Well, maybe. A breakthrough is possible at any time. Earlier this year, there was a research group who claimed to have discovered a room-temperature superconductor, and easy to make, too. While the claims turned out not to pan out, they were taken very seriously in the physics community, because it just might have been true, and if it was, it’d have been huge. What nobody said was “No, that can’t be true, because we’re decades away from developing that”. There’s just no way to know how far away we are from developing a room-temperature superconductor.
And I don’t know if it’s inherently only governments that build maglevs right now. The limiting factor isn’t government vs. private; it’s that the only reason to build one is prestige. Governments value prestige, but then, so do plenty of private companies. I could see someone like Disney putting one in in one of their parks, because they figured the marketing value of it was enough to justify the costs.
I don’t think such thing would be built in the US as the US is way too car centric culture.
There seems be more talk about the hyperloop system that rich people and businesses interested in building the hyperloop system than magnetically-levitated trains.
I guess like others here say magnetically-levitated trains are too costly to build and operate.
They are, but hyperloop is orders of magnitude worse in every conceivable way: construction, running and maintenance costs, security / disaster safety etc.
It’s funny how particular modes of transport can capture the public’s imagination.
Now monorails, there’s a practical tech. Or an escalator to nowhere, how can I invest?
Are maglevs actually faster? The upper limit to typical high-speed trains seems to be the quality of the the railroad it’s running on. If we spent a similar amount per mile of track for each, would there be a significant speed difference?
I’m sure there are multiple threads bashing and defending Elon, so I’ll just sidestep that here.
But, in general, rich people investing doesn’t mean a whole lot when it comes to new tech.
I’m much more interested in what engineers and scientists have to say, and the consensus there is that this is not even vaguely a new idea, with the drawbacks I alluded to, and nothing has changed to make it feasible now.
Almost-certainly yes.
I mean, the ultimate potential of any tech is unknowable, but conventional trains with engineering as we know it, reach a point of diminishing returns at about half the speed that maglevs reach the same tail off.
To clarify again though, I’m not trying to promote maglev. Though I found it very convenient, I accept that right now the cost benefit doesn’t make sense.
I’m interest if rich person or business can build it and operate and make profit of it. I believe he wanted build in by year 2025 or 2030 connecting LA to Vegas.
No worries, I’m more interested in the engineering than the politics. I feel like people focus on the trains when it’s actually the tracks that are the limiting factor.
Maglev surely has less friction than steel wheels on steel rails. (Although I wonder if replacing the axial bearings with magnetic fields would be possible.) But speed isn’t just about reducing resistance, it’s also about power transmission from the motor to the ground. It’s not clear to me that maglev has an advantage over steel on steel with that.
Again, I didn’t want to make this about Elon, but whatever anyone thinks about him, and as much credit as we can give him for his various achievements, it’s inarguable that he’s promised many things that haven’t come to fruition.
More than that; he has claimed to have tech: robots, self driving systems, haulage, that does X and years later there’s zero evidence of anything that can do X.
If I could bet my own money, I’d happily bet that Elon will never make a commercial hyperloop.
There is an absolute upper limit to how much torque steel on steel can absorb. The only way to push more power above that point is to power more wheels on the train. And of course in slippery conditions of rain, ice, and snow, the max deliverble torque per wheel goes down; in many cases waaay down. Convesely, there is no upper limit on how much magnetic force can be generated. Just bump the voltages, add more coils, or reduce the clearances. And weather has zero effect on magnetic coupling.
It’s real obvious that we can drive far more power through magnetics than via steel wheels. An ordinary diesel electric locomotive can readily spin its wheels. And every bit of that torque originates inside the magnetic fields of the electric traction motors turning those wheels.
A big issue with high speed trains is air drag. By the time we’re talking 200+mph, the rolling friction is negligible compared to the air drag. And maglev does nothing to help with that. To the degree the train’s underside can be more aerodynamic without wheels, bogies, etc, sticking out that will help. But that’s still pocket change on the overall debt of wind resistance.
Modern airliners don’t cruise much above 300 knots of ground-level ram pressure equivalent (IAS in the argot). They travel at 500-600 actual knots, but by dint of climbing 5-8 miles above the surface so the drag from that much thinner air amounts to much less than it would down low. Trains (obviously) lack that 3D luxury and are stuck plowing through the thickest part of our atmosphere. (Except in an evacuated tunnel a la Hyperloop. Which has stupid hard problems of its own.)
This is where I have trouble. Superconductors have definite limits on voltage, current, and magnetic field. These are material limits, not theoretical limits, so your point is a good one, but limits nonetheless.
Quite right. I did overstate the case. But for a semi-legit reason.
For current (heh) non-superconducting materials we know how much flux, voltage, heat, etc., we can cram into a linear or rotary motor before it overheats or mechanically destroys itself.
Untill we have actual room temp superconductors we won’t know how hard we can push them mechanically, thermally, electrically, or magnetically. The inverse square law will always apply to flux density and the comparatively loose tolerances of big vehicles and stout tracks will act as a limiter. But will it be the limiter?
No one is going to give up their land for some stupid high speed train. You know what land is worth in congested areas! And it isn’t safe anyway. One rock from an overpass, or one cow on the tracks of a high speed train and that’s it.
So it needs to be underground, in evacuated tunnels for high speed travel.
Don’t invest in trains, invest in high speed automated tunnel boring machines!
You can build a wheeled train that’s just as fast as a maglev. The wheeled train will have to deal with rolling and bearing friction, which the maglev won’t, and so you’ll need enough power to compensate for that, which does have its costs. But it’s less than the costs associated with a maglev.
If your goal is just to move people quickly, then you’ll choose the cheapest way to accomplish that goal. Which is wheels. It’s only if your goal is to impress people that you choose the maglev.
