£5 million flood protection work at Honiton Tunnel
The West of England Line was closed between Axminster and Pinhoe from Monday-Friday September 19-25, to enable Network Rail to carry out work to prevent landslips and mitigate flooding by the entrance to Honiton Tunnel.
NR said it was one of the most at-risk sites in the south of England, with complex layers of clay, silt and gravel. It already had electronic sensors in the cutting sides to monitor movement.
There have been numerous landslips at the site. The most recent was in 2012, but in 2001 a landslip resulted in a train being derailed.
The £5 million project included improved drainage to make the route more resilient to extreme weather.
The ground was described as “waterlogged,” even though the route remains subject to speed restrictions further east in Wiltshire and Dorset, where clay embankments have been drying out and shrinking after months with minimal rain.
A Network Rail spokesman said: “Engineers have encountered many natural springs since beginning work, with pumps in constant use.”
A 5km access road had to be built to get machinery onto site. The cutting sides have been regraded, with deep posts placed near the track to reduce the likelihood of future landslips.
South Western Railway Commercial Director Peter Williams said: “We recognise the decision to close the line for an entire working week will have a significant impact on those who use the line, but this will avoid a more protracted series of closures instead.”