An East Midlands landslip last week followed heavy rain across Britain.
We look closer at landslips and explain how we respond to them…
Network Rail worked around the clock to reopen the East Midlands railway line following a landslip and flooding. The railway between Corby, Oakham and Melton Mowbray reopened last week, allowing train services to run again.
A landslip and flooding on Thursday 13 June led to the line’s closure, with Network Rail engineers removing 40 tonnes of material from the line. Train services ran on alternative routes during the works.
It came days after Network Rail published proposals to better protect the railway in south Devon from landslips, cliff falls and sea damage during extreme weather.
The 1.8km stretch of railway between Parsons Tunnel near Holcombe and Teignmouth closed for six weeks after a substantial landslide in 2014. A public consultation on the proposals has launched and will run for five weeks until 15 July.
The cliffs pose the greatest threat to the railway line in this location so the proposals include moving the railway away from the sections of cliff that pose the greatest hazard.
The design would require some land reclamation to allow a buttress – a sloping rock structure to stabilise the cliffs and protect the railway.
A rock revetment or enhanced sea wall would also absorb the energy of the waves and allow for the railway to be relocated away from the cliffs to protect the realigned railway from the sea.
Meanwhile, we hope to enhance leisure access, cycling and walking routes and provide new amenity areas so visitors Holcombe beach can continue to enjoy the space and views.
What is a landslip?
Landslips happen on the railway when soil, rocks and earth fall on to and cover the track. This is often after long periods of heavy rain, when the ground becomes saturated with water.
Landslips can cause a lot of disruption and delays on the railway by obscuring the track. A train can’t swerve to avoid debris on the line, so we will often need to re-route services.
Our specialist geotechnical engineers work across Britain to stabilise and repair weakened assets, enabling a network more resilient to future risk events, such as extreme weather.
What we do when there’s a landslip
Following an emergency like this, we deploy our engineers to carry out any immediate works to the affected areas; some of our previous weather-related emergency repair works includes stabilising hillsides and repairing cutting slopes.
Even after an initial landslip there continue to be concerns, so our engineers and contractors will assess the site and the damage before they can start to remove the debris from the track. Once a landslip has started to move, it’s much more likely that there will be further landslips.
Some of the slopes – or cuttings – on either side of our tracks need to be strengthened. This work to stabilise the earth can take time.
How we’re reducing delays caused by landslips
- It’s important we identify the sites prone to landslips to ensure we keep passengers and our engineers safe. We use helicopters equipped with laser imaging, detection and ranging to do this.
- Where we know sites are at risk of landslip, we use motion sensors and CCTV to detect soil and rock movement. These sensors send an alarm to the signaller, who will stop the train if alerted and wait until the area has been inspected by engineers.
- We can also stabilise the slope by putting in drainage or using steel rods or soil nails.
- If these options are insufficient, we will re-profile the slope to reduce its angle, making it less prone to a landslip.
- When we get flood warnings from the Environment Agency and Flood Forecasting Centre, we send people and equipment to the at-risk areas so we’re in a position to act quickly.