Reduction of oil outflows at collisions and groundings through improved vessel design arrangement

The paper discusses active and passive methods of reducing the expected oil outflow from collision and grounding accidents. Active measures refer to actions or decisions taken at the time of an accident, while passive measures refer to features built into the design of the ship. Except in cases of large tides, passive measures appear most efficient in reducing the oil spill rates from collision and grounding accidents. The measures discussed in this study include: main hull design and tank arrangement; structural resistance of hull; and other features, like vacuum systems, piping systems for automatic redistribution of oil in case of pressure drop in tanks. Only the influence of the main hull design and tank arrangement on the oil outflow has been analysed in detail. The results reveal that a considerable reduction of the pollution risk may be achieved by careful modification of main particulars and tank sizes compared to current design practice. (author)