Analyzing Historic Process Data to Identify Near Misses and Warning Signs: Examples from the Buncefield Incident

Process data is often analyzed during the investigation of industrial fires and explosions. Our analyses often reveal near misses or warning signs that foreshadow the eventual causes of a catastrophic event. In some cases the facility may have been unaware of these near misses or not realized their frequency. Proactive analysis of process data prior to incidents would allow facilities to identify near misses and warning signs and address problems before a catastrophic event occurs.

In this paper we examine historical process data from the Buncefield Fuel Terminal. A December 2005 explosion and fire at the facility was caused by the overflow of approximately 300 m3 of premium gasoline from a storage tank. Our review of the historical process data from the facility identified multiple reoccurring events that eventually led to the incident. These include sticking of tank level gauges, possible failure of redundant high level switches, reliance of operators on alarms, and possible non-activation of alarms. Had the facility proactively reviewed process data prior to the incident, these warnings signs may have been more fully understood and addressed.

We propose that the proactive review of historic process data may allow facilities to identify additional near misses and warning signs and improve the efficiency and safety of their operations.