Network Rail has said that ground in the south east is at its driest since records began and continued dry weather could result in risk to geotechnical structures on the network.
The organisation has said that almost 3,000t of ballast was placed to stabilise rail lines in the region over the summer to mitigate against the effects of subsidence.
Speed restrictions have been put in place over high risk areas but Network Rail has warned that continued dry weather could result in additional speed restriction being put in place with soil moisture records indicating the ground is at its driest since records began 20 years ago.
“Many railway embankments in the region are made of clay and almost all of them are populated by trees and other vegetation,” said Network Rail route asset manager for the south east Derek Butcher. “So during long periods of hot weather without rain, deciduous trees can suck moisture from the ground faster than it can be replenished causing ground shrinkage.
“With the long range forecast predicting more dry weather, we are braced and ready for more issues.”
According to Butcher, three months’ worth of rain would need to fall in a month for ground water levels to return to normal, which based on current forecasts, he said is highly unlikely in the short term.