UPDATED 16.45 (below)

The Rail Accident Investigation Branch has made its first statement about Monday evening’s head-on collision at Talerddig, in which one man was killed and 15 other passengers injured.

RAIB inspectors have been gathering evidence in a bid to discover how the two passenger trains came to meet on a single line section, about 800m west of the passing loop at Talerdigg. The down train, which apparently ran through the loop without stopping, was the 18.31 Transport for Wales service from Shrewsbury to Aberystwyth.

The up train involved was the 19:09 from Machynlleth to Shrewsbury, also operated by TfW.

The RAIB says initial evidence suggests that the collision occurred at approximately 24 km/h. Four of the 15 injured passengers are now known to have been seriously hurt.

The information from the down train’s data recorder has been downloaded. The track has been inspected, witnesses interviewed and data from radio and signalling systems analysed.

The RAIB’s initial inspection of the track near the collision point has found that wheel and rail adhesion was ‘relatively low’, suggesting that the train may have been affected by wheel slide when the driver applied the brakes to stop in the loop.

The RAIB said it will be issuing a further update soon. The Office of Rail and Road has confirmed that HMRI inspectors are also at the scene.

Meanwhile, a passenger on the down train told the BBC yesterday that the driver had tried to stop but the train still kept moving, which supports the RAIB’s suggestion that the wheels had lost at least some of their grip on the rails.

Welsh cabinet transport secretary Ken Skates said: ‘I am extremely grateful to the emergency services who attended the scene and helped our passengers and staff.

‘The safety of our passengers and staff is, as always, our key priority. Transport for Wales are working closely with all agencies, including emergency services and Rail Accident Investigation Branch, to understand how this incident happened, and they will have my full support.’

UPDATE 16.45  23 October

In a joint statement Network Rail and Transport for Wales said: ‘The Cambrian line between Machynlleth and Shrewsbury will remain closed until at least the end of Friday 25 October following a collision between two trains on Monday night.

‘The incident is currently under investigation by the Rail Accident Investigation Branch and will move to a recovery operation to remove the affected trains over the coming days.

‘Both TfW and Network Rail would like to express our heartfelt thanks to everyone in the local community for the overwhelming level of support they have provided during this difficult incident.

‘A replacement bus operation will remain in place calling at all stations on the route and customers should check before they travel and allow for journeys to take longer than usual.

‘Services between Machynlleth and Pwllheli/Aberystwyth and between Shrewsbury and Birmingham International will continue to run as planned.’