The railway line between East Grinstead and Lingfield, closed since 13 February 2020, is due to reopen on Monday 30 March.
The embankment is near Cookspond Viaduct in Dormansland, Surrey. Constructed in the Victorian period of Wealden Clay and later repaired with steam engine ash (materials that would not be permitted today), it first showed signs of slipping on 28 December. The area was thoroughly inspected and a temporary speed restriction of 20mph imposed, but trains could keep running.
Then, after Storm Ciara on 12 February, it slipped again. Monitors on the slope that had been installed after the earlier slip gave warning of the movement, so the line was closed quickly and passengers were never at risk.
A geotechnical inspection was made to see if the line, or at least one track, could stay open, but the best course of action was that, this time, the railway would be closed completely while repairs were made.
With further storms in the area, five more sites reported minor landslips, so Network Rail, working with contractor BAM Nuttall, had to undertake repair work over the whole area.
Once the old material had been removed, a wall of sheet piles was sunk 13 metres into the ground and was then backfilled using railway ballast.
Two of other landslips took place in a cutting with steep sides. These were cut back and the sides regraded to reduce the slope and make them more stable in future.
John Halsall, managing director of Network Rail’s Southern region, said: “We are on course to return this railway to use on Monday, at an absolutely crucial time, with key workers relying on us to get to their jobs.
“However, I can’t be as confident as I would like to be simply because we are seeing increasing numbers of our colleagues having to leave work to self-isolate and we don’t know what those numbers will be and who will be affected over the next two days.
“It’s been an incredible effort by everyone who has worked on the project to get so far so fast and I am so proud of their work, but we have to be realistic and admit the challenge we face.”
The number of trains that will use the reopened line will, in any case, be reduced due to the current Coronavirus (COVID-19) situation. Steve White, chief operating officer at Govia Thameslink Railway, said: “We would like to thank customers for their patience during this essential work.
“Network Rail really has pulled out all the stops to repair the landslips in this area and I applaud them for their efforts on behalf of the community and the railway.
“Our important message to everyone during this national emergency remains not to travel unless absolutely essential, but, for those key workers and people who have no choice, the completion of this work will be good news, reducing your travel time.”