

Hyperloop speculation – launch assist for electric aircraft  - johncarpinelli
http://electrictakeoff.com/archives/767

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Aqueous
Elon Musk said it was nearly impossible to get injured in his system. Which
means that any aircraft travel is out, because all it takes is an engine
failure to kill everyone on board.

The safety reason is a big reason why I'm going with the underground tubes
between LA and SF.

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thomasjoulin
I don't think it can be underground, since Musk said it would cost $6 billion
to build. Also, the plan is to build something similar for east-west coast
travel, and underground would be even less possible.

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softbuilder
The other consideration aside from cost is that seismic activity, even minor,
can skew a tunnel. (Edit: for deep tunnels, that is. I have no idea about
tunnels right below the surface.) That's bad news at high speed. I've given
the tunnel approach some thought.[1]

And I keep hearing people trying to apply Hyperloop to coast-to-coast travel,
but I don't recall Elon every saying anything about that long of a distance.
In fact I recall him specifically talking about "the right city pairs", which
implies some kind of distance limit.

[1]
[http://www.youell.com/matt/writing/?p=1050](http://www.youell.com/matt/writing/?p=1050)

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danpalmer
"It leaves when you arrive"

This doesn't work for an electric aircraft, or many normal public transport
methods as they are all focused on batching people up into large groups
(planes, trains, etc).

Also, Elon has called Hyperloop 'another type of transport', i.e. nothing like
we already use, whereas I would say this idea is just an aircraft with a new
type of launch system; not as different as Elon suggests it will be.

However I agree that getting the land to build a tunnel on the surface (or a
track of any sort) would cost a lot of money, and tunnels below the surface
would be too costly as well.

Although I think lots of people are converging on the idea, sound waves,
evacuated tunnels, all that sort of stuff, I think everyone so far has missed
the big detail or breakthrough that makes it feasible, after all, these
techniques have been known for a long time, just not been taken advantage of
because they aren't practical.

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SideburnsOfDoom
> This doesn't work for an electric aircraft, or many normal public transport
> methods as they are all focused on batching people up into large groups
> (planes, trains, etc).

True, but as the batch size gets smaller, so does the interval between
vehicles. "one every minute, on the minute" is not much different from "It
leaves when you arrive". This may not work for aircraft, but it certainly
would for automated light rail systems.

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BadassFractal
I've been out of the loop for a while. How long is speculation about the
master plan supposed to go on until Musk reveals what it is?

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lke
Until August the 12th at the most.

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mapt
I'll re-issue my prediction: an STP hydrogen tunnel with elecromagnetic
levitation (my favorite being Inductrack, known for its passive failsafe) and
propulsion, and wheels for low speeds, makes a lot more economic sense than an
evacuated tunnel. Much less drag, much higher speed of sound.

The other things that any modern engineer would never do that an 1870's
railroad technician somewhere built into SOP, like mixed speed segments,
frequent braked unbanked turns, single-tracking, and manual signalling /
switching and grade crossings, will also be consciously avoided; the FRA
regulations are built on making operating under such principles safer.
Applying modern real-time at-speed routing to rail is something the PRT guys
have been dreaming about for decades - the money and organizational will just
hasn't been there to make it happen at a scale sufficient to make it cheap
enough to justify.

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throwaway_yy2Di
Sounds like an insane fire hazard. With large volumes of hydrogen and
breathable air in close proximity, otherwise minor failures would be
catastrophic.

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llomlup
After ruling out underground tubes, electric aircraft and coast-to-coast
travel, teleportation seems to be the only option left. And I haven't really
expected that.

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VandyILL
One of my takes on it is that it has to be some sort of land/underground
interconnection between cities.

My reasoning behind this is that he is open sourcing the designs. My guess
behind this is that if it is a ground based system that requires right of
way/property access etc. then there is tons of transaction costs & government
regulation that would prevent copy cats from destroying the first mover's
capital investments that would normally be protected via IP law.

If it didn't have these high transaction costs associated with it, then any
actor could come and undercut your system after the tech behind the open
source designs becomes cheaper. Traditionally this would be protected because
of IP laws. However, he's dismissing this route & letting anyone up to the
challenge take on the construction challenge with him. I'm guessing this is
likely because the government won't eminent domain/allow/permit etc. extra
routes between SF & LA etc. if there's already a hyperloop.

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milhous
Perhaps it could be an evacuated, semi-flexible, underwater toroidal ring
along the coast?

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pedalpete
Interesting idea, but I don't think it is realistic as air travel, even from a
launch tube, I suspect would be under the rules if the FAA, which I'm sure
would still require the security ....uhhhh, stuff (?) that we currently have
to deal with, so really a very limited benefit.

Plus, if then hyper loop can run along/beside the California aquaduct, I think
that would solve the issue of terrain and land purchase. If elon can convince
the gov't that the hyper loop would secure the passageway, they might go for
that.

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kubiiii
About the land access concern, in France we had the aerotrain which was
developped as an alternative to high speed train but did not survive the
conventional railroad lobbies. There is still 60 km of test track south of
Paris. The track is 10 m above the ground and is built using pillars every 20
m. It has been there for more than 40 years for it's considered too expensive
to dismantle for actual very limited annoyment, more limited than high voltage
power lines for example. However, land is flat there and mostly non urban.

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TsiCClawOfLight
Germany has something similar:
[https://en.wikipedia.org/wiki/Transrapid](https://en.wikipedia.org/wiki/Transrapid)
The Asian maglevs are german engineering.

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seanmcdirmid
Not like Asia is awash in maglevs, I think the shanghai airport link is the
only commercial one.

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TsiCClawOfLight
I think Japan is working on one, but I might be mistaken. But yes, the
Shanghai one is german. :)

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Yaggo
Keeping a passenger aircraft at constant speed of 600 mph is not realistic
with the current (or near-future) battery technology, even if the initial
kinetic energy comes "for free".

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vladimirralev
May be it's a rocket. You just stand in a small rocket vertically, like those
used in the military and cost about 3-4 million each. You get launched to
10-15 miles height making a gravity turn at some point. After that it takes a
relatively small burn to secure a nice trajectory that lands you 500 miles
away. I imagine it's a vertical pipe 1 mile high and you stay on your feet the
whole journey with about 5g being accelerated in the pipe until you reach the
proper delta-v. Then you land with parachute on cushions or grasshopper-style.
Worst case may be an electric propeller.

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noonespecial
Elon Stevens mashup?

 _And again, the [hyperloop] is not something that you just dump something on.
It 's not a big [plane]. It's a series of tubes._

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throwaway_yy2Di
Is there a complete list of Musk's statements about Hyperloop, constraining
its nature?

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zokiboy
[http://en.wikipedia.org/wiki/Hyperloop](http://en.wikipedia.org/wiki/Hyperloop)

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lke
So Musk himself decribed it as a "cross between a Concorde and a railgun and
an air hockey table". So why do people keep talking about tubes ?

Wouldn't a Ground Effect Vehicule
([http://en.wikipedia.org/wiki/Ground_effect_vehicle](http://en.wikipedia.org/wiki/Ground_effect_vehicle))
fit the descripton better ?

Edit : thought a self powered super-sonic GEV would be hard to pull of.

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kineticfocus
one of the more appropriate
links...[https://en.wikipedia.org/wiki/A%C3%A9rotrain](https://en.wikipedia.org/wiki/A%C3%A9rotrain)

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hrvbr
I remember a similar project from the French TV news. The airplanes were
ultralight drones (no pilot and only as many passenger as taxis). I can't find
the source.

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bayesianhorse
I guess Elon Musk does know about stuff like "right of way". Also you might
experience difficulties to launch something into the air from an evacuated
tube...

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lke
He didn't say the tube were going to be evacuated did he ? If you are going to
put something in the air, evacuationg th lauchpad seem to be a bit pointless.

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batemanesque
why is everyone taking this thing so seriously? correct me if I'm wrong but it
seems so vague as to not deserve the current hype, regardless of who Musk is

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khafra
It's a lot more fun to imagine it won't be a massive, Segway-level
disappointment; plus he has a history of making big promises and delivering.
Also, I think humanity is just _ready_ for teleportation technology, now.

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jbverschoor
So my take on it is this:

There will be a guiding rail, and the vehicles will be 2 / 4 person pods that
can be accelerated in the same way railguns work.

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azsromej
An exciting field; I haven't heard anything recent, but former Mint CEO Aaron
Patzer started work on some new transit ideas a couple years ago

