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.
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
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!
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
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.
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."
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.
@@partraiserhc9351 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.
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´.
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".
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.
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
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.
@@GRosa 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.
@@PownyRider 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.
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
@@semurobo 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
If you want crazy, look up the Ligo and Virgo experiments. They are like rulers in that they are devices that measure their own length. These tubes are about 4km long, but this length is known to a precision of a tenth of the width of an atom.
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 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.
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.
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...
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?
@@Runescaper1357 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.
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.
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!
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.
@@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 😎
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
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.
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
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.
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!
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!
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
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).
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.
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.
@@zr4937 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?".
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).
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.
@smeeself Its an explanation of how missile guidance systems work. Google "the missile knows where it is" Essentially, the missile subtracts where it is from where it isn't to find where it's going
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."
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 .
@@godzillas6301 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.
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.
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.
Nice to see the deviation in the measurements is the same as the resolution of the measurement: 100 fps 0,01 s. And now to be as pedantic as Tom would appreciate; the mass of the car does change, as energy in batteries has mass, it's just low enough that the wearing down of the paint on the car by air friction is probably more than the change in weight if the battery, not to mention the moisture loss of the driver or the wear of the tires.
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.
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.
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.
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).
@@web4639 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.
"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...
One of the few good outcomes of the Beeching cuts, though the "unnecessary duplication" of other lines sure could come in useful now when we're stuck on capacity.
I love that there is a constant "Oh, of course! Right! [you make the connection] That would make a difference!" in this whole video. Even the little thing for the turntable and the remote button, you'd think might not make a difference, but then they talk about the ICE versus the EV and then my brain goes: "Oh, of course! Right! That burns fuel... And if they had to turn around the car that would be wasted fuel. And now the turntable is the same time/distance between each run, so you eliminate one more potential variation. The remote is nice and flashy, but even getting out of the car to hit a button would add more time/variables to the overall data... That would make a difference!"
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.
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)'.
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.
It's actually a legal requirement! Bats are a protected species, and you can face fines (up to £5k per bat) and jail time (up to 6 months) for disturbing their nesting sites, blocking entrances etc
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?
@@barneylaurance1865 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.
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.
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.
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.
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.
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)
"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
2:47 - Impressed me that you had to say the line about the camera operator not being in the back twice... to be able to get the shot from the camera operator of you saying that line to blend with the shot from the dash of you saying that line.
What a great video to show to TV networks that want to shove a camera to the outside of a race car during qualifying or a race as if it is "no big deal". It is.
I love that Tom didn't in any way call out that they were doing the test in an EV. He didn't even realize why they were doing so until the guy explained it to him afterward. Classy.
Hey. As an ex-suryeyor. I would excavate a rough tunnel. Fix a high magnified theodolite at both ends. Sight them 2.7 km down each other's optics and use that to create a straight line for levels. Being in a tunnel atmospheric distortion will be significantly reduced to..
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.
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 Yes, I guarantee you that when they started rehabilitating the tunnel, the railbed whcih had been abandoned for 4 decades was not flat, +/- 3mm.
@@andrewalexander9492 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.
Wikipedia teach us that the tunnel was built only because a trench would have spoiled the landscape of the landowner. "A tunnel, a manor house and a nice landscape would make a nice feature" is something we might say while planning a model railroad layout. Not a full scale main line railway.
Well, as the quote goes, the only difference between screwing around and science is writing it down. And you even documented it on video, so it's science!
An electric car driving along a perfectly straight tunnel: 😐 An electric car driving along a perfectly straight tunnel... ...but it's a Tom Scott video: Oh, fascinating!
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.
Thx I guess
Thanks for staying honest. 😊
A good tunnel it was.
It is a nice tunnel.
I am so happy you went with the thumbnail you did. The others feel really clickbait-y
Tom somehow manages to continue his trend of train videos despite not having a single train in sight
"The accidental train special" would be much worse in this case
Train adjacent
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
Ghost train.
@@ethanhoward389 liked this reference😅
I really like that the solution to the problem of "there are bats in the tunnel" was "build a bat hotel".
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!
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
When life gives you bats...
@@kenmcfa make battade…?
@@Sophiebryson510 make a bat hotel
You don't need an excuse to show us really good tunnels
His last excuse to show us really good tunnel was maglev train
especially since he's right. This is definitely one of the best tunnels I've seen
@Max Thrower that's your girls tunnel
Is this intended to sound sexual or is that just a byproduct
Cool to see a professional in the automotive industry refer to it as an "Austin Powers turn".
I liked that
Hilarious reference. Always makes me laugh
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.
That little reference made me unreasonably happy
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."
3mm in 2.7 km? That's an absurd level of precision even for today, much less Victorian England. What the hell?
The victorians were the best engineers in the world. much of their stuff is still in use today
@@TheHobohobbit That's a description, not an explanation. You might as well just say "dwarves did it".
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.
@@partraiserhc9351 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.
@@partraiserhc9351 It's impossible to have a straight line running parallel to the earth's geoid so I don't know what you're smoking.
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´.
Don't forget "throwing drums and a cymbal off a cliff"!
meanwhile, the recommended video at the end is literally Tom standing on a science instrument.
Different kind of "close", but good enough for me
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".
@@vigilantcosmicpenguin8721 and how to call that owl! UN-General secretary Ban Ki-Moon
He didn't say "gotten", he said "got". Tom speaks English.
I love how the multi-point turn has become universally recognized as the 'Austin Powers' turn.
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.
Me too. I used to think it was just me and my mates who used that, but it seems everyone uses it
Not to be confused with the old "Rockford Files" flying J turn.
I also like to use Austin Powers as a verb for getting a car stuck.
"I've Austin Powers'd the car while trying to turn in the alley"
I liked that Tom used the fact that he uses different cameras as a way to thrown some science into the video.
And some meta storytelling
It almost feels like he's breaking the fourth wall.
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
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.
What do you mean by "vertically straightly"?
@@GRosa 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.
I'd have said "flat" as in there are no undulations in the surface
Depends on where your tunnel start. It could also run out from one end.
@@PownyRider 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.
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.
What was your job?
Gonna be honest Tom, I am mostly upset that this video isnt about the Bat Hotel
Hopefully that's the next one. I wonder where the largest bat hotel is on Earth?
Someone get the Tim Traveler to go to it!
@@TsudicoGotham City?
Louisville, Kentucky ?
He can't just leave us... uh... hanging...
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
So a well engineered Austin Powers turn
Reminds me of the time I had the misfortune to go down a no-through-road in Oxford.
So you actually physically touched the Wall? Or you Just went as close as possible without touching anything?
@@semurobo 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
3mm deviation off the laser is absolutely crazy to me. How did they do that?
flat earth
More stringent adherence to set measurements and probably a very accurate plumb line.
If you want crazy, look up the Ligo and Virgo experiments. They are like rulers in that they are devices that measure their own length. These tubes are about 4km long, but this length is known to a precision of a tenth of the width of an atom.
my guess would be literal thread under tension
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)
Tom's obsession with tunnels or just a big hole underground is comparable to the obsession of Sam from Wendover to airplane/logistics.
Tom Scott is a hobbit confirmed
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.
This indeed is a good tunnel
Abracadabra
I wonder what happens if you drive a car in the tunnel up to 141.622kph?
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 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.
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.
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...
"A... fifteen degree per hour drift..." - "Thanks, Bob!"
"Interesting."
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?
2.7 Km is = 8 inches per mile squared, or 52 inches of curve.
@@Runescaper1357 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.
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.
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.
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!
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.
@@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 😎
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
Well-built stuff can save so much time, money, resources.
7:42 - "that's the closest I've got to science in a long time"
Guy from earthquake tower video: *cries*
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.
And this one is in Northamptonshire, at the heart of world motorsport
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
@@davidz2690 Fairly certain Red Bull's F1 team has/does use it.
@@McAdamSandwich Not surprised - seven F1 teams are based nearby
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
"Austin Powers 37 point turn" had me rolling
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.
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!
He's got a point. Although it is probably negligible, 20 liters more or less.
But then you waste more detouring to the petrol station.
@@Robert-cu9bm This exactly! Stopping to get more fuel costs fuel, but my mom would never listen...
@@Robert-cu9bm The solution is to illegally keep a big tank of fuel in your garage and fill up from that as needed.
With all the times Tom and crew have mentioned Thunderbirds over the years, I feel like I've watched the whole thing by now.
100% of what I know about Thunderbirds comes from Tom Scott.
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!
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!
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
1:07 made me unbelievably happy. I'm glad that they opted to relocate the bats while still getting access to the tunnel
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).
@@sarahlouisebutler happy non the less. The last thing we need is more meddling with bats, haha
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.
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.
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.
@@zr4937 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?".
This could help answering whether it's more efficient to lower your car windows or use air conditioning, I've always wondered about that
The Mythbusters did an episode on that.
Mythbusters already did that, use your AC.
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).
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.
Mythbusters tested that.
Fittingly after watching Technology Connection's video about the Ioniq 5's brake lights :P
4:01 As soon as he said deviation, my mind could only think of: "The missile knows where it is at all times"
Not by knowing where it is, but by knowing where it is not.
@Smee Self
The missile knows where it is....
@smeeself Its an explanation of how missile guidance systems work.
Google "the missile knows where it is"
Essentially, the missile subtracts where it is from where it isn't to find where it's going
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."
That would, in itself, be interesting
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 .
@@godzillas6301 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.
He's already announced that he will be retiring in a few years time.
I think he already did a running out of ideas video.
As an Aerospace student who's used a Wind tunnel:
THIS IS SO COOL
I wanna visit!!!
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.
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.
I’m so glad health and safety made you wear hi-vis vests because all the traffic on that roadway
More like to make rescuers see them more easily, in case of a freak accident with all lights going out lots of smoke accumulating
Nice to see the deviation in the measurements is the same as the resolution of the measurement: 100 fps 0,01 s.
And now to be as pedantic as Tom would appreciate; the mass of the car does change, as energy in batteries has mass, it's just low enough that the wearing down of the paint on the car by air friction is probably more than the change in weight if the battery, not to mention the moisture loss of the driver or the wear of the tires.
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.
Someone's going to try trainspotting with a Ouija board.
1:06 I was about to be bummed, but they made them their own little bat hotel how lovely!
(UF Has some MASSIVE Ones)
As a caver, I can appreciate a really good tunnel.
Thanks Tom
As an absolute gash hound, me too!
gl spelunking to the both of you!
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.
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.
I think the scientific answer to that would be: very. 😋
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).
How are those tunnels silly? They seem to be used by 1000's of people per day.
@@SirDragonClaw single lane, no fire exits, build a tram are the main ones iirc
@@web4639 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.
"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...
One of the few good outcomes of the Beeching cuts, though the "unnecessary duplication" of other lines sure could come in useful now when we're stuck on capacity.
I love that there is a constant "Oh, of course! Right! [you make the connection] That would make a difference!" in this whole video. Even the little thing for the turntable and the remote button, you'd think might not make a difference, but then they talk about the ICE versus the EV and then my brain goes:
"Oh, of course! Right! That burns fuel... And if they had to turn around the car that would be wasted fuel. And now the turntable is the same time/distance between each run, so you eliminate one more potential variation. The remote is nice and flashy, but even getting out of the car to hit a button would add more time/variables to the overall data... That would make a difference!"
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.
pugs gotta be the least efficient is my guess
And different sizes of evil henchmen hanging on to the roof with varying weapons.
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)'.
"how's that for timing?" - it's almost like you have been doing this for a while!
Top work, Tom.
GCR was the last and best engineered mainline of the steam era and Catesby Tunnel is testament to that \m/
Aaaand there I am sucked into the rabbit hole of following the geographic patterns of a former railway line through England...
That is a really good tunnel.
I love the concept of taking something from history and using it for advanced science
I actually watched their marketing video on TH-cam and their tagline is “The future is here, and it’s 125 years old” 😊
I bet the acoustic sound and potential in there is incredible 😅
Ask Richard Hammond about loud V8s and tunnels...
Would love to see a series where Tom just visits tunnels. Nest time you are in Pennsylvania, visit the abandoned turnpike tunnel in Breezewood. :)
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.
I always love the timing with your dialogs!
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.
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!
I really appreciate that they were environmentally conscious enough to provide Bat Houses for those they displaced by the reconstruction. 👍👍👍
It's actually a legal requirement! Bats are a protected species, and you can face fines (up to £5k per bat) and jail time (up to 6 months) for disturbing their nesting sites, blocking entrances etc
Tom, bustinh through the door shoort of breath, "I just found a really cool tunnel"
Every sane human on earth, " I'm listening".
Went on a couple of tours of this during its repurposing. Amazing environment inside. Of course, we walked through, so took a little longer.
Must have taken quite a while to reconfigure the tunnel and put in the ceiling and the lighting.
The phrase "That's the closest I've got to science in a long time!" really tickled me 😅
Wild how victorians built better tunnels than Elon Musk.
Everyone can
Nice burn xD
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?
@@barneylaurance1865 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.
That's not hard
Walked through that tunnel back in the 1970s. Amazing piece of engineering.
You had me at "Tom Scott" and "tunnel".
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.
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.
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.
did we see him outside the car during a test at all ?
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.
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)
7:14 i love you for writing the camera costs for all the people in EU, UK and USA even though its exactly the same just different units.
I was not ready for the phrase "Austin Powers 37-point turn" midway through the video 😂
"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
2:47 - Impressed me that you had to say the line about the camera operator not being in the back twice... to be able to get the shot from the camera operator of you saying that line to blend with the shot from the dash of you saying that line.
Haha! But I think there's a boring explanation: There was probably a camera stuck to the rear window or something.
What a great video to show to TV networks that want to shove a camera to the outside of a race car during qualifying or a race as if it is "no big deal". It is.
I like this. Where possible, consider doing more "actually use the facility in some way", even if it is to test something silly.
I love that Tom didn't in any way call out that they were doing the test in an EV. He didn't even realize why they were doing so until the guy explained it to him afterward. Classy.
Glad Tom has been reunited with his true passion.. Tunnels
The turn table at each end is brilliant! That's awesome. Also great timing Tom. Great video. Love this!
that is a very good tunnel, 10/10
Hey. As an ex-suryeyor. I would excavate a rough tunnel. Fix a high magnified theodolite at both ends. Sight them 2.7 km down each other's optics and use that to create a straight line for levels. Being in a tunnel atmospheric distortion will be significantly reduced to..
@» ±I𝟒O𝟓𝟔𝟗𝟖𝟑𝟗𝟕O why setup from either side. As a Surveyor we need the addition of redundancy in our measurements.
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.
Was that a race car that only goes in a straight line?
@@gordonrichardson2972 I think it might have been a racecar that only turns left.
Bruh... Tom, your about to hit 6 MIL. Keep up the great work!
It was a really good tunnel indeed
2:40-2:55 you didn't have to mention reality-video editing-cinematography relations here but I love that you did.
This is intriguing.
I have spent many hours in wind tunnels investigating things such as wind noise in vehicles.
0:41 oh bro, the fact that you had to make that disclaimer 😅🗺️
The tunnel has bats and a turntable. It is obviously a superhero lair.
Ooh! Yes, it must be! 😂 (by the way, it's "lair")
@@eekee6034 thanks for pointing it out. I fixed it.
I just love the thunderbirds style turntable setup they have
Everything about this is cool. Including a old historic tunnel still being used and the fact they still care about the bats.
I really love it, when you show us the bits in the video where you are just happy about timing and such.
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 Yes, I guarantee you that when they started rehabilitating the tunnel, the railbed whcih had been abandoned for 4 decades was not flat, +/- 3mm.
@@andrewalexander9492 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.
He already said in the Japanese hotel video that he isn't allowed to film other guests for privacy reasons. Hence, no bats.
Wikipedia teach us that the tunnel was built only because a trench would have spoiled the landscape of the landowner.
"A tunnel, a manor house and a nice landscape would make a nice feature" is something we might say while planning a model railroad layout. Not a full scale main line railway.
Fantastic approach to measurements!
Well, as the quote goes, the only difference between screwing around and science is writing it down. And you even documented it on video, so it's science!
An electric car driving along a perfectly straight tunnel: 😐
An electric car driving along a perfectly straight tunnel...
...but it's a Tom Scott video: Oh, fascinating!
Nice to see Tom covering this, having seen Motorbase and Team HARD test in it for BTCC!
We have one of these in Pennsylvania at the abandoned turnpike. They used F1 vehicles in it for testing .
Any scientist who makes an Austin Powers reference is my kind of scientist.
As a car and tunnel enthusiast. I appreciate this video.
🎉absolutely marvelous! That we old tunnels like these can be repurposed for data collection that is extremely difficult to obtain otherwise.