Why The London Underground Makes Itself Hotter Every Year

this is a poster from 1926 pitch in London's underground is the best place to um not burn alive in a horrible fire apparently at the time it was a pretty fair pitch in the early 1900s the subway Platforms in the London Underground would remain around 14 degrees Celsius or 57 degrees Fahrenheit year round which is pretty much the ambient temperature of the Earth but then something weird started to happen particularly on London's central line year after year the temperature inside the tunnels would get a little bit hotter than the year before and before you call me a soy boy lid boy science boy and slam your laptop shut no this is not one of my preachy climate change videos climate change is when stuff heats up here this is about stuff heating up here it's an engineering problem and it's a pretty big one these days the temperature inside the central line regularly breaks 30 degrees Celsius or 86 Fahrenheit which has articles on this subject left to point out is technically above the legal limit for transporting most farm animals so in short this tunnel is haunt and it's only getting hotter but why well the question of why the central line is so hot is really the question of why the central line can't be cooled down you see any subway system is going to generate heat and a lot of it these pesky heat molecules come from a couple of different places but they mostly come from the trains themselves you see trains generate a lot of friction starting and breaking over and over again and this friction gets converted into heat which gets trapped in the tunnels yada yada we all learn this in friction class but somewhat unique to London's underground only about 45 of the underground is actually underground and you think that would make it easier to cool the trains down but you'd think wrong when the trains go above ground particularly during warmer sunnier months they absorb a lot of solar radiation and carry it right back underground where it gets trapped and converted into British sweat so Okay subway tunnels get hot but as I mentioned before most Subway systems around the world are not so hot that bringing a pig on them constitutes two different crimes and that's because most Subway Lines have a way to get rid of this heat well the central line does not but to explain why we need to talk about the way that the central line was built you see London's underground has two different kinds of tunnels sub surface tunnels like the circle line and the Metropolitan line and deep tube tunnels like this video's protagonist the central line now the subsurface tunnels were built earlier and to this day they still don't have any problem venting heat when these lines were dug under London they were designed around steam powertrains which meant that they needed plenty of ventilation in order to not poach the trains in their own train juices but when the first deep tube tunnels were dug in the 1890s this wasn't a concern the train running through these tunnels would be powered for the very first time by electricity which in the 1890s was like saying these trains would be powered by Magic and the engineers were like these magic trains sure are great they don't emit smoke or steam or anything so let's just make these tunnels as small as possible and dig as few ventilation shafts as we possibly can because apparently ventilation shafts frighten horses and horses are a thing that will definitely Outlast this metro line so let's all go to the pub and have whatever terrible beers available to drink in the current year 1890. I might be paraphrasing a little bit but that's basically what they said now In fairness to Yola Engineers who didn't force either turn animals gradually heating up to pig roasting temperatures over the course of 13 decades these lines were originally entirely underground and that would have ultimately kept them a whole lot cooler than they are now so let's talk Solutions and because I'm in a bit of a mood let's talk about why most of these Solutions won't work as an American my first impulse when I see something that's too hot is to strap an AC on it but unlike some of the underground's other lines which do have air-conditioned trains the central line can't fit AC units on their trains because the tunnels are hardly big enough for the trains themselves and even if you could design AC systems to fit on these trains which they do plan to do by 2030 it's actually going to make the problem way worse ironically air-conditioned trains tend to generate even more heat since cooling down the inside of the cars means expelling hot air into the tunnels this is one of the bigger cooling problems that the New York City subway faces for example so don't worry londoners you're safe from the scourge of air-conditioned travel for at least another decade the other somewhat obvious solution is to just dig more ventilation shafts that's what they did on the other deep tube tunnels like the Jubilee you know just because the central line was designed before scientists had invented friction doesn't mean we can't go back and fix their mistakes except it kind of does actually the central length other big problem is that it's well Central it's right under some of the busiest and most developed parts of the city and endos has a strict policy against venting boiling Subway fumes into the middle of their restaurant now there have been some mitigating measures put in place or at least pitched like solar reflective paint brakes that absorb the energy that they generate and air conditioning individual stations while just hoping that trains don't ever get stuck in the actual tunnels long enough to bake everyone on board alive but the fact remains that the trains are still generating a lot of heat and about 79 of that heat is still getting absorbed into the clay surrounding the tunnels and I don't know if anyone has realized this yet but this might turn into a giant infrastructure problem if London were to say endure a massive Heat Wave um I'm not sure how to end this video this is just a bad thing it's just a thing that's bad and true so there you go information on the bright side the day is about six minutes closer to being over but if I haven't wasted enough of your time don't worry I figured out how to waste more of it how with a little thing I like to call Four original documentaries produced by me and my team available right now on the educational crater on streaming service nebula you've got the world's most useful airport the story of an international airport on a remote island in the middle of the Atlantic the final years of managero our documentary we filmed in the sinking Marshall Islands Alaska silent summer our coverage of a small Town's tourist economy in the midst of a pandemic and finally the Colorado problem our most recent future length project about America's Colorado River and its dire drier future all of these documentaries are available alongside so much other amazing exclusive content from your favorite educational creators like real life lore's modern conflict series and real engineering's Battle of Britain nebula allows us to create the content that we truly want to create without having to worry about going viral or abusing an algorithm and the cheapest way for you to get access to this content is with the Curiosity stream nebula bundle it's less than 15 for an entire year and also gets you all the other awesome documentaries and shows available on curiosity stream all all you have to do is follow our link curiositystream.com Hai or click the button on screen to sign up and you'll be supporting Hai while you're at it

Channel: Half as Interesting

Views: 1,989,987

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Id: 4MzHt_YLnjw

Length: 6min 15sec (375 seconds)

Published: Tue Aug 09 2022