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Hyperloop

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Re: Hyperloop

#281

Post by jessriedel »

jeffasinger wrote: post #229
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…

The tube is not nearly as wide or heavy as a traditional train, so I don't know that it's fair to say that you can just as easily put a train up on pylons as you could this tube. It's interesting to think about, but also there are probably much higher costs associated with a completely untested system like this than estimated. I wouldn't be surprised if this system, if it actually worked at all, ended up being more e…

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?

Re: Hyperloop

#282

Post by mpyne »

dclowd9901 wrote: post #145
venomsnake wrote: post #81

Earlier quoted context omitted.

Well the pod has compressor - so it literally can hit the fan :) The only thing I really dislike so far is the battery pack in the pod. I would have wanted to see something more elegant instead. And this way we halve the weight of the pod.

For the lack of space between the tube and the carrier, is wireless electrical transfer out of the question? Or is that not feasible with the amount of electricity being dealt with here?

Wireless power transfer would likely significantly complicate the design and construction of the tube itself, which as it stands can be just a dumb hollow cylinder on a stick for the vast majority of its length.

Perhaps the redundant vacuum pumps are spaced frequently enough that the power transfer problem would be easy, but I doubt it.

Re: Hyperloop

#283

Post by munificent »

Osmium wrote: post #199

Reading the entire PDF is highly recommended; it contains a surprising amount of answers already (including many to comments below). I think, if anything, safety aspects haven't been sufficiently explored in the pdf. I'm quite happy to believe it's safer than other modes of transport, but I wouldn't be too quick to overstate it. Also, if anyone can explain what "Tubes located on pylons would limit access to the criti…

> "Tubes located on pylons would limit access to the critical elements of the system." is meant to mean in §4.5.6 I'd be grateful...

You don't have to worry about cows wandering into oncoming vehicles like you do with cars and trains. It's also harder for non-determined people with malicious intent to interfere with operations.

A determined attacker can, of course, scale pylons. But you don't have to worry about stuff like kids lobbing bricks from overpasses, or people pushing others onto subway tracks.

Re: Hyperloop

#284

Post by digikata »

Anechoic wrote: post #224
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…

I don't believe that an experimental tube is going to be somehow magically cheaper and easier to route and build than train tracks. Do you really think the special interests that are making HSR so difficult and expensive would say, "Oh, do whatever you like with your tube."? These are extremely important issues that advocates seem to be glossing over. Putting the guideway on pylons doesn't magically eliminate land is…

> When a train exceeds the shear wave speed, ground-borne vibration waves "build up" in a manner similar to the shock wave created in air when a plane exceeds the speed of sound...

Putting the railway or tubes on pylons would give you an opportunity to dampen or otherwise transform those vibrations wouldn't they?

Re: Hyperloop

#285

Post by karmicthreat »

I would dedicate 6-10 years getting something like this off the ground. Unfortunately I don't think anyone without the political and financial connections could pull this off. Musk could probably do it because of Musk Mania. But few others.

Re: Hyperloop

#286

Post by tomrod »

I hate to be a party pooper, but I see some economic issues.

My takeaway is that while the 7 billion fixed costs will be low, the operating costs are going to be huge.

Battery packs and solar cells will need replacement. Large maintenance teams will be needed with immediate response times to fix issues such as complete seal blowouts, etc.

I think the first few years will be great! But in my opinion maintaining this system over the long term will be very, very expensive compared to slower rail.

I'm still optimistic that most of these and other issues will be worked out in the long term.

EDIT: Did he post what this tube will be made out of? How will he prevent solar degradation?

Re: Hyperloop

#287

Post by julian37 »

axus wrote: post #176
mortenjorck wrote: post #160

Earlier quoted context omitted.

I'm not claustrophobic, but this image ever so slightly terrified me: http://i.imgur.com/lGD9bUP.png I have to wonder, would making the capsule the size of a small subway car completely destroy the economics of it?

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.

Re: Hyperloop

#288

Post by Gravityloss »

mladenkovacevic wrote: post #174
Matti wrote: post #63

"Hyperloop Passenger Capsule The maximum width is 4.43 ft (1.35 m) and maximum height is 6.11 ft (1.10 m). With rounded corners, this is equivalent to a 15 ft2 (1.4 m2) frontal area, not including any propulsion or suspension components." At a first look I didn't get that the proposed passenger capsule would be so small. That's pretty cramped. Edit: Isn't the the ft to m conversion for the height wrong?

Yeah that should definitely be 2.10 meters

Or then the m to ft conversion is wrong.

Re: Hyperloop

#289

Post by HCIdivision17 »

ansible wrote: post #182
acadien wrote: post #80

Earlier quoted context omitted.

But that's at a pressure of 100Pa (1/1000 atm). How much power does it take to maintain a vacuum of 1/1000atm in a tube hundreds of miles long? It seems this point is skipped over in the whitepaper, so perhaps its negligible. Edit: yes I was referring to the power to sustain a vacuum in a leaky system, of course no power is required to maintain a vacuum in a perfectly sealed system :)

How much power does it take to maintain a vacuum of 1/1000atm in a tube hundreds of miles long? It doesn't require any power, if there are no leaks. The power required will be determined by the amount of leakage that is considered tolerable to the system.

Regular mechanical pumps can haul gas to pressures of a hPa. Any lower, and you're looking at something like turbomolecular pumps. (And efficiency may call for a second stage of specialized mechanical pumps.)

But in my experience, small mechanical leaks are usually of the order of a hPa or so, meaning no high vacuum tech will be needed. Just a fleet of giant blowers and mechanical pumps. (I worked on a wide area sputtering machine for a few years with a few hundred HP of mechanical backing pumps for about a hundred foot long chamber with a 10 sq foot average cross section (order of magnitude error for anonymity ;)) The machine would haul down to 10 or 1 hPa with leaks you could _hear_.

So yeah, it could work practically, especially if it's a welded system and not a giant mess of bolts and o-rings.

Re: Hyperloop

#290

Post by slacka »

tptacek wrote: post #76
melling wrote: post #59

Earlier quoted context omitted.

So, we have "light shed" on the current "debacle" and neither system gets built. That's a win? HSR was first commerically available in 1964. Yes, it got really expensive waiting 50 years. I imagine it'll be even more expensive in another 20-30. California is going to get even more crowded.

That's an argument in favor of a useful HSR system. But politics have resulted California's HSR system being deliberately pessimized; it may do more harm than good to the HSR cause, right?

“The man who moved a mountain was the one who began carrying away small stones.” -Chinese Proverb

I've lived in China for over 3 years, and spend countless hours riding the HSR system. HSR combines the speed of a plane, with the cost and convenience of a regular bus. Traveling through the countryside of China at 380km/h made me feel like I was in the future. Coming home and seeing the the sad state of our infrastructure was a harsh reality check.

Granted China has a massive manufacturing/mining complex and cheap labor. But if we hadn't squandered 5 Trillion on "War on Terror" and domestic spying, I'm sure we could kept our lead in infrastructure and still has some left over to boost education / R&D spending.

In the past 20 years China's moved their mountain. Hopefully the hyperloop will help us to catch up.

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