NETWORK Rail staff and contractors were working on a long-term rain-related project in the Rhymney Valley when a downpour in September damaged the same line a few miles further south.

At Sebastopol, near Pontlottyn, more than 400 steel beams have been used to stabilise an embankment which suffered major slips in 1906 and 1932. Increased rainfall was causing the hillside beneath it to move, displacing the railway by more than 150mm a year and leaving trains restricted to 10mph.

Engineers removed and replaced 200 yards of track and 15,000 tonnes of earthworks material during the £8 million project. The reinforced embankment is designed to keep the track in place for a century.

For the main part of the work, the upper Rhymney line was closed from 25 July to 8 September. Two days before the end of that possession, torrential rain wreaked havoc across South Wales.

At Llanbradach, damage to the Rhymney line was so serious that train services were suspended for almost a fortnight, despite engineers working from 6am to midnight each day on repairs. The 30-strong team spent 2,800 hours reinforcing an embankment. They built a new retaining wall, restored the track and repaired a leaking gas main nearby.

Andrew Wozencraft, Network Rail’s infrastructure maintenance delivery manager for South Wales, said: “We were putting the track back in at Sebastopol on that very weekend that we had the downpour and suffered all the disruption across the railway. At Llanbradach there was a localised slip of about six square metres.

“The water came off the mountain and overwhelmed the railway’s drainage system. It flooded the area of Llanbradach station up to about eight inches.”

Part of the embankment was washed away as water found its own path from one side of the railway to the other.

He said working round the clock would have restored services a day or two earlier, but the site was close to local houses. “The residents were fantastic in recognising we had to do the work, but we didn’t want to overstay our welcome.”

Looking back, he said there were severe drainage problems about nine years ago, after which there was a lull.

“Over the last two years it’s raised its head again. We pay more attention to drainage now than maybe has been paid in the last 20 years.

“We’ve dealt with all the places that perhaps were legacy issues, and the drain-age can cope with day-to-day rainfall levels provided we maintain it properly.

“When we have a localised deluge, any system will struggle with that.”

Among those who showed their appreciation was Jeff Cuthbert, Welsh Assembly Member for Caerphilly. He said: “I fully understand the overriding importance of safety and the need to en-sure stability of the track, although it has been inconvenient for commuters and to some people living close to the landslip in Llanbradach.”

And he added: “I congratulate all those who have worked to repair the damage caused by the exceptionally heavy rainfall.”