Rail engineers are fighting back against the effects of the hottest summer on record to keep passengers moving in Sussex.
The prolonged drought means the ground is the driest it has been since soil moisture records began almost two decades ago, with pothole-like defects preventing some trains from running at full speed.
It means some journey times have been extended by a few minutes in localised areas, but with the long-range weather forecast predicting more dry weather, there is a risk of more speed restrictions for safety reasons.
Network Rail engineers have been repairing nine miles of track defects with almost 3,000 tonnes of stone.
Derek Butcher, Network Rail’s route asset manager for the South East and a geotechnics engineering expert which involves the study of soil, said: “The Met Office declared this year’s summer the joint hottest on record with only half the average rainfall in the South East.
“Therefore, it’s not just gardeners bemoaning this incredibly dry weather. Network Rail staff in Kent and Sussex are working around the clock to ensure millions of passengers in the region can travel safely.
“Many railway embankments in the region are made of clay and almost all of them are populated by trees and other vegetation. So during long periods of hot weather without rain, deciduous trees can suck moisture from the ground faster than it can be replenished.
“This causes the ground under the track to shrink and much like potholes on the roads, trains can’t drive at full speed over these defects. We’re doing everything we can to stay on top of these problems and stop the risk of increasing journey times.
“But with the long range forecast predicting more dry weather, we are braced and ready for more issues.”
Network Rail engineers and staff from train operators are monitoring the bumpiness of train rides across the region on a daily basis to identify areas in need of maintenance.
This involves adding more stone to support the tracks, before Network Rail’s special fleet of tamping machines realign the rails. This work is completed at night so services are not disrupted.
Without this work passengers could face delays from speed restrictions, which have to be put in place to slow trains down for safety reasons.
In some areas, and only where it is absolutely necessary, Network Rail will need to clear what are considered the thirstiest trees and vegetation to remove the risk of further damage to the tracks. However, it will always write to neighbours before work begins.
So far in Kent and Sussex, Network Rail has spent almost £300,000 tackling the issue over the past nine weeks and is now increasing resources even further
Network Rail has also spent £283,000 on repairing defects caused by the drought.
Environmental experts have carried out 50 site visits to trees causing the most problems to the safe running of the railway.
Staff are riding trains on all routes every day to monitor track quality and schedule more work where needed.
Mr Butcher added: “We would need three months’ worth of rain to fall in a month for ground water levels to return to normal, which based on current forecasts is highly unlikely in the short term.”
Mark Killick, Network Rail’s chief operating officer for the South East, said: “Of course we would prefer not to implement speed restrictions anywhere because these cause delays for passengers, and indeed we’re sorry for any delays people may have experienced so far.
“However, we’re doing everything we can to ensure we minimise the impact to passengers.”