Formal Safety Assessment of a Marine Seismic Survey Vessel Operation,Incorporating Risk Matrix and Fault Tree Analysis

In maritime safety research,risk is assessed usually within the framework of formal safety assessment(FSA),which provides a formal and systematic methodology to improve the safety of lives,assets,and the environment.A bespoke application of FSA to mitigate accidents in marine seismic surveying is put forward in this paper,with the aim of improving the safety of seismic vessel operations,within the context of developing an economically viable strategy.The work herein takes a close look at the hazards in North Sea offshore seismic surveying,in order to identify critical risk factors,leading to marine seismic survey accidents.The risk factors leading to undesirable events are analysed both qualitatively and quantitatively.A risk matrix is introduced to screen the identified undesirable events.Further to the screening,Fault Tree Analysis(FTA)is presented to investigate and analyse the most critical risks of seismic survey operation,taking into account the lack of historical data.The obtained results show that man overboard(MOB)event is a major risk factor in marine seismic survey operation;lack of training on safe work practice,slippery deck as a result of rain,snow or water splash,sea state affecting human judgement,and poor communication are identified as the critical risk contributors to the MOB event.Consequently,the risk control options are focused on the critical risk contributors for decision-making.Lastly,suggestions for the introduction and development of the FSA methodology are highlighted for safer marine and offshore operations in general.

Application of formal safety assessment in planning VTS

To ensure that limited resources are allocated more effectively to reduce marine risks, formal safety assessment (FSA), a proactive method, is introduced in planning a vessel traffic system (VTS). Based on the data of Wuhan port, some new solutions based on risk-indices are put forward. The weighted number of traffic accidents is predicted after the future weighted vessel traffic volume is estimated by analyzing the trend of trade development. To analyze risk acceptability, the as-low-as-reasonably-practicable (ALARP) matrix is transformed into a new model containing two parameters: the future weighted vessel traffic volume and the future weighted number of traffic accidents. The new risk control options (RCOs)can be identified by a revised Domino model with several feedback loops from all system levels to close a limited window of accident opportunity. The results indicate that the four most beneficial RCOs are a wider sub-area 1 channel, a VTS bridges area, a dredging sub-area 2 main route, and a VTS QSX anchorage to the 3rd bridge. The FSA is a method that is effective in evaluating the rationality, necessity and cost-effectiveness of VTS projects.

A New Criteria to Apply Weight-Dependent CATSthr to Cost-Benefit Analysis within the Framework of IMO EnvironmentaI-FSA Studies

The purpose of this paper is to investigate reasonable cost benefit criteria within the framework of environmental formal safety assessment （FSA）. In this study a statistical analysis of oil spill data was carried out based on the report of International Oil Pollution Compensation Funds. According to the statistical study of actual oil spill from tankers, it is found that collisions and groundings are the most probable causes of the oil spills from tankers. Probability distributions of costs of oil spill and oil spill amount are investigated, and a non-linear regression formula between costs of oil spills and oil spill weight are derived. Using the regression formula, an oil spill weight dependent CATStm （Cost of Averting a Ton of oil Spilt） is proposed. Moreover in order to apply the weight dependent CATSthr to cost benefit analysis （CBA）, a new cost-effective criterion is newly proposed with considering its concrete application to environmental FSA.