Understanding the risk associated with train dispatch

Every year approximately 1.7 billion passenger journeys are made and just under 80 million passenger trains are dispatched on the mainline rail network in Great Britain. Most of these journeys start and end safely, however... [ view full abstract ]

Every year approximately 1.7 billion passenger journeys are made and just under 80 million passenger trains are dispatched on the mainline rail network in Great Britain. Most of these journeys start and end safely, however hazardous events can occur at the platform train interface (PTI) over the duration of the train dispatch process, including the train’s preparation for departure and departure from the platform.  The procedures involved in the train dispatch process are in place to manage the risk from these hazardous events, as well as making sure that the train is safe for the journey and that the train leaves punctually.  Procedures vary by location and can involve different members of staff.  RSSB carried out a project to consolidate the understanding of risks associated with train dispatch, coincidentally, at a time when industrial relations issues were being raised about the role of the guard and further implementation of driver only operation (sometimes also referred to as driver controlled operation).  The project involved a literature review of RSSB research, relevant shared industry standards, and other industry sources relating to train dispatch.  Analysis of 13 Rail Accident Investigation Branch (RAIB) investigations of train dispatch-related incidents was carried out to identify and classify the factors that contributed to these incidents.  In depth analysis of incidents reported into the Safety Management Information System (SMIS) was also undertaken to estimate the risk associated with different methods of train dispatch.

The review and analysis identified the hazardous events that could occur during or as a result of train dispatch.  Possible causes of these hazardous events and the control measures that can be used to manage the risks were also identified.  The hazardous events, causes and controls were arranged into a schematic which provided a structural representation of the risks associated with train dispatch.

The full conference paper will focus on the causes of train dispatch risk and risk analysis of SMIS data.  Consideration of the topics discussed in the paper can help to inform the identification of hazards that may occur during train dispatch and associated control measures.

Analysis of the RAIB investigations identified 117 different incident factors, approximately a third of these involved errors made by passengers, members of the public or staff members.  A further third of incident factors related to the ‘Infrastructure, vehicle, equipment and clothing’ incident factor category.

The analysis of incidents from SMIS considered personal accidents to passengers and the public as well as the risk of collision from signals passed at danger (SPADs) when starting against signal (SAS) at a platform.  Overall the analysis showed that the estimated risk from train dispatch accounts for approximately 1.5% of the overall risk on the GB mainline (excluding suicides).  The analysis also provides an indication of how this risk is distributed across the four different methods of dispatch:

• Driver only from an unstaffed platform

• Driver and guard from an unstaffed platform

• Driver only from a staffed platform

• Driver and guard from a staffed platform