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This is an excuse to show you a really good tunnel

  • Published on May 28, 2023 veröffentlicht
  • The Catesby Tunnel, in the UK, is an old Victorian railway tunnel that has a new use: a secretive car testing facility, like a wind tunnel but in reverse. So rather than just show it to the world, I thought I'd answer a question: if you stick a camera on the outside of your car, how much does the drag cost you? ■ The tunnel: catesbytunnel.com/
    Camera: Jamie MacLeod www.jamiemacleod.co.uk/
    Editor: Michelle Martin mrsmmartin
    This is not an advert, Catesby Projects and the tunnel team had no editorial control and I wasn't paid. (In fact, I paid quite a bit for the fire safety team!)
    Thank you to the many people who suggested this over the years, but in particular to David who was able to put me in touch with them directly!
    I'm at tomscott.com
    on Twitter at tomscott
    on Facebook at tomscott
    and on Instagram as tomscottgo

Comments • 0

  • Tom Scott
    Tom Scott  4 months ago +8163

    There were so many possible titles and thumbnails for this video. "Does attaching a camera to your car cost money?" "It's a reverse wind tunnel." "Testing like this used to be impossible." In the end, I just decided I wanted to show you a good tunnel.

    • Tau
      Tau 4 months ago +35

      Thx I guess

    • claytations
      claytations 4 months ago +66

      Thanks for staying honest. 😊

    • Ben
      Ben 4 months ago +126

      A good tunnel it was.

    • nick parry
      nick parry 4 months ago +44

      It is a nice tunnel.

    • Acre00
      Acre00 4 months ago +32

      I am so happy you went with the thumbnail you did. The others feel really clickbait-y

  • Boneless Watermelon
    Boneless Watermelon 4 months ago +13940

    Tom somehow manages to continue his trend of train videos despite not having a single train in sight

    • Neon Coding
      Neon Coding 4 months ago +471

      "The accidental train special" would be much worse in this case

    • Ethan Howard
      Ethan Howard 4 months ago +130

      Train adjacent

    • Sylvia-Rusty; Babyfae Sings
      Sylvia-Rusty; Babyfae Sings 4 months ago +116

      And this is totes a trains vid, bcuz my train lovin arse even got to have a moment of glee when they used the turn table xD
      I dont think a single trainspotter wudnt be absolutely giddy to be able to ride on a turn table in a disused train tunnel, even if just to flip a u turn xD

    • Travis Cesarone
      Travis Cesarone 4 months ago +8

      Ghost train.

    • Diego García
      Diego García 4 months ago +2

      @Ethan Howard liked this reference😅

  • NEPAAlchey
    NEPAAlchey 4 months ago +2986

    Cool to see a professional in the automotive industry refer to it as an "Austin Powers turn".

    • Bilb Ono
      Bilb Ono 4 months ago +65

      I liked that

    • Steve
      Steve 4 months ago +82

      Hilarious reference. Always makes me laugh

    • MonkeyJedi99
      MonkeyJedi99 4 months ago +173

      The one time I got to drive a steam roller (just pulling into a repair bay) I shouted to the other employee, "Get out of the way!" and he just screamed in mock terror while 'stuck in place'.
      We laughed.

    • Masala
      Masala 4 months ago +43

      That little reference made me unreasonably happy

    • Bald Manc Twat With A Head Like A Fucking Orange
      Bald Manc Twat With A Head Like A Fucking Orange 4 months ago +14

      Everyone I know refers to anything more than a 5-point-turn as an "Austin Powers". We even use it as a verb, e.g. "I Austin Powered my way out of there." or "I might have to Austin Powers it to get out of this one."

  • Avi Rubinoff
    Avi Rubinoff 4 months ago +643

    I really like that the solution to the problem of "there are bats in the tunnel" was "build a bat hotel".

    • George
      George 4 months ago +94

      Bats are a protected species in the UK. As they often make homes in abandoned buildings or other structures, it's common to see issues arising where renovations or demolitions are delayed because it's against the law to disturb/kill bats, damage their resting places or obstruct access to their shelters. Relocating them to a hotel is a great way of giving them a suitable replacement home!

    • aim-to-misbehave
      aim-to-misbehave 4 months ago +88

      And a reminder to people not in the UK that bats are rabies-free here! So while you don't have to worry about deadly diseases if you upset bats, you _do_ have to worry about the fine of up to £5k per bat for disturbing them

    • Kenneth
      Kenneth 4 months ago +9

      When life gives you bats...

    • Save Ticket offices
      Save Ticket offices 4 months ago +17

      @Kenneth make battade…?

    • UltraEdd
      UltraEdd 3 months ago +7

      @Save Ticket offices make a bat hotel

  • Ryan Penrod
    Ryan Penrod 4 months ago +4296

    3mm in 2.7 km? That's an absurd level of precision even for today, much less Victorian England. What the hell?

    • TheHobohobbit
      TheHobohobbit 4 months ago +285

      The victorians were the best engineers in the world. much of their stuff is still in use today

    • J.J. Shank
      J.J. Shank 4 months ago +975

      @TheHobohobbit That's a description, not an explanation. You might as well just say "dwarves did it".

    • Sword Connoisseur
      Sword Connoisseur 4 months ago +216

      The techniques and skills have been lost to time and lowering of quality of material and workers. Money would be a big factor too, with governments using the cheapest options possible.
      There was also the factor of there being a high demand built around a whole industry for the country at large.

    • ModProg
      ModProg 4 months ago +152

      @PARTraiserHC I understood it to mean that it is a straight line within 3 mm, but that straight line isn't actually tangential to earth at the tunnel center.

    • Ildarion
      Ildarion 4 months ago +97

      @PARTraiserHC It's impossible to have a straight line running parallel to the earth's geoid so I don't know what you're smoking.

  • MöhClon
    MöhClon 4 months ago +1270

    I love that last sentence "this is the closest I´ve gotten to science in a long time".
    I´m especially remembering the "toaster numbers don´t mean minutes" and the "I want to destroy my fingerprints with pineapple-based torture" videos as examples of Tom Scott ´doing science´.

    • Mister Mist
      Mister Mist 4 months ago +98

      Don't forget "throwing drums and a cymbal off a cliff"!

    • Lucarr10
      Lucarr10 4 months ago +35

      meanwhile, the recommended video at the end is literally Tom standing on a science instrument.
      Different kind of "close", but good enough for me

    • Vigilant Cosmic Penguin
      Vigilant Cosmic Penguin 4 months ago +36

      I think Tom's greatest scientific work is his audience surveying. He determined important results like the best thing, how weird his audience is, and the variations of "Jingle Bells, Batman Smells".

    • MöhClon
      MöhClon 4 months ago +9

      @Vigilant Cosmic Penguin and how to call that owl! UN-General secretary Ban Ki-Moon

    • Shaun Stephens
      Shaun Stephens 4 months ago +1

      He didn't say "gotten", he said "got". Tom speaks English.

  • Norman G
    Norman G 4 months ago +347

    I love how the multi-point turn has become universally recognized as the 'Austin Powers' turn.

    • Mark Fryer
      Mark Fryer 4 months ago +12

      It's a great universal, non offensive, easily communicated concept. Most Western people have by now seen the film or at least the short of the multi point U turn, so it now works as a shorthand description.

    • leopold
      leopold 4 months ago +3

      Me too. I used to think it was just me and my mates who used that, but it seems everyone uses it

    • Helium Road
      Helium Road 3 months ago +1

      Not to be confused with the old "Rockford Files" flying J turn.

  • N1ppe
    N1ppe 4 months ago +3629

    You don't need an excuse to show us really good tunnels

    • Radek T.
      Radek T. 4 months ago +28

      His last excuse to show us really good tunnel was maglev train

    • Joe theCat
      Joe theCat 4 months ago +18

      especially since he's right. This is definitely one of the best tunnels I've seen

    • Max Thrower
      Max Thrower 4 months ago +1

      Boys, is that the tunnel?

    • Evan Townsend
      Evan Townsend 4 months ago +3

      ​@Max Thrower that's your girls tunnel

    • Arandomcommenter
      Arandomcommenter 4 months ago +1

      Is this intended to sound sexual or is that just a byproduct

  • John
    John 4 months ago +123

    I used to work there. Jon is a great guy and a great boss. I’ve got a lot of respect for what he’s achieved and for how he’s running that place.

    • bhopcsgo
      bhopcsgo 3 months ago +1

      What was your job?

  • Zebra
    Zebra 4 months ago +232

    Loved the editing on that cut from "we don't want to see the cameraman in the back - because he isn't there." Like a magic trick but not exactly secret as to how it works haha

  • Micr0waveMan
    Micr0waveMan 4 months ago +429

    As someone who used to work in notoriously more active tunnels, l can say that the procedure for turning around the wrecker/fire trucks was full lock turn until you hit the wall, full lock the other way until you hit the other, then full lock again into the wall once more if you set yourself up well and twice more if you didn't. The trucks were build with this procedure in mind, the difference those last few inches made was astounding

    • Dr Bright
      Dr Bright 4 months ago +94

      So a well engineered Austin Powers turn

    • Charles Lambert
      Charles Lambert 4 months ago +17

      Reminds me of the time I had the misfortune to go down a no-through-road in Oxford.

    • Semu Robo
      Semu Robo Month ago

      So you actually physically touched the Wall? Or you Just went as close as possible without touching anything?

    • Micr0waveMan
      Micr0waveMan Month ago +4

      @Semu Robo actually contact it. You didn't hit it at speed, and the trucks had bumpstops or a pushpad so there wouldn't be any damage. There wasn't all that much space on either side when the rig was perpendicular, so every inch mattered

  • Mike V
    Mike V 4 months ago +108

    In case anyone is confused by the tunnel being "flat," yet having a gradient: "Flat" is not the same as "level." A level line is a curved line (constant distance from Earth's center of gravity). This tunnel is instead "flat," meaning straight, not curved. It has gradient, because one end is higher in elevation than the other (probably to facilitate drainage), and the elevation difference between the ends would have to exceed the difference of the middle from level. In the absence of gradient, all water that seeps into a flat tunnel would drain to the middle, because that's the point lowest from level.

    • Gabriel Rosa
      Gabriel Rosa 4 months ago +1

      What do you mean by "vertically straightly"?

    • Mike V
      Mike V 4 months ago +5

      @Gabriel Rosa That's a slight editing error. I meant "vertically straight," and by that I mean not curved in the vertical axis, as a level line or a line on the surface of the earth is. A straight line is, of course, the shortest distance between two points, or the trajectory of a laser beam.

    • leopold
      leopold 4 months ago +1

      I'd have said "flat" as in there are no undulations in the surface

    • Rosa Knuffel
      Rosa Knuffel 4 months ago

      Depends on where your tunnel start. It could also run out from one end.

    • Mike V
      Mike V 4 months ago +11

      @Rosa Knuffel Only if a flat tunnel has gradient could water run out one end or the other. If both ends of a flat tunnel had the same elevation, water would drain (or marbles would roll) to the middle, because the middle sags relatively lowest from level (deepest within a spherical earth). The effects of gravity are balanced by levelness, not by flatness. Imagine a hypothetical straight (flat) tunnel from London to New York. Both ends would emerge from the earth at an angle, and its middle would be many miles deep into the earth. Clearly, any water or marbles would pool in the middle.

  • Kice Ou
    Kice Ou 4 months ago +100

    Tom's obsession with tunnels or just a big hole underground is comparable to the obsession of Sam from Wendover to airplane/logistics.

    • Airbourne92
      Airbourne92 4 months ago +10

      Tom Scott is a hobbit confirmed

    • DarkSkay
      DarkSkay 4 months ago +1

      It would also have been interesting to see the tunnel as a kind of canal, with vehicles speeding on the water surface instead of asphalt.

  • MrGreatplum
    MrGreatplum 4 months ago +11

    The Great Central railway main line was built to a phenomenally high standard; it’s no surprise to me that tunnel is so well engineered.

  • Euan Smith
    Euan Smith 4 months ago +49

    Adam Something is correct, even when it comes to designing cars, railways are the answer.
    Another weird, entertaining and informative video from Tom and his crew.
    Now I want to see the same experiments being run with different breeds of dogs with their head out of the window.

    • Zoom
      Zoom 4 months ago +5

      pugs gotta be the least efficient is my guess

    • Pat The Plant
      Pat The Plant 4 months ago +7

      And different sizes of evil henchmen hanging on to the roof with varying weapons.

    • Laurence Fraser
      Laurence Fraser 4 months ago +7

      Nah, if you're saying that about cars, you're wrong. There are real world use cases where a the car is, in fact, the best option. Just a lot less of them than is assumed when designing infrastructure in most of the world these days.
      On the other hand, it would be entirely correct to say 'when it comes to designing Roads, railways are the answer (most of the time)'.

  • Crosier5961
    Crosier5961 4 months ago +57

    I had a friend who would only put $20 worth of fuel in his car because his logic was "more fuel = more weight. More weight = less gas mileage" so he saw that as the perfect balance. This just made me think of that.

    • Paul Haynes
      Paul Haynes 4 months ago +6

      But it would have meant gradually putting less and less fuel in his car. Keep that car long enough, and you're not even going to make it to the shops!

    • Edo Pronk
      Edo Pronk 4 months ago +6

      He's got a point. Although it is probably negligible, 20 liters more or less.

    • Robert
      Robert 4 months ago +36

      But then you waste more detouring to the petrol station.

    • Bubbline
      Bubbline 4 months ago +10

      @Robert This exactly! Stopping to get more fuel costs fuel, but my mom would never listen...

    • Vyl Bird
      Vyl Bird 4 months ago +8

      @Robert The solution is to illegally keep a big tank of fuel in your garage and fill up from that as needed.

  • Ottery Lexa
    Ottery Lexa 4 months ago +14

    I've seen videos on the Catesby tunnel before but this was definitely the best. And a fascinating little bit of science as well, which demonstrates the advantage of the set-up. You'd need a lot more runs to get that data in the open.

    • Ottery Lexa
      Ottery Lexa 4 months ago +5

      As someone else also mentioned, you could also film a very Tom Scott video on the bat hotel. With an interview with an Environmental Conservation officer.

  • nitehawk86
    nitehawk86 4 months ago +14

    Would love to see a series where Tom just visits tunnels. Nest time you are in Pennsylvania, visit the abandoned turnpike tunnel in Breezewood. :)

  • Shiny Agumon
    Shiny Agumon 4 months ago +2608

    I liked that Tom used the fact that he uses different cameras as a way to thrown some science into the video.

  • Invisible Wizard
    Invisible Wizard 4 months ago +11

    Used to live near there, it was on my regular jogging route. I remember when it was just a disused train tunnel - then all the construction, then the new road layout on the A364... Nice to see the inside of it!

  • Gilly The Fish
    Gilly The Fish 4 months ago +120

    With all the times Tom and crew have mentioned Thunderbirds over the years, I feel like I've watched the whole thing by now.

  • Josh h
    Josh h 4 months ago +16

    As someone with a degree in physics, this work site really interests me. I love that it was built buy the victorians. Maybe i should send in my CV and see what happens

  • Craig Evans
    Craig Evans 4 months ago +35

    Another great video as per!
    I love how, even whilst providing an interesting and informative video, Tom is still able to break the 4th wall and make you think about the filming process for thsoe whom are not in the know.

  • KeppyKep
    KeppyKep 4 months ago +3

    That's a nice tunnel.
    And I love how you gave us a little behind-the-scenes peek AND made that half the story of the video!

  • BatterieTyp
    BatterieTyp 4 months ago +4112

    3mm deviation off the laser is absolutely crazy to me. How did they do that?

    • hOnG k0nG fu3y
      hOnG k0nG fu3y 4 months ago +733

      flat earth

    • Glenn Griffon
      Glenn Griffon 4 months ago +793

      More stringent adherence to set measurements and probably a very accurate plumb line.

    • Stefan Madzharov
      Stefan Madzharov 4 months ago +831

      my guess would be literal thread under tension

    • Daniel
      Daniel 4 months ago +435

      especially when considering the fact that over 2.7 km due to the curvature of the earth the tunnel rises 57 cm (22 inches) (making some assumptions)

  • Tim 1
    Tim 1 4 months ago +3

    The turn table at each end is brilliant! That's awesome. Also great timing Tom. Great video. Love this!

  • J.P.
    J.P. 4 months ago +7

    yesterday i didn't know that it would cost you roughly 10 cents per 100 miles in added fuel consumption if you stick a go-pro to a car. but today i do, this is knowledge that I will carry with me for the rest of my life (or until gas prices change)

  • A Barratt
    A Barratt 4 months ago +8

    That's a fabulous facility. It strikes me that it's the kind of thing that nobody thought they needed, until someone built it. And then they all realise they need it. And there's not many dead straight, long, spare tunnels around the world...
    Reminds me of the road testing facility Tom went to in France, with a massively heavy high speed merry-go-round on lorry tyres. Crazy, until you see the results.

    • Z R
      Z R 4 months ago +2

      I live near this facility, and only just now realised what it was for. Growing up in Northampton, saw lots of random places which had abandoned railway tracks from the old railway line that was abandoned in favour of the Northampton-Milton Keynes/London line. We also have a lift tower that, well, was used to test lifts. Now we just abseil down it because we don't need to test lifts here anymore apparently, and at Christmas time we put a tree on top of it. Midlanders are weird.

    • A Barratt
      A Barratt 4 months ago

      @Z R I know the lift tower - driven round it. Listed building now - that's going to cost the owner a lot of money one day.
      Terry Wogan used to refer to it as the Northampton lighthouse. "Why," he would muse, "are they building a lighthouse in Northampton so far from the sea?".

  • davidf2281
    davidf2281 4 months ago +27

    I'm waiting for the video in a couple of decades where Tom just sits down in front of the camera and says, "Sorry folks, I've run out of interesting things having made a video on every single one of them. Let's play cards or something."

    • BunkerFox
      BunkerFox 4 months ago +7

      That would, in itself, be interesting

    • god zillas
      god zillas 4 months ago +6

      In 1945 in mexico 4 men sat down to play cards and each of them was delt a royal flush ........
      True tale ...... now try to work out the odds which are mind boggling .

    • TheGurw
      TheGurw 4 months ago +5

      ​@god zillas well, the odds of being dealt a royal flush is 4 in about 2.6 million. So the odds of 4 royal flushes dealt in one hand would indeed be astronomical.

    • Ottery Lexa
      Ottery Lexa 4 months ago +5

      He's already announced that he will be retiring in a few years time.

    • Kasper Onza
      Kasper Onza 4 months ago

      I think he already did a running out of ideas video.

  • techdaemon
    techdaemon 4 months ago +15

    One interesting nit. Gradient aside, "perfectly flat" (or rather perfectly straight) is not flat for the purposes of coasting a car. Mentioned at the beginning, but earth's surface is curved, so if the tunnel were same elevation at both ends, but perfectly straight then effectively it's actually lower in the middle and you're going uphill slightly toward either end. If water leaked in, it would literally pool up in the middle of the tunnel eventually forming a curved surface.
    With the gradient and straight profile it means that the tunnel is effectively steeper at one end than it is at the other end, relative to the pull of gravity. All of this needs to be accounted for in their calculations.

    • Smee Self
      Smee Self 4 months ago

      Yes. They advertise a constant gradient of 1:176

    • techdaemon
      techdaemon 4 months ago +1

      @Smee Self Cept if it's truly laser straight, then it is *not* a constant gradient in the way that gradient matters (coasting in this case). A level will measure different values at one end, center, and other end.

    • Quill Maurer
      Quill Maurer 4 months ago +2

      This crossed my mind as well. Running these calculations (in a rough approximation that will at least give reasonable order of magnitude) I get a difference in angle of about 0.024°, .04%, or 1 in 2355. My guess is that this effect is so insignificant that it doesn't matter, even at the precision they are doing. Initially I figured this might be less than a rounding error for the given 1:176, but when I tried adding this new gradient I got 1:163, so it would be measurable in that given number - but still probably so insignificant they don't really care. 1:176 is probably the average through the tunnel.

    • Smee Self
      Smee Self 4 months ago

      ​@techdaemon Absolutely. Good point. But the gravitational difference between two ends of a 110km tunnel ( at sea level) is about 0.003m/s.
      For a 3km tunnel it is less than 0.000002. m/s
      ( I'm not sure but local gravitational somnolent might be greater than that so I'll let them pass this time)

    • Smee Self
      Smee Self 4 months ago

      ​@Quill Maurer I got 1:169 ( done very roughly too) but either way, I think your right, it's not going to factor into their work. 👍

  • SupBlizard
    SupBlizard 4 months ago +4281

    Wild how victorians built better tunnels than Elon Musk.

    • Jan Tschierschky
      Jan Tschierschky 4 months ago +464

      Everyone can

    • Bloody Mobile
      Bloody Mobile 4 months ago +95

      Nice burn xD

    • Barney Laurance
      Barney Laurance 4 months ago +20

      Also wondering how that's defined. Won't it depend hugely on which exact points on the tunnel you measure at the beginning and end? I wouldn't expect the shape to be that precisely the same at both ends. Or is it based on an average of measurements from all around the top bottom and side walls of the tunnel at the two ends?

    • Alex
      Alex 4 months ago +249

      ​​@Barney Laurance he literally described how they did it they used a laser that put out a beam from one end to the other and it was 3mm difference.

    • well well
      well well 4 months ago +22

      That's not hard

  • officialmcdeath
    officialmcdeath 4 months ago +32

    GCR was the last and best engineered mainline of the steam era and Catesby Tunnel is testament to that \m/

  • Robot1c
    Robot1c 4 months ago +1

    Absolutely love this! Didn't realise i wanted to learn about a tunnel but now I'm greatful I did :) I appreciated the more scientific elements of this too

  • ümlaut
    ümlaut 4 months ago +29

    1:07 made me unbelievably happy. I'm glad that they opted to relocate the bats while still getting access to the tunnel

    • sarahlouisebutler
      sarahlouisebutler 4 months ago +9

      I love that too, but legally they cannot disturb the bats. Bats and their roosts are protected under law in the UK (possibly internationally but I'm not sure).

    • ümlaut
      ümlaut 4 months ago +1

      @sarahlouisebutler happy non the less. The last thing we need is more meddling with bats, haha

    • John
      John 4 months ago

      I used to work there and it was the biggest hurdle before starting work, more so than any of the engineering bits. Took a looooong time to get sorted.

  • Sean Ehle
    Sean Ehle 4 months ago +6

    Hey Tom! Such a random treat to "run into you" at Heathrow a few days ago. Can't believe I lost my footing like that.
    It's still a highlight of my trip to have met you, even if under unfortunate circumstances.

  • belg4mit
    belg4mit 4 months ago +20

    I like this. Where possible, consider doing more "actually use the facility in some way", even if it is to test something silly.

  • AlexisErudite
    AlexisErudite 4 months ago +990

    Gonna be honest Tom, I am mostly upset that this video isnt about the Bat Hotel

    • Tsudico
      Tsudico 4 months ago +84

      Hopefully that's the next one. I wonder where the largest bat hotel is on Earth?

    • Smee Self
      Smee Self 4 months ago +55

      ​@Tsudico Transylvania?

    • bonecanoe86
      bonecanoe86 4 months ago +28

      Someone get the Tim Traveler to go to it!

    • frzstat
      frzstat 4 months ago +18

      @TsudicoGotham City?

    • Geoffroi Le Hook
      Geoffroi Le Hook 4 months ago +3

      Louisville, Kentucky ?

  • Douglas Mobley
    Douglas Mobley 4 months ago +16

    Went on a couple of tours of this during its repurposing. Amazing environment inside. Of course, we walked through, so took a little longer.

    • Mark Fryer
      Mark Fryer 4 months ago

      Must have taken quite a while to reconfigure the tunnel and put in the ceiling and the lighting.

  • Oba936
    Oba936 4 months ago

    I really love it, when you show us the bits in the video where you are just happy about timing and such.

  • Commodore Sixfour
    Commodore Sixfour 4 months ago +2

    Everything about this is cool. Including a old historic tunnel still being used and the fact they still care about the bats.

  • Sound Hound
    Sound Hound 4 months ago

    Absolutely nuts. I love the science you do Tom. Thank you kindly for sharing this.

  • SockGoblin
    SockGoblin 4 months ago +2

    You turn some of the most mundane into stuff I find fun and interesting. Your energy is great for a smile. Thanks for your work.

  • Mumpy
    Mumpy 4 months ago +582

    I love how Jon Paton had to remind us that the surface of the earth is curved, just in case a certain group of people unironically cite the laser light as proof the earth is flat...

    • MonkeyJedi99
      MonkeyJedi99 4 months ago +47

      "A... fifteen degree per hour drift..." - "Thanks, Bob!"

    • Grimbeard
      Grimbeard 4 months ago +14


    • Inteus
      Inteus 4 months ago +2

      In principle, it's not a dumb argument; there *must* be a distance at which the curvature should be noticeable.
      How long of a perfectly-level run would one need to observe (or not observe) the phenomenon?
      I know of the canal and mast test, and that those results can be disregarded due to not factoring in refraction from air and water.
      I know of a test done on a frozen lake at a distance of roughly 6km that demonstrated no curvature.
      I recall several other long-distance shots (10+ km) of buildings and landscapes from a camera (Nikon P900 I think?) which purportedly ought not to be possible on a curved earth.
      What do you think about the idea?
      What evidence do you know of?

    • ash man
      ash man 4 months ago +3

      2.7 Km is = 8 inches per mile squared, or 52 inches of curve.

    • Adam Boyd
      Adam Boyd 4 months ago +52

      @Inteus The easiest way to see the curvature with the naked eye, is in our shadow on the moon.
      There is also a place in Australia you can see it quite nicely. The Nullarbor Plains, I spent a few hours going across it in a train and it messes with your head. You can't see beyond about 10-20km in any direction. It feels like the world hasn't rendered correctly and your view distance is set to medium.

  • WWJE
    WWJE 4 months ago

    Honestly, I would still happily watch every video if Tom showed us one great tunnel every month. Doesn't have to be a massive occasion.

  • waverlh
    waverlh 4 months ago

    I always wondered if there was anywhere on earth you could get that kind of accuracy. Well, now I know. Thanks, Tom!

  • L Sedge
    L Sedge 4 months ago +1

    This is a very good tunnel. Also, tbf, an interesting quirky little test. It feels like something I'd have found on my physics GCSE some years back as a question.

  • SauronsEye
    SauronsEye 4 months ago +8

    I'd like to see the Bat motel and then the golf ball dimples on a car versus no dimples experiment to see if Myth Busters' got it right.
    Then an episode on how the engineers got the tunnel so level when it was made in the 1800s.

    • Smee Self
      Smee Self 4 months ago +1

      Yes to the bats and the interesting tests, but the flat ( not level) part is the modern test tunnel, not the Victorians

    • Andrew Alexander
      Andrew Alexander 4 months ago +1

      @Smee Self Yes, I guarantee you that when they started rehabilitating the tunnel, the railbed whcih had been abandoned for 4 decades was not flat, +/- 3mm.

    • Smee Self
      Smee Self 4 months ago

      @Andrew Alexander Indeed.

    • Uldis Barbans
      Uldis Barbans 4 months ago +2

      ​@Andrew Alexander They weren't talking about roughness of the surface. Of course every dimple in the wall is also deeper than 3 mm, railbed matters equally little.
      Flatness as they refer to it means something like straightness, or - take the centroid of cross section at entry, take the centroid of cross section halfway in, take the centroid of cross section at the far end - and they would be on one line +/- few mm.

    • Smee Self
      Smee Self 4 months ago

      @Uldis Barbans The flatness means that if you shine a laser up the road, the surface ( not the 'direction') varies from the true straight laser by less than 3mm.

  • WanderingRandomer
    WanderingRandomer 4 months ago +8

    I love how "doing an Austin Powers" is immediately recognisable as a term. I and a lot of people I know refer to that when botching a 3-point turn

  • Ecospider5
    Ecospider5 4 months ago +605

    Excellent reuse of infrastructure. I feel there are a lot of old abandoned things that could be reused. It’s just that the people that could use it don’t know it exists.

    • Goose Not maverick
      Goose Not maverick 4 months ago +28

      Agreed! Reuse of infrastructure could save so much in building materials alone, much less once you consider all the environmental costs that would be reduced significantly by not having to build from an empty lot. Not to mention the cool history that can be saved in ways like this!

    • DJenerate
      DJenerate 4 months ago +16

      It reminds me of something similar near me in Dudley, there's a former rail tunnel that's not being used by the new tram line, so they've repurposed it into part of a test track for 'Very Light Rail'. I guess using a railway tunnel for something running on rails isn't as interesting, but it's still great to see the infrastructure being used again.

    • Goose Not maverick
      Goose Not maverick 4 months ago +10

      @DJenerate in my opinion, anything like that is interesting, I see any reuse of large scale anything, interesting. I mean, bringing back anything as even the same thing as it was, can be a process. Plus, anything developing in rail transport is also interesting 😎

    • first name last name
      first name last name 4 months ago

      It actually happens a lot it's just not made into something cool for a Clip-Share video

      GARGANCHUA 4 months ago +1

      reusing train tunnels for cars is such an amazing idea its a shame we dont do it more often. most people who drive cars like to go out of their way just to use the path with tunnels because vroom

  • mescad
    mescad 4 months ago +35

    I wonder how much having Tom in the car as a passenger affected the tests. Being inside of the car, of course he wouldn't add any direct wind resistance, but I would think his additional weight would affect drag. Likely more than the GoPros, I'd think.

    • AbydosianChulac2
      AbydosianChulac2 4 months ago +10

      It would have been interesting since they'd have had the info from the run with the camera operator and equipment in the back, too, so they'd know how much he affected the run as well.

    • toneddef
      toneddef 4 months ago +2

      Perhaps they were doing a loaded vs unloaded run, to text the affect of weight. What you don't see are the six loaded suitcases and a bag of sand in the trunk.

    • Geoffroi Le Hook
      Geoffroi Le Hook 4 months ago

      did we see him outside the car during a test at all ?

    • Martijn
      Martijn 4 months ago +1

      Tom being in the car would also add 70 kilograms of mass, which means that the car will coast for longer.
      Tom being in the car probably both negatively, as well as positively affected the test.

  • Sandwich247
    Sandwich247 4 months ago +4

    It's absolutely wild to me that it's perfectly flat on top of being constructed over a hundred years ago
    If I had infinite power, money, and resources (after fixing all the other problems) I'd want to make a really long flat tunnel that you could *feel* the angle at either end despite it being flat

  • Vincent Xie
    Vincent Xie 4 months ago

    Its look kinda interesting to see how the tunnel is so straight and bright and it really show how much sight the tunnel really is.

  • Red Uruloki
    Red Uruloki 4 months ago

    This is absolutely fascinating. And now I want to go for a drive down this tunnel ...

  • RootedHat
    RootedHat 4 months ago +2

    It's refreshing to see Tom saying it's actual science he hadn't seen in a while 😂

  • Pietro Nobili
    Pietro Nobili 4 months ago +207

    This could help answering whether it's more efficient to lower your car windows or use air conditioning, I've always wondered about that

    • fireaza
      fireaza 4 months ago +25

      The Mythbusters did an episode on that.

    • T.
      T. 4 months ago +40

      Mythbusters already did that, use your AC.

    • RJFerret
      RJFerret 4 months ago +95

      Mythbusters tested this via measuring fuel usage over a long time around a racetrack, obviously the exact threshold varies based on vehicle, but essentially AC more efficient at high speeds (highway), open windows at low speeds (city).

    • Pyrrha Nikos
      Pyrrha Nikos 4 months ago +27

      Mythbusters did that in real world conditions a long time ago. Their method: Have a transparent tank on the outside of the car where they could see how much fuel they used, and drive around the perimeter of a parking lot several times in varying configurations.
      I believe their result was that the AC was quite a bit more efficient, but keep in mind that was more than 10 years ago so car aerodynamics and AC technology have certainly progressed since.

    • benwisey
      benwisey 4 months ago +2

      Mythbusters tested that.

  • Peter Arnold
    Peter Arnold 3 months ago +1

    Sometimes Tom just has way too much fun doing science, and we love it, was well.

  • Tom H
    Tom H 4 months ago +2

    Tunnels usually freak me out (drippy drippy and the occasional bat panic), but I think I'd like this one :)

  • Tigershark232
    Tigershark232 4 months ago +13

    As an Aerospace student who's used a Wind tunnel:
    I wanna visit!!!

  • Noel Ward
    Noel Ward 4 months ago +1

    This is intriguing.
    I have spent many hours in wind tunnels investigating things such as wind noise in vehicles.

  • diox8tony
    diox8tony 4 months ago +2

    I feel like you should drive in the center both way. The difference in distance to the walls on each side must cause some affect....as you said, the 3mm down slope causes a noticeable affect; I would guess the wall difference has a larger affect. I suppose it depends on the test you are running. A tunnel wall near you is realistic (real tunnels), but not testing the car itself.

  • Garfy
    Garfy 4 months ago +137

    I visited both tunnel heads about 20 years ago as I had an interest in the old GCR. A fascinating piece of engineering and it's pleasing to see you don't have to fight through decades of neglect to get to the tunnel now!

  • Rud
    Rud 4 months ago +38

    Legends has it that if you go in there at midnight on the shortest day of the year, you can still hear ghosts of trains past, going though the tunnel, their whistles blaring right though your soul.

  • Jlaor TheShaman
    Jlaor TheShaman 4 months ago +1

    Everyone of your videos are amazing, I know more about the world, thanks to your work.

  • Trevor Dennis
    Trevor Dennis 4 months ago +2

    Blimey. Who'd have thought? I've worked in the MIRA wind tunnel many years ago and experienced 80mph wind - which was about the limit of being able stay in one spot without being blown away - but we had so many cables and things attached to the vehicles that it would have been impossible to get the consistency we saw in this test.

  • GnomaPhobic
    GnomaPhobic 4 months ago +2

    Very impressive tunnel, especially for the engineers of the time. Still pales in comparison to the pinnacle of modern British engineering: The inestimable Bude Tunnel.

  • ProcrastinaThor
    ProcrastinaThor 4 months ago +1

    Yes, Tom this is great!
    Love your content ❤
    I never knew I was in a mood for tunnel today, but here we go.

  • Izzie
    Izzie 4 months ago +213

    I've heard of this tunnel before, it very much seems they were inspired by Chip Ganassis's testing tunnel (the Laurel Hill Tunnel in Pennsylvania) which was used by his various race teams for testing. I believe Chip Ganassi began using it for testing in 2004.

    • David Z2
      David Z2 4 months ago +20

      And this one is in Northamptonshire, at the heart of world motorsport

    • Sm D
      Sm D 4 months ago +5

      I don't think so. This tunnel is much larger and is available for hire, I believe the only one in the world. used not just for aerodynamics & emissions testing they also have Sunday's where it's available to the public for cycling and the like

    • Adam Terry
      Adam Terry 4 months ago

      @David Z2 Fairly certain Red Bull's F1 team has/does use it.

    • David Z2
      David Z2 4 months ago

      @Adam Terry Not surprised - seven F1 teams are based nearby

  • SevAeris
    SevAeris 4 months ago +1

    This just made me wonder how many cool things Tom is not showing us because he can't find a good excuse

  • Ignacio Aguirre
    Ignacio Aguirre 4 months ago

    There is actually a precedent to this. Chip Ganassi Racing used to own a tunnel somewhere in Pennsylvania. It was a well guarded secret but it eventually came to light, and there is a story about a car actually doing a 360 because of the amount of workforce that car had.

  • DaLoveDonkey Drums and Gaming

    Love every video Tom!! One of my favorite journalist! Thankyou for everything you do!

  • Bill Blair
    Bill Blair 4 months ago +1

    Walked through that tunnel back in the 1970s. Amazing piece of engineering.

  • DigitalDiabloUK
    DigitalDiabloUK 4 months ago +1

    Id heard about this a few months ago; great to see Tom give more details.

  • Some Bystander
    Some Bystander 4 months ago +320

    This indeed is a good tunnel

    • Nils D.
      Nils D. 4 months ago +1


    • MonkeyJedi99
      MonkeyJedi99 4 months ago

      I wonder what happens if you drive a car in the tunnel up to 141.622kph?

  • Xelto Grait
    Xelto Grait 4 months ago +4

    It would be interesting to see the results of sticking a GoPro on an ultra-streamlined vehicle like the (sadly stuck in funding quagmire) Aptera, and compare it to a not-streamlined-at-all vehicle like the Electric Hummer.

  • Molly Anderson
    Molly Anderson 3 months ago +1

    I have to say it was nice and unexpected that instead of removing the bat's they "treaded carefully" and built them their very own bat hotel

  • RecumbentRocks2
    RecumbentRocks2 4 months ago

    That was fascinating Tom, thanks for making another interesting video.

  • Emma Healy 5649
    Emma Healy 5649 4 months ago +7

    As a caver, I can appreciate a really good tunnel.
    Thanks Tom

    • Eadweard
      Eadweard 4 months ago

      As an absolute gash hound, me too!

    • mrlithium
      mrlithium 4 months ago

      gl spelunking to the both of you!

  • Dirk Federmann
    Dirk Federmann 4 months ago +6

    That reminds me of (and I had to look it up) the Laurel Hill Tunnel, where a Racing Team bought(?) the tunnel and used it to develop a race car in (almost) complete secrecy.

    • Gordon Richardson
      Gordon Richardson 4 months ago +2

      Was that a race car that only goes in a straight line?

    • Ottery Lexa
      Ottery Lexa 4 months ago +2

      @Gordon Richardson I think it might have been a racecar that only turns left.

  • Tapio_M
    Tapio_M 4 months ago +87

    Oh god I thought Tom had gone to the silly Tesla tunnel.
    The result is interesting, and I can only imagine that they have also done tests for those roof boxes for skis. They are known to be bad for fuel efficiency, but I would like to know how much.

    • BuzzinsPetRock78
      BuzzinsPetRock78 4 months ago +6

      I think the scientific answer to that would be: very. 😋

    • Web
      Web 4 months ago +5

      I do think that driving back and forth at a constant speed in a straight line would actually be an ideal situation for a computer controlled car (not a tesla, don't want to ruin the tunnel).

    • Daniel Armstrong
      Daniel Armstrong 4 months ago +1

      How are those tunnels silly? They seem to be used by 1000's of people per day.

    • Finn Gardiner
      Finn Gardiner 4 months ago +15

      @Daniel Armstrong single lane, no fire exits, build a tram are the main ones iirc

    • Tapio_M
      Tapio_M 4 months ago +7

      @Web Make a queue out of all those cars and put more seats in them. And ditch the word "car", use something more to the point. Like an underground or a subway. Or a metro.

  • Yikes
    Yikes 4 months ago +1

    "we don't want to see the camera operator in the back, because he's... not there" was such a simple trick but it still got me. unmatched video editing
    the fact that you were doing that line in both shots must have been really funny for the shot where the camera operator was actually there

    • Smee Self
      Smee Self 4 months ago

      Are you sure that there ever was a cameraman? 😮

  • Alex Hughes
    Alex Hughes 4 months ago

    This is right by my folks house and I've always wanted to have a look inside! Thanks Tom!

  • RS200E
    RS200E 4 months ago +1

    Nice to see Tom covering this, having seen Motorbase and Team HARD test in it for BTCC!

  • Andrew Gwilt
    Andrew Gwilt 4 months ago

    I think I saw that on telly before. Could be on Top Gear but it looks incredible since it once was a railway tunnel. Now being used as a proper tunnel for test runs.

  • NorbiPeti
    NorbiPeti 4 months ago

    I read an arguement on Facebook some time ago about having wind farms near roads and how that would affect fuel consumption. It would be interesting to test it here.

  • DogsWithPurpose
    DogsWithPurpose 4 months ago +2

    Glad Tom has been reunited with his true passion.. Tunnels

  • StarTreekGeek47
    StarTreekGeek47 4 months ago

    There's a sister tunnel to this one called the Laurel Hill tunnel. You'll probably never get in to see that one though as it's used by Chip Ganassi Racing to perform secret (and potentially against the rules of IndyCar competition) performance tests.

  • Dave L
    Dave L 3 months ago

    If you haven't done it, you might visit Euro NCAP or IIHS (or similar) to observe a crash test. It's fascinating.

  • LuciferLuckless
    LuciferLuckless 4 months ago +1

    That was indeed a really cool tunnel. Cheers Tom!

  • Tom Blunt
    Tom Blunt 4 months ago +2

    "We've got bats living in this tunnel that we want to turn into a test track, how do we get rid of them?"
    "We don't, we just make that part of the tunnel into a bat hotel, obviously."
    Brilliant 😂

    JNSKM 4 months ago +1

    What a great idea to repurpose a train tunnel for car testing. Good job. 👍🏼

  • NichtcrawlerX
    NichtcrawlerX 4 months ago +5

    "This needs the music from Thunderbirds"
    I know that feeling, it always plays in my head when I see those stair single seat elevators and the like. I also always point it out and I am quite certain by now it always annoys the people I am with...

  • Mentaculus42
    Mentaculus42 4 months ago

    The surface level must have been done in multiple steps. If you look at some of the shots near the floor level that have low grazing incident angle one can see that the surface appears to have been ground and slightly polished (note the flat top of larger rock with the lack of sand attached to the flat surface). This was probably done as the last step with a grinding machine that was sufficiently large to have multiple optical targets being monitored by an optical theodolite. Think of a large lapping machine with optical guidance. Probably did not use a Gyrotheodolite.

  • HAM
    HAM 4 months ago +2

    There's also another nice abandoned train tunnel up in Market Harborough, which is now a walk and bike trail.

  • Andrew Ponti
    Andrew Ponti 4 months ago

    Austin Powers reference absolutely made the video (as well as all the other hard work, as usual!). Love learning about these things!

  • Dave Bell
    Dave Bell 4 months ago

    According to the tunnel's operators the gradient is 1:176 which is 15.33m difference between the ends. Also, it was built from nine shafts. They would have had 10 sections of about 270m.
    I don't think any engineer would build a flat tunnel. They expect water. They started the Simplon tunnel a year after this one was finished and the error where the two halves joined was about 8 inches.
    I am wondering if some of the surveying only worked because the errors were both positive and negative.

  • DaLoveDonkey Drums and Gaming

    I always love the timing with your dialogs!

  • SemiHypercube
    SemiHypercube 4 months ago +3

    That is indeed a really good tunnel

  • Kremmy
    Kremmy 3 months ago

    What I wonder about? Is this economically viable for testing cars that are in late stages of production?
    I guess the advantage with a 'normal' wind tunnel would be, that you don't need to use a fully furnished car, engine and all, right? So you can do it much earlier in the production cycle? At least that's what I assumed.

  • TJ
    TJ 4 months ago +1

    I love the audio in the car, in the tunnel: it’s just so quiet!

  • Masterhitman935
    Masterhitman935 4 months ago +2

    🎉absolutely marvelous! That we old tunnels like these can be repurposed for data collection that is extremely difficult to obtain otherwise.