At around 9.37am on Wednesday August 12, 2020, a passenger train derailed near Carmont, Aberdeenshire. The train, number 1T08, was the 6.38am service from Aberdeen to Glasgow, returning to Aberdeen due to a reported blockage on the line ahead. He was traveling at 73 mph (117 km/h), just below the normal speed of the line concerned. After derailing, the train deviated to the left, before hitting a bridge parapet which caused the vehicles to scatter. Tragically, three people died as a result of the accident and the other six people on board the train were injured.
On the morning of the accident, there was almost continuous heavy rain at the accident site between approximately 06:00 and 09:00. The 51.5 mm of rain that fell at this time at the site of the accident is close to the average rainfall for August in this part of Scotland. Train 1T08 derailed because it struck debris that had been washed out of a drainage ditch. This trench, which had been constructed between 2011 and 2012, contained a perforated pipe that had been installed as part of a project to address a known drainage and trench stability issue in this area. However, the drainage system and associated earthworks had not been constructed to the original design and therefore were unable to safely accommodate the water flows that morning.
RAIB investigators found that a low earth embankment (bund) had been constructed which crossed a slope leading down to the track. The presence of this dyke significantly altered the flow of water such that extreme rainfall events would cause concentrated flow in the steep section of the trench. The evidence indicates that the intensity and duration of this precipitation would have generated water flows in the trench sufficient to wash away the gravel fill and soil immediately surrounding the trench.
No instructions were given by route control or the signalman that train 1T08 should run at a lower speed on its route between Carmont and Stonehaven. At the time, no written process required such a precaution in these circumstances. Therefore, normal railway rules were applied to the movement of trains. The RAIB investigation found that route controllers (responsible for the operational management of Scotland’s rail network) had not received the information, procedures or training they needed to deal effectively with complex situations such as met on the morning of August 12, 2020.
Following this accident, the RAIB made 20 recommendations for improving railway safety. Areas covered include:
- better management of civil engineering construction activities by Network Rail and its contractors
- additional standards and guidance on the safe design of drainage systems
- improved operational response to extreme precipitation events, exploiting the full capabilities of modern technology and based on a detailed understanding of the risk associated with extreme precipitation events
- improve the ability of route control offices to effectively manage complex events
- extend Network Rail’s insurance scheme to cover route control offices
- removing barriers to the effective implementation of lessons learned from accident and incident investigations
- measures to prevent derailed trains from deviating too far from the track (equipment on the track and/or the trains)
- resolve train design issues identified by the investigation and better understand the additional risk associated with operating older trains.
Video summary, including a digital visualization of the accident
Derailment of a passenger train in Carmont
Visualization of the performance of the drainage system in Carmont on August 12, 2020
Visualization of leaching
Simon French, Chief Rail Accident Inspector, said:
“It was a tragedy that devastated the lives of the three families who lost their loved ones and sowed terror and injured six others on the morning of August 12, 2020. Our thoughts are with them all. Nothing can undo this event, but we must everyone affected to strive to learn safety lessons for the future.
“While rail safety in the UK has steadily improved over the past decades, the Carmont tragedy reminds us of how disruptive and potentially dangerous Britain’s unstable weather can be. The rail industry needs to get even smarter in how it counters this threat and better exploit remarkable modern technology that predicts and tracks extreme weather events such as summer convection storms. There is also an urgent need for the railway to provide decision makers with the real-time information, procedures and training they need to manage complex and widespread weather events across the entire railway network.
“Nobody wants to shut down the railway every time it rains. Railways must operate safely and reliably in most weather conditions. If they fail to do so, potential passengers will be forced to use the roads, which are undoubtedly much more dangerous in bad weather. So there is a balance to be found and technology can help find that balance. Modern weather forecasting and monitoring systems can spot truly exceptional events before they happen and as they happen, allowing rail operators to implement precautionary measures when it happens. is prudent to do so. This would benefit line safety (by limiting train speeds or suspending operations, if necessary) while reducing the need to impose general speed restrictions in areas that do not pose a significant risk.
“This investigation highlights the risk of uncontrolled changes to the railway infrastructure during construction. It is so sad that a project designed for the protection of the traveling public has become unsuitable for its intended purpose and has posed a hazard to trains due to these uncontrolled design changes. When something is built in difficult conditions, such as on the side of a steeply sloping trench, changes will often be necessary for practical reasons. Although such changes are normal and can be very beneficial in terms of saving time and money, they should be made with care. In each case, the original designer should understand the proposed change and consider the implications of a change that may seem inconsequential to the onsite team. I hope this example resonates throughout the UK construction industry.
“It is important for all of us in the rail industry not to view this truly heartbreaking accident as a one-time event. The rail industry needs to think about the implications of bad weather on its infrastructure, while considering the behavior of trains if they derail after hitting obstacles such as washouts and landslides. Is there more to be done to keep trains aligned and closer to the track, to minimize the risk of jackknifing, and to keep bogies attached to rail vehicles? The RAIB does not have all the answers, but urges the rail industry to consider ways to guide derailed trains and to consider the longer-term implications of continuing to operate pre-modern standard rolling stock.
Note to Editors
- The sole purpose of RAIB investigations is to prevent future accidents and incidents and to improve railway safety. The RAIB does not establish fault, liability and does not take legal action.
- The RAIB operates, as far as possible, in an open and transparent manner. Although our investigations are completely independent of the railway industry, we maintain close liaison with the railway companies and if we uncover any issues that may affect railway safety, we ensure that the information to their topic is broadcast to the right people as soon as possible. , and certainly well before the publication of our final report.
- For media enquiries, please call 01932 440015.