Rain

Rain

max temp: 17°C

min temp: 16°C

Search

Why are trains cancelled when the weather gets too hot?

PUBLISHED: 12:28 19 June 2017

Some trains to and from London were cancelled due to the high temperatures on Wednesday.  
Picture: SARAH LUCY BROWN

Some trains to and from London were cancelled due to the high temperatures on Wednesday. Picture: SARAH LUCY BROWN

With almost 50 trains being cancelled in the region today because of the hot weather, Greater Anglia has provided details which help explain the disruption.

Why don’t rails get hot in Europe?

The truth is, they do. However, in countries which have been traditionally hotter than ours, rails are stressed to be able to withstand higher temperatures.

Rails in the UK are stressed to 27 degrees, the UK mean summer rail temperature. The rail can withstand some degree of change in temperature either side of this. However, when the air temperature is 30 degrees, the temperature on the rail can actually be up to 20 degrees higher, exceeding the maximum temperature our rails are designed to cope with.

The problem is that when steel rails get hot, they expand and this can cause a type of signalling problem called a track circuit failure and in extreme cases can cause a buckled rail.

If a rail buckles then the train service will not be able to run at all until the buckled rail is replaced with a new one.

When Network Rail assesses that the temperature of the rails is going to exceed what it is designed to cope with they put speed restrictions in place to help prevent buckled rails.

A train going over a hot rail at a slower speed exerts less pressure on the rail and will help to prevent it buckling. Because overhead power lines also expand in the heat and sag, it also prevents the train’s pantograph from pulling the sagging wires down.

It means have trains have to run more slowly, and there will be fewer trains as a result, but this is better than causing a bigger problem and then being unable to run any trains at all.

Why don’t we replace all our rails with ones stressed for higher temperatures?

The UK, and particularly East Anglia, is seeing hotter summers these days so this may seem like the obvious solution. The problem is that if UK rails were stressed to the same degree as those in very hot countries, there would be the risk of rails fracturing when the rails contract as the temperature drops in winter.

Please check before you travel

Greater Anglia would like to apologise for the inconvenience caused by heat-related speed restrictions. While they are in place, please check how trains are running before you travel.

Where possible, we will try to make you aware in advance of any predicted timetable changes due to hot weather.

There will be extra staff at stations giving out water to any customers caught up in any disruption and we will be doing everything we can to get passengers from a to b reliably and in comfort.

Network Rail’s planned programme of engineering works, including the renewal of overhead lines and new rails will help to make the railway more able to cope with hotter temperatures in the future.

3 comments

  • Don't tell me. They don't stress them to more than 27 degrees because it would cost more?

    Report this comment

    chrisd0407

    Monday, June 19, 2017

  • So how do other countries that get hotter summers and colder winters than us copy ?

    Report this comment

    Jacqueline Norlem

    Monday, June 19, 2017

  • Maybe Greater Anglia should look at the other article and what other operators in the UK are doing. No other operator in the UK has so far cancelled trains due to the heat.

    Report this comment

    A Smith

    Monday, June 19, 2017

The views expressed in the above comments do not necessarily reflect the views of this site

A campaign group against the expansion of Stansted Airport has hit out at the airport’s claim that the environment won’t be affected – and has called for an “honest” assessment into the proposals.

Police officers in Essex have launched a search for a 14-year-old girl who has gone missing from her home in Halstead.

The next stage of work to make Ipswich Hospital’s wards dementia friendly has begun as renovations are underway on the Stradbroke Ward.

British comedy queen Sarah Millican is set to return to Ipswich next summer following her successful sold out show on her latest tour.

A 64-year-old man who pleaded guilty to death by dangerous driving has been jailed for seven years.

Suffolk and north Essex are filled with celebrity faces from jockey Frankie Dettori to news presenter Bill Turnbull.

An open event giving free advice and screening tests for tinnitus will take place in Ipswich tomorrow as part of ‘Tea for Tinnitus’ month.

Most read

Eating Out in the Broads

cover

Click here to view
the Eating Out
supplement

View

Visit the Broads

cover

Click here to view
the Visit the Broads
supplement

View

Most commented

Show Job Lists

Newsletter Sign Up

Sign up to the following newsletters:

Sign up to receive our regular email newsletter
MyDate24 MyPhotos24