Risk acceptance criterion for tanker oil spill risk reduction measures.

This paper is aimed at investigating whether there is ample support for the view that the acceptance criterion for evaluating measures for prevention of oil spills from tankers should be based on cost-effectiveness considerations. One such criterion can be reflected by the Cost of Averting a Tonne of oil Spilt (CATS) whereas its target value is updated by elaborating the inherent uncertainties of oil spill costs and establishing a value for the criterion's assurance factor. To this end, a value of $80,000/t is proposed as a sensible CATS criterion and the proposed value for the assurance factor F=1.5 is supported by the retrieved Protection and Indemnity (P&I) Clubs' Annual Reports. It is envisaged that this criterion would allow the conversion of direct and indirect costs into a non-market value for the optimal allocation of resources between the various parties investing in shipping. A review of previous cost estimation models on oil spills is presented and a probability distribution (log-normal) is fitted on the available oil spill cost data, where it should be made abundantly clear that the mean value of the distribution is used for deriving the updated CATS criterion value. However, the difference between the initial and the updated CATS criterion in the percentiles of the distribution is small. It is found through the current analysis that results are partly lower than the predicted values from the published estimation models. The costs are also found to depend on the type of accident, which is in agreement with the results of previous studies. Other proposals on acceptance criteria are reviewed and it is asserted that the CATS criterion can be considered as the best candidate. Evidence is provided that the CATS approach is practical and meaningful by including examples of successful applications in actual risk assessments. Finally, it is suggested that the criterion may be refined subject to more readily available cost data and experience gained from future decisions.

Under-reporting of maritime accidents.

The majority of current maritime regulations has been developed following a reactive approach, often as ad-hoc response to serious accidents, and are characterised as being prescriptive leaving limited space for adapting equivalent solutions rather those described in the regulations. On the premise of providing a more proactive approach for the proposal or the evaluation of regulations, the Formal Safety Assessment (FSA) has been introduced. In the context of FSA, the analysis of accident data is considered to be very important for providing potential input on developing more balanced, proactive and cost-effective regulations. However, it has been argued that the validity of historical data may be undermined by uncertainties. This paper is aimed at showing evidence on serious under-reporting in accident databases, which can be considered as the main contributor to questioning the direct and uncritical use of historical data. By analysing the 10-year tanker accident data from the Lloyd's Register FairPlay (LRFP) and the Norwegian Maritime Directorate (NMD) for vessels registered in Norway, it is found that the reporting performance has an upper bound of 41% for NMD and 30% for LRFP. Furthermore, based on comparison between LRFP data and self-assessment by Flag States, it is seen that accidents reported by the Flag States are also incomplete.

Challenges in global ballast water management.

Ballast water management is a complex issue raising the challenge of merging international regulations, ship's specific configurations along with ecological conservation. This complexity is illustrated in this paper by considering ballast water volume, discharge frequency, ship safety and operational issues aligned with regional characteristics to address ecological risk for selected routes. A re-estimation of ballast water volumes gives a global annual level of 3500 Mton. Global ballast water volume discharged into open sea originating from ballast water exchange operations is estimated to approximately 2800 Mton. Risk based decision support systems coupled to databases for different ports and invasive species characteristics and distributions can allow for differentiated treatment levels while maintaining low risk levels. On certain routes, the risk is estimated to be unacceptable and some kind of ballast water treatment or management should be applied.