THE derailment of a diesel-carrying freight train could affect the Heart of Wales line until Christmas, the Deputy Minister for Economy Transport has said.
Lee Waters has visited the site of the accident near Llangennech, Carmarthenshire, which he described as like something from a disaster movie.
The derailment and the damage to the wagons on the night of August 26 resulted in a major fire and spillage of 330,000 litres of diesel from 10 of the 25 wagons.
A multi-agency response kicked in straight away.
The track is part of the Heart of Wales line running between Swansea and Shrewsbury. Buses have now replaced trains between Llanelli and Shrewsbury.
Mr Waters, who is MS for Llanelli, described the response of all the organisations involved as “phenomenal”.
He said he was struck by serious the accident was – and how much worse it could have been.
“It’s amazing nobody died,” he said. “A short bit further down the track, and there could have been a significant loss of life.
“The scene was something out of a disaster movie.
“The intensity of the heat was extraordinary – the rail bed had disintegrated.”
Mr Waters praised the courage of the train driver and engineer – one of whom, he said, managed to decouple the train from wagons at the rear.
Diesel has been found at various sites in the nearby Loughor Estuary – part of the Carmarthen Bay and Estuaries Special Area of Conservation – and cockle beds and shellfisheries have been closed.
Mr Waters said he feared there would be a profound impact for years to come.
He said he believed Network Rail would be on-site for months, and Natural Resources Wales (NRW) for years.
He added: “The Heart of Wales line will be out of action up to Christmas, I would have thought.”
The rural line, which is popular with tourists, was affected by flooding over the winter.
Mr Waters said diesel-carrying trains which usually used the district line at Llangennech were being re-routed onto the mainline, but that smaller wagons were being used in order not to place stress on the Loughor railway bridge.
He said incidents like the one on August 26, which is being examined by the Rail Accident Investigation Branch, were costly. But he was reassured that cost would not be a limiting factor in this situation.
Accompanying Mr Waters on the site visit were Llanelli MP Nia Griffith and Gower MP Tonia Antoniazzi.
Ms Antoniazzi said: “It took me aback – the devastation at the scene. It was quite scary to see the track burnt out. It’s a major, major incident.”
She said she was concerned that the diesel could affect the Gower side of the estuary, where lambs graze on salt marshes.
She said she has asked NRW to test the water further out, and urged dog walkers and swimmers to report any pollution to the environmental agency.
“I’m pushing that message out – people should be reporting all incidents, however anecdotal they might think they are,” said the Labour MP.
NRW said that the diesel spill has been observed as far as Crofty, North Gower.
Speaking to BBC Wales, Ioan Williams, of NRW, said: “There may well be long-term effects, we don’t know yet is the bottom line.”
Llangennech councillor Gary Jones said the wagons were being taken to Llangennech train station and then transported away on lorries.
Cllr Jones said he was grateful for all the information which the various authorities were providing.
“I’m thankful for the village for their patience – we’ve got a lot of goodwill,” he said.