Speed restrictions are to be imposed across wide parts of the rail network amid warnings of a record UK heatwave.

With temperatures forecast to soar into the high 30s, steel rails could top 50C in the sun – leaving the risk of buckling under pressure. Our network is made of 20,000 miles of steel track, which absorbs heat easily. In the summer, the track can get up to 20 degrees hotter than the air temperature. When steel becomes very hot it expands and if there is no room for the rail to expand further, this can cause the rail to buckle. If rails buckle the line has to be closed for repair before trains can run again.

In some locations we may have to introduce speed restrictions during the hottest part of the day at vulnerable locations as slower trains exert lower forces on the track and reduce the likelihood of buckling.

To protect passenger safety, speed limits are being halved on the Midland Main Line south of Leicester. This is set to lead to train cancellations, longer journey times and busier services. The speed limit on the East Coast Main Line will also be halved south of Peterborough. 

Rob McIntosh, Managing Director of Network Rail Eastern, said: “Passenger safety will always be our number one priority. And with forecasts of unprecedented temperatures, we have to take action to keep people safe.

“Reducing speed limits will mean fewer services and busier trains on our main routes into and out of London.

“So I’d like to ask all passengers to think about whether their journey is really necessary and, if it is, to make sure they plan well ahead.

“I’m sorry for the disruption this will cause, but it is essential to maintain the safety of the travelling public.”

The speed limit of the Midland Main Line is 125mph in normal circumstances. But the extreme weather is set to see that limit reduced to 60mph at the southern end of the line.

Train operating companies are working on revised schedules, but there will be significantly reduced services, with longer journey times and the likelihood of overcrowding.

Anyone who has to travel should consult operators for the latest travel information, allow extra time for their journey and carry water with them.

It is hoped services will return to normal on Friday, with temperatures forecast to drop.

ENDS