Since the very date of its foundation in 1995, the Ship Stability Workshop has provided the industry experts with the excellent opportunities to gather together and also present the very latest research results. The present Workshop is intended to give some sort of overview of the current situation and the discussions that have been developed from technical presentations is forms a part of the meeting.
These notes are sort of attempt to summarize the discussion in each of the areas, but the very nature of the discussion leads in interesting directions, not necessarily tied in to the topic which initiated the thought. Therefore, there is some structure to these notes, but they certainly are not a verbatim record of the meetings, and they have been edited to make them more structured, since similar topics arose at different times during the meetings. The summaries are ordered in the same sequence as the presentation topics.
The first presentation is intended to highlight some of the developments in the area of numerical and physical modeling of intact stability. This includes hybrid models, use and validation of numerical models, simple capsize criteria, visualization of the data etc. The hybrid models are essentially linear, however there is some non-linear capability. In this chapter a new method for expanding the ship theory type programs is presented and include capsizing due to the stability failure...
The purpose of this brief essay is to put into perspective ongoing research involving the simulation of intact ships in waves and wind, including conditions leading to capsize. A major challenge lies in the conversion of theoretical knowledge and numerical models to practical and useful information. One necessary condition for such knowledge transfer to be successful is a strong link between the research world and the "real" world, like ship operators and regulatory bodies.
In conjunction with the present Cooperative Research Navies project on Dynamic Stability, work has been carried out with the following objectives: modeling of capsize physics and risk analysis, development of "rational" design criteria, development of decision support tools (ship operation) improvement of training/education, The numerical simulation of ship capsizing and broaching plays a central role in this process. To establish confidence levels in the time domain tool developed in recent years, Quality Assurance is essential. This includes the development of QA procedures, benchmark tests, and validation through model tests and full scale data.
Without any further elaboration, I would like to mention that research is carried out along similar lines for damaged ships within the same navy framework. This work relies heavily on the methods and procedures developed for intact ships, as discussed below.
Another compendium of the articles relating to the latest developments in the ship stability and collected during the Fifth International Workshop dedicated to the stability and operational safety of the vessels. Among the topics covered by the programme of the conference there were wave environment monitoring, guidance to the heavy weather sailing and assessment of the risk of capsizing, case studies on SEM (static equivalent method), design of the fishing vessels in a regulation-driven environment, operational requirements and practical experience for the risk management under the conditions of marginal stability, newly developed methods of analysis of the ship and MODU dynamics in a realistic seaway, probability of capsizing of a vessel in random beam waves, model experiments to analyze damage stability of the ro-ro ferries, memory effect for prediction of the ship's capsizing and its importance, some of the newly established guidelines to conduct the HSC model tests, violent free surface flow, direct/parametric excitation analysis, numerical simulation, direct freak waves simulation, nonlinearity effect in yaw motion, non-ergocity of rolling motion of large amplitude, asymmetric surging and surf-riding etc.
The trend of current LNG newbuildings is that the cargo capacity keeps increasing every year. The shipyard proposal keeps adding the numbers of tank capacity until there is no limit to the membrane LNG carriers. Prior to this phenomenon, the Large LNG Carriers standard designs are limited to 130,000 cbm to 138,000 cbm In 2004, Qatar Gas selected two designs proposed by Hyundai Heavy Industries/Samsung Heavy Industries Consortium and Daewoo Shipbuilding and Marine Engineering to build larger than 200.000cbm capacity LNG Carriers. The contract of the Very Large LNGCs clearly showed that there is no limitation of what is coming to the industry.
The construction of the LNG newbuildings around the world will increase until the Qatar Gas acquisitions of LNG ships settled sometime in 2012. Previously in the past, any LNG newbuildings will be based on a fixed charter contract between the Charterer and the Owner. However, recent trend of the LNG newbuildings is now moving towards the spot charter market and speculative in nature making the newbuildings slots for LNG very tight among the LNGC capable shipyards. In order to become pro—active player in the LNG transportation market and promoting high quality standards in LNGC newbuildings, MISC would like to share the experience gained during supervision of newbuildings of Large LNGC. MISC experience in LNGC newbuildings is further augment by the fad thai most of the newbuildings ordered in the recent years are based the membrane—type insulation rather than other type of insulation like the Moss—type or independent tank—type. In 2004 alone, the big three shipyards in Korea won almost 90 percent of the LNG tanker contracts awarded...
This pack of files contains the most actual proceedings of the 12th ISSW which was hosted by David Taylor Model Basin together with the SNAME Chesapeake Section in Washington, United States, in 2011. There were ten major sessions covering such the most important aspects of stability as early stage design criteria as applied to the intact stability of the vessel, compliance and regulatory matters related to the damage stability, operational issues, assessment of the vessel stability using the numerical simulation and various experimental techniques, stochastic dynamics, progressive flooding and capsize issues, basic theory and roll damping, stability issues integrated into the overall risk assessment, and, finally, design for survivability after the vessel has been damaged.
The first session, as stated above, addresses the early-stage design criteria of the ship's intact stability, touching the vulnerability criteria for both surf-riding and parametric rolling, some relevant considerations on parametric roll and dead ship conditions, lateral accelerations taken into account in the ship design rules, validation attempts on the new stability criteria...
The pack of files presented to your attention contains the materials of the Eleventh ISSW hosted by MARIN (The Netherlands) in 2010. The list of sessions of that conference includes ones dedicated to the goal based intact and damage stability standards, special problems and risk based methods of analysis, naval ship stability, safety of damaged ships, recent developments in the field of intact/damage stability, operational safety and roll damping, etc.
The first chapter of this compilation is dedicated to the current status of the developments of the intact ship stability criteria. It addresses such the important aspects as the vulnerability criteria, possible stability failure, direct stability assessment, various relevant regulations governing the stability of the vessels, such as 2008 Intact Stability Code released by the IMO. This part of the volume also deals with design of the stability criteria and researches relating to the container shipping.
The other numerous papers included in this book cover goal-based damaged stability, risk based analysis, freak waves, capsize risk, stability standards allied to the landing crafts, evaluation of the dynamic stability, emergency response, ship roll damping, non-linear roll damping and many other interesting topics.
This pack of files contains the proceedings of the Tenth International Ship Stability Workshop held in Daejeon in 2008. The materials collected in this set have been arranged in nine major sessions. The opening session is fully dedicated to the numerical prediction of ship's intact stability - it addresses ship seakeeping, fast ship behavior in oblique seas, CFD application to the vessel stability problems.
In the second session the authors of the articles dealt with theoretical prediction of steady stated for parametric ship roll and its experimental verification, explain how to properly apply the criteria of parametric roll to naval vessels, assessment of such type of rolling, together with capabilities and problems. The next session touches the behavior of the vessel in following and quartering waves, including analytical predictions and experimental validation experimental studies, broaching phenomenon etc.
The remaining sessions cover such important topics as probabilistic assessment of intact stability of the vessel, motion prediction envelopes, critical wave groups concept, numerical prediction of flooding/damage stability, design support systems, operational stability safety, closure on survival time, accident investigation and others.
The present excellent collection of documents has been made of the selected papers and presentations of the IMO-WMU Global R&D Forum relating to the Emerging BWM Systems held some years back in Sweden. Nowadays, the great demand is there within the maritime industry for the development of the environmentally-friendly and also efficient BWM systems.
Taking this demand into account, the today's technological community has been dealing with the active developing of the various BWM systems to be able to cater to the emerging market of the ballast water technology, The systems in question have to undergo various applicable approval processes including the testing as per the established testing procedures, in compliance with the requirements of the BWM Convention plus the Guidelines. While several systems are currently under development or approval process, testing among the BWM system TF, i.e. test facilities worldwide shows the gaps in the harmonization and methodology.
This has significantly contributed to the confusion and lack of confidence among the people involved in the development of the subject systems, and also among the ship owners. Therefore, it is really imperative that the end-users of the BWM systems have enough confidence that consistent and reliable testing methodologies are applied.