted by shipyards worldwide. The purpose of this paper is to present an analytical-and-numerical-combined method (ANCM) to improve the drawbacks of existing methods. In comparison with the Holzer method (or TMM), the presented ANCM has the following merits: the mass of the rotating shaft is inherently considered, the damping effect is easily tackled, and the forced vibration responses due to various external excitations are obtained with no difficulty. Since the order of the overall property matrices for the equations of motion derived from the ANCM is usually lower than that derived from the conventional finite-element method (FEM), the CPU time required by the former is usually less than that required by the latter, particularly in the forced vibration analysis. Besides, the sizes (and the total number) of the elements for the FEM have a close relationship with the locations of the disks and the dampers and so does the accuracy of the FEM, but various distributions (or locations) of the disks and the dampers will not create any problems for the ANCM.
Low-Emission Medium-Speed Diesel Engines
Authors: Koehler Horst W. , Windelev Claus
Published: January 2021

In today's environmentally aware society the large-bore diesel engine is not alone in coming under scrutiny. Although only 0.25 to 0.35% among the total exhaust gases produced by this type of engine are toxious compounds, even such small amounts still need to be reduced further. MAN B&W Diesel, market leaders in the production of large-bore two-and four-stroke diesel engines covering the output bracket between 680 hp and almost 100 000 hp per engine (Fig. 1), have been facing up to this challenge for almost a decade. Taking state-of-the-art MAN B&W four-stroke engines as its example, this paper outlines the causes and effects of the major pollutants, including carbon dioxide, the "greenhouse gas," and describes some of the options available for reducing them [1]. The NOx emission control measures implemented in the current generation of MAN B&W diesel engines ensure that they comply with statutory emission limits. Since the time this paper was compiled (January 2000) much progress has been achieved in reducing pollutant emissions from diesel engines, in particular as regards smoke emissions from cruise vessels slow-steaming in strictly protected tourist areas. As an example the authors' company introduced an IS version (IS = invisible smoke) for their largest medium-speed diesel engines in September 2000, featuring invisible exhaust plumes in transient operation between idling and full load. Fig. 1MAN B&W slow-speed and medium-speed diesel engine program (status: 1999)
Bayesian and Neural Networks for Preliminary Ship Design
Authors: Clausen H. B. , Lu¨tzen M. , Friis-Hansen A. , Bjørneboe N.
Published: January 2021

To ease the determination of the main particulars of a ship at the initial design stage it is convenient to have tools which, given the type of ship and a few other parameters, output estimations of the remaining dimensions. To establish such a tool, a database of the characteristics of about 87 000 ships is acquired and various methods for derivation of empirical relations are employed. A regression analysis is carried out to fit functions to the data. Further, the data are used to learn Bayesian and neural networks to encode the relations between the characteristics. On the basis of examples, the three methods are evaluated in terms of accuracy and limitations of use. For different types of ships, the methods provide information on the relations between length, breadth, height, draft, speed, displacement, block coefficient and loading capacity. Thus, useful tools are available to the designer when he chooses the preliminary main characteristics of a ship.
Fatigue Prediction Verification of Fiberglass Hulls
Authors: Miller Paul H.
Published: January 2021

The growing use of marine composite materials has led to many technical challenges and one is predicting lifetime durability. This analysis step has a large uncertainty due to the lack of data from in-service composite vessels. Analytical models based on classical lamination theory, finite-element analysis, ship motions, probability and wind and wave mechanicswere used in this project to predict hull laminate strains, and fatigue tests were used to determine S-N residual stiffness properties of coupons. These predictions and test data were compared against two cored fiberglass sisterships having significantly different fatigue histories and undamaged laminates representing a new vessel. Strains were measured while underway and good correlation was achieved between predictions and measurements. Fatigue damage indicators were identified which could be used in vessel inspection procedures. Endurance limits were found to be near 25% of static failure load, indicating that a fatigue design factor of four is required for infinite service with this material. Standard moisture experiments using boiling water were compared with long-term exposure. Results indicated the boiling water test yielded significantly conservative values and was not a reliable means of predicting long-term effects. Panel tests were compared with a combined coupon and finite-element procedure. Results indicated the proposed procedure was a viable substitute, at least for the materials studied. A rational explanation for using thicker outer skin laminates in marine composites was identified through single-sided moisture flex tests. These showed that the reduced strength and stiffness due to moisture of the outer hull skin laminate could be compensated by increased thickness. Although the resulting unbalanced laminate is not ideal from a warping standpoint, the approach leads to consistent tensile failure of the inner skin when subjected to normal loads. Permeability considerations make this desirable for hull laminates.
Design of the Schooner Denis Sullivan
Authors: Pudlo Mark D.
Published: January 2021

The design of the three-mastered schooner Denis Sullivan is presented, with discussion of the vessel's origin and purpose, design background, regulatory issues, arrangement, performance and construction. Specific features of the design considered noteworthy are discussed, including structural criteria, tonnage, machinery, stability, watertight doors and launching.
CNC Robotic Manufacturing of Large Shapes for Fiberglass and Composite Production Tooling
Authors: Blount Donald L. , Blount Douglas L. , Blount William L.
Published: January 2021

A computer numeric controlled (CNC) robotic machining capability has demonstrated the capacity to manufacture large, unique shapes which are utilized for fabrication of industrial molds and tooling for fiberglass and composite parts. Single parts as large as 25 m × 4.6 m × 2.9 m (82 ft × 15 ft × 9.5 ft) can be machined from low-density materials by two 7-axis CNC robots operating from parallel tracks. Large parts can be assembled by joining several pieces. This capability demonstrated that rapid prototyping is possible via both limited production and full production tooling/molds being machined from surface and/or solid computer models. The paper also includes an overview discussion of prototype production methods that have evolved in the boating and yacht building industries in recent years. Factors influencing decisions for the equipment and materials selected are discussed. The process is discussed from design to manu-facture of a plug suitable for fabricating a production mold.