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Hyperloop: Pipes of Fancy

economist.com

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Re: Hyperloop: Pipes of Fancy

#261

Post by smikhanov »

marvin wrote: post #252
smikhanov wrote: post #25

Earlier quoted context omitted.

> the likelihood of failure is high but the expected value is positive Except when the new technology was proposed and marketed by a loony, of course.

Yes, all those poor Tesla IPO investors who got misled by a loony are lining up for shareholder lawsuits and yelling for prosecution, due to the obviously financially irresponsible management of their investment. (Refresh my memory here - would an 88X return on investment after IPO be classified as high returns on a high-risk investment?)

I sense some notes of disagreement with calling the Tesla CEO "a loony"

Re: Hyperloop: Pipes of Fancy

#262

Post by vidarh »

jeffreyrogers wrote: post #142
sudosysgen wrote: post #110

Earlier quoted context omitted.

Another thing, is that anyone that punches a hole big enough in the tube basically transforms half of the hyperloop into a bomb. Energy = pressure * volume. That's a lot of energy smashing through a hyperloop capsule. Basically, imagine if 3% of the tube was filled with pipe bombs, but in reverse.

Also, what happens if the pods leak? Seems like the air in the pods will diffuse through the tube and the people will suffocate.

As long as pod moves, there's a constant pressure build-up of air in front of it, to the point that the design includes a compressor to pump air from the front of the pods because passively preventing the buildup by letting it blow through the pod would be insufficient.

So a leak would be a piffling little annoyance in comparison - there'd not be enough volume of air inside the pods to cause a problem compared to the air the compressor on the pod will be actively pumping from the front of the pod to get it out of the way.

Re: Hyperloop: Pipes of Fancy

#263

Post by vidarh »

pilaf wrote: post #146
anitil wrote: post #97

Earlier quoted context omitted.

It's very irritating talking about whatever hyperloop is, because that the bar for what the hyperloop is keeps changing (Is it tunnels? Is it in a vacuum? If there's no vacuum isn't it just a tunnel? Is it your own car or a pod? There's solar panels somehow?). If we wanted better transport we should invest in busses and trains, which have better carrying capacity and better failure modes than whatever hyperloop is su…

> It's very irritating talking about whatever hyperloop is, because that the bar for what the hyperloop is keeps changing (Is it tunnels? Is it in a vacuum? If there's no vacuum isn't it just a tunnel? Is it your own car or a pod? There's solar panels somehow?). The Hyperloop concept is exclusively a pod in a vacuum tube. The electric cars in a tunnel concept is called the Loop (no Hyper), and it's a different idea e…

Even for hyperloop, the level of evacuation of air from the tunnels is an optimization problem. It's a question of where exactly is the intersection of cost of reducing the air pressure further vs. gain from being able to further increase pod speed.

Of course with no evacuation you're left with just a train in a tunnel, so I'd argue the defining factor of a hyperloop type transport is that at least partial evacuation of air from the tunnel, with a mechanism for preventing pressure buildup in front of the pods is the main defining characteristic.

Re: Hyperloop: Pipes of Fancy

#264

Post by bildung »

aaron695 wrote: post #253
bildung wrote: post #235

Earlier quoted context omitted.

But right of way extends underground in the US - literally "all the way to hell"? https://en.wikipedia.org/wiki/Cuius_est_solum,_eius_est_usqu... How is this something that can be solved with the yet to be invented new TBM?

Watch The Hummingbird Project (2018) it's an interesting little movie. From your link - "The "ad infernum" theory positing property ownership "to the center of the Earth" has also been eroded. A review of modern American jurisprudence demonstrates that the theory is more poetic hyperbole than binding law, and that broadly speaking, the deeper the disputed region, the less likely courts are to recognize that the surfa…

I know, and this affects all players equally. For subways this usually is less of a problem because the actual subways don't need to travel vertically. Cars would need to get up and down, though, which means boring gets more expensive and throughput gets smaller.

Re: Hyperloop: Pipes of Fancy

#265

Post by ashtonkem »

richardw wrote: post #221
ashtonkem wrote: post #206

Earlier quoted context omitted.

There are two huge problems here: First, very little freight is latency sensitive. The vast majority of cargo is cost sensitive, which is why most bulk goods coming from abroad arrive via cargo ship rather than airplane. There are a ton of companies that’ll accept days or weeks of delay to reduce overall cost; so a loop must compete with rail freight and semi trucks on cost. Theoretically a cargo hyper loop network c…

I never mentioned bulk goods. I mentioned items that are time sensitive. Most e-commerce is latency sensitive. I recently started getting groceries on an hour delivery. It’s a game changer. Amazon could probably power a network like that by itself. What would a 2 hour Amazon delivery to most cities do? What markets does it enable access to? How do you compete with that? It’s too easy to think of why something won’t w…

> Don’t use my examples, make your own.

That’s ... not how arguments work. You’ve got to provide your own examples. I’m not going to do your work for you.

> Saying “no” to that question is to bet against human desires and ingenuity

This is genuinely a bad way to approach these things, as you’re presuming that it’ll work based on enthusiasm and not evidence. This exact same logic would’ve led you to advocate for flying cars, as you would’ve assumed that ingenuity would triumph over the practical issues that have so far prevented them from working. Ingenuity is great, but market demand actually pays for the bills.

And predicting exactly what the market will do is impossible, but given the fact that this will cost trillions of dollars to actually build, it should be possible to predict use cases that’ll bring in billions of revenue.

> Allow Amazon to compete with local stores.

Amazon is already crushing local stores on price. It turns out that consumers value delivery speed but not as much as they value low cost.

A hyper loop might improve the speed of goods between Amazon warehouses (or run fewer), but it would do nothing to improve the “last mile” problem, which is where all the cost is.

Drone delivery + a hyper loop would actually be faster; but I’m dubious that this use case alone covers said trillions of dollars of cost; especially when drone delivery from local warehouses would work too.

> Will top restaurants pay for that?

No. Restaurants can barely afford the delivery fees of people with cars. Maybe Michelin Star restaurants can afford a bit more, but not that much.

> Allows medical supplies to get there in a surge.

Much easier to just shove it in the back of a C130J. And it requires us to invest a grand total of $0 in new infrastructure or hardware.

> I’m sure you can think of something.

Again, if you’re going to advocate that it will work, that’s your job.

Re: Hyperloop: Pipes of Fancy

#266

Post by ashtonkem »

_ph_ wrote: post #227
ashtonkem wrote: post #198

Earlier quoted context omitted.

Of course, if they can reduce the cost of digging, they’re also reducing the cost of the hyperloop’s biggest logical competitor; the subway.

The Boring company has nothing to do with the Hyperloop concept. The Boring company is about creating cheap tunnels quickly. Current tunneling technology is severely limited by its price. It is really open-ended, which transport system is going to be used inside these tunnels. Hyperloop might be one option, but currently, Elon is not pushing into that direction. Currently, they are using Tesla cars. For higher capaci…

“For higher capacities, special vehicles for those tunnels could be constructed”.

Congratulations, you’ve rediscovered the subway.

If Musk wants to make the argument that he’s found a way to drastically reduce subway construction cost, I’m all ears. But he should jump straight to that, rather than this ludicrous idea of zipping personal cars around under the streets; a proposal that doesn’t come anywhere close to the transit density needed for an actual mass transit system.

Re: Hyperloop: Pipes of Fancy

#267

Post by alexisread »

jcranmer wrote: post #165
keenmaster wrote: post #121

Earlier quoted context omitted.

>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. I disagree with your conclusion. Hyperloop technology is so lucrative that it might galvanize America to update its…

> - 2-3x speed of bullet trains. Can change the way we perceive geographic distance. > - Cost isn't as much of a concern because a national hyperloop network would create a lot more value than a bullet train equivalent. High speed brings with it some pretty severe problems. The most well-known is curve geometry: curve radii scale with the square of velocity. Transition track (how long the "S" of a S bend needs to be)…

The best transport option might be smartrail (similar to http://openprtspecs.blogspot.com/2011/11/climbing-chain.html but steel wheel/LIM and faster).

Smartrail and PRT are designed as a point to point separated-grade network carrying on av. 1 person or a pallette of goods. With a hanging rail you don't need heavy batteries, parking for the vehicles, you can run a pod straight into the factory to pickup goods, and large/rich places can pay to have track straight to their door.

You can prefab the rail and as land usage is just poles in the ground it can be rolled out over fields etc quickly. Track is one-way to eliminate junctions. Pods are on-demand ie. No waiting.

Accessibility improves, you can use the top of the rail to generate (solar) power, run highspeed internet cables in the rail to improve comms across a country, and save on distribution center logistics as you're going point to point.

The last mile may possibly be an issue, but forklift drones and bicycles can take most of the load I feel.

Drivers for this are that it would go fast (200mph+ as light pods so little wear), can go overnight (sleeper pods), you could buy track to your door, personal transport (like a cinema room if you want). The main real issue with cars is that there's a large lobby behind what is a legacy transport solution...

By way of example, UltraPRT has been running flawlessly at Heathrow airport for 10 years, was built on time, on budget, and performs exactly as predicted/modelled.

For more info checkout http://faculty.washington.edu/jbs/itrans/ in particular Swedetrack (https://web.archive.org/web/20060202013014/http://www.swedet...)

Re: Hyperloop: Pipes of Fancy

#268

Post by ashtonkem »

andbberger wrote: post #216
nick_kline wrote: post #166

Earlier quoted context omitted.

Well, they don't run them all day because of the cost of the use of the trains and the cost of the crews. The crews can't be paid all day to do nothing.

The crews can absolutely be paid all day to do nothing.

They often are already.

Besides, capital costs of construction and vehicle acquisition absolutely dominates the cost of operation. The problem isn’t that running constantly available service isn’t affordable, the problem is that we lack the political will to make mass transit a meaningful alternative to cars.

Re: Hyperloop: Pipes of Fancy

#269

Post by stevehawk »

sudosysgen wrote: post #109
Miraste wrote: post #103

Earlier quoted context omitted.

This article[0] talks about how locals were shooting at it, although it doesn't mention the berms (talking to the sheriff must not have worked out). I think a hyperloop could avoid this problem by not locating in Louisiana. [0] https://www.225batonrouge.com/article/good-vibrations

What do you do when a terrorist shoots a hyperloop tube causing a pressure wave that will kill everyone inside?

What do you do when American citizens shoot at airplanes? Quit flying?

Yesterday an Air Force helicopter was shot at and the pilot injured. Not to mention the number of citizens pointing lasers at cockpits.

https://www.wusa9.com/article/news/local/virginia/military-h...

You can't refuse to do something just because you're scared of a few bad actors. Otherwise we have to stop making cars (they get driven into crowds), building tall buildings (they get bombed or have aircraft flown into them), drinking public water (they get threatened with poisoning attempts), blah blah blah.

Re: Hyperloop: Pipes of Fancy

#270

Post by _ph_ »

ashtonkem wrote: post #266
_ph_ wrote: post #227

Earlier quoted context omitted.

The Boring company has nothing to do with the Hyperloop concept. The Boring company is about creating cheap tunnels quickly. Current tunneling technology is severely limited by its price. It is really open-ended, which transport system is going to be used inside these tunnels. Hyperloop might be one option, but currently, Elon is not pushing into that direction. Currently, they are using Tesla cars. For higher capaci…

“For higher capacities, special vehicles for those tunnels could be constructed”. Congratulations, you’ve rediscovered the subway. If Musk wants to make the argument that he’s found a way to drastically reduce subway construction cost, I’m all ears. But he should jump straight to that, rather than this ludicrous idea of zipping personal cars around under the streets; a proposal that doesn’t come anywhere close to the…

Yes, he claims to have found a way to drastically reduce construction consts. First of all, reducing the tunnel diameter, as the digging speed is constrained by volume. Second, he tries to improve the technology of tunnel boring machines. With the smaller tunnels, there is the requirement for smaller vehicles. You can't run standard trains through these tunnels. For now, he is using Teslas (quite obvious choice) to demonstrate the tunnels, but equally it is obvious, that to increase the capacity of tunnels, you want more bus or train-like vehicles. It is so funny how people critisizing Musk assume, he wouldn't understand so simple connections like seats per vehicle and transit density.
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