Heatwave 22-27 June - effect on the UK Railway

[Peterthegreat]

As the next few days are forecast to be very hot, especially over Southern England and the Midlands, I thought it would be useful to start a thread as I'm sure there will be some issues arising.

Incident: Hot weather | National Rail

Hot weather may affect your journey in England and Wales today: please check before you travel. Find details of all current incidents on National Rail Enquiries.

www.nationalrail.co.uk

Met Office are advising that heatwave conditions are forecast for parts of England and Wales with temperatures expected to remain high until at least Saturday 27 June.

The hot weather is set to be widespread over England and Wales, and highs of up to 38°C are possible in some areas this week. An amber weather warning has been issued for extreme heat covering parts of England and Wales from today, Monday 22 to Thursday 25 June.


To start things off :-
Northern have already cancelled all the Yorkshire Flyers in both directions quoting "more trains than normal requiring repairs". As they did this during the May heatwave it is likely to be linked to the extreme weather and worries over unit availability.
Any other changes?

 

[speedy1]

edit: removed repeating of bad information

 

[skyhigh]

The heat wave is so powerful it is causing psychosis, TOCs imagining morning temperatures that don't exist. They couldn't run Sheffield-Leeds this morning because of the blistering 15-18c temperatures?

Northern have already cancelled all the Yorkshire Flyers in both directions quoting "more trains than normal requiring repairs". As they did this during the May heatwave it is likely to be linked to the extreme weather and worries over unit availability.

It's just coincidence. There are 18 diesel units stopped on Neville Hill today for repair/exam so the issue is poor fleet availability, not heat.

 

[Horizon22]

The heat wave is so powerful it is causing psychosis, TOCs imagining morning temperatures that don't exist. They couldn't run Sheffield-Leeds this morning because of the blistering 15-18c temperatures?

If rail has recently been relaid or not fully stressed then the rail temperature threshold can be surprisingly low. @Bald Rick has previously explained how he’s had to explain this counter-intuitive behaviour. If that is even indeed the reasons for the cancellations.

That being said, 35+ degrees C is not low on any metric.

 

[Haywain]

If rail has recently been relaid or not fully stressed then the rail temperature threshold can be surprisingly low. @Bald Rick has previously explained how he’s had to explain this counter-intuitive behaviour. If that is even indeed the reasons for the cancellations.

That being said, 35+ degrees C is not low on any metric.

And rail temperature can be up to around 20 degrees higher than air temperature. Ironically, I read a piece about this last night in an old copy of Modern Railways magazine.

 

[Freemo]

It's just coincidence. There are 18 diesel units stopped on Neville Hill today for repair/exam so the issue is poor fleet availability, not heat.

The Yorkshire Flyer I was on a week ago had the radiator next to me stuck on which definitely would've been suboptimal this week.

 

[GB]

I remember a few years ago that during a spell of hot weather all freight movements were banned between about 10am - 8pm in East Anglia. Any word if that is likely to happen again?

 

[mike57]

Does anyone know if Rolling stock procurment and/or Network Rail are or have adjusted their specifications based on the fact that the highest summer temperatures have increased by about 4-5C over the last 25 years. Looking at the forecast for this week it also appears that the July 2022 40C was not an outlier or a 'hundred year event but the new norm.

 

[Benjwri]

Does anyone know if Rolling stock procurment and/or Network Rail are or have adjusted their specifications based on the fact that the highest summer temperatures have increased by about 4-5C over the last 25 years. Looking at the forecast for this week it also appears that the July 2022 40C was not an outlier or a 'hundred year event but the new norm.

Most modern rolling stock handles the heat okay in the last 40C summer.

It’s a lot more tricky for NR because we also have cold winters. It is difficult to make the railway operate over stuck a large temperature range and switching it to allow us to operate in 40 degree heat like Spain for example would lose our ability to operate in colder weather.

 

[The exile]

It’s a lot more tricky for NR because we also have cold winters. It is difficult to make the railway operate over stuck a large temperature range and switching it to allow us to operate in 40 degree heat like Spain for example would lose our ability to operate in colder weather.

Much of central continental Europe has a similarly wide temperature band to cope with. What they haven’t had (yet) is that much high-speed rail.

 

[DarloRich]

Does anyone know if Rolling stock procurment and/or Network Rail are or have adjusted their specifications based on the fact that the highest summer temperatures have increased by about 4-5C over the last 25 years. Looking at the forecast for this week it also appears that the July 2022 40C was not an outlier or a 'hundred year event but the new norm.

for future stock / equipment perhaps but any "in flight" specifications will be locked in with a cost associated with changing the spec.

( Uncontrolled specification change being one of the big problems with government contracts imo)

 

[Haywain]

Does anyone know if Rolling stock procurment and/or Network Rail are or have adjusted their specifications based on the fact that the highest summer temperatures have increased by about 4-5C over the last 25 years. Looking at the forecast for this week it also appears that the July 2022 40C was not an outlier or a 'hundred year event but the new norm.

For Network Rail, it's not something that can be easily done in the short term. You can't just relay all the track to be stressed for higher temperatures without having years to do it.

 

[Nicholas Lewis]

Much of central continental Europe has a similarly wide temperature band to cope with. What they haven’t had (yet) is that much high-speed rail.

Indeed they have a wider diurnal range than the UK and I believe they set the stress free temperature (SFT) higher than UKs 27 Deg C. Theres probably a case now in the UK to have a higher South SFT given climatic changes. There are equal risks when it gets too cold as the rail can pull apart as it contracts and leave a gap of several cm's that is a derailment risk hence why the lower SFT should be kept for Northern half of the country.

 

[voyagerdude220]

Looking on the GWR Journey Check page, it appears as if GWR have removed stops at Twyford, Maidenhead and Slough on their London Paddington to Didcot Parkway services and vice versa due to "severe weather." Some longer distance trains have had extra stops added to compensate.
Infrastructure issue?

 

[CalderRail]

And rail temperature can be up to around 20 degrees higher than air temperature. Ironically, I read a piece about this last night in an old copy of Modern Railways magazine.

I did notice Network Rail have re-upped their explainer page on the issue; presumably in the hope that some journalist might read it before asking stupid questions: https://www.networkrail.co.uk/rail-travel/delays-explained/buckled-rail-and-summer-heat/

When Britain enjoys a summer heatwave, rails in direct sunlight can be up to 20°C hotter than the air temperature. Steel rails expand as they get hotter and can start to curve, a phenomenon known as ‘buckling’.

Most of the network can operate when track temperatures reach up to 46°C, which is roughly equivalent to an air temperature of around 30°C. However, rails have been recorded at temperatures as high as 51°C.

 

[Ashley Hill]

I would imagine that there might be some diesel haulage on Heritage railways today.

 

[Mcr Warrior]

Looking on the GWR Journey Check page, it appears as if GWR have removed stops at Telford, Maidenhead and Slough on their London Paddington to Didcot Parkway services and vice versa due to "severe weather."

Twyford, presumably? Be somewhat off route if it was Telford!

 

[1D54]

I remember a few years ago that during a spell of hot weather all freight movements were banned between about 10am - 8pm in East Anglia. Any word if that is likely to happen again?

Must make things quiet interesting at the port of Felixstowe.

 

[GB]

Must make things quiet interesting at the port of Felixstowe.

Makes it a lovely shift!

 

[DarloRich]

I would imagine that there might be some diesel haulage on Heritage railways today.

Oil fired loco in use on the Vale of Rheidol according to the socials. I wonder if Omaha is in use on the NYMR ( unsure if in general service yet)

 

[mike57]

You can't just relay all the track to be stressed for higher temperatures without having years to do it.

No but any work going forwards would take account of the changes surely...

Much of central continental Europe has a similarly wide temperature band to cope with.

I would have thought Mid west USA has an even higher temperature range, but of course speeds are lower, and its mainly freight.

any "in flight" specifications will be locked in with a cost associated with changing the spec.

But if the current spec is going to cause a problem in the future given that rolling stock lifetimes can be 30 years then surely not dealing with it is just creating another 'self inflicted' problem.

 

[Haywain]

No but any work going forwards would take account of the changes surely...

It would take a long time to have any significant impact.

== Doublepost prevention - post automatically merged: 22 Jun 2026 ==

Aside from rails, the other significant impact of hot weather is on overhead lines, where heat causes sag and the tensioning is by weights which can only go so far before they become ineffective.

 

[CharlieSpotted]

Most modern rolling stock handles the heat okay in the last 40C summer.

The rolling stock may handle 40c, but the infrastructure sure doesn't! On one of the 40c days that year sagging overhead wires caught on a train in the tunnels at New Street, which pulled it all down, resulting in the evacuation of several trains, crippling New Street, in the evening peak.

In the ensuing chaos I was unfortunate enough to be on a train to Wolves that was misrouted and we were turfed off onto the platform at Tame Bridge Parkway (there could hardly be a worse place in the midlands to be left!) and had to wait a considerable amount of time there, with little to no shade, in 40c temperatures to be rescued... back to New Street.

I won't be commuting to the office this week.

 

[Kilopylae]

Looking on the GWR Journey Check page, it appears as if GWR have removed stops at Telford, Maidenhead and Slough on their London Paddington to Didcot Parkway services and vice versa due to "severe weather." Some longer distance trains have had extra stops added to compensate.
Infrastructure issue?

Speculating, but perhaps it's because a full-and-standing 387 isn't adequately stocked with emergency water bottles, or ventilated enough, to be safe? So they're keen to avoid overcrowding on suburban units/at least push it onto the properly stocked 800s.

 

[ChrisHogan]

Speculating, but perhaps it's because a full-and-standing 387 isn't adequately stocked with emergency water bottles, or ventilated enough, to be safe? So they're keen to avoid overcrowding on suburban units/at least push it onto the properly stocked 800s.

Avoids using the Dolphin crossovers, only recently renewed, to cross from Reliefs to Mains. It means pushing more people onto the Elizabeth Line trains.

 

[thenorthern]

Yesterday I was on an Avanti train and they advised passengers to avoid Coach D as the Air Conditioning was broken. That is one of the worst things to happen when it's hot.

 

[Lighteight123]

If rail has recently been relaid or not fully stressed then the rail temperature threshold can be surprisingly low. @Bald Rick has previously explained how he’s had to explain this counter-intuitive behaviour. If that is even indeed the reasons for the cancellations.

That being said, 35+ degrees C is not low on any metric.

If rail has recently been re-railed the CRT shouldn’t drop (it actually usually raises due to it being re-stressed). It’s a track condition code 2 from TRK/001/MOD14 meaning there is no negative modifier to the SFT (Stress Free Temperature).

Track work will only affect CRT if there was a ballast disturbance during it, which isn’t the case for re-railing.

If there are any teams leaving rail in cold or unstressed at this time of year (which I don’t necessarily doubt) they need to buck up their ideas.

 

[sh24]

Any thoughts on likely WCML disruption? London-Manchester-Stoke-London in the next 36 hours for several important meetings and want to be back for the football on Tuesday night.

 

[Haywain]

Any thoughts on likely WCML disruption? London-Manchester-Stoke-London in the next 36 hours for several important meetings and want to be back for the football on Tuesday night.

It wouldn't be a surprise to see speed restrictions imposed, if nothing else, so you should anticipate longer journey times than advertised.

 

[mike57]

Yesterday I was on an Avanti train and they advised passengers to avoid Coach D as the Air Conditioning was broken. That is one of the worst things to happen when it's hot.

I had a journey back home from Sheffield on Saturday afternoon on a 170 where the aircon had failed, the staff apologised, and Saturday wasn't the hottest day in our area recently. Not improved by large numbers of extra passengers making for Doncaster because of the Bedford accident. Drank my 'emergency supply' of water, which I always keep at the bottom of my bag