Railroad Forums 

  • Hyperloop and other vactrains

  • General discussion of passenger rail systems not otherwise covered in the specific forums in this category, including high speed rail.
General discussion of passenger rail systems not otherwise covered in the specific forums in this category, including high speed rail.

Moderators: mtuandrew, gprimr1

 #1481570  by bostontrainguy
 
Don't know what's so unique about the Boring Company's technique, but if what you are saying is true, they should be used for Gateway and the Cross Harbor Freight Tunnel too. Faster and cheaper - what are we waiting for?

P.S.Their website claims their newest machine is10 times faster then existing machines. That's amazing.
 #1481575  by mtuandrew
 
bostontrainguy wrote:Don't know what's so unique about the Boring Company's technique, but if what you are saying is true, they should be used for Gateway and the Cross Harbor Freight Tunnel too. Faster and cheaper - what are we waiting for?

P.S.Their website claims their newest machine is10 times faster then existing machines. That's amazing.
That's what I've been trying to ascertain too, the company's videos aren't clear on the difference between their boring machines and a standard TBM. I think part of the difference is that these tubes are built for a small vehicle, considerably smaller in diameter per passenger/hour than a standard subway or train, so maybe they're easier to bore & excavate quickly.
 #1481583  by NorthWest
 
Hyperloop is just maglev in a vacuum tube... It's just taking an astronomically expensive existing technology and putting it in even more expensive tubes.

Is there any barrier to it? Just economics...
 #1487877  by D40LF
 
NorthWest wrote:Hyperloop is just maglev in a vacuum tube... It's just taking an astronomically expensive existing technology and putting it in even more expensive tubes.

Is there any barrier to it? Just economics...
You're right, the economics don't make much sense.

I would say there are also physical barriers. None of the Hyperloop companies have (to my knowledge) explained how they would deal with the expansion problems presented by a long, exposed steel tube. They also haven't really considered the safety implications of a vacuum breach, which could prove fatal and cause serious damage to the entire system.

Either way I see this going nowhere fast, yet the media keep hyping Elon Musk's ridiculous (and in many cases unoriginal) ideas.
 #1488682  by djlong
 
1) It's not a vacuum.

2) The reason that the press gives Musk all the ink is becuase, love him or hate him, he's done more things that "have never been done before" than anyone else in recent memory. It's been historically unwise to bet against the guy.

Now, I'm not a total fanboy.. The one thing Musk *consistently* gets wrong (sometimes by incredible margins) is his scale of time - when he thinks a given 'something' can be delivered.

He practically invented internet banking (PayPal). He took over a small startup car company that had produced nothing and built electric cars that *nobody* thought possilbe (and, full disclosure, I own a Tesla Model 3). He also invested his PayPal profits into creating a rocket company from scratch, becoming the first private corporation to put a rocket in orbit (as opposed to a government-funded program), and then has made more and better rockets that are doing things that were science fiction not too long ago (simultaneously landing booster rockets???) - to say nothing of his price/performance ratios that beat the pants of of everyone from NASA/ULA to Roscosmos and even have the Chinese wondering how he does it.

So when he's talking Hyperloop, people listen. Let's face it, when Musk released his white paper, there were a lot of people who said it would never work and that we'd never see anything you could actually touch. Now we have prototypes on test tracks going over 200mph.

I have a button in my collection that says "I didn't know it was impossible when I did it".
 #1488694  by ConstanceR46
 
He practically invented internet banking (PayPal).
He wasn't very good at it as he got kicked out 2 years later.

He took over a small startup car company that had produced nothing and built electric cars that *nobody* thought possilbe (and, full disclosure, I own a Tesla Model 3).
While managing to be Really Bad at supply chain management and even getting into fights with the Union Pacific.
becoming the first private corporation to put a rocket in orbit


That's just flat-out wrong. Space Services Inc's Conestoga was the first private rocket in orbit.
more and better rockets that are doing things that were science fiction not too long ago
Falcon Heavy's not better until it's actually launching things.

tl;dr Apartheid Man isn't as good as you think he is.
 #1488942  by D40LF
 
djlong wrote:1) It's not a vacuum.
Its basically a 99% vacuum, so if it fails, it'll be very similar to an actual vacuum failure.
djlong wrote: So when he's talking Hyperloop, people listen. Let's face it, when Musk released his white paper, there were a lot of people who said it would never work and that we'd never see anything you could actually touch. Now we have prototypes on test tracks going over 200mph.
Over 200mph. So what? Maglevs could do that several decades ago, without having to run in an expensive, impractical, depressurized tube. The only Hyperloop test tracks that have been built thus far are very short, and have done little to prove the practicality or commercial viability of this idea. And besides, Elon Musk didn't even invent this concept (he only gave it a new name). Its an idea that's been around since the early 1900s (look up Goddard Vactrain), and yet it never seems to go anywhere.

Here's an interesting article in Railway Gazette about this: https://www.railwaygazette.com/analysis ... -hype.html" onclick="window.open(this.href);return false;
 #1488948  by electricron
 
D40LF wrote:
djlong wrote:1) It's not a vacuum.
It's basically a 99% vacuum, so if it fails, it'll be very similar to an actual vacuum failure.
The faster trains go, the higher the resistance from air.
Check out planes, and how altitudes effect the corresponding atmospheric pressure.
https://www.mide.com/pages/air-pressure ... calculator" onclick="window.open(this.href);return false;
-5000 feet 1.19 atm 17.55 psi
-4000 feet 1.15 atm 16.95 psi
-3000 feet 1.11 atm 16.36 psi
-2000 feet 1.07 atm 15.79 psi
-1000 feet 1.04 atm 15.24 psi
-500 feet 1.02 atm 14.96 psi
0 feet 1.00 atm 14.70 psi
500 feet 0.98 atm 14.43 psi
1000 feet 0.96 atm 14.17 psi
2000 feet 0.93 atm 13.66 psi
3000 feet 0.90 atm 13.17 psi
4000 feet 0.86 atm 12.69 psi
5000 feet 0.83 atm 12.23 psi
10000 feet 0.69 atm 10.11 psi
20000 feet 0.46 atm 6.75 psi
30000 feet 0.30 atm 4.36 psi
40000 feet 0.19 atm 2.72 psi
50000 feet 0.11 atm 1.68 psi
60000 feet 0.07 atm 1.04 psi

Between 30,000 and 40,000 feet above sea level is where most commercial jetliners fly, betwwn 1/4 and 1/5 atmosphere pressure, or if you want to look at it the other way around, between 75% and 80% vacuum. They could not reach the cruising speeds they fly at if there wasn't a partial vacuum. Trains can't either, hyperloop, meglev, or high speed rail.
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