The Cambrian Line in Wales, known as the first rail route in the United Kingdom equipped with the European Rail Traffic Management System (ERTMS), is set to reopen today for regular services following a tragic collision last week. This incident marked the first fatal rail accident in the UK in several years, leading to a thorough investigation into the collision’s causes, including an analysis of how the standardized European safety system, designed to minimize such incidents, functioned during the event.
Investigation and Line Clearance
On Friday, Network Rail and Transport for Wales (TfW) confirmed the completion of their on-site investigation in central Wales, which allowed engineers to begin removing the two damaged trains from the scene. Both organizations noted that services on the Cambrian Line, a vital regional route, are expected to resume on Monday.
The collision, which occurred near Llanbrynmair in Powys, central Wales, claimed the life of one person and injured fifteen others when two passenger trains collided last Monday evening. The trains reportedly collided at a relatively low speed of around 30 km/h, with the deceased individual believed to have suffered a fatal heart attack following the impact.
For nearly a week, traffic along the line was halted, causing significant disruptions in the region. The Rail Accident Investigation Branch (RAIB), an independent agency, is now examining how both trains ended up on a collision course, aiming to uncover the sequence of events leading up to the accident.
Network Rail’s Safety Measures
Since the accident, Network Rail engineers have conducted repairs, maintenance work, and extensive inspections along the Cambrian Line, as UK authorities sought to reassure the public about the route’s safety. Test trains ran over the weekend to ensure a smooth resumption of services today. However, Network Rail has advised that short-term impacts on rail services may persist, and passengers are encouraged to check schedules before traveling.
“The tragic events of Monday night will remain with me always, and my thoughts go out to everyone affected,” said Nick Millington, Wales & Borders Route Director at Network Rail. “Fortunately, such incidents are extremely rare on the rail network. I am grateful to the local community for their understanding last week as we managed this incident. I would also like to thank passengers for their patience, understanding, and support over recent days as our teams worked tirelessly to restore the railway as quickly as possible.”
Investigation Focus: Autumn Conditions and Track Adhesion
The RAIB team has indicated that one focus of the investigation will be the low wheel-to-track adhesion, which suggests the train may have slid along the track when the driver attempted to brake. Professor Stuart Cole, Emeritus Professor of Transport Economics, mentioned in Nation.Cymru that investigating wheel surface smoothness could shed light on the issue.
The Cambrian Line is surrounded by wooded areas, and the heavy leaf fall is suspected as a factor in the low adhesion. When compacted on tracks, layers of fallen leaves can create a slippery surface, disrupting the wheel-to-rail contact and potentially impeding braking.
In recent years, the UK’s system for leaf removal on railways has seen substantial improvements. Leaf-cleaning trains now use powerful water jets to remove leaf residue, and an adhesion modifier made from sand, aluminum, and adhesive is applied after cleaning to help increase grip on the rails.
Single-Track Line Risks
Another point of concern is the Cambrian Line’s status as a single-track railway. While it includes passing loops to allow trains traveling to Aberystwyth and Shrewsbury to pass safely, one of these loops is located on a gradient near Talerddig, one of the UK rail network’s highest points. Since its construction, this setup has posed operational challenges.
Single-track railways, where trains run in both directions, inherently carry higher risks compared to double-track routes. To ensure safety, Transport for Wales has imposed speed restrictions on all single-track lines, including the Cambrian Line. Several “dynamic” loops on the Cambrian Line also allow trains to pass each other without stopping, maintaining the flow of traffic.
ERTMS and Potential for Errors
The primary safety system on the Cambrian Line is the European Train Control System (ETCS), the signaling component of ERTMS, which was introduced in 2011 as the first ERTMS installation in the UK. Network Rail is currently adapting its system to meet European standards, theoretically enhancing safety. However, last week’s accident raises some concerns.
In October 2017, an investigation into the Cambrian Line found a failure to communicate critical speed restrictions during adverse weather conditions, which allowed trains to exceed safe speed limits. The issue arose from a data upload error following a routine computer reboot, leading to uncommunicated speed restrictions despite the system indicating that data was loaded. While ERTMS is intended to significantly increase rail safety, both human and technical errors remain possible.
“We are working closely with emergency services and a multi-agency team to fully understand what happened and why,” stated Martin Frobisher, Director of Safety and Engineering at Network Rail. “Our immediate priority is to support those affected and assist investigators in determining the cause of the accident. Serious rail accidents are rare, and we are committed to making them even rarer.”
The investigation’s outcome will likely contribute to ongoing efforts to improve the UK rail network’s safety standards, especially as autumnal conditions present additional challenges for single-track lines like Cambrian.
This article is originally published on railtech.be
