A probabilistic model for accidental cargo oil outflow from product tankers in a ship-ship collision

- Probabilistic model for accidental oil outflow in product tanker collision shown.
- Bayesian network enables reasoning under uncertainty in risk assessment.
- Integration of models estimating ship collision damage and tank arrangement.
- Oil outflow assessment when only limited data concerning ship is available.
- Validation framework builds confidence while highlighting uncertainty and bias.

In risk assessment of maritime transportation, estimation of accidental oil outflow from tankers is important for assessing environmental impacts. However, there typically is limited data concerning the specific structural design and tank arrangement of ships operating in a given area. Moreover, there is uncertainty about the accident scenarios potentially emerging from ship encounters. This paper proposes a Bayesian network (BN) model for reasoning under uncertainty for the assessment of accidental cargo oil outflow in a ship-ship collision where a product tanker is struck. The BN combines a model linking impact scenarios to damage extent with a model for estimating the tank layouts based on limited information regarding the ship. The methodology for constructing the model is presented and output for two accident scenarios is shown. The discussion elaborates on the issue of model validation, both in terms of the BN and in light of the adopted uncertainty/bias-based risk perspective.