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Hyperloop


DaRocketCat

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The Internet's exploding with this awesomeness:

http://www.teslamotors.com/blog/hyperloop

http://www.spacex.com/hyperloop

Any thoughts? Seems awesome to me, especially as a resident of California fed up with waiting for a high speed rail network.

Gov. Brown's attended Tesla events, I hope he takes the initiative to at least get a board to consider this.

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Meh. A flight from SFO to LAX is an hour long. The wait time on the ground is several hours long. Guess which one I would rather see shortened. I'll keep waiting for my train, thanks.

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Hyperloop is basically an light rail system, the good idea is the air hockey levitation. Benefit is that its 2-3 times faster than fast trains and is probably cheaper to build.

Has some downsides, especially on long trips, any fails in the system will take it down completely, no way to patch around using alternative routes or one track like you can with trains.

Even evacuating the wagons if you have an stop would be an problem.

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I honestly think they should just scrap all these "revolutionary" ideas and just go with a safege or alweg. Alwegs, if done right like the Seattle one, can efficiently evacuate the entire train onto the beam without a lot of confusion because both ends of the train have a door, and that leads to a meter wide beam where people can stand. Instead of building extra walkways on the side, the beam can be the walkway. Safege isn't as good at this because the train is below the beam, but it would be nice to see a long-distance version of either of them.

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It's an interesting proposal, I just read the whole document and can't see any obvious technical flaws with it. Most transit systems have to have some degree of partial or complete shutdown in an emergency or breakdown, I've been on BART trains that had to sit stuck waiting for a broken-down car to be driven off the track from a station ahead of it.

What I suspect will happen is it will be used by opponents of the CA high speed rail project (and there are plenty, with varying reasons for their disapproval, some more legitimate than others) to take money away from that project and try to stall it, without necessarily actually wanting to pay for a replacement idea. What really needs more fleshing out is where the cost estimates are coming from, and whether those reflect reality or not. It took voter approval to take out the initial bonds for the high speed rail project, and they're far enough along that they're not about to jump ship and try to build hyperloop instead. Where else would that amount of money come from?

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I think they may be overlooking some basic issues.

You are putting people inside a small tube for at times over an hour that you cannot even stand up in.

I believe quite a few people may not feel comfortable traveling inside a small windowless tube that long.

Then you have the issues of each car needing a chemical toilet and how do you move people from their seats to it without half crawling.

How are elderly or disabled individuals going to get to it.

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Little more cramped than a small turboprop plane like a Saab 340, but I doubt it would be any more claustrophobic than a car. Boeing has done a lot of studies for the blended-wing body about not having windows, and they found if you have big LCD monitors that look like windows, it's pretty much fine. Don't think you need a toilet for a nominally half-hour trip, probably just in case of emergency stops.

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I not sure if the LCD screen would work the same way in this case.

I'm assuming the Boeing one would show a live view of the outside of the plane?

That wouldn't work for a vehicle traveling at mach speeds 5 meters or so above the ground.

I suppose you could try generic nature shots, but I don't know if they would have the same effect and the proposed Boeing plane is much bigger to begin with.

But it might be a possible solution.

You are right that there are smaller planes and cars to travel by, though they have real windows in them.

Personally 30 minutes without access to a toilet normally isn't an issues, but when that door closes and you realize that last cup of coffee or energy drink was one too many..... :)

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the travel time is proposed to be around half an hour. I live in one city and work in another and the buss (with no toilet in it) iam going with has first stop after 36 minutes of riding. And i never seen anyone piss themselves in the buss. So no need of toilet there.

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biggest problem is the assumption that it can all be built in a year or so when he only has a mockup that's basically a 1980s style couch sat in front of a large diameter PVC pipe.

When I saw the video reports, my first impression was a guy having found a way to scam venture capitalists out of billions before making a run for it.

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I hate to say it but... He didn't think of this. Well first. I saw a video a few years ago with a transport system called ETT evacuated tube transport. It had a maglev system in a vacuum tube that sent it at hypersonic speeds. He may have bought the idea but it still wasn't his first. I wish people would stop praising him for just making rockets.

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the travel time is proposed to be around half an hour. I live in one city and work in another and the buss (with no toilet in it) iam going with has first stop after 36 minutes of riding. And i never seen anyone piss themselves in the buss. So no need of toilet there.

Exactly! I don't know who came up with this fake problem of missing toilets. Anyone who's been using public transportation their whole lives knows it's not a problem.

To kocour: Zdravím z Brna!

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I hate to say it but... He didn't think of this. Well first. I saw a video a few years ago with a transport system called ETT evacuated tube transport. It had a maglev system in a vacuum tube that sent it at hypersonic speeds. He may have bought the idea but it still wasn't his first. I wish people would stop praising him for just making rockets.

I hate to say it but... He isn´t actualy suggesting to evacuate the tube of all it´s air, but to use it to keep the plug itself floating inside the tube. It´s not intended to be frictionless either, like some ideas (and in this case, reporters) suggest either. That´s why the relatively "low" speed of only 2-3 times as fast as other bullet-trains.

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I saw a video a few years ago with a transport system called ETT evacuated tube transport. It had a maglev system in a vacuum tube that sent it at hypersonic speeds.

Yeah, evacuating the tunnel isn't a particularly novel idea. Pretty obvious really. According to the wiki page it was actually Robert Goddard who first looked into the idea in any detail, over 100 years ago. There was a mad idea to span the entire Atlantic with a submerged maglev running at crazy speeds.

Musk's idea is toned-down version of the proposed full-vacuum tubes, with air bearings replacing the vertical component of the maglev system. I suspect in reality it would suffer from the same drawbacks as maglev, namely eye-watering construction costs per track mile.

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The vacuum in the tube looked kind of needed because I see a cylinder, not the most aerodynamic thing in existence. Either way, not making the tube a vacuum is a bad idea. It slows it down crazy amounts you could travel nearly mach 10 in a vacuum tube like this one. The issue is boarding and servicing the tube.

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The vacuum in the tube looked kind of needed because I see a cylinder, not the most aerodynamic thing in existence. Either way, not making the tube a vacuum is a bad idea. It slows it down crazy amounts you could travel nearly mach 10 in a vacuum tube like this one. The issue is boarding and servicing the tube.

the problem with going mach 10 in a confined area is that you would need to use insane tolerances in order for the system to not suffer catastrophic failure. even if you manage to do that comes the issue of turn radi. the sr-71 had a problem of being able to turn around in the airspace over 3 states, and that was only mach 3. your track would need to be very straight, turns would have to be the size of entire continents. as for boarding and servicing, i believe they call them airlocks.

Edited by Nuke
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The vacuum in the tube looked kind of needed because I see a cylinder, not the most aerodynamic thing in existence. Either way, not making the tube a vacuum is a bad idea. It slows it down crazy amounts you could travel nearly mach 10 in a vacuum tube like this one. The issue is boarding and servicing the tube.

Friction is indeed a problem in most any case. In this case, it is intended solved (and as is written in the PDF released) by having an electric turbine at the front of the pod/train/thingy wich compress the air in front of the pod, and both use that to make a cushion of air underneath it to lower friction and the rest is vented out the back of the pod.

In addition, the tube itself is intended to work at a reduced airpressure, using simple off-the-shelf fans to evacuate whatever amount is practical. So even if parts are at full atmospheric pressure, it will still function.

And considering that the intention is to run the pods at high but subsonic speeds, it should be decently robust against leaks, alow for sharper turns, and be a lot simpler to maintain.

Linear engines mounted in the tube itself is the main propulsion.

Limits are ofcourse speeds and size. So as he says, it might not be practical or economical for the longer trips.

The PDF is worth a read. Both as it explains a lot of the concept and idea. And it explains sollutions and preemptive safety measures that could handle most problems.

Edited by Thaniel
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I thought the original ETT was a pure straight line most of the way, even if it wasn't then it would still be able to turn just very slowly. I could see the ETT used to give rockets a HUGE boost to suborbital space.

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I thought the original ETT was a pure straight line most of the way, even if it wasn't then it would still be able to turn just very slowly. I could see the ETT used to give rockets a HUGE boost to suborbital space.

To get the most out of ETT, it should probably be built only in straight lines. Using such constructions to accelerate rockets is entering the realm of linear accelerators and such. And there´s been proposed different sollutions for that. I think one of the most ambitious lately is one where the tube, (wich is kept at close to hard vacuum) is also kept up by a magnetic field, and held down by wires, and the exit of the tube is high up in the atmosphere, 70 000 feet or so.

Anyway, here´s a link to some info on that : http://nextbigfuture.com/2012/03/startram-more-technical-details.html

One of the challenges with using tubes/cannons and the likes for launching rockets into space, is that the rocket also have to be able to withstand the acceleration, friction and other forces while traveling in and exiting the tube. To handle that, they may have to be quite robust, and that means some added weight, and that means smaller cargo, and that means larger rockets for putting more cargo into orbit, and that means larger tube, and that means more power needed to launch, and so on and so forth.

Wich is also one fo the reasons Musk´s proposal for the hyperloop is meant for relatively small units at a time. It will lend itself to only use the power needed when transporting, and keep as much capacity at standby as possible, and be more robust against downtime by service to the pods, due to the numnber of pods in the system. Smaller and lighter units means less friction to fight, less stress on materials and such, and that will help keep the cost down in the long run.

Edited by Thaniel
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When I saw the video reports, my first impression was a guy having found a way to scam venture capitalists out of billions before making a run for it.

Why would Elon Musk bother scamming venture capitalists out of money, and exactly where would he go that people wouldn't recognize him?

I mean sure, if I proposed this you'd either say "She's a scam artist" or "She's plain nuts" But when the guy who did, PayPal, Tesla Motors and SpaceX proposes something big... Well... it's kinda to be expected.

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