Snow and ice can cause serious problems for the railway. Particularly at risk are areas where trains move more slowly, such as the approach to stations and points. Snow can get compacted by passing trains into solid ice which prevents points working, and ice can coat the electrified rail, preventing trains from drawing power.
Snow can be blown into signalling cabinets and cause a short-circuit; the system is designed to fail safe, so any problem turns signals in the area to red and trains cannot pass through.
Wind can cause snow to drift: if drifts reach 30cm, trains cannot run safely unless they're fitted with snowploughs. Heavy snow can cause branches to break off trees which can damage overhead wires and block the track.
When water seeps into tunnels, it can form sheets of ice inside which can damage passing trains when they become dislodged.
Winter conditions can affect trains too, with ice build up causing problems including jamming doors.
How Network Rail are minimising disruption caused by snow and ice
- Network Rail have six Snow and Ice Treatment Trains fitted with snow ploughs, hot-air blowers, steam jets, brushes, scrapers and jets for heated anti-freeze and compressed air to quickly de-ice tracks.
- Train companies run empty trains through the night to help keep tracks clear, and passenger trains can be fitted with snow ploughs which can clear up to 6 feet of snow – if it's deeper, Network Rail send in our fleet of dedicated snow ploughs.
- Major routes that are the most at risk have been fitted with fences that prevent snow blowing on to the tracks.
- Thousands of Network Rail staff patrol the tracks day and night clearing snow and ice from junctions and tunnels.
- Anti-icing fluid and heating strips are used on live conductor rails to prevent ice building up and preventing trains from drawing power; the addition of heating strips has reduced ice-related incidents by up to 80%.
- Network Rail are attached heaters and NASA grade insulation to points to prevent ice forming and added protective covers to 4,000 points and 2,500 points motors to keep snow out and prevent damage by ice falling from trains.
- Network Rails remote temperature monitoring and a helicopter fitted with thermal imaging cameras identify points heaters that are not working effectively.
- In areas badly affected by “frost heave” where water in the ballast freezes, expands and moves the track, Network Rail have re-laid it using a shallower bed of ballast to reduce the movement.
- Vegetation that is too close to the track is cut back – a continuous challenge as there are over 20,000 miles of track.
- Network Rail work with train companies to optimise the performance of their rolling stock, including upgrades to train software, heated couplings and improvements to door designs to prevent ice build-up. Network Rail share best practice with Sweden, Switzerland and other countries to improve our practices.