scholarly journals IMO Second Generation Intact Stability Criteria: General Overview and Focus on Operational Measures

2020 ◽  
Vol 8 (7) ◽  
pp. 494
Author(s):  
Nicola Petacco ◽  
Paola Gualeni
Keyword(s):  
Second Generation ◽  
Methodological Approach ◽  
Ship Design ◽  
Stability Assessment ◽  
Stability Criteria ◽  
Comprehensive Overview ◽  
Complementary Action ◽  
Intact Stability ◽  
Insight Into ◽  
Operational Aspects

At the beginning of 2020, after a long and demanding process, the Second Generation Intact Stability criteria (SGISc) have been finalized at the 7th session of the International Maritime Organization (IMO) sub-committee on Ship Design and Construction (SDC). At present, SGISc are not mandatory, nevertheless IMO endorses their application in order to assess their consistency and validity. It is envisaged that SGISc can support the design of safer ships, nevertheless such a rules framework might have an impact also on the ship operational aspects in a seaway. In fact, within the SGISc framework, Operational Measures have also been implemented providing guidance and limitations during navigation. After a comprehensive overview about SGISc vulnerability levels and direct stability assessment, this paper provides a specific insight into the methodological approach for the Operational Measures extensively addressed as a complementary action to ship design.

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.

Application of the Second Generation Intact Stability Criteria in Initial Ship Design

2014 ◽  
Author(s):  
M. Tompuri ◽  
P. Ruponen ◽  
M. Forss ◽  
D. Lindroth
Keyword(s):  
Second Generation ◽  
Failure Modes ◽  
Ship Design ◽  
Stability Criteria ◽  
Parametric Roll ◽  
Safety Measures ◽  
Main Emphasis ◽  
Intact Stability ◽  
Surf Riding ◽  
Additional Safety

The International Maritime Organization (IMO) is revising the Intact Stability Code. The so-called second generation intact stability criteria will provide additional safety measures against stability failures in waves. The draft regulations for three failure modes, parametric roll, pure loss of stability and surf-riding/broaching are reviewed and sample calculations for a fast RoPax ship are presented. The main emphasis is on the sensitivity of the results to the applied input data, which is not very accurate in the initial design phase. The implementation and effects of the new calculations to the ship design are discussed.

scholarly journals Second Generation Intact Stability Criteria: on the validation of codes for direct stability assessment in the framework of an example application

2013 ◽  
Vol 20 (4) ◽  
pp. 52-61 ◽  
Author(s):  
Gabriele Bulian ◽  
Alberto Francescutto
Keyword(s):  
Vulnerability Assessment ◽  
Second Generation ◽  
Stability Assessment ◽  
Stability Criteria ◽  
Recent Discussion ◽  
Fishing Vessels ◽  
Intact Stability ◽  
Series Of Experiments ◽  
Semi Empirical ◽  
Operational Guidance

ABSTRACT The Sub-Committee on Stability and Load Lines and on Fishing Vessels Safety (SLF) of the International Maritime Organization (IMO) has undertaken the development of so-called “Second Generation Intact Stability Criteria” (SGISC) with the intention of providing a new set of rules covering those phenomena which are not properly covered by present, mostly semi-empirical, requirements. The first two levels of the envisioned 3+1 tiers structure of SGISC are so-called “vulnerability assessment” levels: most of the discussion has so far been dedicated to these levels. At the highest level there is the so-called “Direct Stability Assessment”, which is also strictly linked with the development of ship-specific “Operational Guidance”. Recent discussion on the topic of “Direct Stability Assessment” (DSA) has touched the issue of “validation” of numerical codes to be employed at this level. Stimulated by, and in view of, the ongoing IMO discussion, this paper presents the results of a recent series of experiments in beam waves (mono-/bichromatic, irregular) and associated simulations based on a 6-DOF blended code. Nonlinear harmonic and sub-harmonic resonances are observed and simulated.

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.

Influence of Systematic Hull Shape Variations on Ship Stability Performances in Waves

2020 ◽  
pp. 1-14
Author(s):  
Nicola Petacco ◽  
Giuliano Vernengo ◽  
Diego Villa ◽  
Antonio Coppedé ◽  
Paola Gualeni
Keyword(s):  
Second Generation ◽  
Design Space ◽  
Failure Modes ◽  
Free Form ◽  
Stability Criteria ◽  
Ship Stability ◽  
Parametric Roll ◽  
Modern Approach ◽  
Intact Stability ◽  
Geometric Variation

The sensitivity of ship stability performance in waves to geometric variation has been investigated by means of a simulation-based design framework. The study was devoted to assess the influence of hull geometry variations on some stability failure modes, namely, parametric roll (PR) and pure loss of stability (PLS). The application has been developed by using a representative model of a postpanamax container vessel. PR and PLS phenomena have been investigated by the application of second-generation intact stability criteria (SGISc). The initial multidimensional design space has been filled by 500 design configurations identified by means of a design of experiments approach. A method developed in-house, combining the subdivision surface and free-form deformation approaches, has been used to create the whole set of design alternatives. The generated design configurations have been assessed analyzing the results derived from application of the first- and the second-level SGIS vulnerability criteria for both the selected stability failure modes. To strengthen the correlation behaviors, the design space has then been further explored by using 10k design configurations exploiting the capabilities of a surrogate model-based approximation, relying on a Gaussian process formulation. The study has been focused on the correlations among the variables and the response functions, i.e., the outcomes of the SGIS vulnerability criteria. The significance, in terms of effects, of each geometry shape variable has been investigated. Results have been discussed in the light of the SGISc structure, to provide further insight into this innovative safety framework for a modern approach to intact stability. 1. Introduction In the last 10 years, the development of the so-called second-generation intact stability criteria (SGISc) has been one of the most engaging topics addressed by the Sub-Committee on Safety Design and Construction (SDC) of the International Maritime Organization (IMO).

The Direct Evaluation Method of Dead Ship Stability for Intact Ship

2019 ◽  
Vol 161 (A3) ◽  
Keyword(s):  
Second Generation ◽  
Evaluation Method ◽  
Stability Criteria ◽  
Ship Stability ◽  
Direct Evaluation ◽  
Intact Stability ◽  
Capsizing Probability ◽  
The Dead ◽  
The Difference ◽  
Effective Wave

The International Maritime Organization is currently establishing second generation intact stability criteria, the dead ship stability is considered one important criterion, so the development of its direct stability assessment regulation has become a topic undergoing close review. In this paper a peak-over-threshold (POT) method is proposed to evaluate the dead ship stability, which focuses on the statistical extrapolation that exceed the threshold, also the traditional Monte Carlo simulation is carried out to approve the method. On the basis of verification calculation of the sample ship CEHIPAR2792, the capsizing probability of a certain warship is also conducted. Moreover, the influence of initial stability height GM and effective wave slope coefficient on the capsizing probability is analysed. The results and the possible reason for the difference are examined. This study is expected to provide technical support for the second-generation stability criteria and establish the capsizing probability of damaged dead ship stability.

Study on the IMO Second Generation Intact Stability Criteria of Surf-riding/Broaching Failure Mode

2015 ◽  
Author(s):  
Peiyuan Feng ◽  
Xingrong Shen ◽  
Sheming Fan
Keyword(s):  
Failure Mode ◽  
Model Experiment ◽  
Ship Design ◽  
Sensitivity Analyses ◽  
Numerical Code ◽  
Stability Criteria ◽  
Intact Stability ◽  
Free Running ◽  
Surf Riding ◽  
Potential Impact

A series of investigations on the vulnerability criteria for the surf-riding/broaching stability failure mode is conducted. First and foremost, free running model experiment of a purse seiner in severe following waves is performed to demonstrate the fatalness of surf-riding/broaching. The latest IMO proposal to assess broaching stability failure mode is then studied in detail. A numerical code with user interface is developed to facilitate sensitivity analyses and sample ship calculations. The appropriateness of the proposal is analyzed and its potential impact on ship design is discussed.

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