The fatal collision of two trains between Talerddig and Llanbrynmair in rural Wales on Monday evening is, in many respects, unique in Britain’s recent rail experience. No head-on crash had been recorded this century, and there had only been one fatal passenger train crash since 2007 in the UK.
Inspectors from the Rail Accident Investigation Branch (RAIB), who arrived on the scene in Powys on Monday night and resumed in daylight, are likely to release an early report this week.
While any conclusions drawn before the official investigation are speculative, reported witness testimony of a train unable to stop, the low speed and the time of year, all make leaf fall a likely line of inquiry, especially given the track was in a deeply wooded region of Powys.
As Network Rail puts it, leaves on the line are the rail equivalent of black ice on roads. In autumn, specialist rail-head treatment trains run daily, or more when necessary, to blast leaves from the rails.
The astonishing account from passengers of a driver running into the carriage warning them to brace for impact underlines the very low speed of the collision – seemingly less than 20mph – and the possibility that at least one train was out of control.
The incident occurred about 900 metres (1,000 yards) beyond a passing loop where the Aberystwyth-bound train would have been expected to stop and wait for the other to pass, but somehow travelled right through to the point of impact.
The last UK passenger train collision, in autumn 2021 in Salisbury, was found by investigators to have been caused by leaves on the line, when the driver’s attempts at braking were insufficient to stop the train passing through a red light in strong wind and rain.
There may also be another area of inquiry. The Cambrian line where the two small Transport for Wales sprinter trains collided, despite being mostly single-tracked and running through some of the least-populated parts of Britain, benefits from some of the most hi-tech signalling.
It was used as the pilot for the introduction of digital signalling and train control systems known as European rail traffic management system (ERTMS) and European train control system (ETCS), which are now being installed on part of the east coast mainline between London and Edinburgh a decade after being operational in mid-Wales. That means a crash is unlikely to be due to human error by signallers or drivers; a train should automatically brake should another train be ahead, even if the driver fails to do so.
But the system itself has been the subject of previous RAIB reports: in October 2017, the loss of safety-critical data on the Cambrian line was investigated after temporary speed restrictions due to weather conditions were not relayed properly, meaning trains exceeded the safe speed limits.
Whatever the cause is found to be, the collision represents another tragic blemish on the UK railway’s comparatively strong safety record. The story of most of the last two decades, after a sequence of appalling crashes in the early days of privatisation under Railtrack from 1999-2002, has been a huge focus on safety and, for many years, zero passenger deaths.
Rail remains by far the safest form of travel. Even as investigations resumed on the Welsh railway on Tuesday morning, the M6 motorway was closed again for another car crash.
However, the latest incident comes only three years after the Salisbury collision, and if leaf fall proves to be the culprit, will put Network Rail’s rigorous autumnal cleaning processes in the spotlight again.
It also follows the Stonehaven crash in 2020, where heavy rainfall and a substandard drainage system ended up derailing a ScotRail train and killing three people, including the driver and a guard. That prompted warnings that Britain’s railway would need more investment to protect from ever more extreme weather and a changing climate.
Rail professionals will say they never took the proud safety record for granted, when more than a decade passed without a crash. Three collisions in four years starts to look like a more uneasy sequence.
• This article was amended on 23 October 2024 to clarify that the European train control system is being installed on part of the east coast mainline between London and Edinburgh, not on all of the route.
