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Hyperloop

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Re: Hyperloop

#721

Post by SkyAtWork »

Daniel_Newby wrote: post #709
robomartin wrote: post #630

Earlier quoted context omitted.

There's a difference between theory on a piece of paper the the reality of building something. In the real world unions will be all over a project like this. Up every crevice. So will environmental groups and other special interest groups. None of this is good for any major civil engineering project. I asked a question in my post. Can you name any new major civil engineering project in the US in the last fifty years?…

> Can you name any new major civil engineering project in the US in the last fifty years? Most of the interstate highway system, any number of lakes, many major bridges, the completed portion of the superconducting supercollider underground chambers, the brilliant Alaska pipeline pylon system, Florida's long elevated marine highways, the Norfolk (?) tunnel, the NYC aqueduct, most major airport runways. What man has d…

The Florida highway through the Keys dates to the 1930s and the NYC Catskill aqueduct to roughly 1916 - those are certainly great projects but aren't the last fifty.

Largely agree with the rest of your comment though :)

Re: Hyperloop

#722

Post by 6ren »

Anechoic wrote: post #357
pxtang wrote: post #339

Earlier quoted context omitted.

I recall reading that the pylons had vertical and horizontal dampers to protect against earthquakes (among other minor natural changes), so wouldn't those dampers be able to cancel out the shear waves?

No. Well, I suppose you could design an active vibration system to (almost) completely cancel the vertical vibration motion, but know you're talking about a powered system in each pylon of incredible complexity. Passive resilient systems could help with higher frequency vibration (above say 100 Hz or so, depending on the forces and weights involved), but for lower frequency vibration (especially below 20 Hz), the res…

Ah! Note that the pods are far lighter than trains, being more like a lightweight aircraft. This would reduce the effect considerably.

Re: Hyperloop

#723

Post by parasubvert »

robomartin wrote: post #630
revelation wrote: post #588

Earlier quoted context omitted.

Wow, can you not abuse this wonderful idea for a political forum on unions , of all things?

There's a difference between theory on a piece of paper the the reality of building something. In the real world unions will be all over a project like this. Up every crevice. So will environmental groups and other special interest groups. None of this is good for any major civil engineering project. I asked a question in my post. Can you name any new major civil engineering project in the US in the last fifty years?…

The Boston Big Dig. At 190% cost overrun, it was almost a bargain.

http://en.wikipedia.org/wiki/Big_Dig

Expensive != impossible.

California is ready to spend $70. billion. dollars.... On a much slower technology rail platform.

Re: Hyperloop

#724

Post by parasubvert »

wikiburner wrote: post #652
gammarator wrote: post #646

Earlier quoted context omitted.

Can you name any new major civil engineering project in the US in the last fifty years? Boston's Big Dig ( https://en.wikipedia.org/wiki/The_big_dig )?

I'm assuming you're being facetious. A picture of the big dig belongs in the dictionary under the word boondoggle, and proves robomartin's point better than almost any other example could.

Boondoggle would imply it wasn't worth it.

Yes, the Big Dig cost a lot of money. More than expected. It was still worth it.

Re: Hyperloop

#725

Post by parasubvert »

robomartin wrote: post #672
aasarava wrote: post #656

Earlier quoted context omitted.

Can you name any new major civil engineering project in the US in the last fifty years? New San Francisco Bay Bridge. (No, it's not a refurbish -- it's a completely separate bridge with a separate design to replace the existing Eastern span.)

This one: http://en.wikipedia.org/wiki/Eastern_span_replacement_of_the... It only supports my point. It's 2.2 miles long. Construction started in 2002. It was supposed to open in 2007. It will not open until the end of this year. Total cost is currently at six billion. The Hyperloop is 400 miles long, will be built in seven years and will cost six billion. See my point now?

I think it supports your point that the cost is probably off by a lot.

I don't think it supports your point that US unions are destroying the country. That's complete hyperbole.

Cost overruns can be attributed to many factors, the largest being that they're usually underestimated on purpose to sell the idea in the first place.

Re: Hyperloop

#726

Post by jacquesm »

Retric wrote: post #604
dredmorbius wrote: post #563

Earlier quoted context omitted.

At 700+ MPH you'll need more than 100' of freeway median to contain potential incident fallout.

Depends on how strong the tunnel is. Assuming your taking 3/4 atmospheric difference your starting at ~11 pounds per square inch add in a 3-5x safety factor and that tunnel would be one tough son of a bitch. Not to mention it's got to be really close to a strait track so your more dealing with scraping forces than a direct strike.

Does the minimum bending radius of the tube match the centerline of the highway? If not that might be a real problem.

Re: Hyperloop

#727

Post by netrus »

LockeWatts wrote: post #681
mortehu wrote: post #623

Earlier quoted context omitted.

> the three factors that determine how many people you can move past a given point per unit of time are the frequency of the vehicles, the capacity of the vehicles, and the speed of the vehicles Why is speed relevant?

Because it's per unit of time. The faster you go, the higher throughput you'll have.

The frequency already accounts for the time component.

(People/Car)*(Car/Hour) = (People/Hour) = Throughput

At a constant frequency and higher speeds, you will simply have less trains on the track at the same time.

Re: Hyperloop

#728

Post by lmm »

jarek wrote: post #591
dllthomas wrote: post #527

Earlier quoted context omitted.

The R&D can't happen in government, but in some ways that's better - government projects are slower than this needs to be. What we need is for someone(s?) with deep pockets to bank-roll prototypes &c.

Sounds vaguely like maglev a couple of decades ago. It too was a neat idea on paper.

I take it you've never travelled between Shanghai and its airport?

Re: Hyperloop

#729

Post by ravingraven »

julian37 wrote: post #287
axus wrote: post #176

Earlier 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.

Also, the Helios Airways Flight 522.

Re: Hyperloop

#730

Post by TsiCClawOfLight »

jarek wrote: post #591
dllthomas wrote: post #527

Earlier quoted context omitted.

The R&D can't happen in government, but in some ways that's better - government projects are slower than this needs to be. What we need is for someone(s?) with deep pockets to bank-roll prototypes &c.

Sounds vaguely like maglev a couple of decades ago. It too was a neat idea on paper.

Are you guys serious? https://en.wikipedia.org/wiki/Maglev#Operational_systems_ser... Linimo, Shanghai, Daejon, and then all the test tracks, e.g. the transrapid in germany... Maglev is reality now. It simply happened to be built in China, Japan and South Korea rather than in the US.
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