Bowties in rail - case studies
The bowtie method can be used in various risk assessment contexts. For example, a company might develop a bowtie analysis to show how they manage a particular hazard in all their stations, linking the control measures or barriers to specific processes and procedures in their safety management system. They might then use the bow tie model as an audit support tool to verify that the controls are being effectively implemented in different stations.
Another example might be their use in understanding an emerging new risk, such as Covid-19 infection of passengers using the trains. This could be used to shape, and direct discussions as new information develops and understanding improves.
It is possible to develop a bow tie following an incident or accident, to understand what actually happened, why things went wrong, and where there might be weaknesses in the safety management or set of controls that we can learn from.
A recent example of using bow tie analysis as part of a Taking Safe Decisions process was a cross-industry investigation of concerns over freight derailment. The development of the bow tie brought together several disciplines, and representatives of different stakeholder companies. The freight derailment bow tie model supports the activities to manage freight risk under the rail industry’s health and safety strategy Leading Health and Safety on Britain's Railway.
RSSB, together with rail industry stakeholders, has developed bow tie models for several risk areas including: