In the majority of England and Wales, railway speed limitations have been implemented because record temperatures could compromise the safety of steel lines.
The majority of trains will be limited to 90mph, down from 100mph or 125mph, while some may travel as slowly as 20mph.
The Met Office has issued a red warning for excessive heat in England and a yellow warning for Scotland and Wales.
When steel becomes extremely heated, it expands, causing tracks to bend, flex, and in extreme situations buckle, according to Network Rail.
It advised only essential travel and cautioned that travels would take substantially longer than usual and disruptions would be more likely.
Those who choose to travel were encouraged to wear cool clothing, bring portable fans, and drink lots of water.
Many railway companies will operate with shortened schedules; travelers are encouraged to check before departing.
Steel trains readily absorb heat and tend to be approximately 20 degrees Celsius (68 degrees Fahrenheit) warmer than the surrounding air temperature.
Because a train produces less force when moving more slowly, the rail is less prone to buckle in the heat due to the constraints.
In warmer weather, overhead electrical lines can also expand and sag, especially older ones; therefore, traveling more slowly decreases the chance of damage.
“Extraordinary tension”
Jake Kelly, who is in charge of disruption management for Network Rail, stated that the heat will throw the railways under “extraordinary stress.”
Mr. Kelly stated that the rail operator’s decision to reduce service was not made lightly, but added, “we have never experienced such extreme temperatures before.”
“We advise consumers in England and Wales to travel only if necessary today and tomorrow,” he stated.
Mr. Kelly expressed optimism that normal service will resume on Wednesday.
The West Coast Mainline will be restricted to 90mph, and operator Avanti West Coast has warned that there would be “much fewer” trips on Monday and Tuesday.
Customers having advance tickets for travel on July 18 and 19 who choose not to go will receive a full refund at the time of purchase,” the business stated.
“Alternatively, tickets are valid for travel through Wednesday, July 20.”
Tuesday between 12:00 and 20:00 BST, the East Coast Mainline between London and York and Leeds will be closed. This is because the line is more susceptible to high temperatures than others due to the design of the wire supports.
‘Hot places’
In other regions, including departures from King’s Cross station in London, trains will be limited to 60mph between 12:00 and 20:00 BST, extending a typical two-hour journey to around four hours.
To prevent excessively hot rails, Network Rail paints “hot spot” sections of track white so that they absorb less heat.
Extreme weather action teams, or “EWATs” of Network Rail, will be stationed at critical hotspots to monitor trackside temperatures and respond to possible problems caused by the heat.
Mr. Kelly stated that Network Rail was spending “hundreds of millions of pounds annually to make the railway more resilient, but eventually, the infrastructure will suffer in the face of unprecedented weather.”
He added that the lack of operable windows on modern train cars was one of the reasons for the reduction in service.
