The tube infrastructure is difficult to adapt because of its age and the surrounding clay. Photograph: Linda Nylind/The Guardian

‘Like a sauna’: London tube travellers swelter in temperatures higher than legal limit for cattle

The tube cannot easily be adapted to cope with heatwaves, making conditions almost unbearable

As the escalator descends below ground at King’s Cross St Pancras station in London , the shift from what was already a hot station entrance to the furnace-like subterranean depths is perceptible.

On the tube it’s worse: a man leans back in his seat, eyes closed, sweltering; people hold electric fans an inch away from their faces. London commuters are known for their stoicism and the heat appears to be another tribulation to accept. They will need to: heatwaves in the capital are becoming routine.

“We’re quite lucky that this platform is almost empty, because when the platform gets packed it’s [like a] sauna,” Anna, a passenger at Oxford Circus, says. “When it’s peak hours, it’s quite difficult.”

In the UK, it is illegal to transport cattle above 30C, but the mercury hit 32C on the train and 34C on the Victoria Line platform at Finsbury Park. Photograph: Linda Nylind/The Guardian

Anna says she usually adapts well to hot temperatures, but even she finds the heat on the platform hard to bear. Craig, another passenger, says he has to travel in gym clothes and change into his work clothes at the office because of the heat on the tube.

London’s underground isn’t adapted for the 30C+ heatwaves that have hit the city over the last few summers. Lines such as the Victoria line – the deepest on the network – and the Bakerloo line – which TfL says has some of the oldest trains in passenger use anywhere in the country – are particularly bad when it comes to withstanding the heat.

A traveller tries to keep cool with a handheld fan. Photograph: Linda Nylind/The Guardian

Sharmin, a barista at the Pret a Manger stationed by the barriers at King’s Cross St Pancras, says she has seen people faint in and around the station. She finds the heat so oppressive that she has asked to go home early during some of her shifts this week. She wonders why there are no coolers or industrial fans set up near Pret or the barriers. “I’ve felt like I was going to faint,” she says.

A quick glance at the thermometer I’m carrying on this unscientific investigation shows that the station is about 30C. On the platform and tube it crawls up to 32C, and then at the Victoria line platform at Finsbury Park it hits 34C. In the UK, it is illegal to transport cattle above 30C; transporting people at 34C, though, might be becoming the norm.

Anna, pictured at Oxford Circus, says the platform becomes like a ‘sauna’ during peak hours. Photograph: Linda Nylind/The Guardian

It’s ten degrees higher underground than it is outside at this point, according to my iPhone’s built-in weather app. Between 8am and 9am the thermometer shows readings of 34C on the Victoria line platforms at Finsbury Park, on the Victoria and Bakerloo line platforms at Victoria, and on the northbound Bakerloo line platform at Oxford Circus.

Tube tunnels are ‘basically radiators’, taking on the heat of the clay and concrete around them. Photograph: Linda Nylind/The Guardian

Asher Minns, executive director of the Tyndall Centre for Climate Change Research, a partnership across several UK universities, says that tube tunnels are “basically radiators”, taking on the heat of the clay and concrete around them. The carriages, platforms and surrounding tunnels are also warmed by the hundreds of kilowatts of heat the trains produce while breaking. And the warmer it is outside, the worse it gets underground.

But Minns adds that the infrastructure is difficult to adapt because of its age and the surrounding clay. It will likely be years before the network is better suited to dealing with the heat, so for now he says the focus needs to be reducing risks to passengers.

“It can’t go on like this, and it’s not going to get any better,” he says. “[The underground] absolutely has to adapt to the impacts of climate change, but right now I think [the focus] has to be looking after passengers.”

Craig has to travel in gym clothes and change into his work clothes at the office because of the heat on the tube. Photograph: Linda Nylind/The Guardian

He suggests limiting the number of passengers allowed to travel when the temperature is above a certain limit, or reducing the number of tubes in service during heatwaves.

Nick Dent, TfL’s director of customer operations, said TfL was continuing to invest in making the network more resilient and comfortable as hotter summers become more common, as well as introducing new air-conditioned trains on the Piccadilly line and DLR.

Dent added that the “short-term and stop-start nature of funding over recent years has meant that TfL has had to carefully prioritise its investment and – while remaining open to measures that will help manage the impact of increasing temperatures due to climate change – has focused on programmes that will see the biggest benefits to customers”.

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