Hyperloop • Hacker News Board

Re: Hyperloop

#231

Post by dkrich » Mon, Aug 12, 2013, 9:46 PM UTC

The main reason why air travel continues to be the most practical, cost-effective means of high-speed transport is that the politics involved in connecting two points with a transit system are enough to make you lose faith in humanity.

Take for instance, the DC metro system. There is an expansion underway to extend the system west to Dulles Airport, about 30 miles or so from downtown DC. A huge project, no doubt, but it is about ten years behind schedule. What was a seemingly great idea (mass transit to a major airport and outlying regions of DC) was almost ruined by all the fighting.

This is for a project spanning 30 miles. Imagine the politics and fighting that occurs between politicians, contractors, lobbyists, and residents on a public works project that spans hundreds of miles between two of the most populous cities in the world.

A project this ambitious is only well-suited for a small, independent group of like-minded people, which unfortunately will never be possible with all the interests involved.

Re: Hyperloop

#232

Post by jcromartie » Mon, Aug 12, 2013, 9:46 PM UTC

mercurial wrote: post #138

I was thinking that a well-timed explosive charge on a support pylon would make for a nice mess, but I suppose it's not any easier to secure a conventional railway.

The distance between the pylons is small enough that adjacent pylons may be redundant. It's also a massive steel tube which would be pretty strong in itself compared to rails (or roads).

Re: Hyperloop

#233

Post by matthewcford » Mon, Aug 12, 2013, 9:46 PM UTC

I love the fact that Musk is publishing this publicly preemptively blocking future patent claims on the basis of prior art.

Re: Hyperloop

#234

Post by clarkmoody » Mon, Aug 12, 2013, 9:46 PM UTC

ansible wrote: post #197

clarkmoody wrote: post #144

I love this concept! My main concern is the air-bearing suspension system. Barring very high flow rates, the fly-height of an air-bearing system is very small. Some systems[1] fly at 5 microns, for instance. That being the case, any sort of particulate or imperfections in the tube will cause the air-bearing to 'land' with a large amount of friction. Perhaps this is alright if you're already going 700mph, but it would…

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 Hyperloop system, then for segments of the trip it might be much better to have a different gas. But again, it might simply be better to invest in better vacuum pumps for certain legs of the journey to get lower drags and higher speeds.

Re: Hyperloop

#235

Post by jessriedel » Mon, Aug 12, 2013, 9:47 PM UTC

OK, so he says it's much cheaper than high-speed rail mostly because pylons require taking much less land through eminent domain. Can anyone explain to me then why high speed rail can't be built on pylons?

Re: Hyperloop

#236

Post by jcromartie » Mon, Aug 12, 2013, 9:47 PM UTC

Does anybody else wonder how easily the rotor will slot into the stator at 700 MPH? It looks like pretty small tolerances. Maybe guide rails leading up to it?

Re: Hyperloop

#237

Post by milesskorpen » Mon, Aug 12, 2013, 9:47 PM UTC

LekkoscPiwa wrote: post #206

aresant wrote: post #32

"In the case of the Hyperloop, Musk started focusing on public transportation after he grew disenchanted with the plans for California’s high-speed rail system." And who says that big government stifles entrepreneurial innovation? If ALL Musk does with the Hyperloop announcement is shed more light on the potential debacle that is to be our $70b+ high-speed rail in California, we owe him a debt of gratitude. PS - Dire…

but why to ask California State for subsidy? Why not to build it using private funds? I'd imagine that if this is economically sound idea there must be potential investors lining up to have their share in the Project? The estimated cost is $7B. Now, Musk just needs to make a few calls to his friends at Google, Amazon, etc. Can't these guys just form a company together just to build it? Maybe I'm naive... or maybe Mus…

The proposal calls for the line to built alongside I-5, which requires government involvement.

Re: Hyperloop

#238

Post by cma » Mon, Aug 12, 2013, 9:47 PM UTC

goodcanadian wrote: post #188

I am intrigued, but not overwhelmed. Many of his reasons why his hyperloop is superior to high speed rail are not specific to the hyperloop. For example, you can put railway tracks up on pylons, too, with very little impact on the ground. It is common to do this in urban areas, but it is rarely done in rural areas because it is flat out cheaper to put it on the ground. I don't believe that an experimental tube is goi…

Can you elevate rail as easily? We're talking a lot more weight being carried by the pillars in that case. Plus you don't get the same natural banking off the walls he talks about, which is relevant at these speeds. While rail could bank, you better be going at the right speed when doing so, too slow and you just fall laterally off the tracks.

Re: Hyperloop

#239

Post by [deleted] » Mon, Aug 12, 2013, 9:47 PM UTC

lmg643 wrote: post #180

aresant wrote: post #32

"In the case of the Hyperloop, Musk started focusing on public transportation after he grew disenchanted with the plans for California’s high-speed rail system." And who says that big government stifles entrepreneurial innovation? If ALL Musk does with the Hyperloop announcement is shed more light on the potential debacle that is to be our $70b+ high-speed rail in California, we owe him a debt of gratitude. PS - Dire…

Interesting point that big government provoked the advancement of the hyperloop idea - counterintuitive idea, and clearly yes. but any idea like this will need government cooperation. The real test of big government will be how they respond to the hyperloop. magic response: "of course we may be wrong, we'll look into this immediately." and then they decide to build it. likely answer: praise, perhaps even an evaluatio…

[deleted]

Re: Hyperloop

#240

Post by digikata » Mon, Aug 12, 2013, 9:48 PM UTC

jared314 wrote: post #36

> Hyperloop is considered an open source transportation concept. I'm glad they didn't just let the idea die on a drawing board somewhere because of a lack of time/money. Now, someone has to just develop it faster than someone else can legislate against it.

It would be more interesting to see a company with the technical (and probably political) chops to pick it up. GE comes to mind because they have the industrial and scale out know how in multiple system areas needed for hyperloop. But maybe it would interfere to much with their air and train businesses. Then again, if you established yourself as being able to build all components of a hyperloop system, I imagine that could be a long lucrative business market...

The question for GE and other similar industry companies which have build-in capability to construct this is if they can lift themselves out of the comfort their existing markets.