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www.sea-technology.com November 2016 / st 37 T he fusion of cutting-edge flooding simulation technol- ogy and conventional accident investigation expertise is strengthening the industry's response to catastrophic situa- tions at sea. This multidisciplinary approach can bring about dramatic cost, resource and safety improvements. Although the shipping industry is constantly striving to improve its safety record, emergency stability situations re- main a significant challenge, with considerable financial, environmental and human costs. The sequence of events causing a vessel to list, capsize or sink is unique to each incident. However, what is consistent is the need to investi- gate the incident and its cause. Historically, accident investigations hinged on opinion- based evidence or simple static analysis, meaning that con- clusions depended on the strength of opinions put forward by industry experts. However, flooding simulation technol- ogy helps marine accident investigators to identify the root cause of an accident by simulating the behavior of flood- water through a vessel during a major incident. It enables investigators to identify failures that lead to critical damage of a vessel, explain why such failures occur and how they can be addressed to prevent further incidents. Furthermore, because flooding simulations are based on a physical model of the flooding process, it is possible to simulate key parts of an incident, demonstrate the calcula- tions used to arrive at the version of events presented, and show how these conclusions led to the loss or damage of the vessel. The fact-based nature of this process means that all parties involved in a case are able to see the calculations and conclusions and check them for accuracy. Flooding simulations also aid in understanding the dy- namics of the subsequent actions taken following an inci- dent. Where previously conventional analysis could pro- vide a definitive "yes" or "no" when considering whether a vessel is stable following an incident, flooding simula- tions are able to go one step further, introducing a time element. This means that not only can a simulation show whether a scenario could cause a vessel to capsize, sink, list, etc., the technology can also put time scales to the incident. This is critical, as it enables investigators to understand the sub- sequent time available to evacuate or attempt to recover the vessel following stability failure. Flooding simulations have also been used to support effective crisis planning for flood- ing incidents. Origins of Flooding Simulation Funding has supported the development of flooding simulation over the last two decades, during which time in- depth research into vessel complications at sea has been undertaken. The research culminated in an in-depth under- standing of what happens to a vessel when it suffers criti- cal damage and made it possible to determine how fast the event unfolded. This truly novel work has changed the land- scape of accident investigations. For the first time, it provid- ed the time and resource to identify and solve the root cause of accidents, as opposed to just identifying the individual(s) or company at fault. In 1997, flooding simulation came to the fore when the Stockholm Agreement introduced new damage stability re- quirements for all Ro-Ro ferries in northern Europe to ac- count for the accumulation of water on deck. The Stock- holm Agreement was introduced following the sinking of the Estonia in 1995, with the loss of 852 lives. Although the Estonia perished due to the detachment of the bow doors, the incident raised concerns about the im- pact that damage to the side of a Ro-Ro ferry could have on overall stability. The sinking of the Estonia, along with previous incidents, highlighted the stability implications of large amounts of water on deck and compelled the industry to "raise the bar" toward greater stability and safety. As a result, retrospective vessel design requirements introduced through the Stockholm Agreement called for vessels either to be able to demonstrate damage stability with water on deck by static calculations or by physical ex- periments in waves witnessed by the relevant authorities. Achieving compliance posed significant issues for shipown- ers because of the time and cost implications of upgrading and the impact on available cargo space. While experts from Brookes Bell Safety at Sea had be- gun work on flooding simulation technology before the Estonia disaster, the team's expertise was first applied on a large scale after the Stockholm Agreement. At this time, ferry owners in northern Europe heavily relied on the team to support them in identifying and implementing necessary upgrades to their vessels. The most effective way to achieve Stockholm Agreement compliance was via model testing, which involved build- ing a model of a vessel with design modifications aimed at protecting the ship in the event it took water on deck. This model was then tested in wave conditions (based on the Flooding Simulations And Forensic Expertise Combination Approach Increases Vessel Safety By Anthony York