As the authorities investigate the causes of the recent Stonehaven train crash, ICE’s rail experts discuss the next steps in ensuring the future safety of rail networks in the face of extreme weather.
An official investigation has begun into the Stonehaven train derailment on Wednesday, 12 August that left three people dead.
The driver, Brett McCullough, a conductor Donald Dinnie, and one passenger,Christopher Stuchbury, were killed when the 6.38am Aberdeen to Glasgow Queen Street train derailed near Stonehaven amid heavy rain and flooding. Six other people were injured and taken to hospital, as well as four firefighters who were hurt while dealing with the aftermath.
The Rail Accident Investigation Branch has now confirmed that the accident was caused by the train hitting a landslip.
The risk of landslips to railway networks
Landslips are widely recognised as one of the greatest risks to Britain's railways and given Scotland's geography, are a particular concern. A changing climate will increase this risk. Heatwaves and droughts can dry out steep embankments, weakening them, while increased and heavier rainfall make landslips more frequent.
An annual health and safety report by the Office of Rail Regulation highlighted that there were six times more flooding events on Britain’s railways in 2019-20 than during the previous 12 months and noted a spike in landslips, demonstrating the “vulnerability” of the network.
Scotland's Transport Minister Michael Matheson has confirmed the conditions were a factor and Network Rail footage shows there were landslides in the area. Matheson told The Guardian: "I think one of the things we will see from the investigation is whether the pace of that type of mitigation work needs to be stepped up; that’s not just a challenge across Scotland, it’s across the whole of the UK."
Jonathan Buttery, Chair of the Railway Civil Engineers Association told ICE that Network Rail operate a regular assessment of structures:
“Network Rail own and maintain some 16,000km of railway in the UK, which includes a variety of earth structures. Much of the railway is more than 150 years old. Network Rail operate a regime of regular inspections and assessment of earth structures including maintenance, repair and strengthening works.
“Chances of landslides increase after an intensive rainfall, which results in an increase of pore pressure within the earthworks and is a common cause of landslides, across the UK within railway infrastructure," says Buttery. "Clearly this is early days in the investigation and it will be for Network Rail to determine what has happened and the route cause. This will include determining if weather was a factor, what steps were taken and what steps may need to be taken in future to further safeguard the railway against the risk of such events.”
In the wake of the accident Prime Minister Boris Johnson told The Times there should be an investigation into the impact of torrential rain on UK infrastructure. Government advisers and leading infrastructure experts have said ministers must do much more to protect the UK’s infrastructure from extreme weather.
So what steps should be taken to ensure future safety against increasingly adverse weather conditions?
Alan Taggart, a civil engineer with KPMG says the impact of heavy rain on transport infrastructure has been well documented with the Department of Transport issuing a report on the impact of flooding and climate change on infrastructure over 10 years ago.
"Inevitably landslides on aging, largely Victorian infrastructures should be expected at an increased frequency not only because of age but because of the increased severity of storms," continued Taggart.
Network Rail has a documented risk-based approach for inspections for earthworks but with limited funds they will need to make decisions on when they inspect and what they repair. I don’t have the information at hand to know if the correct procedures had been applied but no doubt that would be the subject of an investigation."
Richard Coackley, a past ICE President adds: "Scotland appears to have been seriously impacted by storm events recently. It does appear that localised weather events may be increasing in their intensity. If this is the case it will have an effect on our transport, water, communications and energy services that we all heavily rely on every day right across the UK. This calls for detailed risk assessment of our infrastructure assets and potential remedial measures to be taken where necessary to safeguard us all against loss of life".
Geoff French, another past ICE President told The Guardian that it's essential that regular checks are carried out on areas such as cuttings and slopes around railways. “The challenge is to identify the most critical infrastructure and deal with that. You need to reduce the knock-on impact, when one piece of infrastructure fails," says French.
As Alan Taggart says: "The tragic loss of human life brings the impact of these decisions home."
Head over to our Civil Engineer blog section for further comment on rail infrastructure from Jim Young, Chair of ICE Scotland's Public Voice Committee .