Recent Coast Guard Research into Vessel Stability

1974 ◽  
Vol 11 (04) ◽  
pp. 329-339
Author(s):  
D. M. Bovet ◽  
R. E. Johnson ◽  
E. L. Jones
Keyword(s):  
Coast Guard ◽  
Stability Criteria ◽  
Fishing Vessel ◽  
Following Seas ◽  
Intact Stability ◽  
Passenger Ships ◽  
Computer Simulation Program ◽  
General Cargo ◽  
The University ◽  
Vessel Stability

The paper outlines the development of intact stability criteria for U. S. merchant vessels. Present stability criteria for passenger ships, general cargo ships, tugboats, etc. as well as stability criteria recommended by the Intergovernmental Maritime Consultative Organization are discussed. The paper describes the research into intact stability phenomena that is being sponsored by the U. S. Coast Guard. Results and the scope of the programs at the University of California at Berkeley to investigate ship stability in a seaway and Hydronautics, Inc. to investigate tugboat and fishing vessel stability and the applicability of present criteria are presented. The last section of the paper describes a computer simulation program developed by one of the authors to predict capsizing in following seas.

Assessing Intact Stability

1980 ◽  
Vol 17 (02) ◽  
pp. 163-173
Author(s):  
William A. Henrickson
Keyword(s):  
Energy Balance ◽  
Coast Guard ◽  
Assessment Methods ◽  
University Of Michigan ◽  
Stability Criteria ◽  
Intact Stability ◽  
The University ◽  
Righting Moment

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

Sailing Vessel Stability—with Particular Reference to the Pride of Baltimore Casualty

1989 ◽  
Vol 26 (02) ◽  
pp. 87-104
Author(s):  
Howard A. Chatterton ◽  
John C. Maxham
Keyword(s):  
Coast Guard ◽  
Critical Element ◽  
Stability Criteria ◽  
Safe Operation ◽  
Intact Stability ◽  
Velocity Relationship ◽  
Small Craft ◽  
Vessel Stability ◽  
Relationship Of ◽  
The U.S

Stability is a critical element in the design and safe operation of sailing vessels. This paper discusses U.S. Coast Guard requirements for the intact stability of sailing vessels with emphasis on wind heel and dynamic stability criteria for passenger and sailing school vessels. The effects of deck edge immersion, downflooding angle, range of stability and intended route are examined in detail. The righting energy and wind velocity relationship of the U.S. Navy's small craft criteria is analyzed and applied. The Pride of Baltimore casualty is reviewed as an example of wind effects on a sailing vessel under various conditions of sail.

scholarly journals Implementation of the IMO Second Generation Intact Stability Guidelines

2021 ◽  
Vol 10 (1) ◽  
pp. 41
Author(s):  
Kyle E. Marlantes ◽  
Sungeun (Peter) Kim ◽  
Lucas A. Hurt
Keyword(s):  
Second Generation ◽  
Practical Implementation ◽  
Container Ship ◽  
Stability Criteria ◽  
Fishing Vessel ◽  
Intact Stability ◽  
Industry Collaboration ◽  
Comparison Of The Results

This paper provides a discussion of the technical and theoretical ambiguities, requirements, and limitations to develop a practical implementation of the IMO Second Generation Intact Stability criteria. This discussion is the result of industry collaboration, where two implementations of the guidelines were developed jointly, albeit independently. Both implementations were then used to assess four sample cases: C11 container ship, KRISO container ship (KCS), barge, and fishing vessel, for which the detailed particulars and results are given. Conclusions on the practicalities of use, a comparison of the results, and suggestions on how the criteria might be integrated into a workflow are also given.

A Systematic Study of Wave Phasing on Righting Arm Curves for Fishing Vessels

2005 ◽  
Author(s):  
John Womack ◽  
Bruce Johnson
Keyword(s):  
Software Package ◽  
Cost Effective ◽  
Future Research ◽  
Stability Criteria ◽  
Fishing Vessel ◽  
Fishing Vessels ◽  
Software Packages ◽  
Wave Effects ◽  
Vessel Stability ◽  
Naval Architect

This paper summarizes the results from the SNAME funded T&R grant titled Preliminary Development of the Next Generation of Stability Criteria for Small Fishing Boats. The principal goal of this project was to take a broad look at effects of head and following waves on the current still water based stability evaluation methods to focus the needs for future research in the development of new performance based stability criteria. The wave effects were calculated using an off the shelf naval architect software package of the type typically used in small fishing vessel stability evaluations to explore the ability of these software packages to perform cost effective meaningful stability research. The use of the off the shelf naval architect software package also allowed the authors to explore new performance based stability criteria formats that utilized software and basic concepts already available to the naval architect.

Investigation of the 2nd Generation of Intact Stability Criteria for Ships Vulnerable to Parametric Rolling in Following Seas

2013 ◽  
Author(s):  
Stefan Krüger ◽  
Hannes Hatecke ◽  
Heike Billerbeck ◽  
Anna Bruns ◽  
Florian Kluwe
Keyword(s):  
Dynamic Stability ◽  
Direct Calculation ◽  
Stability Criteria ◽  
Parametric Rolling ◽  
Following Seas ◽  
2Nd Generation ◽  
Direct Assessment ◽  
Intact Stability ◽  
New Criteria ◽  
Level 2

The existing IMO intact stability criteria (IS-Code 2008) do not generally provide sufficient safety against dynamic stability failures such as parametric rolling for modern ships. Therefore, new stability criteria have been developed by IMO / SLF. These so-called Second Generation Stability Criteria shall ensure sufficient dynamic stability. The criteria are structured in a three level approach, where the first level consists of quite simple formulae. If a ship does not pass the first level, it is assumed that the ship is vulnerable to the phenomenon addressed, and the second level of criteria shall then be applied. This level consists of computations which are a little more complex, but they still treat the problems addressed in a strongly simplified manner. If now the ship does not pass the second level, a third level shall be applied to ensure that the ship can be designed and operated safely. This third level consists of direct calculation methods which shall be applied, however no criteria or procedures have yet been developed for this third level. We have applied the level 1 and level 2 criteria to a reference ship where a direct stability assessment has been performed during the design. The results showed extremely large scatter in the required GM-values of the criteria, and none of the criteria showed GM values roughly comparable to the direct assessment. The paper shows why the application of the criteria is challenging for the design of RoRo-ships and why a third level (direct assessment) is urgently required before the first two levels are put into force. Some conclusions are also drawn for the possible treatment of the new criteria in a stability booklet.

An Evaluation of Intact Stability Criteria

1978 ◽  
Vol 15 (03) ◽  
pp. 259-265
Author(s):  
George C. Nickum
Keyword(s):  
Coast Guard ◽  
Stability Criteria ◽  
Fishing Vessels ◽  
Intact Stability

Coast Guard and Navy intact stability criteria which were in existence in 1952 are described. The evolution of the IMCO criteria for fishing vessels and for all other vessels under 100 m (328 ft) in length and of the Coast Guard criteria for offshore supply vessels and towing vessels is described. The conclusion is reached that these criteria properly applied are adequate to ensure stability for seagoing vessels.

scholarly journals Intact Stability of Historic Passenger Ships in Light of the Second Generation Intact Stability Criteria

2021 ◽  
Vol 163 (A1) ◽  
pp. 119-130
Author(s):  
I Bačkalov ◽  
S Rudaković ◽  
M Cvijović
Keyword(s):  
Second Generation ◽  
Point Of View ◽  
Stability Assessment ◽  
Stability Criteria ◽  
Cruise Ships ◽  
Design Changes ◽  
Intact Stability ◽  
Passenger Ships ◽  
The Dead ◽  
Dead Ship Condition

The paper examines the intact stability of historic passenger ships from the point of view of the contemporary notion of the intact stability, i.e. the Second Generation Intact Stability Criteria (SGISC) framework. An intact stability assessment using the Vulnerability Level 2 calculation procedures of SGISC for the dead ship condition was performed on four ocean liners: RMS Titanic, RMS Queen Mary, SS United States and SS Michelangelo, and two cruise ships: MS Song of America and MS Costa Concordia. In addition, the intact stability of the selected ships was appraised using the present-day mandatory intact stability requirements contained in the 2008 Intact Stability Code. The selected ships are believed to be good representatives of the main trends in passenger ship design over a one-hundred-year span bounded by two well-known maritime catastrophes: the sinking of the Titanic in 1912 and the Costa Concordia disaster in 2012. The paper offers an insight into how major design changes have affected the intact stability properties of passenger ships over this period. It was found that the examined ocean liners would perform well in terms of intact stability in the dead ship condition even from the point of view of the SGISC. The analysis also confirmed the advantages of the approach using the SGISC framework over simplified, (semi)empirical stability assessment methods. By looking into the evolution of the intact stability of ocean liners and cruise ships from the contemporary perspective, the paper draws the conclusions which are considered useful for the design of future passenger ships.

Sailing Ship Intact Stability Criteria

1996 ◽  
Vol 33 (03) ◽  
pp. 218-232
Author(s):  
Chris Cleary ◽  
John C. Daidola ◽  
Christopher J. Reyling
Keyword(s):  
Coast Guard ◽  
Ship Motion ◽  
Large Displacement ◽  
Stability Criteria ◽  
Intact Stability ◽  
Improved Stability ◽  
Design Requirements ◽  
Sailing Ship ◽  
The U.S

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.

Evaluation of the Dynamic-Response-Based Intact Stability Criterion for Floating Wind Turbines

2015 ◽  
Author(s):  
Marco Masciola ◽  
Xiaohong Chen ◽  
Qing Yu
Keyword(s):  
Wind Speed ◽  
Dynamic Response ◽  
Wind Turbines ◽  
Stability Criterion ◽  
Area Ratio ◽  
Operating Conditions ◽  
Dynamic Responses ◽  
Stability Criteria ◽  
Intact Stability ◽  
Overturning Moment

As an alternative to the conventional intact stability criterion for floating offshore structures, known as the area-ratio-based criterion, the dynamic-response-based intact stability criteria was initially developed in the 1980s for column-stabilized drilling units and later extended to the design of floating production installations (FPIs). Both the area-ratio-based and dynamic-response-based intact stability criteria have recently been adopted for floating offshore wind turbines (FOWTs). In the traditional area-ratio-based criterion, the stability calculation is quasi-static in nature, with the contribution from external forces other than steady wind loads and FOWT dynamic responses captured through a safety factor. Furthermore, the peak wind overturning moment of FOWTs may not coincide with the extreme storm wind speed normally prescribed in the area-ratio-based criterion, but rather at the much smaller rated wind speed in the power production mode. With these two factors considered, the dynamic-response-based intact stability criterion is desirable for FOWTs to account for their unique dynamic responses and the impact of various operating conditions. This paper demonstrates the implementation of a FOWT intact stability assessment using the dynamic-response-based criterion. Performance-based criteria require observed behavior or quantifiable metrics as input for the method to be applied. This is demonstrated by defining the governing load cases for two conceptual FOWT semisubmersible designs at two sites. This work introduces benchmarks comparing the area-ratio-based and dynamic-response-based criteria, gaps with current methodologies, and frontier areas related to the wind overturning moment definition.

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