Hyperloop One Reveals Test Track Progress (computerworld.com.au)

Hyperloop One has released the first photographs of its "proof of concept" test track near Las Vegas, Nevada, and there's now also a couple short videos online. Slashdot reader angry tapir quotes Computerworld: The company revealed its progress on Tuesday at the Middle East Rail conference in Dubai, sharing pictures and footage of its Nevada development site dubbed "DevLoop." Taking Elon Musk's Hyperloop concept of a levitating pod in a low-pressure tube, Hyperloop One has developed what is so far the only full-scale, full-system Hyperloop test site...and says it plans to test the entire apparatus this year.
In addition, Investopedia reports that Hyperloop One has now also signed letter of intent agreements to investigate the feasibility of building more hyperloop systems in Finland and the Netherlands.

Comments

Re:Emergencies?

[JustAnotherOldGuy]

Looking at photos of the test track, you have to wonder how the hell do you get out if something goes wrong?

You cut the bodies out with the Jaws of Life and vacuum up the remains with a ShopVac.

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What happens if there is a sudden "repressurization"?

You cut the bodies out with the Jaws of Life and vacuum up the remains with a ShopVac.

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What if the motive element fails and the pod comes to a halt? There you are, stuck in a sealed tube.

You cut the bodies out with the Jaws of Life and cart them away on gurneys.

Re:Emergencies?

[religionofpeas]

How do you get out of an airplane when something goes wrong ?

Re:Emergencies?

[amiga3D]

Sure, try jumping out with a parachute at 30K feet from a jetliner running 550 knots. I did see one design for a commercial passenger jet with ejectable modules for all passengers. A ticket in something like that from NY to LA would run about 50 thousand dollars. Considering air travel is safer than any form of land travel on a passenger mile basis I guess they decided to forgo the expense.

Re:Emergencies?

[Zocalo]

...able to withstand massive amounts of pressure from a vacuum.

I never cease to be amazed how many people think vacuum exerts a massive amount of pressure; Hollywood has a *LOT* to answer for for all those ridiculous explosive decompression scenes. The pressure between hard vacuum and atmosphere at sea level is exactly 1 atmosphere; you can get more pressure differential in a typical swimming pool. There's a reason spacecraft are about as rigid as a tin can and submarines are built out of many tonnes of steel and titanium, and it's that one has to deal with some pressure and the other... doesn't. If anything, the tube of the hyperloop is likely to be under more stress from the capilliary action of the vehicles (are we going with rail terminology and calling them "cars" or something else?) and bowshock in the less than perfect vacuum then pressure from the external atmosphere.

Re:Emergencies?

[JustAnotherOldGuy]

I never cease to be amazed how many people think vacuum exerts a massive amount of pressure; Hollywood has a *LOT* to answer for for all those ridiculous explosive decompression scenes.

In space the pressure is an outward force, in atmosphere it's an inward force.

Vacuum can create the exertion a LOT of pressure. Try the old experiment where you lay a ruler hanging halfway off of a table and cover the end on the table with a sheet of newspaper. Now bang on the end of the ruler that's off the table and see what happens. The ruler stays right where it is because the pressure of the air against the newspaper is actually very significant. Figure 15lbs per sq inch on a 20"x20" sheet of paper (400 sq inches) is 6000 lbs.

People who haven't seen this demonstration are always shocked when the ruler doesn't fly up and take the newspaper with it. You're much more likely to break the ruler off at the edge of the table. Try it if you don't believe me.

Or if you're lazy, watch a demonstration here: https://www.youtube.com/watch?...

I worked with high vacuum quite a bit in my younger days and the forces involved can be immense. The forces involved with the hyperloop are really quite insane and the possibility of an accident is very, very high. The results could be catastrophic to say the least.

Re:Emergencies?

[Anonymous Coward]

You are probably not far off

https://www.youtube.com/watch?...

wrong

[s.petry]

Thunderf00t correctly points out that a small weakness in the structure will cause a full atmosphere of pressure to attempt to breach the vacuum and the initial tearing will become massive in a tiny fraction of a second. The energy required to create a vacuum is quite large, and all of that energy will be inverted in a split second. If you don't believe Thunderf00t's science, try Mythbusters who did something similar with a rail car tanker.

There is an amazing amount of science denial in this thread, and worse.. up moderation of flat out science denial.

Re:wrong

[Rei]

"Thunderf00t" is a biochemist and the fact that people cite him as an expert in anything except biochemistry never ceases to amaze me.

Sorry, but inch thick steel does not peel back like a banana when you make a hole in it simply because there's a mere 1 ATM pressure differential. Nor does some supermassive shock travel like a brick wall hundreds of miles leading to instant repressurization. The behavior of rapidly progressing pressure waves is known as the shock tube problem. It's well studied physics, and with such a long length to diameter ratio and length to shock velocity ratio, "non-catastrophic" doesn't even begin to describe it. Yes, the wave travels very fast (several times faster than the speed of sound), but it does not carry a lot of force in these conditions, nor does it instantly raise the mass density to atmospheric over long distances, nor does "several times the speed of sound" equate to instant arrival a many hundreds of kilometers away. The same viscosity / wall friction limitations that apply to all tubes applies to Hyperloop.

As for the Mythbusters, DOT-111 railcars ,like the Mythbusters used, are not designed to hold a vacuum. They're not even designed to hold positive pressures; they're designed to hold unpressurized liquids. They're given a small (7 bar) requirement to meet in new condition, but that's it. There is nothing in their design that is supposed to prevent pressure-related collapse when damaged. And it still took about half a second second to collapse across such a short length (the length of a tanker car).

Nobody in their right mind would ever engineer a vacuum pipeline that can catastrophically collapse along its length. It is in no way, shape or form some sort of fundamental property of vacuum lines, and only a person who has never worked in engineering would think so.

If "Thunderf00t" (Phil Mason) says something about biochemistry, listen to him. If he starts ranting about fields that he has no understanding of, close the window.

Re:Emergencies?

[Solandri]

The energy from pressurization is pressure * volume. At a 2.23m diameter (3.906 m^2 cross-sectional area), every km of tube pumped to 95% vacuum represents 376 MJ of energy. With an estimated 500 miles of tube, this represents 188 GJ, or about as much energy as 45 tons of TNT. Granted it's spread out over 500 km so is equivalent to about 82 grams of TNT per meter. That's not an insubstantial amount of energy. But I think a steel tube could be designed to withstand it.

The problem is what happens when a train car traveling 700 mph hits a section of tube damaged by a localized implosion. If a section of tube were somehow weakened, it would fail when the stresses it experienced were highest. This would probably be right when the first car of a train passed it. The weakened section fails inward, and the following train cars hit it at 700 mph.

Yes we fly 500+ mph in planes every day. But those planes don't fly a few cm from things that can suddenly pop out and strike the plane.