Just finished reading the pdf and now I understand why this is by far the most popular HN post for a long time (ever?). I now post my feeble comment to be lost in a sea of enamored nerd buzz. Fucking awesome, Elon.
Can you explain? I'm at job and don't have that many time to read whole PDF.
Just read the first part, it's only a few pages.
It's an exciting approach to high-speed land travel at a proposed cost of far far less than the California coastal rail's $70 billion minimum price point.
So, a sealed tube from A to Z, passing B through Y. No benefit to B through Y at all. So why do B through Y allow the tube to pass through? When railways happened, B through Y believed they would see economic benefit, and often did. They got a station. Not so here, correct? There for, wouldn't this need a government to force it through? How would that happen in the USA? To me this is where the idea runs in to the buf…
The tube will hew closely to existing highway I-5 eliminating most right-of-way issues (since the state controls the land already.
Also B-Y is currently very low density and paying someone $X,XXX/yr for this nearly silent tube to pass through their field is not exactly a hard-sell.
Musk put $40m into Tesla and his stake is worth billions. The people put $465m into Tesla and their stake is worth nothing, after making a paltry $12m in interest. In addition, while Tesla was paying the government 3% on that loan, they were paying Musk 10% on his loans, in effect shoveling government money directly into Musk's account. This is a classic example of socializing the risk while privatizing the profits.…
Sounds like he took advantage of an ignorant government. I'd do the same. So did Wall Street, but we got less back from that one.
Why was the government ignorant?
They had a loan program to kick-start electric vehicles. One of their loans was largely responsible for the existence of Tesla and its ensuing success. The loan was paid back.
Should the government have been more profit-maximizing? Do we want civil servants taking large equity stakes in private companies? We fund research (both directly and through the university system) all the time with the understanding that the net benefits to society outweigh the direct costs of the programs.
This is very serious first proposal. As a professional mechanical engineer I have worked on high quality steel tubes (nuclear submarines) before. The immediate thing that sticks out to me in this proposal are the tight mechanical tolerances that have to be maintained. Talking about tens of thousandths of an inch tolerances on a 10' diameter tube is not to be dismissed lightly. That is going to be tough to maintain -…
If I read the proposal correctly, the system is less sensitive than the tolerances you describe. There is a tight tolerance to maintain between the "air skid" and the wall of the tube, but the air skid is mounted on a suspension system that is probably intended to deal with small variations away from the ideal tube shape. Those variations will manifest to passengers as "bumps" and will also result in transient additional drag, I suspect.
It would be cool if you could take another look and see if the tolerances are truly what you describe, or if there's actually more room for variance.
Or you could read the design document: > In the event of a large scale leak, pressure sensors located along the tube would automatically communicate with all capsules to deploy their emergency mechanical braking systems.
yeah, imagine claustrophobic passengers got stuck in a capsule, midway, blocked by other capsules from each side, running out of air. Are they gonna cut them out of the tube or what?
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 :)
To me, a 1/1000 atmosphere vacuum system IS a really leaky machine :) Anecdotally, the machine I used to work on would gleefully chew on that for hours idling while we scrambled to find the hiss on the system. It made an awesome sound when it ground into the atmospheric pressure on initial pumpdown, but at about 1/100 atmo it got bored (mere minutes), and without additional high speed stages the mechanical pumps woul…
I'm sitting here in a lab with a vacuum system that is in the process of being repaired for use in testing some new spaceflight components. 1/1000 of the atmosphere, even on this broken, leaky thing, is nothing. Mind you, it's also runnng off of pumps that are a decade or two old and cobbled together from various other labs around here.
It's got three short (1 km, 9 km, 30 km) deployments around 40 years after work first started. Are you saying that's the kind of deployment record Musk would like to see for his wundertechnology?
it does have commercial application, which is more than I think the parent expected.
The parent was me. I like maglev but it's hard to deny that as a mainstream transportation method it was completely trounced for the first 30 years of its existence by more traditional methods.
If California ditches its HSR plans for hyperloop today and ends up with a 700 km/h line running in 30 years' time, busiest lines in Japan and China will have been upgraded to maglev or another 500+ km/h technology and they would have had 300+ km/h technology for the interim 30 years. Meanwhile California would have had what, driverless car trains on freeways going 200 km/h 5 years from now?
Easy? Think it through..... Who? How much? All the same? When? Then imagine all the people from B to Y who see an opportunity to screw the project for huge amounts of cash. Decades of lawyers arguing in court over every conceivable point, or opportunity. And that before environmental, and god know what else, groups get involved. Sorry, no, not easy at all. Not even slightly.
The high speed rail wasn't going to stop at B through Y anyway, and the hyperloop supposedly takes less space.
> The high speed rail wasn't going to stop at B through Y anyway
Untrue [1].
[1] http://www.hsr.ca.gov/docs/newsroom/fact%20sheets/High-Speed... - all but the "Northern California Unified Service" and "Amtrak Surfliner" runs are planned HSR lines/stations, and all (including those) are getting upgrades/improvements or new rail/connections as part of the HSR project.
If you can't stand being in an enclosed space like that, there's still the interstate. Is not meant to be everyone's ideal solution, it's meant to be a good solution for most people.
Given ADA, would it be even legal for the California government to build this instead of a classic HSR? It's not even about claustrophobics, people in wheelchairs couldn't be serviced at all and obese people would be trouble too.
I think it is a pretty fair question, even though I am not entirely sure of what is the definition of minority on this matter. What is the percentage of people that the system should take care of? There are always outliers for which this (or any) transportation will never be a possibility.
Now, I am sure that some variations on the system (have one row with only one chair for obese or no chair to allow people with wheelchair) would increase the % of people that can use the hyperloop.