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What won’t work, does? Hyperloop

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Posted by 7j43k on Monday, November 16, 2020 10:02 AM

And you can throw in incompetence.

On the plus side, there is little if any government involvment.  Yet.

 

Here's a fun read on another hi-tech rail system:

https://www.latimes.com/california/story/2020-08-10/california-bullet-train-bridge-snafu

 

Ed

 

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Posted by BaltACD on Sunday, November 15, 2020 11:31 PM

Electroliner 1935
 
7j43k
Electroliner 1935 
7j43k
In one, the pod uses air bearings to support itself on rails.  There has to be enough air for the compressor on the pod to supply the pressurized air.  The air pressure inside the tube is 0.17% of outside the tube. 

What is the plan to extricate passengers when the "car" gets stuck in the tube. Or are we assuming "NOTHING CAN GO WRONG..GO WRONG...GO WRONG" 

https://hyperloopconnected.org/2020/06/evacuating-the-hyperloop/ 

Ed 

Thanks, that is a little more than I had seen. Sounds possible but I would want to see more specifics about the air locks and spacing, etc. Bean counters could cut corners. 

Not just bean counters - construction contractor cut corners too.

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Posted by Electroliner 1935 on Sunday, November 15, 2020 10:42 PM

7j43k
Electroliner 1935 
7j43k
In one, the pod uses air bearings to support itself on rails.  There has to be enough air for the compressor on the pod to supply the pressurized air.  The air pressure inside the tube is 0.17% of outside the tube. 

What is the plan to extricate passengers when the "car" gets stuck in the tube. Or are we assuming "NOTHING CAN GO WRONG..GO WRONG...GO WRONG" 

https://hyperloopconnected.org/2020/06/evacuating-the-hyperloop/ 

Ed

Thanks, that is a little more than I had seen. Sounds possible but I would want to see more specifics about the air locks and spacing, etc. Bean counters could cut corners. 

 

 

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Posted by 7j43k on Sunday, November 15, 2020 3:10 PM

Electroliner 1935

 

 
7j43k
In one, the pod uses air bearings to support itself on rails.  There has to be enough air for the compressor on the pod to supply the pressurized air.  The air pressure inside the tube is 0.17% of outside the tube.

 

What is the plan to extricate passengers when the "car" gets stuck in the tube. Or are we assuming "NOTHING CAN GO WRONG..GO WRONG...GO WRONG"

 

 

 

https://hyperloopconnected.org/2020/06/evacuating-the-hyperloop/

 

 

Ed

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Posted by Electroliner 1935 on Sunday, November 15, 2020 1:24 PM

7j43k
In one, the pod uses air bearings to support itself on rails.  There has to be enough air for the compressor on the pod to supply the pressurized air.  The air pressure inside the tube is 0.17% of outside the tube.

What is the plan to extricate passengers when the "car" gets stuck in the tube. Or are we assuming "NOTHING CAN GO WRONG..GO WRONG...GO WRONG"

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Posted by 7j43k on Sunday, November 15, 2020 9:37 AM

BaltACD

Despite having stayed at a Holiday Inn Experss at some point in the past.  I doubt vaccum alone will provide sufficient propulsive force real world enviornment as the vehicle itself moving through the tube will create a low pressure area behind itself that will create 'drag' against the vacuum that is trying to pull the vehicle ahead.  Space is not limited in scope as the Hyperloop by its very existance on Earth is.

 

 

 

The reason there is a semi-vacuum* in the tube is to minimize air resistance, not to propel the pod.  That is done with a linear induction motor.

No motor; no go.

 

Note also the ridiculously bad fit of the pod in the tube:

 

 

If it were to be propelled by pressure differential, the fit would have to be MUCH better.

 

Ed

*The support method for the pod comes in two versions.  

In one, the pod uses air bearings to support itself on rails.  There has to be enough air for the compressor on the pod to supply the pressurized air.  The air pressure inside the tube is 0.17% of outside the tube.

The other version is the well-known maglev.

It appears that maglev is currently being used.  

 

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Posted by BaltACD on Sunday, November 15, 2020 7:17 AM

7j43k
 
BaltACD

If we are going to have the Hyperloop, operate at high speeds - in addition to vacuum on one side of the vehicle, pressure will be required on the other side of the vehicle, with the vehicle providing a reasonable seal between those forces in the tube in which it is operating.

Case in point on a smaller scale

https://www.youtube.com/watch?v=cqidD7kVnxY 

No.

It is not required to have pressure on "the other side of the vehicle" unless you are using that pressure to propel the vehicle.

It is possible to propel a vehicle through a space that is entirely a vacuum.

Think:  "space ship" 

Ed

Despite having stayed at a Holiday Inn Experss at some point in the past.  I doubt vaccum alone will provide sufficient propulsive force real world enviornment as the vehicle itself moving through the tube will create a low pressure area behind itself that will create 'drag' against the vacuum that is trying to pull the vehicle ahead.  Space is not limited in scope as the Hyperloop by its very existance on Earth is.

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Posted by 7j43k on Saturday, November 14, 2020 11:48 PM

BaltACD

If we are going to have the Hyperloop, operate at high speeds - in addition to vacuum on one side of the vehicle, pressure will be required on the other side of the vehicle, with the vehicle providing a reasonable seal between those forces in the tube in which it is operating.

Case in point on a smaller scale

https://www.youtube.com/watch?v=cqidD7kVnxY

 

 

No.

It is not required to have pressure on "the other side of the vehicle" unless you are using that pressure to propel the vehicle.

It is possible to propel a vehicle through a space that is entirely a vacuum.

Think:  "space ship"

 

Ed

 

 

 

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Posted by BaltACD on Saturday, November 14, 2020 10:12 PM

7j43k
 
tree68 
Electroliner 1935
MY concern is what happens when an anomaly occurs 40 miles from a terminal. 

Probably along the lines of many tunnels that have an accompanying smaller tube for wiring, etc, and to allow access throughout the tunnel without having to travel in the problem tube.  Such access tubes would likely have surface access at reasonable distances. 

The tube is going to have to be divided into sections, with an airlock between each one.  There will be emergency access doors in the tube.  To use a door, the vacuum in that section will have to be released.  Because there will be the airlocks, the vacuum will not have to be released in the entire tube.  And "pods" in those sections can continue.  Or, of course, return from whence they came. 

Ed

If we are going to have the Hyperloop, operate at high speeds - in addition to vacuum on one side of the vehicle, pressure will be required on the other side of the vehicle, with the vehicle providing a reasonable seal between those forces in the tube in which it is operating.

Case in point on a smaller scale

https://www.youtube.com/watch?v=cqidD7kVnxY

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Posted by 7j43k on Saturday, November 14, 2020 8:31 PM

tree68

 

 
Electroliner 1935
MY concern is what happens when an anomaly occurs 40 miles from a terminal.

 

Probably along the lines of many tunnels that have an accompanying smaller tube for wiring, etc, and to allow access throughout the tunnel without having to travel in the problem tube.  Such access tubes would likely have surface access at reasonable distances.

 

 

The tube is going to have to be divided into sections, with an airlock between each one.  There will be emergency access doors in the tube.  To use a door, the vacuum in that section will have to be released.  Because there will be the airlocks, the vacuum will not have to be released in the entire tube.  And "pods" in those sections can continue.  Or, of course, return from whence they came.

 

Ed

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Posted by tree68 on Saturday, November 14, 2020 7:10 PM

Electroliner 1935
MY concern is what happens when an anomaly occurs 40 miles from a terminal.

Probably along the lines of many tunnels that have an accompanying smaller tube for wiring, etc, and to allow access throughout the tunnel without having to travel in the problem tube.  Such access tubes would likely have surface access at reasonable distances.

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Posted by 7j43k on Saturday, November 14, 2020 6:52 PM

CMStPnP

There is also a speed limit that has not been mentioned so far.   They reported in the hyperloop tests as well as some of the maglev tests that above a specific speed some humans feel physical discomfort, disorientation or dizziness.   Forget what speed that is but they hit it with the Maglev in China and I am not sure how they fixed it or if they fixed it.   Virgin has run into it with it's slower speed tests.

 

It doesn't seem to be 268 mph.  I rode the Shanghai maglev, and noted nobody in distress.  Maybe they kept it to themselves.

I don't recall the noise level, but it certainly wasn't obnoxious.  I could easily talk to my seatmate.  The ride was reminiscent of a regular train on good track at about 60 mph--a little movement now and then--no problem walking around.

I had a great time, especially watching us pass cars on the freeway like they were parked.

I'd sure like to hear more about this odd phenomenon.

 

Ed

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Posted by 7j43k on Saturday, November 14, 2020 5:46 PM

Electroliner 1935

And the tube is built to hold a vacuum so it is strong.

 

Well, it's strong enough.  But it doesn't take much for a tube to resist 15 psi of compression.  The strength will more needed to keep the tube from sagging between supports.  And then there's the other strength:  not-leaking (much).

 

Ed

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Posted by Electroliner 1935 on Saturday, November 14, 2020 4:43 PM

MY concern is what happens when an anomaly occurs 40 miles from a terminal. It would be like being stuck in an elevator. And the tube is built to hold a vacuum so it is strong. The base tunnels under the alps have thoughtful plans for contingency. I would like to see the hyperloops' plans for contingencys. With out one, I ain't about to get aboard. At least when I get on METRA, they announce where the emegency windows are.

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Posted by Overmod on Saturday, November 14, 2020 12:31 PM

Paul Milenkovic
the answer is 7 hours and 9 minutes?

It's actually worse than that.    The 54 minute figure was for Federal Express; there is little potential passenger traffic most of the places these aircraft would go.  But the figure also applies to any other set of points on a great circle, and at the peak speed for semiballistic flight a simple load of tungsten rods in one of the load bays, plus another crewmember with a hammer, and you've got real trouble.

It's interesting to consider what would have happened if the air transport industry had in fact invested heavily in followons to the 2707 and sold expensive quick travel instead of wide body commodity.  I think we'd still see People Express-like small-aircraft 'convenience' for everyone not needing the high speed, and widebodies for volume...

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Posted by BaltACD on Friday, November 13, 2020 10:28 PM

Gramp
That last mile is a killer. 

In most forms of transportation - the first mile and the last mile are the most difficult miles.

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Posted by Gramp on Friday, November 13, 2020 10:17 PM

That last mile is a killer. 

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Posted by Paul Milenkovic on Friday, November 13, 2020 6:18 PM

I guess this needs to be posted on the Humor thread, but the answer is 7 hours and 9 minutes?

Why 7 hours and 9 minutes you say?

54 minutes for the "semi-ballistic flight", one hour to get through Security, a half hour to wait for parents with small children, the elderly, credentialed active-duty military, and weenies who have accumulated good will for someone else paying for their many flights to board first, 15 minutes for the flight attendants to plead with people who cannot find overhead bin space to allow their overstuffed roll-aways to be placed in the cargo hold, 15 minutes at the other end waiting for a gate and another 15 minutes trying to get off the rocket ship while other passengers wrestle their anvils out of the overhead bins.

Wait a minute, you say, that only adds up to 3 hours and 9 minutes?

Yeah, but then you have to allow another 2 hours for ground transportation at each end! Hmm

If GM "killed the electric car", what am I doing standing next to an EV-1, a half a block from the WSOR tracks?

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Posted by Overmod on Friday, November 13, 2020 5:01 PM

NittanyLion
For instance, we could easily build a spaceplane capable of kangaroo flights from, say, New York, reaching any point on Earth in under 45 minutes.

The cost-effective number I saw was 54 minutes, net of takeoff and landing time at non-semiballistic speeds.  (This does somewhat assume no assertion of national 'space rights' for overflight...)  Yes, with more modern materials I wouldn't be surprised to find it's under 45 minutes now.

In case anyone is wondering, the limiting distance is half the great circle containing antipodal points.  Distance to any other two points will be less.  

Does anyone still have an URL for that Lockheed spoof progress report from 1965?  They stated the case for hypersonic economics rather well by noting that for an additional outlay of some more or less astronomical number they were increasing the number of seats in their design from 8 to 10...

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Posted by Overmod on Friday, November 13, 2020 5:00 PM

NittanyLion
For instance, we could easily build a spaceplane capable of kangaroo flights from, say, New York, reaching any point on Earth in under 45 minutes.

The cost-effective number I saw was 54 minutes, net of takeoff and landing time at non-semiballistic speeds.  (This does somewhat assume no assertion of national 'space rights' for overflight...)

In case anyone is wondering, the limiting distance is half the great circle between the two points.  

Does anyone still have an URL for that Lockheed spoof progress report from 1965?  They stated the case for hypersonic economics rather well by noting that for an additional outlay of some more or less astronomical number they were increasing the number of seats in their design from 8 to 10...

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Posted by NittanyLion on Friday, November 13, 2020 3:46 PM

BaltACD

There is a long, long, long way between 'proof of concept' to a operating system with a positive economic return on investment - be that investment public or private.

 

That's the bugaboo people have a hard time with, even in the face of a working model.  There's a ton of stuff we could build, quite arbitrarily, that would never, ever be feasible.  Somehow, this is unperceived.

For instance, we could easily build a spaceplane capable of kangaroo flights from, say, New York, reaching any point on Earth in under 45 minutes.  There's nothing to actually develop, just sit down and start bending metal with knowledge we already have.  Tickets would be on the range of hundreds of millions of dollars, though.  But, we could actual build it if we wanted to.

Feasible?  Never.  By the time you'd get your launch costs down low enough, you'd likely see your vehicle superceded by other technologies.

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Posted by Overmod on Friday, November 13, 2020 7:39 AM

n012944
What about us brain dead slobs?

You'll be given cushy pandemic-recovery jobs.

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Posted by n012944 on Thursday, November 12, 2020 2:58 PM

zugmann

 

 
Paul Milenkovic
Monorail!  Monorail!

 

I hear those things are awfully loud...

 

What about us brain dead slobs?

An "expensive model collector"

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Posted by blue streak 1 on Thursday, November 12, 2020 2:45 PM

Paul Milenkovic

 600 MPH by air?  In which century?

Airliners fly much slower than that to save on fuel.

 

 
Depending on altitude, outside air temperature and indicated airspeed many aircraft fly at 460 - 480 knots true airspeed.  That equals to 529 - 552 MPH true air speed.  Of course your ground speed is never that due to upper level winds,  Not really part of this coversation.
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Posted by zugmann on Thursday, November 12, 2020 1:49 PM

Paul Milenkovic
Monorail!  Monorail!

I hear those things are awfully loud...

It's been fun.  But it isn't much fun anymore.   Signing off for now. 


  

The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any

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Posted by 54light15 on Thursday, November 12, 2020 1:45 PM

You're right about such systems. Remember when Disneyland opened and the future was monorails? Didn't happen, did it? 

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Posted by Fred M Cain on Thursday, November 12, 2020 10:11 AM

SD60MAC9500
 

MagLev is much further along than Hyperloop. I expect to see the infant phase of an intercity MagLev system break ground within this decade.

<SNIP>

I'm not sure about this.  The real disadvantage of maglev - and it's a big one, is that its equipment is not able to use conventional tracks nor can conventional equipment use maglev tracks.

In France, the TGVs use/used convential tracks to reach certain terminals and in other areas as well while new right of ways were being developed.  That's a BIG plus that shouldn't be overlooked.

The top experimental speed of convential high-speed rail is about that of maglev or at least comes close anyways (around 300-325 mph).

Lyndon Henry who helped launch the Light Rail Now website refers to maglev, hyperloop, monorail, etc. as "gadgetbahn".  That's a good name for it.  All of these systems will probably be built and put into operation at some point and at some location.  (There are already at least several maglevs operating).

But will any of these gadget-like technologies prevail in the end?  I believe that the jury is still out.  Way out.

Regards,

Fred M. Cain

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Posted by Erik_Mag on Wednesday, November 11, 2020 9:45 PM

Paul Milenkovic

600 MPH by air?  In which century?

Airliners fly much slower than that to save on fuel.

600MPH is about Mach 0.9 at cruising altitude, ISTR that airliners typically fly M0.80 to M0.82 (~530 MPH). This is kind of funny as the Republic XR12 piston engine recce plane could cruise at 450+MPH and Republic was trying to get interest in an airliner version.

OTOH, the whole rationale for the Hyperloop design is that air drag at sea level becomes a real problem much above 100mph. Developing an short haul electric airliner could easily cost less than the CA HSR project.

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Posted by Electroliner 1935 on Wednesday, November 11, 2020 8:13 PM

MY concern is what happens when an anomaly occurs 40 miles from a terminal. It would be like being stuck in an elevator. And the tube is built to hold a vacuum so it is strong. The base tunnels under the alps have thoughtful plans for contingency. I would like to see the hyperloops' plans for contingencys. 

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