Process, methods and tools for ship damage stability and flooding risk assessment

Development of damage stability as a scientific subject, specifically in damage ship hydrodynamics and, generally, flooding risk assessment, has evolved primarily by inquisitive academics with support by people with vision and passion towards maritime safety enhancement from industry and Government, the latter in the wake of serious accidents. Notwithstanding this, the subject has seen remarkable development in a short period of time in terms of understanding process, and developing methods and tools for practical implementation of such developments. The stage has now been reached where large-scale EC and industry-funded projects are bringing all requisite knowledge and experience together towards implementation by end users with the view to institutionalizing such developments. The paper critically traces and presents key developments starting from basic concepts to a complete framework for performing numerical simulations of ship survivability in operational conditions in the seaway, leading to flooding risk assessment with application potential for new and existing ships with focus on the design phase but with operation potential in ship operation, the latter involving emergencies

Aligning intact and damage stability in a multi-level-assessment framework

Against the background of using the Index of Subdivision as a reference to address the safety level of ships when damaged, following primarily collision incidents, the EC-funded FLARE project is making inroads towards a direct assessment of flooding risk, which is ship, operating environment, and accident-type specific by addressing all the underlying elements, using a two-level approach; level 1 being semi-empirical with risk models informed through a newly composed accident database and level 2 with flooding risk, in the form of Potential Loss of Life, calculated from first principles, using time-domain flooding simulation tools and evacuation analyses in pertinent emergencies. In addition to addressing all accident types and modes of loss, the FLARE framework and methodology target active and passive measures of risk prevention and control, hence with application potential to both newbuildings and existing ships as well as facilitate real-time flooding risk evaluation for risk monitoring and effective control in emergencies. A key objective of the FLARE project is to provide the technical basis and a proposal for the revision of relevant IMO regulations towards a risk-based approach to contain and control flooding emergencies. The paper provides a complete example of one cruise ship and one RoPax where levels 1 and 2 of flooding risk evaluation are presented and discussed, and a summary of results for a further 8 sample ships from Project FLARE, leading to conclusions on the progress made and recommendations for the way forward

Alternative evacuation procedures and smart devices' impact assessment for large passenger vessels under severe weather conditions

Within the expansive domain of maritime safety, optimizing evacuation procedures stands as a critical endeavour. After all, evacuation is literally the last and fundamental safety level afforded to mariners and passengers. Recent incidents have rekindled interest in assessing the performance of this ultimate safety barrier. However, addressing evacuability requires a holistic approach. The authors present herein the setup, simulation, and ultimately evaluation of a novel approach and its ability to rigorously assess multiple innovative risk-control options in a challenging, realistic setting. Moreover, its benchmarking against conventional regulation-dictated evacuation processes is captured distinctively along with the relative effectiveness of each proposed measure. Such measures include smart technologies and procedural changes that can result in substantial improvements to the current procedures. These will impact the ongoing discourse on maritime safety by providing insights for policymakers, vessel operators, emergency planners, etc., and emphasize the need for further research and development efforts to fortify the industry against evolving safety challenges

Evacuation dynamics in the maritime field: modelling, simulation and real-time human participation

The topic of evacuation analysis is becoming increasingly important in the maritime field, especially after the recent approval of relevant amendments to SOLAS. These amendments make evacuation analysis in early design stage mandatory not only for ro-ro passenger ships, as in the past, but also for other passenger ships, constructed on or after 1st January 2020, carrying more than 36 passengers. Tools used to perform evacuation simulations are generally run in a non-interactive batch mode. However, the introduction of the possibility for humans to interactively participate in a simulated evacuation process together with computer controlled agents in an immersive virtual environment, can open a series of interesting possibilities for design, research and development. Therefore, with particular reference to the maritime field, the research described in this dissertation is focused on the development and implementation of a mathematical model for simulating the dynamics of evacuation processes, which also allows real time human interaction through the use of virtual reality. The developed mathematical model, which is capable of naturally embedding human interaction, was verified and validated through a series of tests and through comparisons with other models and experimental data, as well as by referring to the relevant guidelines proposed by the International Maritime Organization (IMO). Particular attention was given to the calibration and validation of the counterflow model, developed during the research activity, and to the analysis of flow-density relation. The possibility of real time user participation, consisting in the user taking control over an agent inside the simulation, was introduced along with a vibrotactile haptic interface which was created to enhance the user perception of the surrounding virtual environment. The developed tool and user interfaces were adopted in an experiment where the subject was immersed in a virtual environment and interacted with simulated agents. The analysis of experiments provided results on the effects of the developed haptic interface on the subjects\u2019 behaviour. Moreover, the obtained data allowed comparing the behaviour of subjects with that of simulated agents. The mathematical model was subsequently extended with the introduction of ship motion effects on agents behaviour, considering that, in the maritime field, the platform is usually moving. Fictitious forces, in the developed model, are directly applied to the agents and might therefore modify their trajectories. This represents an added value of the proposed model, because, usually, the effects of ship motions are embedded in simulation models only through a speed reduction. The model was used to assess ship motion effects in some IMO test cases. Finally, the tool was tested on a specifically developed case targeting the maritime field whose geometry was ideated as a simplification of the general plan of a real cruise vessel. The evacuation simulations were run firstly without ship motions, then with some representative situations combining heel, trim and periodic motions and, finally, with motions due to irregular waves. Ship motions, in this latter case, have been generated considering a notational cruise vessel whose dimensions were in line with the cruise vessel the test geometry was inspired to. A model introducing ship motion effects on the control of the avatar was finally developed, together with an approach to provide perception of ship motions through the developed vibrotactile interface. Models and results presented in this dissertation provide new insight to the field of ship evacuation analysis and to the application of virtual reality in this field

Passenger ship evacuation - design and verification

This paper introduces the concept of escape and evacuation from passenger ships from a perspective of ship design and risk management. As part of that process, the use of computer simulation tools for analysing the evacuation performance of ships carrying large numbers of persons on board is becoming more relevant and useful. The objective of this paper is to present the pedestrian dynamics simulation tool EVI, developed to undertake advanced escape and evacuation analysis in the design verification of cruise vessels, passenger ferries and large offshore construction vessels, among others