I'm pretty sure the first Hyperloop will be built in China.
Hyperloop
391–400 of 983 posts
Re: Hyperloop
#392The key advantages of a tube vs. a railway track are that it can be built above the ground on pylons and it can be built in prefabricated sections that are dropped in place and joined with an orbital seam welder. Did anyone else read this and imagine laser beams fired by satellites?
Not really. It's a valid welding http://en.wikipedia.org/wiki/Orbital_welding ), but I imagine it might be quite a task to scale it up to pipes as large as would be needed for this project.
Orbital welding on this scale and much larger is already done in the offshore oil industry.
Re: Hyperloop
#393Earlier quoted context omitted.
It's also scary that the passengers would suffocate if the life support system failed.
Isn't that the case with planes also? As far as I know, at 35,000 feet altitude you'd die, too, if cabin pressure drops and the plane's life support system fails. And I don't recall ever hearing of an air plane accident that involved suffocation.
Look at the Armstrong limit (at 62,000´), a mayor problem to overcome if the tube is going to be at the equivalent pressure of 150,000´
http://en.wikipedia.org/wiki/Armstrong_Limit
http://en.wikipedia.org/wiki/Time_of_useful_consciousness
Also look at the TUC (time of useful consciousness) that it´s below 5 secs when flying that high. That means that you have less than 5 secs to put your oxigen mask on before you lose conciousness, or behave with out knowing what is happening. Also due to the extreme low pressure, you´ll have a horrible a horrible stomach ache due to the expansion of the gases inside you. Your blood (or at least the corporal fluids exposed directly to the low pressure) will start boiling.
Not funny. Maybe one solution could be wearing some kind of pressure suit for this trips. But that is not going to be very convinient..
Re: Hyperloop
#394Earlier quoted context omitted.
Can you elevate rail as easily? The short answer is, "yes." I've ridden on it. The slightly longer answer (as another commenter has pointed out) is that it depends on the weight of the train versus the weight of the hyperloop. I see no fundamental reason to assume that the hyperloop is lighter than the train. It could be so, but then, we could make smaller and lighter trains, too (light rail). Plus you don't get the…
"I see no fundamental reason to assume that the hyperloop is lighter than the train." Did you actually read the PDF? It doesn't carry its motor with it. That's a pretty big reason. Nor does it need the heavy-duty (and heavy!) trucks of a standard rail car.
Turn down the nastiness. It's totally non-obvious that this isn't overshadowed by the weight of the tube. And it does carry a motor with it, just not one that's responsible for initial acceleration or for large air resistances.
Re: Hyperloop
#395Earlier quoted context omitted.
It was approved by a ballot measure, so in this case it may be the "idiocy" (or will) of the voter. http://ballotpedia.org/wiki/index.php/California_Proposition...
They approved it at a much lower budget ($9.95 billion). It would be interesting for the voters to get another vote based on the current cost projections.
The $9.95 billion was for the initial bond issuance. The estimate on the ballot was $40 billion versus the current estimate of between $98.5 billion and $118 billion.
Edit: correction from dragonwriter, via wikipedia [1]:
"The cost of the initial San Francisco-to-Anaheim segment was originally estimated by the CHSRA to be $33 billion (2008) / $35.2 billion (2013), but a revised business plan released in November 2011 by the CHSRA put the cost at $65.4 billion (2010) / $68.9 billion (2013) / $98.5 billion (YOE). The latest plan has revised the costs down to $53.4 billion (2011) / $54.5 billion (2013) / $68.4 billion (YOE)."
[1] http://en.wikipedia.org/wiki/California_High-Speed_Rail#Fund...
Re: Hyperloop
#396Earlier quoted context omitted.
It was approved by a ballot measure, so in this case it may be the "idiocy" (or will) of the voter. http://ballotpedia.org/wiki/index.php/California_Proposition...
They approved it at a much lower budget ($9.95 billion). It would be interesting for the voters to get another vote based on the current cost projections.
[deleted]
Re: Hyperloop
#397Earlier quoted context omitted.
From the report: "...with capsules departing as often as every 30 seconds from each terminal and carrying 28 people each. This gives a total of 7.4 million people each way that can be transported each year on Hyperloop."
Eventually hits up against this problem: http://books.google.com/books?id=DenWKRgqzWMC&pg=PA67&lpg=PA...
"We have a circulating system with a fixed population..." Not quite the same since people getting off the hyperloop won't be turning around to get on it again.
Re: Hyperloop
#398Earlier quoted context omitted.
As an aside, I would like to see trade studies done on filling the tube with other gasses whose speed of sound is much higher than air's, allowing the capsules to travel even faster before shocks begin to form. I don't think this is a good idea for production use, because then you have to worry about air leaks to/from the passenger compartment. As it is, you still have to guard against explosive decompression for the…
Well that's the point of a trade study: look at the cost/benefit of different gasses. Obviously one of the costs would be the increased engineering um...pressure put on the capsule design. Your gut feeling is probably right, though, at least for this length of trip. The increased cost of a different tube gas probably won't outweigh the benefits of arriving 5-10 minutes earlier. Now if there were a cross-continent Hyp…
http://www.phy.mtu.edu/~suits/SpeedofSoundOther.html
The only ones I see that are significantly higher than nitrogen/oxygen are methane, hydrogen, and helium.
Helium is mondo-expensive. It's not cheap even in welding-tank quantities, much less in the amounts you'd need here.
Hydrogen is flammable and/or explosive (depending on mixture) and is a huge pain in the butt to keep confined (so is helium).
Methane is cheap (but not as cheap as air :-)), and we have lots of experience with keeping it confined in big pipes. However, it's also flammable or explosive.
Using anything but air is going to require some sort of complicated replenishment/purging system and an air lock at both ends, whereas air leaks just require pumping it out again.
Re: Hyperloop
#399Earlier quoted context omitted.
But why make it a traditional train? Just build a lightweight train if it gets you all of the hyperloop's cost advantages without the additional costs and complexity of a tube?
On trains the cars have to be connected to each other. The structure has to bear the load of all of them at once. Not the case with hyperloop.
It's totally implausible that that's the primary factor.
Re: Hyperloop
#400Earlier quoted context omitted.
> something like this has never been built before That was true of everything, once.
Doesn't mean building the first one should be expected to be easy.
What about the 2nd through the 5000th?
All the cost skeptics want to roll all the R&D costs into one line. That wouldn't be the case.