Engineering work to keep rail traffic moving

The maintenance programme is to mitigate against extreme weather during the summer.

Network Rail’s engineers have been preparing the track and other infrastructure for hot spells and to maintain the smooth movement of passengers and freight.

Rails in direct sunlight can be as much as 20°C hotter than air temperatures and expand as they heat up, causing them to curve or buckle.

Engineers have been stressing sections of track (artificially stretching the rails) in known hot-spot areas to help them cope with sudden rises in temperature and painting the rails white in key locations to reflect the sun, keeping them up to 10°C cooler and helping prevent buckling.

Overhead power lines can also expand in prolonged heat, causing them to sag, which can disrupt services on busy routes as speed restrictions need to be introduced to prevent trains snagging on the wires. To combat this, the tension in the wires at some locations has been adjusted to levels that will help prevent sagging and keep trains running.

Summer rain can also cause flash-flooding with water quickly running off dry ground on to low-lying rail lines.

Tilt meters are being used to detect slope movement near the railway at nearly 100 sites across Scotland – alerting the railway’s controllers of potential problems within two minutes of an alert.

Aerial inspections are also helping to identify and fix faults at an early stage while meteorologists are monitoring the weather from a specialist control room to prepare for adverse conditions.

Liam Sumpter, Route Director, said: “We’re continuing to prepare for extreme weather using the latest technology, including tilt meters, remote temperature monitoring equipment and thermal imaging equipment for aerial inspections. Our engineers and everyone else on Scotland’s Railway are working hard to keep the railway reliable for all customers through the summer.”