Train services in Wales could be affected for the rest of the year, Transport for Wales has warned, after two Sprinter units were damaged by colliding with a mini digger which had been abandoned on the line near Craven Arms. No one was hurt.

The accident on Sunday night (22 May) started a fire, and Transport for Wales says the damage caused by the 60mph (97 km/h) collision will take several months to repair. TfW has warned that the absence of the trains will disrupt some services.

The mini digger is believed to have been stolen from a nearby rental yard before being abandoned on the line. British Transport Police has launched a major criminal investigation and is appealing for information about the incident.

Sprinters are the only trains used on many TfW routes, including the Core Valley Lines to Treherbert, Aberdare and Merthyr Tydfil.

Engineering work is also continuing at Radyr, and TfW has temporarily reduced Valley Lines services for the next few days, including suspending services on the City Line. Rail tickets are being accepted on local buses, and replacement buses are also being used to take pupils to the Bishop of Llandaff Church in Wales High School.

TfW planning and performance director Colin Lea said: ‘We’re hugely relieved that the incident at Craven Arms was not more severe. The quick actions of our driver and conductor ensured the trains were safely evacuated, and many colleagues worked hard to reopen the line as quickly as  possible once forensic investigations were complete.

‘The impact of this serious criminal act will however continue to be felt for some time. The loss of two trains will make it far more challenging to  provide additional capacity for busy services over the next few months, particularly for this summer’s major events at the Principality Stadium such as the Stereophonics and Tom Jones concerts in June.

‘We’re working with our industry partners to source any additional trains available to cover for the damaged units, and hope to be able to announce a temporary arrangement soon.’