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Hyperloop

spacex.com

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Re: Hyperloop

#701

Post by mightybyte »

verbin217 wrote: post #303

Seems like this would be particularly vulnerable to terrorist attacks. There is a huge surface area that needs to be protected (tubes/pylons). If there are pods leaving every thirty seconds and traveling at supersonic speeds then taking out one pylon could kill several hundred people and leave the entire train inoperable. In a future where this design was used extensively to connect cities on the coasts it would quic…

Nope. Read the document. Subsonic speeds with capsules 2 minutes apart. In the event of a catastrophic depressurization (i.e. bomb on a capsule or a pylon), all capsules stop. Worst case, 28 people in one capsule die. The rest are stuck for awhile until they can be evacuated. Not very spectacular.

Re: Hyperloop

#702

Post by omegant »

ricardobeat wrote: post #525
omegant wrote: post #393

Earlier quoted context omitted.

Look at the Armstrong limit (at 62,000´), a mayor problem to overcome if the tube is going to be at the equivalent pressure of 150,000´ http://en.wikipedia.org/wiki/Armstrong_Limit http://en.wikipedia.org/wiki/Time_of_useful_consciousness Also look at the TUC (time of useful consciousness) that it´s below 5 secs when flying that high. That means that you have less than 5 secs to put your oxigen mask on before you los…

From the linked article: At or above the Armstrong limit, exposed bodily liquids such as saliva, tears, and the liquids wetting the alveoli within the lungs — but not vascular blood (blood within the circulatory system) — will boil away without a pressure suit As mentioned above, we have been boarding planes without pressure suits for decades, and the hyperloop has two security advantages: it has a large supply of co…

A dedicated hypoxia document by the FAA:

http://www.google.be/url?sa=t&rct=j&q=&esrc=s&source=web&cd=...

You got to think that a decompression will happen. Something traveling that fast inside a tube is probable to develope vibrations and material fatigue if something is not working properly (like the compressor or a air cushion), also there can be small parts released from the front pod impacting on the next one.

It doesn´t need to be a huge crash, just a crack on the hull, it will decompress that small pod in seconds.

Also what will happen when of tens of pods traveling that fast, find that there is a sudden recompression of the tube? How fast are they going to stop due to the front overpressure (the compressor is relatively low powered)?. Is not going to be a gentle stop either.

I still think that it´s a great idea, and that there will be ways of solving those problems, but it´s going to be difficult and require lots of R&D.

Re: Hyperloop

#703

Post by [deleted] »

thrownaway2424 wrote: post #688
LockeWatts wrote: post #677

Earlier quoted context omitted.

You're still missing the part where it incurred interest, so it wasn't free in the least.

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.…

[deleted]

Re: Hyperloop

#705

Post by zimpenfish »

mcintyre1994 wrote: post #424
jfb wrote: post #379

Earlier quoted context omitted.

Well, fast trains or no new trains. It is still technically possible to get on BART in San Francisco and get off from a train in Los Angeles. You wouldn't choose to do this -- nobody would choose to do this [1] -- but it is possible. [1] http://www.nytimes.com/2009/06/14/magazine/14Train-t.html?pa...

I see, fair enough, cheers for pointing that out. I'm in the UK and we're pretty well connected by rail, I wasn't expecting the alternative to be that ridiculous, just normal slower trains.

Whilst our train service in the UK is a mess (and it really is), I suppose at least we have a mess that we can moan about rather than "buy a car, hippy".

Re: Hyperloop

#706

Post by magicalist »

thrownaway2424 wrote: post #688
LockeWatts wrote: post #677

Earlier quoted context omitted.

You're still missing the part where it incurred interest, so it wasn't free in the least.

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.…

No, it's a very visible example of socializing the risk while privatizing the profits. It's pretty small potatoes compared to the normal contract guarantees to even, say, companies doing highway maintenance, and let's not get into the "socialization" of science funding. Where are our guaranteed ROIs on NSF grants?

The government makes these investments all the time. In fact, usually the (barely implicit) goal of government funding is to also encourage job and wealth growth. $12 million isn't much of a return, but even revenue neutral is a win for the average government investment. And, like the tax breaks to encourage people to buy the very cars the government was helping pay to produce, the idea is to help kickstart an industry that might not have the differential to self-start, but has the potential to eventually be self sustaining and bring outsize benefits compared to the investment. Basically the same reason we fund basic science research as well.

And again, this is highly selective outrage. You can disagree with the whole category of government-sponsored industry, but you have a bit of an uphill battle there. Meanwhile, there are far more "classic" examples all around, not to mention the two other major car companies that together received nearly 16x what Tesla received and have so far not exactly put in a great showing for the industry-creating change that money was supposed to help fund.

Re: Hyperloop

#707

Post by RyanZAG »

numbsafari wrote: post #451
RyanZAG wrote: post #143

Earlier quoted context omitted.

What happens if a brawl erupts inside a moving bus or taxi? What happens if a suicide bomber boards a train or bus? What happens if a suicide bomber rents a car and crashes it into you as you walk along the sidewalk? Rather than living in perpetual fear, you could try making the world a place where people who can't get food or work aren't trying to blow you up as a last resort? Americans seem to be the most worried a…

Americans seem to be the most worried about suicide bombings out of anybody else, yet America has probably seen the least suicide bombings per capita of any country in the world. Not that I approve of many of the things we do to "prevent" them, but... Perhaps worrying about preventing certain things sometimes actually helps reduce them?

I'd agree in some cases, but realistically there isn't much you can do against people using bombs to blow up bridges - or in this case, hyperloop pylons. It's just not something that you can 'design around'. Designing the pylons to survive if one is blown up? If someone can put a bomb on one pylon, he can put 5 bombs on 5 pylons. Or under 5 cars.

Spending your time trying to prevent that kind of thing is futile and an enormous waste of resources. See: TSA

Re: Hyperloop

#708

Post by zimpenfish »

mjn wrote: post #475
pbreit wrote: post #471

Earlier quoted context omitted.

Uh, the number above is $70b and the TGV was built 30+ years ago so you could at least double that number based on inflation.

Even the most expensive TGV lines, have a per-km cost of around $20m/km in present dollars, and that's high enough to cause controversy. The bulk of the network was built for prices of $2-4m/km at the time, which is about $3-5.5m/km if you adjust for inflation. For a 700-km line like SF-LA, even the $20m outlier cost would work out to only $14 billion. Where's the 8x multiplier coming from? No TGV line has cost >$100…

Crossrail is 118km and is going to cost 16bn GBP or about 135m GBP per km (~$209m/km) (if I've done my maths right.)

Though it's somewhat difficult to separate out the 42km of new tunnels (expensive) and a whole bunch of new stations (expensive) including a whole bunch of revamped ones in the centre of London (very expensive).

Re: Hyperloop

#709

Post by Daniel_Newby »

robomartin wrote: post #630
revelation wrote: post #588

Earlier quoted context omitted.

Wow, can you not abuse this wonderful idea for a political forum on unions , of all things?

There's a difference between theory on a piece of paper the the reality of building something. In the real world unions will be all over a project like this. Up every crevice. So will environmental groups and other special interest groups. None of this is good for any major civil engineering project. I asked a question in my post. Can you name any new major civil engineering project in the US in the last fifty years?…

> Can you name any new major civil engineering project in the US in the last fifty years?

Most of the interstate highway system, any number of lakes, many major bridges, the completed portion of the superconducting supercollider underground chambers, the brilliant Alaska pipeline pylon system, Florida's long elevated marine highways, the Norfolk (?) tunnel, the NYC aqueduct, most major airport runways.

What man has done he may aspire to do again.

These things move in cycles. Political patronage projects currently are in vogue, but their star is falling. You cannot credibly claim that unions will make any LA-SF project cost $100B, because Mr. Bond Market is about to have a mountain comes to Mohammed moment. At some point the market for rational projects will reopen for a few decades, like it does from time to time.

Elon Musk is just the man to make it happen. He already killed the Space Shuttle program and its standing army of $1B/yr payroll patronage jobs. Extending that to other projects is a matter of will and personality.

Re: Hyperloop

#710

Post by krichman »

kamjam wrote: post #583
Maxious wrote: post #570

Earlier quoted context omitted.

Too late: http://www.seattlepi.com/technology/businessinsider/article/... > If you don't want to be searched at the train station, you have the freedom to not ride the train.

I wonder what the security checkpoints would be like on the HyperLoop if it ever got built? They are saying capsules could depart 30 seconds apart. Imagine is there was an attack in on of them, with several others travelling at high speed just behind. http://www.bbc.co.uk/news/world-us-canada-23677205 I'm sure there some contingency has been thought of, unfortunately it's just the world we live in these days :(

If they turn off the compressor there's a giant air cushion in front of them and the capsule no longer has air bearings. It probably lands on wheels and can then engage the breaks. A small capsule has low inertia as well.

Most likely safer than a train.

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