A railway line has reopened following a six-month operation to avert “total environmental disaster”, Network Rail said.
The derailment of a freight train in Llangennech, near Llanelli in South Wales, on August 26 last year caused a huge fire and the spillage of around 350,000 litres of diesel.
There was major concern for a wildlife conservation area and waterways when the accident happened.
Network Rail, Natural Resources Wales and other organisations put in a total of 37,500 hours of work to protect the local environment, remove the 25 train wagons and repair the damaged railway.
This included 30,000 tonnes of fuel-soaked soil being excavated and replaced with clean material, while nearly 1,740ft (around 530m) of new track was laid.
The closed section of railway was at the southern end of the Heart of Wales line, which runs from Shrewsbury to Swansea.
Freight services resumed on Friday, with passenger trains returning on Monday.
Network Rail route director Bill Kelly said the project was “one of the biggest environmental recovery operations Network Rail has ever been involved in”.
He continued: “It is thanks to our quick-thinking frontline teams, along with our partner agencies, that the fuel spill was able to be contained so swiftly, allowing us to prevent what could have been a total environmental disaster.
“Our teams have worked non-stop for the past six months and their dedication has paid off.
“We can confidently say the measures we have taken will protect the local environment for generations to come.”
Natural Resources Wales compared the scale of the incident to the Sea Empress disaster of 1996, in which a tanker spilled 72,000 tonnes of crude oil and hundreds of tonnes of fuel when it ran aground off the Pembrokeshire coast.
Martyn Evans, who chairs its Recovery Co-ordination Group, described the reopening of the railway as “a huge milestone in what has been a complex, challenging and ultimately successful recovery operation at a location of international environmental significance”.
Lee Waters, member of the Senedd for Llanelli, said: “When we first visited the site after the derailment it was like a disaster movie, but each time I have revisited since it has been clear to see the amount of effort that has gone into saving the environment and reinstating the railway.”
The train, owned by DB Cargo UK, was travelling from Robeston oil refinery in Milford Haven, Pembrokeshire, to a fuel distribution terminal in Theale, Berkshire, when the accident happened,
The derailment caused several explosions, leading to a major incident being declared and 300 people being evacuated from their homes.
The Rail Accident Investigation Branch issued a preliminary report in September 2020 stating that some of the train’s wheels were damaged by a fault with the brakes after a component became loose.
Investigators said there was “no record of any check on the tightness of the fastenings ever having been made”.