We're working to repair and reopen the railway following a freight train fire at Llangennech 

This is a multi-agency incident and we are working closely with DB Cargo – who operated the freight train, Puma Energy – who own the fuel that DB Cargo were carrying, Natural Resources Wales, British Transport Police and other agencies.

What happened?

Derailed freight wagons at Llangennech

At 23:17 on Wednesday 26 August a DB Cargo freight train carrying diesel derailed and caught fire near Llangennech.

The two railway colleagues on this freight service were both uninjured, and managed to separate the service to reduce the amount of wagons at risk of catching fire. The train was made up of 25 loaded wagons – each capable of holding 100,000 litres of diesel or gas oil. Of these, five wagons derailed and four were on fire. 14 wagons and the locomotive have been separated and are now away from site.

The resulting fire was significant due to the quantity of fuel the freight was carrying and as a precaution Dyfed-Powys Police evacuated a large number of homes within a radius of the fire and closed local roads. Residents were allowed to return to their homes once the Mid and West Wales Fire and Rescue got the blaze under control.  

An investigation has been launched by the Rail Accident Investigation Branch (RAIB), in conjunction with the Office of Rail and Road (ORR) and British Transport Police (BTP). Network Rail will cooperate fully with this investigation.  

The railway line remains shut; the passenger services that normally operate along this section of railway are currently replaced with bus services until the railway can reopen. Natural Resources Wales are on site to assess the impact of the diesel spillage on the local environment including marine and wildlife.


What are we doing?

Update: Wednesday 10 February

We’re continuing to make great progress at Llangennech, where our frontline teams are working round the clock to reopen the railway for essential journeys and freight.

Despite a number of challenges on site, including the extreme weather brought by Storm Christoph, we’re delighted to confirm that we remain on course to complete our work on site in early March.

This means we can fully reopen the Heart of Wales line from Shrewsbury to Swansea for the first time since August 2020, with passenger and freight services also resuming operations via the Swansea District line.

With the installation of 530 metres of brand-new track nearly complete, the final stage of our work at Llangennech involves repairing the signalling equipment that was damaged during the derailment.

Our partners at Transport for Wales are also busy, delivering refresher training for their drivers so that we can restore a rail service for the length of the Heart of Wales line as soon as possible once it is reopened.

The work to reinstate the railway follows one of the biggest environmental recovery operations Network Rail has ever been involved with.

Over 30,000 tonnes of contaminated soil has been removed from site to help protect the precious local environment for generations to come, and our frontline railway colleagues played a key role in helping avert an environmental disaster – working with our partners at Natural Resources Wales and the many other agencies involved.

Update: Friday 11 December

Remediation work to remove and replace 12,000 cubic metres of diesel contaminated soil around the site has begun.

Specialist environmental contractors Adler and Allan and Jacobs are carrying out the complex operation. They will be working around the clock for the coming weeks to complete the work safely and as swiftly as possible.

The remediation plan has split the contaminated site into cells. Each cell will be carefully excavated, removing up to 30 cubic metres of affected soil at a time. It will be removed from the site by lorry and safely treated at a licenced waste management facility near Merthyr Tydfil.

The excavated areas will then be filled with clean quarried materials specifically selected to match the pH levels of soils in the area, and the replacement railway line is expected to be put in place, if all goes to plan, early in the new year.

An area of woodland to the north east of the incident site on Coal Authority land will also be similarly restored.

Multi-agency strategic and tactical groups are overseeing the recovery effort.They include representatives from Natural Resources Wales, Carmarthenshire County Council, City and County of Swansea, Network Rail, British Transport Police, Food Standards Agency, Welsh Government, Public Health Wales and the Coal Authority. They’re working together to reduce any potential for impact of the incident on the local community, the environment and the economy.

Monitoring and sampling work at the derailment site and the surrounding area will continue. This includes monthly sampling of cockles to ensure there is no risk to public health through further seepages of diesel into the wider environment.

Work site at Llagennech
Remediation work has begun

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