Assessing Safety Risks for the Sea Transport Link of a Multimodal Dangerous Goods Transport Chain

Doctoral thesis, 2011

Transport of goods in containers and cargo transport units by sea as part of multimodal transport chains presents unique challenges from a safety perspective. The units can hold a broad mix of cargo types, including dangerous goods with hazardous properties. The purpose of this thesis was to assess the risk of carrying dangerous goods as packaged cargo by sea, with a main focus on transport safety. A better understanding of this risk can lead to fewer human, environmental, and economic losses. Studies on the safety risks associated with sea transport of containerised goods were carried out, starting with an investigation into the overall risk of fires on container ships, continuing with analyses of the risk of dangerous goods carriage, and concluding with an investigation into the factors contributing to the release of dangerous goods on board. The sea transport link of the transport chain was of prime interest from a safety perspective, but earlier parts of the chain were also considered for the investigation of contributing factors. Analysis of accident, incident, and inspection reports and databases was a key part of the approach taken to carry out the work. Risk analysis techniques, primarily event tree and fault tree techniques, were used both quantitatively and qualitatively to estimate risk and develop explanatory models. The container ship risk analysis modelling work determined that the fire/explosion accident category was the second largest contributor to overall human safety risk, and the analysis of historical data found it to be responsible for the most crew fatalities reported for the period 1993 – 2004. The cargo area was found to be the location of fire initiation for 32% of serious fire/explosion events on container ships for a later period investigated (1998 to 2008) and undeclared dangerous goods were found to be involved in 25% of these cargo area fires. Dangerous goods involvement was identified for 15% of crew fatalities resulting from container ship casualties during this 11-year period. The investigation of release of packaged dangerous goods during maritime transport found most contributing factors originated prior to the goods being loaded on to the ship. The findings are useful from a safety perspective as they identify where in the transport chain faults are occurring and also the importance of dangerous goods incidents and fires in relation to other accident types.