Hyperloop may become reality in Dubai(bbc.com)
bbc.com
Hyperloop may become reality in Dubai
http://www.bbc.com/news/technology-37908915
118 comments
1. From a sane point of view, this argument makes sense but the UAE don't have a money problem and prestige/aura of modern technology is weighted much heavier than economical reasoning. It would be a huge attraction and a big reputation boost - they could again argue that UAE is where the future is built, not the USA.
2. It is hot down there but from what I have experienced, the thermal swings are lower than on a normal Central European or American day. This means in October 35 C during the day, 30 C at night.
2. It is hot down there but from what I have experienced, the thermal swings are lower than on a normal Central European or American day. This means in October 35 C during the day, 30 C at night.
The hyperloop's thermal problems are not the result of day-to-day swings, they are the result of overall swings. This is because the entire track has to be a single length of welded steel tubing. The thermal expansion at the ends is just ridiculous -- hundreds of meters. It doesn't matter if this happens over the course of a day or over the course of a year, it's still going to be a show-stopper.
If the thing is built underground thermal swings wont matter.
Furthermore, there is definitely a large market for people that want to get between AD and Dubai in as short as possible a time. Sure, high speed rail would be great but people would be willing to pay extra to shave off 12 minutes.
Furthermore, there is definitely a large market for people that want to get between AD and Dubai in as short as possible a time. Sure, high speed rail would be great but people would be willing to pay extra to shave off 12 minutes.
> If the thing is built underground
That would make it the longest subway in the world by a factor of 3. Not going to happen.
That would make it the longest subway in the world by a factor of 3. Not going to happen.
I agree with your point #1, but your point #2 makes very little sense. Yes, thermal expansion problem solution from the original Hyperloop paper [1] is yet to be proven to work in practice. For one, nobody has built long enough straight tube for the thermal expansion problem to matter.
However, I don't see how the difference in thermal swings between California and Dubai matters. The proposed solution probability of success or failure should be the same no matter what are the thermal swings. We are talking about (maybe?) 300 meters vs 500 meters per day of expansion for the same tube length. And Dubai - Abu Dhabi route length is much shorter than SF - LA, as you've correctly noticed.
[1]: "The tube will be supported by pillars which constrain the tube in the vertical direction but allow longitudinal slip for thermal expansion <…> Specially designed slip joints at stations will be able to take any tube length variance due to thermal expansion."(http://www.spacex.com/sites/spacex/files/hyperloop_alpha.pdf, page 28, section 4.2.3)
However, I don't see how the difference in thermal swings between California and Dubai matters. The proposed solution probability of success or failure should be the same no matter what are the thermal swings. We are talking about (maybe?) 300 meters vs 500 meters per day of expansion for the same tube length. And Dubai - Abu Dhabi route length is much shorter than SF - LA, as you've correctly noticed.
[1]: "The tube will be supported by pillars which constrain the tube in the vertical direction but allow longitudinal slip for thermal expansion <…> Specially designed slip joints at stations will be able to take any tube length variance due to thermal expansion."(http://www.spacex.com/sites/spacex/files/hyperloop_alpha.pdf, page 28, section 4.2.3)
> I don't see how the difference in thermal swings between California and Dubai matters.
It doesn't really. But whatever thermal expansion problems you have in California you will have them worse in Dubai.
> Specially designed slip joints at stations will be able to take any tube length variance due to thermal expansion
See:
http://www.leancrew.com/all-this/2013/08/hyperloop/
for a detailed explanation of why this is not an adequate solution.
It doesn't really. But whatever thermal expansion problems you have in California you will have them worse in Dubai.
> Specially designed slip joints at stations will be able to take any tube length variance due to thermal expansion
See:
http://www.leancrew.com/all-this/2013/08/hyperloop/
for a detailed explanation of why this is not an adequate solution.
Yes, I'm aware of this post. Unfortunately, its author failed to discuss the solution from the Hyperloop paper. The author incorrectly assumed the tube is attached rigidly to the pillars and then proceeded to criticise this wrong assumption.
You need to go back and re-read this paper more carefully. The author does discuss exactly the proposal in the paper. He even quotes it:
"But the real problem isn’t with the slip joints at the ends; it’s with the pillar supports along the way. Musk thinks the dampers, “tucked away inside each pylon,” need to accommodate only “the small length changes between pylons.” Wrong."
In other words, the original hyperloop white paper assumes that the movement at each pylon is small, and that the only large-scale movement is at the ends. But this is wrong. There is large-scale movement throughout the system. The thermal expansion motion reaches a maximum at the ends, but it doesn't magically go away as soon as you leave the station. If the tube at the station is moving 100m then the tube near the station is moving 100 meters minus epsilon.
"But the real problem isn’t with the slip joints at the ends; it’s with the pillar supports along the way. Musk thinks the dampers, “tucked away inside each pylon,” need to accommodate only “the small length changes between pylons.” Wrong."
In other words, the original hyperloop white paper assumes that the movement at each pylon is small, and that the only large-scale movement is at the ends. But this is wrong. There is large-scale movement throughout the system. The thermal expansion motion reaches a maximum at the ends, but it doesn't magically go away as soon as you leave the station. If the tube at the station is moving 100m then the tube near the station is moving 100 meters minus epsilon.
This quote is from the first part of the paper for which Musk "apologize[s] in advance for my loose use of language and imperfect analogies". It's just an intro.
The later parts of Hyperloop paper are more precise. I've already quoted "longitudinal slip for thermal expansion" from section 4.2.3. And, unfortunately, leancrew.com article author missed the proposed solution for the problem they spent many words talking about.
> If the tube at the station is moving 100m then the tube near the station is moving 100 meters minus epsilon.
Yes, of course. I agree that the problem of 100m thermal expansion is real and needs to be solved. And I'd like some arguments about why won't Hyperloop "longitudinal slip" solution work (where tube could freely move past the pillars).
The later parts of Hyperloop paper are more precise. I've already quoted "longitudinal slip for thermal expansion" from section 4.2.3. And, unfortunately, leancrew.com article author missed the proposed solution for the problem they spent many words talking about.
> If the tube at the station is moving 100m then the tube near the station is moving 100 meters minus epsilon.
Yes, of course. I agree that the problem of 100m thermal expansion is real and needs to be solved. And I'd like some arguments about why won't Hyperloop "longitudinal slip" solution work (where tube could freely move past the pillars).
Would you please post a copy of the text that you consider to be "the proposed solution for the problem" that you think leancrew missed? Because I just re-read all of 4.2.3 and I don't see it.
I've already quoted it in my very first comment in this thread.
You could argue that writing "pillars which constrain the tube in the vertical direction but allow longitudinal slip for thermal expansion" and "slip joints at stations…" is not detailed enough. I've concluded this "longitudinal slip" means some kind of linear bearing on top of each pillar, where straight tube could slowly move without constraints in the direction of the cumulative thermal expansion, while being constrained vertically.
Leancrew author missed the "longitudinal slip" part, because most of the article proves that thermal expansion accumulates. Of course it does! Thus the "longitudinal slip" solution.
Yes, Hyperloop paper could be more detailed and more clear. Indeed, it confused leancrew author.
Do you anyone knowledgable (in mechanical engineering?) who could comment on "longitudinal slip" solution? How feasible is it?
You could argue that writing "pillars which constrain the tube in the vertical direction but allow longitudinal slip for thermal expansion" and "slip joints at stations…" is not detailed enough. I've concluded this "longitudinal slip" means some kind of linear bearing on top of each pillar, where straight tube could slowly move without constraints in the direction of the cumulative thermal expansion, while being constrained vertically.
v v
-------------
tube
-------------
^ ^
| |
| |
v v
-------------
tube
-------------
^ ^
| |
| |
Leancrew author missed the "longitudinal slip" part, because most of the article proves that thermal expansion accumulates. Of course it does! Thus the "longitudinal slip" solution.
Yes, Hyperloop paper could be more detailed and more clear. Indeed, it confused leancrew author.
Do you anyone knowledgable (in mechanical engineering?) who could comment on "longitudinal slip" solution? How feasible is it?
> You could argue that writing ... is not detailed enough.
Indeed.
> How feasible is it?
Not even remotely feasible. You would need to have bearings at each column. Friction slip joints would introduce way too much stress.
Remember: the tube is not only moving hundreds of meters at the ends, it's moving >>1m along (very nearly) its entire length.
Indeed.
> How feasible is it?
Not even remotely feasible. You would need to have bearings at each column. Friction slip joints would introduce way too much stress.
Remember: the tube is not only moving hundreds of meters at the ends, it's moving >>1m along (very nearly) its entire length.
> Not even remotely feasible. You would need to have bearings at each column. Friction slip joints would introduce way too much stress.
That's the kind of discussion I'd love to have! Of course, you need linear bearings [1] at each column. But what kind of bearings? Ball or roller bearings? [2] Plain/solid bearings? [3] Something else? What are the forces the tube would produce while expanding? What would be the linear expansion speed? What bearings would be able to sustain those speeds and forces? Would the tube and the pillars be able to sustain them? Do bearings with necessary parameters even exist? How expensive would they be? So on and so on.
Unfortunately, I haven't seen such discussion yet. I could try doing the calculations myself (starting at [4], for example). But I'm afraid I would make some silly newbie mistake in the process.
> Remember: the tube is not only moving hundreds of meters at the ends, it's moving >>1m along (very nearly) its entire length.
Yes, of course the tube is moving by hundreds of meters along most of its length. The questions are: how fast? with what load against the pillar?
[1]: https://en.wikipedia.org/wiki/Linear-motion_bearing
[2]: https://en.wikipedia.org/wiki/Ball_bearing
[3]: https://en.wikipedia.org/wiki/Plain_bearing
[4]: http://www.pbclinear.com/Blog/Calculating-PV-for-a-Plain-Bea...
That's the kind of discussion I'd love to have! Of course, you need linear bearings [1] at each column. But what kind of bearings? Ball or roller bearings? [2] Plain/solid bearings? [3] Something else? What are the forces the tube would produce while expanding? What would be the linear expansion speed? What bearings would be able to sustain those speeds and forces? Would the tube and the pillars be able to sustain them? Do bearings with necessary parameters even exist? How expensive would they be? So on and so on.
Unfortunately, I haven't seen such discussion yet. I could try doing the calculations myself (starting at [4], for example). But I'm afraid I would make some silly newbie mistake in the process.
> Remember: the tube is not only moving hundreds of meters at the ends, it's moving >>1m along (very nearly) its entire length.
Yes, of course the tube is moving by hundreds of meters along most of its length. The questions are: how fast? with what load against the pillar?
[1]: https://en.wikipedia.org/wiki/Linear-motion_bearing
[2]: https://en.wikipedia.org/wiki/Ball_bearing
[3]: https://en.wikipedia.org/wiki/Plain_bearing
[4]: http://www.pbclinear.com/Blog/Calculating-PV-for-a-Plain-Bea...
These are the questions that would need to be answered by a hyperloop proponent, not me. The burden of proof is on the person making the claim. The only claim I'm making is that no one has proposed a solution. The two sentences that the Hyperloop white paper devotes to this issue is not a solution.
But what the hell, I need to get my mind off politics, let's do the math.
The fatigue limit stress for steel is about 200MPa. You'd want a 50% safety margin, so let's limit it to 100MPa (which also make the math a little easier). The maximum stress is in the middle of the run, where you are pushing or pulling against N/2 pylons on both sides. Pylons are spaced every 30m. LA to SF is ~450 km. Let's call it 300 to make the math easier. So that's 30k pylons.
There are two different tube designs: passenger only, and passenger plus vehicle. Let's just do passenger only. The tube diameter is 2.23m with a wall thickness of 20-23mm, so the cross-sectional area of the steel is 0.14-0.16 m^2. Let's call it 0.15. So the maximum tensile load we can tolerate is 15 mega-newtons, or about a kilonewton of differential stress per pylon.
The mass of the tube segment borne by each pylon is 0.15 x 30m x 8000kg/m^3 (density of steel) = 36 tons. The weight of this segment is about 350 kilonewtons. So you'd need a coefficient of friction no greater than 1/350. Interestingly, that seems to be just about what you can get out of an industrial roller bearing, so there is no way that you can get anywhere close to that from a sliding bearing.
I wasn't able to find cost figures for roller bearing capable of handling a 36 ton load. I'm sure they exist. I'm equally sure that they're pretty frickin' expensive and require a lot of maintenance.
But what the hell, I need to get my mind off politics, let's do the math.
The fatigue limit stress for steel is about 200MPa. You'd want a 50% safety margin, so let's limit it to 100MPa (which also make the math a little easier). The maximum stress is in the middle of the run, where you are pushing or pulling against N/2 pylons on both sides. Pylons are spaced every 30m. LA to SF is ~450 km. Let's call it 300 to make the math easier. So that's 30k pylons.
There are two different tube designs: passenger only, and passenger plus vehicle. Let's just do passenger only. The tube diameter is 2.23m with a wall thickness of 20-23mm, so the cross-sectional area of the steel is 0.14-0.16 m^2. Let's call it 0.15. So the maximum tensile load we can tolerate is 15 mega-newtons, or about a kilonewton of differential stress per pylon.
The mass of the tube segment borne by each pylon is 0.15 x 30m x 8000kg/m^3 (density of steel) = 36 tons. The weight of this segment is about 350 kilonewtons. So you'd need a coefficient of friction no greater than 1/350. Interestingly, that seems to be just about what you can get out of an industrial roller bearing, so there is no way that you can get anywhere close to that from a sliding bearing.
I wasn't able to find cost figures for roller bearing capable of handling a 36 ton load. I'm sure they exist. I'm equally sure that they're pretty frickin' expensive and require a lot of maintenance.
Wow, your calculations are totally awesome (and seem correct)!
It looks like our estimation of "Hyperloop thermal expansion problem solution" feasibility now comes down to your last sentence:
> I wasn't able to find cost figures for roller bearing capable of handling a 36 ton load.
I don't know, railroad car steel wheel? Max load per axle for train cars: 26 - 40 ton. Searching on alibaba.com for "train car wheelset" and "train car bogie" never comes up with more than $2500 per piece. Maintenance seems doable, if we look at millions of train car running around the planet.
> These are the questions that would need to be answered by a hyperloop proponent, not me. The burden of proof is on the person making the claim. The only claim I'm making is that no one has proposed a solution. The two sentences that the Hyperloop white paper devotes to this issue is not a solution.
Yeah, I agree with that sentiment. Luckily, we are not the people making an actual practical decision on Hyperloop. Like you said, we are just trying to get our minds off politics.
It looks like our estimation of "Hyperloop thermal expansion problem solution" feasibility now comes down to your last sentence:
> I wasn't able to find cost figures for roller bearing capable of handling a 36 ton load.
I don't know, railroad car steel wheel? Max load per axle for train cars: 26 - 40 ton. Searching on alibaba.com for "train car wheelset" and "train car bogie" never comes up with more than $2500 per piece. Maintenance seems doable, if we look at millions of train car running around the planet.
> These are the questions that would need to be answered by a hyperloop proponent, not me. The burden of proof is on the person making the claim. The only claim I'm making is that no one has proposed a solution. The two sentences that the Hyperloop white paper devotes to this issue is not a solution.
Yeah, I agree with that sentiment. Luckily, we are not the people making an actual practical decision on Hyperloop. Like you said, we are just trying to get our minds off politics.
I the thermal expansion problem is solved in Dubai, it also means that it can be solved on many more places. From a prototypal standpoint, it's a pretty good place.
It is far from clear that the thermal expansion problem can be solved at all. AFAICT no one has ever proposed a solution that is even remotely close to being viable.
Could you please show why very-low-speed, low-precision linear bearing to "allow longitudinal slip" of the tube past the pillars, is not "even remotely close to being viable". It's an honest question. I know very little about bearings, but I have yet to find a serious discussion about it anywhere.
Why do you keep posting this article? It can't be a critique of the free "longitudinal slip" linear bearings proposal, because the author assumed the tube is rigidly attached to the pillars. (And it is not.)
> Hyperloop was originally an idea from Tesla's boss and tech entrepreneur Elon Musk, who conceived the technical details of the transport system but left it to commercial firms to make the vision a reality.
The BBC needs to get their facts straight. Elon Musk did not conceive the Hyperloop. This concept has been around for much longer. The trademarked name Hyperloop is what's generally known as a vactrain and the idea has been around for at least 100 years. https://en.m.wikipedia.org/wiki/Vactrain
The BBC needs to get their facts straight. Elon Musk did not conceive the Hyperloop. This concept has been around for much longer. The trademarked name Hyperloop is what's generally known as a vactrain and the idea has been around for at least 100 years. https://en.m.wikipedia.org/wiki/Vactrain
Well, if there's one place in the world a project is likely to get done despite making no practical or economic sense it's Dubai.
I predicted this a few weeks ago on YC.[1] Dubai to Abu Dhabi is 50 miles of flat desert, mostly empty. It's the easy case for the Hyperloop technology.
But I bet it turns out to be maglev in a vacuum tube, not aerodynamic flying.
[1] https://news.ycombinator.com/item?id=12708576
But I bet it turns out to be maglev in a vacuum tube, not aerodynamic flying.
[1] https://news.ycombinator.com/item?id=12708576
If it's maglev but it's running in a near vacuum rather than a hard vacuum I personally think we could still call it Hyperloop even though it wouldn't be exactly like Elon Musk's proposal. I.e. it's the "near vacuum" part rather than the air caster part that's significant.
Now if someone successfully builds a maglev in a hard vacuum tube, then that would definitely not be a Hyperloop, it would just be a classic vactrain. On the other hand, I don't think Musk would be the least bit disappointed if somebody was able to actually build an operational vactrain.
Now if someone successfully builds a maglev in a hard vacuum tube, then that would definitely not be a Hyperloop, it would just be a classic vactrain. On the other hand, I don't think Musk would be the least bit disappointed if somebody was able to actually build an operational vactrain.
I'll bet it turns out to be a maglev without the vacuum tube. Either that or plain old high-speed rail like TGV or Shinkansen. 50 miles is not nearly enough to make it worth accelerating past 200 MPH or so.
Yes, but it would be even more interesting as a closed loop from Abu Dhabi to Dubai to Al Ain to Abu Dhabi. That would be the ultimate transit system for the country.
Dubai is hosting the World Expo 2020 which means they are spending an insane amount of money on new projects right now in time for the expo. It will be interesting to see if spending continues after the expo or if the city will be effectively 'complete' by then.
I went to the Expo in Milan in 2015. What a waste of time and money.
I'm sure they'd like to host prestige events like the Olympics or the World Cup.
I think it's more likely that the project gets funded; this is one of those engineering projects that is almost certainly doomed beyond that stage. Still, as you say, Dubai.
I love their spirit so much. I can't wait until they attempt some farming projects and grow entire avocado farms in the desert or something
Ah yes, the spirit of oil money and slave labor, truly inspiring stuff.
[deleted]
What happens when Hyperloop breaks the sound barrier inside a tunnel? Will it always be slower than the speed of sound? If yes, why don’t we invest in MagLev trains instead?
Huh, I thought that speed of sound increases when pressure decreases, but it seems to be the opposite.
Yep. Intuitively, sound propagates when particles bump into each other and transfer energy. Lower pressure means lower density, so there are fewer particles, which means it takes longer before an energized particle happens to bump into another one and propagate the wave.
Here's a graph I found. It appears highly non-linear.
https://sooeet.com/speed/speed-of-sound-in-atmosphere-graph....
https://sooeet.com/speed/speed-of-sound-in-atmosphere-graph....
Probably because that isn't just v vs. pressure, it probably takes the temperature into account as well.
The speed of sound is invariant to changes in pressure, it is temperature that matters.
The low pressure means not much happens. Further low pressure makes a dramatic difference in energy needs.
The maximum designed speed is less than the speed of sound inside the tube, so I don't believe this will be a problem.
Will I love the technology and would absolutely work for Hyperloop, I would never want them to make deals with the UAE. The abuse of human rights is just to much of an issue over there in these kingdoms.
https://www.hrw.org/middle-east/n-africa/united-arab-emirate...
"The government arbitrarily detains, and in some cases forcibly disappears, individuals who criticized the authorities, and its security forces face allegations of torturing detainees."
https://www.hrw.org/middle-east/n-africa/united-arab-emirate...
"The government arbitrarily detains, and in some cases forcibly disappears, individuals who criticized the authorities, and its security forces face allegations of torturing detainees."
They have very good explanation: They are only 10 years old, they don't have 1000s years of laws of europe or china. They are just studying. Isn't USA still electrify innocent people some times?
1. Practically most of governments in the world are guilty of this.
2. I don't see how boycotting the governments/nations will help resolve this issue. In fact, it'll probably make it worse.
2. I don't see how boycotting the governments/nations will help resolve this issue. In fact, it'll probably make it worse.
"Practically most of governments in the world are guilty of this."
In which way is this relevant to the argument?
In which way is this relevant to the argument?
Was Elon Musk really the one first posing this idea?
He certainly popularised this idea.
Or was it the other way around. What did the Hyperloop thing do to his image?
I think it elevated him to a visionary status in quite a short time. So in a way, it worked quite well for him, even if the idea itself ends up not working at all.
I think it elevated him to a visionary status in quite a short time. So in a way, it worked quite well for him, even if the idea itself ends up not working at all.
Hyperloop came after Paypal, SpaceX, Tesla and Solar City. Musk was already very well thought of before this idea was made public.
You are missing the point. He was elevated to the status of a grand visionary from just an billionaire entrepreneur, with these big, grand "ideas"...
No, he's not missing the point. He was already elevated thanks to SpaceX and Tesla by the time he described Hyperloop.
SpaceX and Tesla are not doing anything really new..
Not sure how it elevates him from yet another billionaire entrepreneur...
Not sure how it elevates him from yet another billionaire entrepreneur...
You've missed the whole "first mass-market fully electric car that actually makes sense" thing and the whole "kicked the space industry in their lazy butts" thing, but the one thing that actually does the elevating is that he's not doing it for profit, but for forcing the electrification of transport and getting humans to Mars.
Landing the booster stage of rockets is really new. Building mass-market electric cars that are supported by continent-spanning fast-charging networks and can drive themselves is really new.
And with that, I'll stop feeding the trolls.
And with that, I'll stop feeding the trolls.
>Landing the booster stage of rockets is really new..
Wait a minute. Was there any new, ground breaking tech involved in it. Will you call delivering pizzas using drones ground breaking, even if it was not done by anyone else before?
>Building mass-market electric cars that are supported by continent-spanning fast-charging networks and can drive themselves is really new...
Same thing...Wait a minute, can drive themselves? Ok. I am done here.
Wait a minute. Was there any new, ground breaking tech involved in it. Will you call delivering pizzas using drones ground breaking, even if it was not done by anyone else before?
>Building mass-market electric cars that are supported by continent-spanning fast-charging networks and can drive themselves is really new...
Same thing...Wait a minute, can drive themselves? Ok. I am done here.
No, and different versions of the concept have existed for not only decades, but over a century.
But he was the first with a marketing budget for it.
But he was the first with a marketing budget for it.
>But he was the first with a marketing budget for it.
Only if you count the SpaceX student competition, but that's not marketing, it's recruiting.
Only if you count the SpaceX student competition, but that's not marketing, it's recruiting.
Hyperloop yes, however this is just an evacuated tube which is a very old idea. His idea is closer to an electric aircraft in a tube than a train in a tube.
After all if you are going to use a train just add cars to increase capacity.
After all if you are going to use a train just add cars to increase capacity.
It's not quite an evacuated tube, which makes it different enough from the old concepts to be interesting. The pressure in the hyperloop tube is very low, but it's not a vacuum. This means that the tube can be relatively leaky, and the air that it does contain is also used to lift the vehicle.
It's very very close to vacuum - 0.015 psi (99.85% vacuum). For all practical purposes, calling it vacuum is very reasonable.
Being able to have a leaky tube and use the air for lift seem like practical purposes to me.
All vacuums are partial. It's not a binary quality, rather vacuums are graded by how close to absolute vacuum they are. Much like 0 kelvin does not exist, but cryogenic systems are making things colder.
I'm well aware. The traditional evacuated tube is a pure vacuum for all practical purposes, with any remaining air being undesirable and having no important effects on the machine. Hyperloop requires a certain amount of air in the tube.
Early vacuum systems where actually using steam that was then condensed. So, it's not particularly high and only a 'pure' vacuum for relevant purposes.
Don't forget vacuum cleaners are hardly high vacuum systems.
Don't forget vacuum cleaners are hardly high vacuum systems.
Is there a point to this besides pedantry? My actual point is that the Hyperloop is something new, not just a rebranding of previous evacuated tube systems. If you have something to dispute that point, then by all means go ahead, but if you just want to quibble over me being insufficiently specific in my explanations then I'll let it be.
Adding cars affects throughput, not latency. For goods that doesn't matter much (hyperloop seems like a bad idea for goods anyway) but for passengers it could make a world of a difference.
Sure, but adding cars does not increase the latency either. So, everything stays the same but if you can send 5x the people for significantly less than 5x the price. Personal Rapid Transit is a great when there are lot's of destinations, but this is going to have minimal stops.
The tone and sarcasm of this video aside, the guy makes strong arguments that the Hyperloop cannot work technically. Worth watching as he makes good arguments. https://www.youtube.com/watch?v=RNFesa01llk
edit: actually it can work technically, but it's not practical at all
edit: actually it can work technically, but it's not practical at all
And here's a playlist of videos debunking Thunderfoot's videos on the subject:
https://www.youtube.com/playlist?list=PLSPi1JFx4_-Gz0Fm0qq2K...
https://www.youtube.com/playlist?list=PLSPi1JFx4_-Gz0Fm0qq2K...
And I may become rich someday.
Note how elegantly that statement sums up step 1 & ???????? = magic final result.
Note how elegantly that statement sums up step 1 & ???????? = magic final result.
> Initially, it will explore the feasibility of building a line linking the two cities.
So now it's one of those "feasibility" projects?
Hyperloop suffers from the same problem as Solar Freakin' Roadways and Artificial Gills, I'm afraid: too much saying, not enough doing. I am instantly suspicious of projects that have lots of hyped up marketing but little to no prototypical substance.
To me, Hyperloop One still seems like a sci-fi pipe dream (pun intended).
So now it's one of those "feasibility" projects?
Hyperloop suffers from the same problem as Solar Freakin' Roadways and Artificial Gills, I'm afraid: too much saying, not enough doing. I am instantly suspicious of projects that have lots of hyped up marketing but little to no prototypical substance.
To me, Hyperloop One still seems like a sci-fi pipe dream (pun intended).
I am not sure even Dubai has enough money to make a hyperloop work. I mean, it sounds so good until you break out the details and examine it piece by piece and then you start to realize exactly what they are proposing
Because it is a bad idea it is probably for the best that there is more saying than doing.
Just curious but why is it a bad idea?
Different poster.
The Hyperloop is technically possible. It will struggle for the same reason Maglev struggled: It won't be cost effective to build or maintain within the safety factors people are comfortable with.
You really have to look at the history of Maglev because the parallels are considerable. Maglev undeniably works, but nobody is building Maglev systems aside from a few pet vanity projects because High Speed Rail is "Good Enough" and cheap!
Hyperloop takes all of the cost issues that Maglev had and makes them worse. Even if the tube didn't have a negative pressure (just a tube with atmospheric pressure) it would be a cost nightmare, but you add in the costs of building something which can withstand negative pressures and the whole thing is just a farce.
Maglev, like Hyperloop, initially wanted to build on raised towers. But it largely wasn't because being able to escape during an emergency is kind of a big deal, same reason why the Euro-Tunnel is 2x larger than it needs to be to support escape tunnels.
A project like Hyperloop won't ever be able to win against real life problems like bombings, earthquakes, fires, extreme weather, and so on. Or at least it won't within the normal realms of cost.
The Hyperloop is technically possible. It will struggle for the same reason Maglev struggled: It won't be cost effective to build or maintain within the safety factors people are comfortable with.
You really have to look at the history of Maglev because the parallels are considerable. Maglev undeniably works, but nobody is building Maglev systems aside from a few pet vanity projects because High Speed Rail is "Good Enough" and cheap!
Hyperloop takes all of the cost issues that Maglev had and makes them worse. Even if the tube didn't have a negative pressure (just a tube with atmospheric pressure) it would be a cost nightmare, but you add in the costs of building something which can withstand negative pressures and the whole thing is just a farce.
Maglev, like Hyperloop, initially wanted to build on raised towers. But it largely wasn't because being able to escape during an emergency is kind of a big deal, same reason why the Euro-Tunnel is 2x larger than it needs to be to support escape tunnels.
A project like Hyperloop won't ever be able to win against real life problems like bombings, earthquakes, fires, extreme weather, and so on. Or at least it won't within the normal realms of cost.
> nobody is building Maglev systems aside from a few pet vanity projects because High Speed Rail is "Good Enough" and cheap!
Japan is building the Chuo Shinkansen, which will be a major intercity Maglev line. It's expected to connect Tokyo and Nagoya in 40mins, down from 100mins on the Tokaido Shinkansen (although a good chunk of that is due to a more direct route through the mountains), and later Osaka.
I could believe it's not necessarily a cost effective investment, but I don't know if I'd call it a vanity project. My impression is that they're trying to duplicate the success of the original Shinkansen, by building something similarly ahead of its time.
Japan is building the Chuo Shinkansen, which will be a major intercity Maglev line. It's expected to connect Tokyo and Nagoya in 40mins, down from 100mins on the Tokaido Shinkansen (although a good chunk of that is due to a more direct route through the mountains), and later Osaka.
I could believe it's not necessarily a cost effective investment, but I don't know if I'd call it a vanity project. My impression is that they're trying to duplicate the success of the original Shinkansen, by building something similarly ahead of its time.
Given this is the UAE, I'm not sure they care about the costs. :)
For them, this is just another innovation to put the country on the map of the world as an innovative and futuristic place, and that attracts tourism; which is said to be a large part of the economy here.
For them, this is just another innovation to put the country on the map of the world as an innovative and futuristic place, and that attracts tourism; which is said to be a large part of the economy here.
In addition to what the other guy said, think about vulnerability to terrorism.
Blow up a support for a segment of tube in the right spot at the right time, and you turn the train into a kinetic kill weapon. (it's traveling 50% faster than a 747!) I'd hate to see that done when it was going through a city.
Blow up a support at any point at the right time, and you've murdered a tube of passengers, plus completely shut down an entire segment of transportation infrastructure for a significant amount of time. Do you know how much it cost the US to shut down all air traffic on 9/11?
Basically, hyperloop is a lot more feasible in a world without homicidal nutjobs - but, alas...
Blow up a support for a segment of tube in the right spot at the right time, and you turn the train into a kinetic kill weapon. (it's traveling 50% faster than a 747!) I'd hate to see that done when it was going through a city.
Blow up a support at any point at the right time, and you've murdered a tube of passengers, plus completely shut down an entire segment of transportation infrastructure for a significant amount of time. Do you know how much it cost the US to shut down all air traffic on 9/11?
Basically, hyperloop is a lot more feasible in a world without homicidal nutjobs - but, alas...
All your points apply to rail as well, yet rail works fine.
(what rail lacks in speed it makes up in tonnage)
Yes, the Madrid 2004 bombing happened, but events like that have been very rare. Do you think they'd be more frequent against a hyperloop?
(what rail lacks in speed it makes up in tonnage)
Yes, the Madrid 2004 bombing happened, but events like that have been very rare. Do you think they'd be more frequent against a hyperloop?
I have a different POV on this given I currently live in Dubai, UAE. They have a 74KM automated rail system (Dubai Metro) and most of it is built on raised towers. This proposed system from what I understand is going to cross mostly empty dessert area.
Secondly, UAE is a pretty safe country in terms of terrorism. At least thats the perception you get if you live here. I haven't heard of one terrorism related activity here. That may be because the media is tightly controlled, but word still gets out if something that major were to happen here. This might just be because they have very tightly controlled borders, and are surrounded by friendly states that also have a relatively good security record (Saudi, Oman).
Just my take on these issues. I don't have any hard data, this is just my perception from having spent 3 years in this country.
Secondly, UAE is a pretty safe country in terms of terrorism. At least thats the perception you get if you live here. I haven't heard of one terrorism related activity here. That may be because the media is tightly controlled, but word still gets out if something that major were to happen here. This might just be because they have very tightly controlled borders, and are surrounded by friendly states that also have a relatively good security record (Saudi, Oman).
Just my take on these issues. I don't have any hard data, this is just my perception from having spent 3 years in this country.
I don't think Hyperloop is going to result in anything particularly useful. It seems to have a lot of fundamental problems. I'm sure it's no coincidence that Elon Musk tossed the idea out with minimal support rather than having one of his companies build it, or founding a new one.
However, it seems a bit premature to say that it's too much saying and not enough doing. It's only been out there for about three years. There have been scale-model pods built, and test tracks are under construction. If anything, progress seems remarkably fast for such a radical machine.
However, it seems a bit premature to say that it's too much saying and not enough doing. It's only been out there for about three years. There have been scale-model pods built, and test tracks are under construction. If anything, progress seems remarkably fast for such a radical machine.
It's not our money funding this company, I don't see the utility in trying to take them down a notch. If they fail, only their investors lose. If they succeed, we all win.
If it's an HN thread about the latest social media startup, the lament is that SV doesn't innovate enough. If it's about a company tackling something hard, out come accusations of 'vapourware', and predictions of their imminent doom.
If it's an HN thread about the latest social media startup, the lament is that SV doesn't innovate enough. If it's about a company tackling something hard, out come accusations of 'vapourware', and predictions of their imminent doom.
"If they fail, only their investors lose"
You realize that isn't actually how a capital market based economy works, right? Investors are the "command" part of the economy, responsible for allocating resources. If they decide to only invest in ridiculous, worthless ideas then we all definitely lose. So far that hasn't happened, but never forget that it is very important for us all where investors put their money.
You realize that isn't actually how a capital market based economy works, right? Investors are the "command" part of the economy, responsible for allocating resources. If they decide to only invest in ridiculous, worthless ideas then we all definitely lose. So far that hasn't happened, but never forget that it is very important for us all where investors put their money.
Wealth is the only credential required for investing. If some or all of today's investors crash and burn, loads of other wealthy people will find better opportunities with reduced competition from today's foolish investors. (Maybe they aren't investing now because their risk profiles require better opportunities to get the cash out of the mattress.) If one hasn't somehow hitched her wagon to the fools, their poor investments can't hurt one at all.
This "somewhere, someone is losing money!" concern trolling fallacy is one "usefully idiotic" source of our repeated bailout follies, so I'd like never to see it again.
This "somewhere, someone is losing money!" concern trolling fallacy is one "usefully idiotic" source of our repeated bailout follies, so I'd like never to see it again.
The Dot Com and Real Estate crashes(both fueled by very poor investment choices) didn't hurt anyone? Interesting take.
The particular crashes you cite didn't hurt me. We're not all in this together when Jaimie Dimon is enjoying his luxuries. Why would we all be in it together when he makes a dumb investment?
Because when lots of people collectively make dumb decisions, then the whole macroeconomic picture goes bad and people like you and I, otherwise not involved find ourselves out of work because of general layoffs in a down economy.
One bad decision here or there won't make much of a difference, because it doesn't dent the whole, and it likely doesn't affect anyone directly connected to us. But many bad decisions is a whole other ballgame.
One bad decision here or there won't make much of a difference, because it doesn't dent the whole, and it likely doesn't affect anyone directly connected to us. But many bad decisions is a whole other ballgame.
At the top of this thread, one could see the goalposts. At that point a "live and let live" attitude toward speculative investing was advocated, appropriately for a site like HN.
Here the argument seems to be that a transportation project in Dubai is somehow the same as Goldman purchasing CDSs from AIG.
Here the argument seems to be that a transportation project in Dubai is somehow the same as Goldman purchasing CDSs from AIG.
And I agree with that argument. Where I must respectfully disagree is when you say the previous two major economic upheavals didn't affect you personally, as if implying they shouldn't affect anyone else either, which is silly. You probably didn't mean to imply that, but that's what people are going to read (myself included.)
I'm not against helping out "little people" who need help. A cursory examination of the bailouts, however, makes clear that nothing of the sort was ever contemplated. All payments were to giant financial firms. Briefly, certain shameless pundits claimed there would be some sort of "trickle down" effect, but no one really expected it.
When the general welfare is invoked to justify extraordinary action, but the action itself doesn't contribute to that at all, the original argument ceases to convince. Cui bono?
When the general welfare is invoked to justify extraordinary action, but the action itself doesn't contribute to that at all, the original argument ceases to convince. Cui bono?
> This "somewhere, someone is losing money!" concern trolling fallacy is one "usefully idiotic" source of our repeated bailout follies, so I'd like never to see it again.
I had trouble parsing this, is there an idiom in here that I'm not familiar with?
Thanks!
I had trouble parsing this, is there an idiom in here that I'm not familiar with?
Thanks!
Maybe more than one such idiom? I probably skipped some commas. Also, I'm a bit of a nut, so most people will disagree with at least part of that sentence. Piece by piece:
"somewhere, someone is losing money": Any functioning market in securities will have winners and losers, so it isn't automatically a problem that someone has lost in any particular situation.
"concern trolling": This is when e.g. I pretend that I'm worried about something bad that might happen to you, but in reality the advice I'm giving is meant to help myself instead. We see this typically when a consultant from one political party claims to be worried about consequences for the other political party.
"fallacy": Something lots of people believe, that isn't true.
"usefully idiotic": A "useful idiot" is someone who believes the bullshit peddled by class enemies to such an extent that she'll repeat that bullshit in all seriousness, to her own detriment.
"bailout follies": We've had lots of economic downturns, but somehow only those overseen by Goldman alumni as Treasury Secretaries have required the taxpayer to give Wall Street lots of money.
"somewhere, someone is losing money": Any functioning market in securities will have winners and losers, so it isn't automatically a problem that someone has lost in any particular situation.
"concern trolling": This is when e.g. I pretend that I'm worried about something bad that might happen to you, but in reality the advice I'm giving is meant to help myself instead. We see this typically when a consultant from one political party claims to be worried about consequences for the other political party.
"fallacy": Something lots of people believe, that isn't true.
"usefully idiotic": A "useful idiot" is someone who believes the bullshit peddled by class enemies to such an extent that she'll repeat that bullshit in all seriousness, to her own detriment.
"bailout follies": We've had lots of economic downturns, but somehow only those overseen by Goldman alumni as Treasury Secretaries have required the taxpayer to give Wall Street lots of money.
secfirstmd(6)
1. Dubai and Abu Dhabi is only 100 miles. That's not nearly enough to make the Hyperloop economically attractive even if it were to work (which it won't, see point #2). Regular high-speed rail can make this trip in 30 minutes. It's just not worth paying N times as much for some value of N>>1 to shave 18 minutes off of that. 300 miles (like San Francisco to LA) is about the minimum distance for the hyperloop to compete with conventional high speed rail even under ideal circumstances.
2. Dubai has bigger thermal swings than California, so the thermal expansion problem -- which is still unsolved -- will be that much worse in Dubai.