13yo Invents a Better Hyperloop - It's still a STUPID IDEA

[nctnico]

I stopped watching after "globaly reducing transportation emissions".

Then, like every good scientist, I  searched and found  a reason to justify my behavior:

In absolute terms, the picture is clear. Worldwide, road users account for about 71% of transport CO2 emissions, with railway companies making up less than 1.8%, next to 12.3% for aviation and 14.3% for shipping, according to the International Energy Agency and International Union of Railways.

https://www.theguardian.com/sustainable-business/greener-travel-car-or-rail

So go ahead..... fix the 1.8% problem!!!!!!!!!!!!!!!!!!

Well... hyperloop isn't about fixing railways but creating a better alternative for transport over road because conventional just trains don't cut it. Especially when it comes to moving freight. In Europe the effective speed of a freight train is around 30km/h. The Dutch hyperloop firm Hardt is going to build a 3km long test track in the next couple of years and their first target is to transport freight quickly and efficiently.

[DimitriP]

Well... hyperloop isn't about fixing railways but creating a better alternative for transport over road because conventional just trains don't cut it.

I got the impression the main "target" would be trains hence the railway reference.
Attempts to solve "global transportation pollution" issues that depend  on "new" mass transit methods and technologies seem to overlook the fact that the problem exists in large part because not enough  people use the old mass transit  methods and technologies

[vk6zgo]

BTW, you can see the exact same invention here, except the tube is below the tracks, but same magnetic attachment:

https://www.wired.com/story/flight-rail-vectorr-atmospheric-railway-train/

The video is interesting. At 1:45 you can see the piston as well. This works in curves, too, because it has a torus at each end, and the middle is smaller than the tube. Main advantage compared to normal trains is that it is much lighter, because it doesn't need a heavy motor, so e.g. it can climb steeper grades, as the say and demonstrate in the video. It would be possible to accelerate and break much faster as well, and with less energy. Maybe the whole system needs even less energy than traditional trains. Doesn't look that stupid anymore after seeing the real size prototype.

I think the Wikipedia article shows that the main problem of previous inventions was that they used valves in the tube for attaching the piston to train (rats were eating the leather valves etc.), because they didn't have these strong magnets back in the days.

The magnets, rather than solving the problem are part of it.

The only cheap materials for making a tube which are strong enough are Steel, an Aluminium alloy, or reinforced concrete.

Magnets don't work very well through steel, & as has been pointed out, a rapidly moving magnet will introduce eddy currents in the steel, creating large energy losses.

Aluminium is non-ferrous, but eddy currents will still occur.

Reinforced concrete is, by its nature thicker, so the magnet will need to be stronger.
The reinforcement is steel  so there will still be eddy currents, albeit reduced.

So we are pretty much stuck with using some other material.

Maybe non-metallic materials like carbon fibre?
Such alternatives require special handling & processing, & are largely unproven in tubes of many kilometres length.

[ogden]

Railroads are less of a problem compared to trucks and airplanes. Source: wiki.

[EEVblog]

Well... hyperloop isn't about fixing railways but creating a better alternative for transport over road because conventional just trains don't cut it. Especially when it comes to moving freight. In Europe the effective speed of a freight train is around 30km/h. The Dutch hyperloop firm Hardt is going to build a 3km long test track in the next couple of years and their first target is to transport freight quickly and efficiently.

Why not just use Maglev?

[EEVblog]

Do the math for a 100 ton locomotive, compared to an air pressure powered lightweight train.

Yes, please, do the math and let us know.
BTW, even lightweight cars weigh in at over 20 ton each.

[EEVblog]

My question would be, if it is possible to drive a train with some compressed air. How much pressure do you need and how big needs the tube to be? And how does it work in curves? How strong needs to be the magnet? How does it stop? And right, as you mentioned in the video, it can't be a steel tube if it uses magnets to attach to the inner moving part. Also towing it from the side will create a high shear force, which will result in high friction.

The ultimate question is how fast can it go?
Because if it can't beat fast rail or Maglev then it's not even a starter. We already have trains. The only thing about Hyperloop that matters is the claim it can go faster than the fastest Maglev.
Remember, Hyperloop is nothing more just MagLev inside a low pressure tube to make it go faster than normal MagLev.

[EEVblog]

BTW, you can see the exact same invention here, except the tube is below the tracks, but same magnetic attachment:
https://www.wired.com/story/flight-rail-vectorr-atmospheric-railway-train/

The video is interesting. At 1:45 you can see the piston as well. This works in curves, too, because it has a torus at each end, and the middle is smaller than the tube. Main advantage compared to normal trains is that it is much lighter, because it doesn't need a heavy motor, so e.g. it can climb steeper grades, as the say and demonstrate in the video. It would be possible to accelerate and break much faster as well, and with less energy. Maybe the whole system needs even less energy than traditional trains. Doesn't look that stupid anymore after seeing the real size prototype.

That is not a real size prototype, it's very neat model train that weighs bugger all and doesn't carry any significant weight or at any substantial speed.
Great demonstrator, hats of to the guy, but the question is does it scale, and does it have any useful performance advantage at scale?
And by performance advantage I mean speed, because if all it's got to offer is using less energy then that's not solving a real problem.

[EEVblog]

What hyperloop? ? ? ? ? ?
I heard no mention of hyper-loop in the video. So where has this come from. Did someone see the tube and draw a conclusion?

It's in the CNN article. Several quotes from her mention Hyperloop and how this improves on issues it has.

[EEVblog]

As for hyper loop, it's just another rich kids theme park ride.

Nope, it's not even going to get that far.
If humans ever ride in a several hundred km long low pressure Hyperloop at 1000km/h, I'll eat my hat.

[nctnico]

Well... hyperloop isn't about fixing railways but creating a better alternative for transport over road because conventional just trains don't cut it. Especially when it comes to moving freight. In Europe the effective speed of a freight train is around 30km/h. The Dutch hyperloop firm Hardt is going to build a 3km long test track in the next couple of years and their first target is to transport freight quickly and efficiently.

Why not just use Maglev?

Because Maglev doesn't solve the problem with air friction (which needs exponentially more energy versus speed to overcome) and it is not that much faster compared to the speeds reachable with conventional railroad tracks. Also a Maglev track is quite expensive. The one in Shanghai has cost about 37 million dollars per kilometer. All in all a Maglev is nice but the cost versus gain is not great.

Hardt claims to have raised several million euro to build a 3km test track so price-wise a hyperloop doesn't seem that expensive (it basically is just a tube). Hardt also says a hyperloop is (cost wise) on par with an underground railway and much cheaper compared to Maglev. As I wrote before: in the end it comes down to whether the financials make sense.

[EEVblog]

Because Maglev doesn't solve the problem with air friction (which needs exponentially more energy versus speed to overcome) and it is not that much faster compared to the speeds reachable with conventional railroad tracks. Also a Maglev track is quite expensive. The one in Shanghai has cost about 37 million dollars per kilometer. All in all a Maglev is nice but the cost versus gain is not great.

Correct, but if speed is the primary driver, Maglev still wins.

Hardt claims to have raised several million euro to build a 3km test track so price-wise a hyperloop doesn't seem that expensive (it basically is just a tube).

LOL, it's hardly "just a tube". Hyperloop is a reduced pressure tube. The technical hurdles to get this working over hundreds of km are insane.

Hardt also says a hyperloop is (cost wise) on par with an underground railway and much cheaper compared to Maglev. As I wrote before: in the end it comes down to whether the financials make sense.

No, it's a technical feasibility problem to do with creating a low pressure inside a massive long and wide tube.

If you want to argue "it's just a tube", then it's not Hyperloop, in that case it's just a train/maglev inside a tunnel/tube.

[StillTrying]

What hyperloop? ? ? ? ? ?
I heard no mention of hyper-loop in the video. So where has this come from. Did someone see the tube and draw a conclusion?

It's in the CNN article. Several quotes from her mention Hyperloop and how this improves on issues it has.

But nowhere does she say she's tried to invent a better version of Hyperloop(assuming the idea of HL is very high speeds), to me she keeps trying to distance herself from HL

"Crouchley says, eradicating the potential safety risk posed by propelling passengers in a vacuum."

""Hyperloop is very high risk," says Crouchley."

"It's also safer than Hyperloop."

Her main idea seems to be to get the diesel engines off the trains because of air pollution, which is all she mentions when she gets to speak not through a journalist.

"Caroline developed a sustainable method of public transportation that eliminates the need for a diesel engine or electric motor in trains." https://www.youngscientistlab.com/entry/2049
https://www.youtube.com/watch?v=UygzcFNDVAk&feature=youtu.be&t=118

In the EEV video I don't think you mention 'air polution', but you've separated out the journalism, HL, and the 13yo fine.

Electric motors are the some of the lightest, most powerful and efficient machines we can make, so it's still a useless idea.

[nctnico]

Because Maglev doesn't solve the problem with air friction (which needs exponentially more energy versus speed to overcome) and it is not that much faster compared to the speeds reachable with conventional railroad tracks. Also a Maglev track is quite expensive. The one in Shanghai has cost about 37 million dollars per kilometer. All in all a Maglev is nice but the cost versus gain is not great.

Correct, but if speed is the primary driver, Maglev still wins.

But if nobody can afford the ticket there is no ROI.

Hardt claims to have raised several million euro to build a 3km test track so price-wise a hyperloop doesn't seem that expensive (it basically is just a tube).

LOL, it's hardly "just a tube". Hyperloop is a reduced pressure tube. The technical hurdles to get this working over hundreds of km are insane.

Says who? There are lots of pipelines around the globe spanning hundreds of km which are operating at much higher pressures. Don't step into Thunderfoot's FUD.

This link says oil pipelines use pressures around 40 bar to 70 bar.
https://www.nrcan.gc.ca/our-natural-resources/energy-sources-distribution/clean-fossil-fuels/pipelines/faqs-federally-regulated-petroleum-pipelines-canada/5893

Diameters of pipelines can be up to 150cm:
https://en.wikipedia.org/wiki/Pipeline_transport

Now tell me how it is impossible to build a tube which is 1000km long which has an internal pressure near 0 (approx. -1bar relative to atmospheric pressure).

Hardt also says a hyperloop is (cost wise) on par with an underground railway and much cheaper compared to Maglev. As I wrote before: in the end it comes down to whether the financials make sense.

No, it's a technical feasibility problem to do with creating a low pressure inside a massive long and wide tube.

If you want to argue "it's just a tube", then it's not Hyperloop, in that case it's just a train/maglev inside a tunnel/tube.

The thing is that I'm not a mechanical / structural engineer even though I have built lots of stuff from wood / plastic / metal. I'm not even pretending to be one while sitting in an armchair. I have worked on several projects which involve other disciplines. I've learned that the least productive thing I can do is to question the work done by specialists in other disciplines and/or the financial viability of a project. Usually the real mechanical engineering specialists come up with awesome solutions I would have never even dreamed of. Again, I'm not saying that a hyperloop is possible or not. I just look at the money going in a certain company and the companies behind it. Hardt looks pretty serious with some major companies backing it. Now before you are going to say Hardt is yet another government subsidy sponge; AFAIK the Dutch government has not put a single dime into Hardt.

[FrankBuss]

Ok, I'll try to do some math. A train like the ICE 3 weighs about 400 tons, is 200 m long, and has a capacity for 460 passengers. According to this article, the ICE 3, commissioned in 2012, should have regenerative brakes. Usually the efficiency is up to 17%. Fortunately I don't have to calculate this all by myself, as Dave mentioned in his video, the ICE 3 needs 59 Wh / seat / km.

Here is a train which runs with a rope. The 3rd generation has a capacity for 100 persons and weighs 12.5 tons. This is just a real world example how light a train can be for a given number of passengers, if it doesn't have motors. So use 5 of it, and you could transport more persons than with the ICE 3, but it would weigh only 62.5 tons, 1/6 of the ICE 3. Could be less with modern materials, but might need more, if it runs faster for more stability, and for more comfort, say 100 tons. The 300 tons weight difference is plausible, because a big locomotive can weigh 200 tons, and the ICE has distributed the motors over the wagons, which I guess increases the weight. 500 passengers might weigh worst case additionally 50 tons. To accelerate 150 tons to 320 km/h, you would need at least 591 MJ for the air train (1/2mv^2). To accelerate the 400 tons ICE to 320 km/h with additional 50 tons passengers, you would need 3 times more energy, at least 1.77 GJ.

I guess the loss because of friction is lower as well with the air train, because it is lighter. But let's assume the same as for the ICE, because of the additional friction of the piston mechanism. Breaking could regenerate energy as well, just close a valve at the other side and use the air pressure to power a turbine. And efficiency could be higher because of stationary motors and generators, but assume the same. Then it could be 3 times more efficient than an ICE. But I think this is a very conservative calculation, because the piston mechanism gives it more stability, so the required weight might be reduced even more (they added extra 1.5 tons masses in the floor per wagon for the ICE to increase stability with strong side winds).

Of course, I know nothing about mechanics, and it would need some serious new inventions and tests (graphene tube ), and maybe it doesn't scale to ICE size like trains, but in theory it could be more energy efficient, just because of less weight, that's basic physics.

PS:  For a typical distance between two stations of say 50 km, and if the ICE 3 accelerates to 320 km/h, and with the theoretical minimum energy of  1.7 GJ, it would be 74 kJ / seat / km, so 20 Wh / seat / km. About 1/3 of the 59 Wh in the study, so I guess efficiency of the motors and the regenerative brakes might be not that good, and the friction, wind resistance etc. needs energy, too. But still pretty good, and it shows that the numbers are plausible.

[StillTrying]

How could you control a 100T train from an air valve 2 miles away, how would the train driver control the air valves.

[excitedbox]

My idea is to put small wings on the side of maglev trains. Once you get up to speed the wings create the lift so the magnets don´t have to. Where is my science award 

[FrankBuss]

How could you control a 100T train from an air valve 2 miles away, how would the train driver control the air valves.

Controlling could be wireless. I guess the Flight Rail company has done the math. They claim the compressors can be 80 km apart. Use some relay stations in between, then it is no problem for a wireless connection:

http://www.flightrail.com/our-technology.html

BTW, the model they built weighs 1 ton and it is 1/6 scale. They claim a full size train could accommodate between 240 and 800 passengers. This would mean it would be much lighter than what I assumed. No need to move 100 tons.

Of course, the low hanging fruit would be to move half of the car and truck transports to trains with better logistic and routing software, and you could probably extend the railway network multiple times and you would still save lots of energy with the existing conventional technology.

[StillTrying]

The air in the tubes will weigh tons, too springy, and assuming the pressure changes travel at the speed of sound there'll be 10s of seconds before there's any change at the train.

[FrankBuss]

I guess they need high pressure. If they use e.g. 100 bar, like used in gas pipelines, then the speed of sound would be 10 times the normal speed. But right, for 80 km/h the delay would be still 23 seconds worst case. They need to plan acceleration very well But for emergency brakes, their prototype has an additional brake system for the rails as well. But with the elevated guideway you wouldn't have much emergencies.

[GeorgeOfTheJungle]

At 100 bar, what diameter of piston do you think you'd need to accelerate a train?

[StillTrying]

At 100 bar, what diameter of piston do you think you'd need to accelerate a train?

A 6 inch piston would have about 19 tons of pressure on it, a 12 inch piston about 75 tons. This piston/magnet would have to have wheels spinning at great speed and very good 100bar seals that work at 100+mph.

[FrankBuss]

At 100 bar, what diameter of piston do you think you'd need to accelerate a train?

Physics class is long time ago, but I'll try it, too. Assuming the 6 inch piston, this would be an area A = (0.1524m / 2) ^ 2 * pi = 0.018 m^2. And 100 bar is 1e7 Pa. Then we have force F = A * p, with p pressure in Pa, which would be 180e3 N, so 19 tons of pressure is about right. For a 100 ton train, this would result in an acceleration of a = F/m = 180e3 N / 100e3 kg = 1.8 m/s^2 = 0.18 g. Maximum acceleration for the latest ICE 4 is only about 0.06 g, so it would accelerate much faster. Conclusion: you probably need much less pressure, which makes it easier to construct the tubes.

edit: corrected the acceleration calculation

[GeorgeOfTheJungle]

At 100 bar, what diameter of piston do you think you'd need to accelerate a train?

Good. Thanks. Let's do some numbers:

3 inches radius / 6 inches diameter:
pi*((2,54*3)^2)= 182,5 cm2 @ 100bar => 18250 kgf (what you said)

I googled "How much does a freight train weigh??" and found this:

Locomotives weigh anywhere from 120 to 240 tons each, depending on the size.  Mainline units are the heaviest, switcher units and yard engines are the lightest.

Rail cars can weigh anywhere from 30 tons (empty) to 140 tons (loaded) each.  Special cars designed to carry extra heavy loads can weigh well in excess of 200 tons.  Generally speaking, these loads are special moves, given their heavy weight, and usually require special handling.

The heaviest train I've ever had was around 13,000 tons.  Generally speaking, though, most are in the 3,000-8,000 ton range.

Let's say our train weight is 5500 tons, and we want it to go @ 200 km/h:

f= m*a => a= 19*9,8/5500 = 0,03385454545 m/s2
200km/h= 200e3/3600= 55,55 m/s
55,55/0,03385454545 = 1641s => 1641/3600= 0,45 h

It takes 0.45 hours to get to speed.

Let's see how much air (compressed @100 bar!) do we have to pump into the piston to achieve that:

55,5*100*100/182,5= 3041 m3/s of air @100bar => 3041*12,5= 38 tons of (compressed) air per second.

In total 38*0,45*3600= 61560 tons of compressed air.

In total (100*100/182,5)*0,03385454545*(1641^2)/2= 2498 m³ of compressed air = 31225 tons.

Edit:
Fixed force in N not kgf.

Edit2:
I also goofed up the piston force :-) (fixed)

Edit 3:
Goofed up the rate and totals of compressed air too. LOL.

[StillTrying]

I did the pressure in pounds and inches.

"For a 100 ton train, this would result in an acceleration of a = F/m = 180e3 N / 100e3 kg = 1.8 g."

Without working it out I'd say 19T on 100T train would give only 1/5 g acceleration. ...which happens to be about ~1.8m/s^2.