This study aims at assessing the optimum hull girder safety level of a Suezmax tanker using a cost benefit analysis (CBA), as proposed by the FSA (Formal Safety Assessment) Guidelines. The objective is to establish an optimum safety level for the tanker ship, considering as a risk control option (RCO) the change in deck scantlings and to assess its effect on the reduction of risk (reduction on total expected cost of hull girder failure). This involves the evaluation of the effect of the RCO on the probability of failure of the ship hull girder assessed by means of structural reliability analysis and the assessment of the cost of failure in terms of property damage of the ship, pollution due to spillage of oil and loss of life of the ship’s crew. Due to the recent developments in environmental criteria at the IMO level, special attention is given to the influence of the environmental criterion in the optimum safety level, as such two approaches are followed in the definition of this input variable: a “Cost of Averting a Ton of oil Spilt” (CATS) and a volume dependent approach for the cost per ton of oil spilt agreed and included in the annex 7 of the revised IMO FSA Guidelines.

This content is only available via PDF.
You can access this article if you purchase or spend a download.