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Hyperloop One Becomes ‘Virgin Hyperloop One’

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Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#231

The original Hyperloop paper quotes its design pressure as “about 1/6 the pressure of the atmosphere on Mars” [1]. Martian atmospheric pressure is “about 0.6% of Earth's mean sea level pressure” [2]. So 0.1% of Earth’s surface pressure, or a 1,000:1 pressure change. To put that in perspective, the Boeing 787’s GEnx-2B67, the most powerful GEnx engine variant, generates a 43:1 pressure ratio [3]. To get a sense of the…

> The Hyperloop’s thermal issues are a hard enough problem that they alone put this in the domain of materials science. That’s the same category of problems separating us from a space elevator.

What? What are you even talking about?? That's a completely ridiculous statement. The pressure inside and outside the lunar landing module was 1,000,000,000,000,000x. 100 kPa to 10^-10 Pa. It makes zero sense to apply this kind of ridiculous relative measurement to pressures because it has no relation to how pressure works. The structural challenge in building a tube that works to .001 atmospheres is only 25% harder than building a tube that works to .2 atmospheres (same as an airplane). And it isn't any more dangerous.

The only challenge that occurs is sealing in that atmosphere without any leaks and that part isn't hard either. 100 Pa is achievable by a $50 pump.

I also have yet to see any compelling argument that there will be thermal issues. Floating mounts and expansion joints are hardly untested technology.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#233
post #175
post #165

Just as a thought experiment, could the promotion of these "hyperloop" projects be a clever political ploy to misdirect/divert attention and prevent a viable high speed rail network from being built? Elon's main business is electric cars and (one of) Branson's is airlines. So a reasonable competitor to both is fast and cheap(er) public transport along a major travel corridor in the USA. This means that by promoting t…

Interesting idea. In Denver, they're partnering with our regional transportation district to evaluate a hyperloop system here. Unfortunately RTD has been completely incompetent with existing rail programs to date so there isn't much confidence in their ability to pull this off. Could potentially be designed to fail.

Yeah, Denver being chosen just convinced me that this whole thing is pump and dump cash grab.

CDOT has this thing for "public/private partnerships" which are just thinly veiled schemes siphoning off taxpayer money. The whole US36 debacle proved to me that they aren't capable of negotiating a good deal on the part of the taxpayers.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#234
post #206

Earlier quoted context omitted.

It's a good thought experiment, and not without precedent.. however the main problem holding high-speed rail back in the United States is that freight trains have priority over passenger trains. Without changing this, high-speed rail in the US will never be a reality without building an entirely separate rail network.

Are they? AFAIK, passenger trains have priority. However, if the passenger company rents a specific timeslot from the railway and isn't on time, it isn't surprising if there is traffic along the way. And high speed trains usually require dedicated tracks to operate at full speed anyways.

I was also under the impression that freight trains had priority, so I looked and found this article:

http://www.sfgate.com/opinion/article/Amtrak-has-priority-ov...

I've experienced these delays many times riding the California Zephyr, and the conductors always say something about the freight trains having priority. According to the article this is because Amtrak is persistently ceding priority, despite federal regulations prioritizing passenger trains.

edit: According to the WaPo article linked by jey in this thread, this ended up overturned in federal court, so I guess as of 2017, freight does have priority over passenger trains in the U.S.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#235

The original Hyperloop paper quotes its design pressure as “about 1/6 the pressure of the atmosphere on Mars” [1]. Martian atmospheric pressure is “about 0.6% of Earth's mean sea level pressure” [2]. So 0.1% of Earth’s surface pressure, or a 1,000:1 pressure change. To put that in perspective, the Boeing 787’s GEnx-2B67, the most powerful GEnx engine variant, generates a 43:1 pressure ratio [3]. To get a sense of the…

Wait, who said that they need to compress the air all the way to Earth pressure? None of your critique makes sense without that assumption, and nowhere in your post do you say where that comes from.

> Wait, who said that they need to compress the air all the way to Earth pressure?

No one. The Hyperloop alpha paper explicitly contradicts this assumption on page 18, where the flow diagram gives the compressor input at 99 Pa and the output at 2.1 kPa (a 21:1 pressure ratio).

http://www.spacex.com/sites/spacex/files/hyperloop_alpha-201...

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#236
post #182

Earlier quoted context omitted.

Isn't that because the freight companies are the ones that actually built, own, and operate the tracks? If Amtrak or another passenger company owned the tracks, their trains would get priority.

On land gifted to them by the government.

Given the key function railroads had in opening up the west, I think you'll struggle to argue that that was even close to a bad deal.

Indeed, that, if anything, is exactly the kind of investments that a government should be making.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#237
When does Hyperloop One get a go on the Dubai - Abu Dhabi line?[1] That's quite feasible. Straight route across flat, open desert.

Hyperloop One is a maglev vactrain. It doesn't "fly" aerodynamically, like Musk's original plan. This means a more expensive track in the tube, but higher riding height. Musk's original plan required a ride height of 0.3mm to 1.3mm, which means a really smooth tube. Maglev clearances are typically 1-2 cm, which is much easier to maintain over many kilometers of tube. Also, only the track has to be flat; the tube can have seams and expansion joints, so it can be fabricated by standard piping techniques. Vehicles can draw power from the track; Musk's original design was battery powered. Maglev track is expensive, though. That's why maglevs are rare.

If somebody in Dubai has the money, there's no reason it shouldn't work. Japan already has 42km of maglev running, part of the Tokyo-Osaka maglev route under construction, with full-sized trains. That's mostly in tubular tunnels. Hyperloop One is easier than that.

Hyperloop One's test track uses a 3.4 meter tube, instead of Musk's original 2.4m tube. Maybe larger in the production version. Musk's very optimistic cost proposals are based on his undersized tube. Hyperloop One will work, but it may not be all that cheap.

[1] https://www.youtube.com/watch?v=3fu-6IDp3Fo

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#238
post #87

Earlier quoted context omitted.

Also, planes are a terrible idea. I mean how do you evacuate people from them if something goes wrong? I think this whole airplane thing is just vaporware.

The question isn't "will this ever work?", the question is (while keeping with your airplane analogy) is Elon Musk's design closer to the Wright brothers airplane or Da Vinci's ornithopter. I'd guess the latter personally.

The Wright brothers had a bicycle shop, whereas Da Vinci was more of a painter.

The main thing Musk has in common with the Wrights is running an electric car transportation company and sending private rockets into space via SpaceX.

I think you should revisit whether that makes it more Wright brothers or Da Vinci.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#239
post #165

Just as a thought experiment, could the promotion of these "hyperloop" projects be a clever political ploy to misdirect/divert attention and prevent a viable high speed rail network from being built? Elon's main business is electric cars and (one of) Branson's is airlines. So a reasonable competitor to both is fast and cheap(er) public transport along a major travel corridor in the USA. This means that by promoting t…

Of course it is. Organizations that benefit from road infrastructure expansion actively work to discredit and defund government transit initiatives.

Historically there is the example of 1920s era GM funding initiatives to convert tram lines into bus lines, which required further investment in road networks, which benefited their private car ownership business as transit was defunded and discredited.

Re: Hyperloop One Becomes ‘Virgin Hyperloop One’

#240
post #116
post #86

Earlier quoted context omitted.

Okay, we'll bookmark this for the future. Amtrak estimated a HSR/"bullet train" from D.C. to Boston would cost ~$151 billion. Since LA to SF will only be two stops, and we can assume Amtrak estimated at least 4 (Philly and NYC) let's bring the number down closer to $100 billion to make it even. Do we think the Hyperloop costs are more or less than that? 1/8 of a theoretical $100b is $12.5b -- is $12.5billion for Hype…

You cannot compare D.C to Boston with SF to LAX. The east coast has much denser population so that you need more tunnels. LAX to SF HSR would not cost $151bn. Start and end are expensive but the part in the middle is "relatively" cheap.

Right, for comparison's sake I chopped off $51 billion bucks from the Northeast Corridor projection in the interest of balancing out the two.

Just because I felt like doing some more Google-fu, I found an article in the LA Times[0] that says a California HSR/bullet-train project is going to overshoot it's original budget (and deadline) of $68 billion. There's a lot of info out there about this project, and it's potential overruns, but let's forget all that and just stick to the original planned cost: $68 billion, so, about half of the cost of Amtrak's northeastern bullet. Let's use that number for our comparison.

If we are going to hold Elon to his "we can do it for 1/8th the cost" blurb, then we are giving him like $8.5 billion to use for his SF/LA Hyperloop. Still, that doesn't sound unreasonable, right? He'll get a good deal on tunnel boring with his other company, and fuselage manufacturing can be handled by SpaceX. When it comes to financing, I don't think it's a major issue compared to other infrastructure works out there.

Like I said, though, I'm just going off the top of my head. I don't know finance or economics or vacuums or magnets.

There's a new LIRR train being dug in NYC called East Side Access. This is a commuter rail line, and is going to cost ~$10 billion or so[1]. Logistically these aren't the same, obviously, but if adding to the LIRR is worth ~$10b then surely the Hyperloop experiment is as well, right?

EDIT: Also, just for disclosure, I don't live in California and I'd probably never end up using the Hyperloop myself so I'm neither for nor against it versus any HSR. I just want to entertain the idea that cost shouldn't be the main focus of discussion IMO.

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0. http://www.latimes.com/local/california/la-me-bullet-train-c... 1. http://web.mta.info/capital/esa_alt.html

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