Risk evaluation for RoPax vessels

The paper presents the results of a recent risk evalua-tion study for RoPax vessels, carried out as part of the activities of the SAFEDOR Integrated Project. The objective of the study was to investigate hazards and their causes during RoPax operation and to quantify, to the extent possible, their frequencies and conse-quences. A previous study on the safety assessment of RoPax vessels sailing in North-West European waters, covering the period until 1994, was used as the basis in putting together a high-level risk model for the current study. All scenarios are presented in the form of event trees, quantification of which is done on the basis of world-wide accident experience (from 1994 to 2004), relevant past studies and judgment. The study esti-mates the risk of loss of life among passengers and crew (by calculating for each scenario the Individual Risk, the Potential Loss of Life – PLL and plotting the corresponding F-N curves), and compares them with current risk acceptance criteria

The thematic network SAFER EURORO : an integrated approach to safe European roro ferry design

For a period of more than 10 years, a safety culture approach has been promoted through the theme'Design for Safety,' which aims at integrating safety cost effectively in the ship design process. There isa considerable wealth of information amassed over these years of research and development on safetycriticalareas. One of the main elements of the research and development (R&D) work is the assurance ofsafety within the ship design process, in the continuous search for improving the current state of affairs.Through bold steps in the direction advocated by 'Design for Safety,' it is slowly but steadily beingrecognized that this approach can greatly contribute to the overall cost-effective improvement of safety inshipping while nurturing the evolution of proper practice in the field. On this background, the paper attempts a thorough overview of related R&D developments over the lastdecade. Particular emphasis is placed on the developments that have taken place as part of the activitiesof the Thematic Network SAFER EURORO and associated research projects, which have led to thedevelopment of a recent major research initiative, the Integrated Project SAFEDOR, which is expected tolead research development in the area for the years to come

Damage survivability of cruise ships - evidence and conjecture

This paper delves into damage stability legislation as it applies to passenger ships. The Concordia accident, like many others before it, has shaken the maritime profession once again with many questions being asked without being able to provide credible answers. Old ships have been designed to lower standards (it is common knowledge that new ships are safer than old ships, with the latter comprising the majority of the population), new standards are holistic and goal-based offering knowledge of the standard these ships are designed to, which is not true for old ships, emergency response is an altogether different science in modern ships and many others. Notwithstanding this state of affairs, there is another more fundamental weakness in the regulations for damage stability, perhaps at the heart of most problems with cruise ships safety, old and new. A critical review into damage stability legislation, as it applies to passenger ships, offers compelling evidence that cruise ship characteristics and behaviour have not been accounted for in the derivation of relevant damage stability rules. As a result, the regulatory instruments for damage stability currently in place do not provide the right measure of damage stability for cruise ships and, even more worryingly, the right guidance for design improvement. This leads to a precarious situation where cruise ships are underrated when it comes to assigning a damage stability standard whilst depriving designers of appropriate legislative instruments to nurture continuous improvement. Documented evidence is being presented and the ensuing results and impact discussed. Recommendations are given for a way forward

Damage stability of cruise ships - evidence and conjecture

This paper delves into damage stability legislation as it applies to passenger ships. The Concordia accident, like many others before it, has shaken the maritime profession once again with many questions being asked without being able to provide credible answers. Old ships have been designed to lower standards (it is common knowledge that new ships are safer than old ships, with the latter comprising the majority of the population), new standards are holistic and goal-based offering knowledge of the standard these ships are designed to, which is not true for old ships, emergency response is an altogether different science in modern ships and many others. Notwithstanding this state of affairs, there is another more fundamental weakness in the regulations for damage stability, perhaps at the heart of most problems with cruise ships safety, old and new. A critical review into damage stability legislation, as it applies to passenger ships, offers compelling evidence that cruise ship characteristics and behaviour have not been accounted for in the derivation of relevant damage stability rules. As a result, the regulatory instruments for damage stability currently in place do not provide the right measure of damage stability for cruise ships and, even more worryingly, the right guidance for design improvement. This leads to a precarious situation where cruise ships are underrated when it comes to assigning a damage stability standard whilst depriving designers of appropriate legislative instruments to nurture continuous improvement. Documented evidence is being presented and the ensuing results and impact discussed. Recommendations are given for a way forward

Risk analysis for RoPax vessels

The paper presents the results of a recent risk analysis study for RoPax vessels, carried out as part of the activities of the SAFEDOR Integrated Project. The objective of this study was to investigate the causes of hazards during RoPax operation and quantify, to the extent possible, their frequencies and consequences. Potential scenarios initially identified and prioritised during a Hazard Identification (HAZID) session were used in the pro cess. The work has been performed in accordance with the IMO FSA Guidelines (IMO 2002). A previous comprehensive study on the safety assessment of RoPax vessels sailing in North West European waters, covering the period until 1994, was used as the basis in putting together a high-level risk model for the current study. All scenarios are presented in the form of event trees, quantification of which is done on the basis of world-wide accident experience (from 1994 to 2004), relevant past studies and judgment. The study estimates the risk of loss of life among passengers and crew (by calculating for each scenario the In di -vidual Risk, the Potential Loss of Life – PLL and plotting the corresponding F-N curves), and compares them with current risk acceptance criteria. The resulting high-level risk model is used to provide recommendations for improvement in the form of proposed risk control options (RCOs)

Sensitivity analysis of the probabilistic damage stability regulations for RoPax vessels

In the light of the newly developed harmonised probabilistic damage stability regulations, set to come into force in 2009, this article presents a systematic and thorough analysis of the sensitivity of the Attained Subdivision Index with reference to a wide range of related design parameters. The sensitivity of the probabilistic regulations was investigated for a typical large RoPax vessel, with variation of parameters, such as the number, positioning and local optimisation of transverse bulkheads; the presence and position of longitudinal bulkheads below the main vehicle deck; the presence of side casings; and the height of the main deck and double bottom. The effects of water on deck and of operational parameters (draught, centre of gravity and trim) were also investigated. The results of the study, presented in graphical form, can provide valuable assistance to the designer when determining subdivision characteristics at the very early stage of the design process, resulting in optimal, efficient and safe ships

Potential assessment of cargo liquefaction based on an UBC3D-PLM model

Fluidization of fine particle cargoes, resulting in cargo shift and loss of stability, has caused the loss of many lives in numerous marine casualties over the past decades. Since the dangers of cargo fluidization have long been known to the shipping industry, the question of why the phenomenon is resurfacing now would be a legitimate one. With this in mind, an UBC3D-PLM model based on FEM theory in the commercial software PLAXIS is presented in this paper to consider soil DSS (Direct Simple Shear) test to verify the model. To assess the cargo fluidization potential, an evaluating method is presented in the paper considering cargo fluidization. Shaking table tests with different amplitude, frequency and initial degree of saturation of cargos were studied to predict time-domain characteristics. This method in the paper could be feasibly used as a reference and possibly support a suitable regulatory framework to the fluidization analysis of ship stability

Risk-based design-realising the triple-a navy

"Design for Safety" refers to a design paradigm introducing safety in design as another objective. This requires explicit consideration and quantification of safety, which is equivalent to evaluating risk during the design process; hence the term “Risk-Based Design”. The essential advance attributable to Risk-Based Design is the holistic, explicit, rational and cost-effective treatment of safety, without which optimal design solutions are not feasible. This is achieved on the basis of principles that support multi-discipline design optimisation and promote the use of knowledge in all forms. More specifically: •A formalised procedure to measure safety consistently (risk analysis / risk assessment / risk management). •Flexibility to allow trade-offs between Performance, Earnings, Risk and Costs; hence focus on life-cycle issues. •Integration of such procedure in the design process (integrated design environment) with focus on holistic optimisation. The “Design for Safety” philosophy and the ensuing formalised methodology, “Risk-Based Design (RBD)” were introduced in commercial shipping as a design paradigm in the 1990s to help bestow safety as a design objective and a life-cycle imperative. This was meant to ensure that rendering safety a measurable (performance-based) design objective, through using first-principles tools, would incentivise industry to seek cost-effective safety solutions, in response to rising societal expectations. It turned out that removing rules-imposed (largely-conservative) constraints and the adoption of a performance-based approach has had much more profound effects than originally anticipated, the full impact of which is yet to be delivered. This is particularly true for knowledge-intensive and safety-critical ships, such as naval vessels and the giants of the cruise ship industry being built today, where the need for technological innovation creates unprecedented safety challenges that cannot be sustained by prescriptive-regulation-based safety. Drawing from the implementation of Risk-Based Design in the cruise ship industry, this paper presents and discusses the process of implementation and impact, demonstrating that all prerequisite scientific and technological developments are in place for Risk-Based Design to be fully implemented in the naval sector as the platform to deliver active, adaptive and affordable vessels

Life-cycle risk (damage stability) management of passenger ships

Inadequate damage stability, the Achilles heel of passenger ships, has been a critical research objective that industry and academia delved to improve every time following accidents with passenger ships. Most achievements focused on design phase, either for the new-made regulations or rather novel pro-active methodology of risk-based design, which ignored thousands of existing ships and wasted state-of-art knowledge on damage stability. Considering this situation, a framework of life-cycle risk (damage stability) management of passenger ship and its related damage stability verification framework were introduced and established in this paper

Reconfiguring passenger ship internal environment for damage stability enhancement

The traditional risk control option adopted in naval architecture to meet safety-related objectives is by regulations, targeting damage limitation, nominally instigated in the wake of maritime accidents claiming heavy loss of life. These primarily concern the introduction of watertight bulkheads, i.e., permanent (passive) reconfiguration of the internal ship environment to enhance damage stability. This has been the most common measure, manifesting itself in the wake of every serious flooding accident since the beginning, back in the 19th century. However, traditional flooding protection through watertight subdivision, to an extent dictated by IMO regulations, has a physical limit which, if exceeded, a safety plateau is reached. This is currently the case and with damage stability standards progressively increasing, the safety gap between existing and new ships is dangerously widening and with design stability margins progressively eroding, stability management is unsustainable, leading to loss of earnings at best. The need for managing the residual risk through active intervention/protection over the life-cycle of the vessel drives industry to searching and adopting a new normal. This new normal is the innovation being explained in this paper by addressing safety enchantment through a systematic reconfiguration of the ship environment for passive and active protection in flooding accidents. In this respect, the "design-optimal" internal arrangement of a vessel, is adapted and reconfigured, using passive and active containment systems for flooding incidents, in the form of high-expansion foam products. The innovation is briefly explained, claiming transformational reduction in flooding risk in the most cost-effective way available. To support wider understanding and appreciation for the latter, the paper critically reviews the whole evolution of internal ship space reconfiguration, chronologically and systematically, concluding that new technological developments and breakthroughs will bring sustainable changes to the traditional evolutionary maritime safety enhancement