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Hyperloop: Pipes of Fancy

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Re: Hyperloop: Pipes of Fancy

#151

Post by Robotbeat »

jojobas wrote: post #98
AlexandrB wrote: post #9

This is evergreen when talking about Hyperloop: http://www.cat-bus.com/2017/12/gadgetbahn/ The problems with building this have nothing to do with technology but with right-of-way, investment, and politics. If those factors were solved, we'd already have high-speed rail in places where Hyperloop has been proposed. The fact that we don't says that Hyperloop is unlikely to be feasible as well.

Three words: vacuum expansion seals.

There are multiple ways to solve this problem. It’s not a showstopper.

1) Bury the lines. Basically isothermal at depth.

2) insulate the tube and maintain stable temperature

3) use materials that don’t drastically change length with temperature

3) allow the tubes to change length. Put them on rollers.

4) use vacuum expansion joints just like us common in vacuum engineering.

People act like vacuum is this new thing. Physicists (well, Engineers/technicians hired by physics projects) have been making really long tubes with extremely high vacuum and incredibly high tolerances. This is easy in comparison.

Re: Hyperloop: Pipes of Fancy

#152

Post by nickik »

reitzensteinm wrote: post #57
nickik wrote: post #52

Earlier quoted context omitted.

They were actually not. And in the cases tax payer funding was involved it was not some sort of blank check. SpaceX got to orbit and was financed privately. Only once SpaceX had proven that capability, they were selected by the government to deliver cargo to ISS. SpaceX had to submit a competitive bid and was selected because they were the cheapest. SpaceX has fully executed on this contract and it was by far cheaper…

> Its important to not that GM, Ford and Fiat-Chrysler received far, far, far more resources in the 2008-2012 timeframe and most of that has unlike Tesla not been payed back Most has not been paid back? What figures are you using for this? My understanding is that the bailout was ~$80bn, but the final cost to the government was approximately $9bn. When people complain about Tesla being taxpayer funded, they're genera…

I have not researched this in many years but not all that money has been payed back by Ford, GM and so on. Just recently Ford moved back another payback claiming Corona as an excuse.

I assume the majority has been payed back but I have not followed this in exact detail. However the point stands that Tesla has not received the majority of government help.

> When people complain about Tesla being taxpayer funded, they're generally referring to EV incentives, not the DoE loan. Tesla has indeed been supported quite a lot in that way.

Frankly, this is just a wrong believe people have. Tesla has the exact same EV incentives as the competition, that amounts to 7500$ per car. Tesla has long run out of these, as they only cover 250'000 vehicles and then fall off. GM just like Tesla has made use of this and has also almost ran out as well. Ford still has many left and will and does make use of that to make their upcoming Mach-E a more price competitive product.

So there really is nothing Tesla specific and the competition has profited just as much.

Next up, there are credits based on fuel standard compliance. This existed long before Tesla. These are competitively sold for California (and other states) and Europe. Tesla does make a money from these this is not from the government or tax payers, rather other car companies who do not comply with fuel standards. Its a fine for car makers who fail to comply with regulation. But again, all car manufactures have the exact same opportunity to engage in that market.

Re: Hyperloop: Pipes of Fancy

#153

Post by rossjudson »

cyrrus wrote: post #46
grecy wrote: post #18

Earlier quoted context omitted.

Which is why the first Hyperloop will probably be built outside the USA. Melbourne to Sydney always seemed like a good choice to me. It's one of the busiest air routes in the world[1], there is obviously tons of solar, lots of open land beside the existing road, no seismic activity to speak of and it's a good long distance to get up to speed (~1000km). [1] (actually #3 in the world by number of passengers) https://en…

Seismic activity is apparently not really an issue. The damage from earthquakes tends to be a ripple of the ground in the first few meters and that’s it.

There's a second reason. The hyperloop tubes can slide back and forth on the pylons. If you shake the ground underneath them, the pylons can move around but the tube (tube system) stays still (like moving your hand underneath a baseball -- the ball stays still, rolling).

Re: Hyperloop: Pipes of Fancy

#154

Post by [deleted] »

liability wrote: post #107
GuB-42 wrote: post #45

Can someone explain me how Hyperloop is supposed to work? There are so many things wrong with it. - Hyperloop is a vactrain, a century old idea, and to this day, despite numerous attempts, nothing came close to a working prototype, let alone something production-ready. - By contrast, high-speed trains carries millions of passengers every day in many parts of the world. They are safe, comfortable, and commercially via…

> "Can someone explain me how Hyperloop is supposed to work?" 1) Mass transit competes with cars. 2) Elon Musk sells cars. 3) High speed rail projects get derailed by people saying "but if we wait N years we could build a hyperloop instead" That's how Elon Musk intends Hyperloop to work.

[deleted]

Re: Hyperloop: Pipes of Fancy

#155

Post by Robotbeat »

aaron695 wrote: post #131
AlexandrB wrote: post #9

This is evergreen when talking about Hyperloop: http://www.cat-bus.com/2017/12/gadgetbahn/ The problems with building this have nothing to do with technology but with right-of-way, investment, and politics. If those factors were solved, we'd already have high-speed rail in places where Hyperloop has been proposed. The fact that we don't says that Hyperloop is unlikely to be feasible as well.

The entire point of the Hyperloop is to get around right of way and politics. That is it's design. That is exactly what Elon is doing. You might argue it can't do what it's setting out to achieve, but this has never been a technological solution. He's designed a technology to fit with current societal processes rather than the old, get society to accept a technology.

Exactly this. That’s why The Boring Company is focusing on reducing the costs of tunneling dramatically. And they started by just using existing technology. With that (and without the cost inflation that many corrupted projects experience), they were able to achieve about $10 per mile of tunnel. A lane of highway per direction is $1m to $8m depending on if it’s rural or urban.

They’ve developed a new machine, Prufroc, that’s supposed to be much faster and capable of “porpoising” (ie angling back up and curving straight) so you can avoid having to excavate a deep station through other means.

If they can get the cost equivalent to a typical surface street in urban areas, they can now compete with surface streets. Much easier to autonomously drive in purpose-built tunnels. Or put a train or a bike trail or moving walkway or whatever.

So they are actually trying to solve the right problem. And using cars is a good idea because cars are really cheap per passenger in terms of upfront capital cost, and they meet the speed, autonomy, safety, and electrification requirements while also allowing use on just regular paved surfaces. If the one-dimensional autonomy works well, they might be able to reduce follow distance at speed enough to exceed a highway lane throughout. And with high occupancy, also a typical light rail train or whatever.

Would be kind of neat to have autonomous driving at 120mph immune to weather and with low enough capital cost that we could afford to crisscross the country with them, without much impact to existing land uses. A clear win if it works. Actually, a clearer win than full autonomous driving on existing roads, as that might quickly clog up surface streets. Plus this is probably technically easier than perfected level 5 autonomy which is still a sort of open ended problem.

Re: Hyperloop: Pipes of Fancy

#156

Post by nickik »

alacombe wrote: post #75
nickik wrote: post #61

Earlier quoted context omitted.

> So for me it just a daring publicity stunt (a borderline scam IMHO), something that Elon Musk is also known to be good at. I think this is a very unfair and cynical way of looking at it. How it is a scam? He said, he thinks its a good idea and he released basically a little concept whitepaper on what his ideas are. He has never attempted to make any money from it, and he clearly just thinks its a good idea and that…

> He has never attempted to make any money from it, That's a blatant lie. https://www.engadget.com/2019-07-25-elon-musk-raises-120-mil... https://www.reuters.com/article/us-boring-company-fundraisin... .

Maybe you should learn the basics about a topic before trying to argue about it. The Boring company fund raiser is not based any promises about Hyperloop.

Re: Hyperloop: Pipes of Fancy

#157

Post by flukus »

thescriptkiddie wrote: post #39
grishka wrote: post #29

Earlier quoted context omitted.

> Elon seems to have moved on to non-vaccuum underground tunnels via The Boring Company So, a subway?

But with cars. No, I'm not making this up. https://twitter.com/elonmusk/status/1285819565407002624

So a subway but only for 8 people?

Re: Hyperloop: Pipes of Fancy

#158

Post by cossatot »

cyrrus wrote: post #46
grecy wrote: post #18

Earlier quoted context omitted.

Which is why the first Hyperloop will probably be built outside the USA. Melbourne to Sydney always seemed like a good choice to me. It's one of the busiest air routes in the world[1], there is obviously tons of solar, lots of open land beside the existing road, no seismic activity to speak of and it's a good long distance to get up to speed (~1000km). [1] (actually #3 in the world by number of passengers) https://en…

Seismic activity is apparently not really an issue. The damage from earthquakes tends to be a ripple of the ground in the first few meters and that’s it.

This is false. In the case of the original Hyperloop idea which crosses the San Andreas Fault, a major earthquake on that fault in line with the 1906 earthquake in San Francisco should produce accelerations the ground surface within 10 km of the fault in either direction of around 1 g (i.e., 9.8 m s^-2), corresponding to Modified Mercalli intensities of disruption to people and infrastructure of X ("Extreme: Some well-built wooden structures destroyed; most masonry and frame structures destroyed with foundations. Rails bent")[1] Vertical Accelerations above 1 g will literally throw anything not bolted to the ground into the air. Not much will make it through this unscathed.

This isn't to say that engineering around these sorts of events is impossible. The Transalaksa oil pipeline crosses the Denali fault, and during the M7.9 Denali earthquake in 2002, the pipeline survived because it was built on sliders near the fault so it would bend when the earth shifted instead of breaking [3]. However, this is a big bend in the pipe; the lateral displacements are on the order of 5-10 m in an earthquake of this size, over a similar across-fault distance. Do you want to go at Hyperloop velocities through a tube with a bend this sharp?

[1]: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.833...

[2]: https://www.usgs.gov/media/images/modified-mercalli-intensit...

[3]: https://pubs.usgs.gov/fs/2003/fs014-03/pipeline.html

Re: Hyperloop: Pipes of Fancy

#159

Post by brianwawok »

sudosysgen wrote: post #115
Alupis wrote: post #82

Earlier quoted context omitted.

When you are directly comparing how much something cost to build, such as a mile of track, in USD, Purchase Power doesn't matter, does it? This is what the Parent post was asserting. China builds a mile of track at half the price because they literally pay their people half the price (or less). It doesn't matter that their local Purchase Power might be greater. Taking it a step further, the Parent was comparing a mil…

Well, if at labour prices at half of the US average China can build high speed trains at a fifth of the price that we can build tunnels, there is more to it than that.

How much does it cost the respective governments for right of way land? Environmental studies?

Re: Hyperloop: Pipes of Fancy

#160

Post by noahtallen »

rtpg wrote: post #73
owenversteeg wrote: post #47

Earlier quoted context omitted.

That "Gadgetbahn" article is great, but I do have one criticism. From the article: "If the idea is viable and the people behind it are competent, it should have attracted private investment, as there should be a potential to make profit selling the technology. After all, the proposal has been around for 23 years." High speed rail on a large scale is really something that has to come from the government. While there a…

High speed rail is also a bit of a red herring. In dense areas you’re not actually going to go fast! “Normal” trains would work fine and be helpful. TGV and Shinkansen go really far! But what makes people in France or Japan take the train a lot is much more around local trains that are just going at normal speeds.

I think the counterpoint in the US is that most cities are very far apart and there is practically nothing in between. Obviously places like the northeast corridor or the Bay Area are much more dense. But even a route from SF->Seattle is mostly traveling through non-dense areas. That gets even better across the west and Midwest
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