The Race To Create a Hyperloop Heats Up (wsj.com)

An anonymous reader writes: When Elon Musk unveiled his idea for the "Hyperloop" transportation system based on capsules zipping through depressurized tubes, much was made about the enormous technical challenges the system would face in development. However, that didn't stop a number of companies and organizations from starting to work on it. Several companies are pushing the development work hard, and it's shaping up like a race to a workable prototype. University teams are only increasing their efforts as well. "The Illinois team enters the SpaceX contest with a strong competitive edge. This is its fourth Hyperloop design project, the first dating to fall 2013, and the Hyperloop is now a part of the MechSE curriculum. The team has assembled an interdisciplinary network of faculty from aeronautical engineering, thermal dynamics, mechanical engineering, electronic engineering and software, and two of the team members have interned at SpaceX."

Comments

The pod has been pressurized to minimize the G

[trout007]

"The pod has been pressurized to minimize the G forces effects on a passenger."

Really? How is that little trick performed?

Re:The pod has been pressurized to minimize the G

[Anonymous Coward]

A gradient in air pressure exerts a force on all volumes.

A gradient in the same direction and opposite sense as the acceleration reduces G force.

Re:The pod has been pressurized to minimize the G

[Anonymous Coward]

How can you have a gradient in air pressure without flow? Pressurizing the inside of the pod would produce a uniform pressure throughout the pod.

Re:The pod has been pressurized to minimize the G

[BarbaraHudson]

Doesn't work that way, same as you can still talk in a supersonic jet. Increasing the pressure enough to have the effect you propose in the pod will just kill the occupants (nitrogen narcosis, and the bends when you reduce the pressure). Reducing the pressure in the tubes, on the other hand (which is right there in the summary) ...

Re:The pod has been pressurized to minimize the G

[SharpFang]

I believe this is an extremely roundabout and misguided way of describing the pod maintaining a constant pressure so there's no "ear popping" and other silly effects connected with changes of altitude.

Re:The pod has been pressurized to minimize the G

[Type44Q]

How is that little trick performed?

Duh: having a cushion of air inside the capsule would obviously reduce G-forces; think about how a shock absorber works.

(Alright, kid but I wonder how many right-brained, artistic types would have been taken-in by my simple "logic?" *grin*)

Re:The pod has been pressurized to minimize the G

[bennebw]

I'm pretty sure the pod is pressurized so they can breathe.

Re:The pod has been pressurized to minimize the G

[hey!]

"The pod has been pressurized to minimize the G forces effects on a passenger."

Really? How is that little trick performed?

Simple: they depolarize the tachyon flow to the defector dish. It's almost like you've never even seen an episode.

Re:The pod has been pressurized to minimize the G

[painandgreed]

"The pod has been pressurized to minimize the G forces effects on a passenger."

Really? How is that little trick performed?

Simple: they depolarize the tachyon flow to the defector dish. It's almost like you've never even seen an episode.

They could just reverse the neutron flow.

Re:The pod has been pressurized to minimize the G

[BlueStrat]

(Alright, kid but I wonder how many right-brained, artistic types [washingtonpost.com] would have been taken-in by my simple "logic?" *grin*)

Much of the public and a good portion of government officials (those officials who aren't pushing the "hyperloop" boondoggle solely for purely cynical political, ideological, and/or cronyism reasons).

Strat

Re:The pod has been pressurized to minimize the G

[penguinoid]

"The pod has been pressurized to minimize the G forces effects on a passenger."

Really? How is that little trick performed?

It's the principle of buoyancy; at higher pressures air is more dense and therefore you appear to weigh less. So at double atmospheric pressure you'd appear to weigh about 50-100 grams less. That, and you'd have an easier time breathing and more oxygen in your blood.

Re:The pod has been pressurized to minimize the G

[Anonymous Coward]

Yeah, but then you start to risk the bends when you want to get out of the damn thing.

Re:The pod has been pressurized to minimize the G

[gweihir]

Sounds like nonsense to me as well. Like the whole project.

Re:The pod has been pressurized to minimize the G

[Bengie]

More Oxygen is not always a good thing. You only want to inhale a certain number of moles of Oxygen per kg of body mass. As you increase the pressure, the moles goes up, which means you need to reduce the percentage, which means to mess with the ratio, which creates another bunch of problems.

.. pressurized to minimize the G forces effects?

[jimtheowl]

TFA lost me here:

"The pod has been pressurized to minimize the G forces effects on a passenger"

You can pressurize a pilot suit to redirect blood flow in order to mitigate g-forces in a fighter plane, but this is nonsense.

An even better design?

[goombah99]

they should bury it so it can be a straight line tube cutting into the earth's curvature. Then you can just "fall" from Los Angeles to SF with no propulsion needed. The theoretical transit time, ignoring the friction, is 43 minutes. the energy you need to supply is to overcome the friction. Since gravity will be both accelerating this and decelerating this there's no need for a complex propulsion system, decelleration system with energy reclamation. Less to go wrong, and less abrupt acceleration of the passengers, and probably greater safety.
Of course the hard part of this is you have to tunnel underground to make a straight line cutting in to the earth. Since LA to SF is about 400 miles along the surface and the earth's circumference is about 25000 miles this means arc length is about 0.016 radians. thus 25000/2/pi*(1-cos(0.016/2)) = 0.127 miles.
so the center of this would be roughly 1/8th of a mile buried or 672 feet at the deepest point (ignoring the mountains). This doesn't seem radically crazy as a depth for boring a hole.

Re:An even better design?

[SharpFang]

No can do. Lava too shallow.

10-15km deep will hardly make a difference and we can't really go much deeper without ridiculous amount of work on thermal isolation.

Plus tectonics will really rain all over the parade unless it's built as a flexible maglev in a way oversized tunnel.

Re:An even better design?

[Anonymous Coward]

lava is not at 600 feet and the temperature will be pleasant. ever been in a mine? there are already very long tunnels and plate tectonics does not affect them

Re:An even better design?

[Scottingham]

Then you can just "fall" from Los Angeles to SF with no propulsion needed.

I've found that if you use the word 'just' when describing anything related to engineering it's WAY more complex than you think it is, and usually impossible.

Re:An even better design?

[DrXym]

And as an added bonus people come out the other side roasted to perfection.

Re:An even better design?

[SharpFang]

https://en.wikipedia.org/wiki/...

12km, or 40,000ft and they were unable to keep up due to heat melting the drill.

If you're going to cut into Earth curvature, in a straight line with maximum 10km depth the longest you can go is 714km.

Re:An even better design?

[Rei]

One of the main points of Hyperloop is to *save* money. You don't save money by tunneling from LA to SF.

Re:An even better design?

[Software]

You're talking about a project that's 10 times longer than the Channel Tunnel, which took 6 years and cost £13 billion in today's dollars. Of course, there's no English Channel overhead, so you can make boreholes overhead and pull out the rock that way instead of hauling it along the length of the tunnel. But on the other hand, you don't have the advantage of being able to choose the tunnels' path to get favorable geology - given the higher speeds, you're pretty much stuck with going through whatever rock is in your way.

Plus, a straight line tube is not going to accelerate rapidly enough to get you there in 43 minutes. Are you assuming that you're going to be accelerating at 9.81 m/s^2? I think you'd be closer to 0.3 m/s^2.

Re:An even better design?

[careysub]

Because you only want to travel 100 km?

Clearly you do not understand the OPs statement about "a straight line tube cutting into the earth's curvature". Such a straight line is called a chord, the max depth of the chord is called the sagitta. A 200 meter sagitta ("600 feet") means that the total length of the journey is only 100 km. To go from LA to SF, a distance of 630 km, the depth of the sagitta increases to 7.8 km. Currently the deepest anyone has ever dug a tunnel is 3.9 km (the TauTona Mine in South Africa).

Re: An even better design?

[goombah99]

Please show your calculation. My calculation was shown. Did I make an error? By my calculation the straight line Sagitta is 600 feet deep for 400 miles.

Re:An even better design?

[mjr167]

Except the earth isn't a sphere. It's an oblate spheroid that is better modeled as an ellipsoid. This matters. A lot. The radius at the poles is significantly less then the radius at the equator.

And the rocky mountains are pretty damn big. So are the Appalachians (when you talk about tunneling under them). You can't just hand wave them away.

Re: An even better design?

[Anonymous Coward]

1/2 a t^2 = 320 km where t is 20 minutes. Solve for "a".
So no one does not need a high acceleration.

Re: An even better design?

[goombah99]

Oops I did indeed drop a factor of two pi in the arc distance calculation. Correcting that it is more than 5 or so miles at the deepest point.

Re:An even better design?

[dotancohen]

Since LA to SF is about 400 miles along the surface and the earth's circumference is about 25000 miles this means arc length is about 0.016 radians. thus 25000/2/pi*(1-cos(0.016/2)) = 0.127 miles. so the center of this would be roughly 1/8th of a mile buried or 672 feet at the deepest point

Now imagine a gradient 200 units long, which slopes down for 1/8th of a unit. What rate of acceleration do you imagine a craft sliding with no friction down that gradient will have? And with friction? Now do you see the need for propulsion?

Re:An even better design?

[firewrought]

Assuming you can do it for an ultra-cheap $60M/mile, that's a total construction cost of $24 billion dollars for just the tunnel itself. That's roughly 5 times the estimated ~$4.85 billion cost for pylons, tunnels, and land rights that you would need for an over-land route. (Musk estimated $7.5 billion for the project as a whole, though commentators say he's being optimistic.)

Re:An even better design?

[careysub]

The Gravity Train is a well established idea. The article also explains why no one builds them.

Re:An even better design?

[RKThoadan]

Okay, so it's not a good idea for people. It sounds like it's perfect for cross-country pizza delivery. It cooks while it's on the way!

Re:An even better design?

[Firethorn]

714 km a shot doesn't seem too terrible. Plus, at some point you might as well start curving it because you don't want to go too fast.

Re:An even better design?

[SharpFang]

Initial descent incline 3.2 degrees. Not too impressive ;) I'd rather see the tunnel curving - first descending steeply from the station then straightening out at some 2km.

Still, tectonics are going to be a nightmare. I've been to a mine. I saw what they can do.

Re: An even better design?

[Anonymous Coward]

Not pizza--burritos. http://www.idlewords.com/2007/04/the_alameda_weehawken_burrito_tunnel.htm

Re:.. pressurized to minimize the G forces effects

[Crowd Computing]

Since the top speed is barely supersonic, wouldn't the g-forces here be comparable to a commercial jet plane?

Huckleberry Musk

[Thud457]

boy, painting this fence is really fun.

Re:Huckleberry Musk

[sexconker]

Pretty much. People are so desperate for a new Steve Jobs that anytime Musk or Zuckerberg say "You know, I was taking a shit the other day and I thought plozzing would be cool." every company under the sun starts shouting about how they can ploz, how they plan to increase their plozzing over the next 5 years, etc.

Re:Huckleberry Musk

[gweihir]

Indeed. And basically almost none of these ideas will ever pan out and the few that do will not do so anytime soon. Swarm-stupidity at work.

other enormous challenges not considered.

[nimbius]

1. the majority of americans outside a handful of cities still consider public transportation to be a mark of poverty and avoid it at all costs. others cant be bothered to even consider a greyhound to the next state, let alone a train, and once they arrive the local public transit infrastructure based on their destination is either so poor as to be unusable or nonexistent through legislative fiat.

2. We cant keep up. our bridges, roads, highways and railroads are crumbling further into the dirt each year, and neither body of legislation seems capable of passing meaningful funding. the hyperloop would surely face the same fate as a majority invested government project that eventually turned into public private, then abandoned once the payout wasnt suitable for corporations, and finally maintained at about a quarter of its original capacity.

3. the initial projection for this works project (and, it would be a works project) is six billion dollars. America cant manage to keep its government running for more than 2 years at a time in this foul year of our lord 2015. It wont fund education, its states wont fund healthcare, and its been cutting federal public transit funding for 35 years. the only way a hyperloop is getting built is if it somehow includes a rider to invade a neighbouring country.

the only real reason companies even thought of doing work with the hyperloop is to do what companies do: suckle at the taxpayer teat. You start by investing in a renewable effort, secure grants and loans, develop a few proof of concept ideas, sell out to a capital management firm, and then declare bankruptcy.

Re:other enormous challenges not considered.

[SenatorPerry]

Five year bill:
http://www.politico.com/story/...

Re:other enormous challenges not considered.

[Anonymous Coward]

I got rich by valuing money and being frugal with it. Riding public transportation saves money and time! Now that I am rich, I still ride public transportation, because doing so remains consistent with my values.

Americans who associate this with poverty are stupid.

Re:other enormous challenges not considered.

[SharpFang]

What percentage of Americans consider flying with commercial airlines to be the mark of poverty?

Hyperloop isn't a replacement for buses or city cars. It's a replacement for airplanes. Supersonic travel with high initial but low unit cost - airplanes are very wasteful because they need to use a lot of energy just to prevent falling. Hyperloop train, once running, keeps running with only minimal friction losses and can recuperate most of energy used on acceleration during braking.

It actually drives a lot of funds towards science/education. But yeah, the initial investment is huge. I mean, something like, 6% the amount any of the wars USA started!

Re:other enormous challenges not considered.

[Anonymous Coward]

you're a fucking idiot. But you already knew that.

Re:other enormous challenges not considered.

[known_coward_69]

the problem is not that it is seen as a sign of poverty, it's that the trains don't go where people need them to go. most jobs are far from the stations so it doesn't make sense to take the train. instead of sitting in traffic you would have to drive to a park and ride, pay money for parking, take the train and then a bus or whatever to your job instead of simply driving all the way. this is around NYC as well. taking the train into manhattan isn't that big a deal, it's taking the train outside of NYC if you work there that is the problem. a lot of the job parks and malls are miles from the train. and if you don't brown bag lunch then all the lunch places are miles from the job parks so you have to drive to lunch as well if you want trains in the suburbs you have to build free parking lots as well and price the trains to compete with driving and work with employers to build office buildings close to the station.

Re:other enormous challenges not considered.

[Anonymous Coward]

Most of the U.S. doesn't have the population density to make public transportation a viable option. So enough with the self righteous bullshit.

Re:other enormous challenges not considered.

[Anonymous Coward]

3. the initial projection for this works project (and, it would be a works project) is six billion dollars.

That's actually a plus for California.
Back in 2008, the state proposed an inner-state high speed rail (with a stop in Vegas). The cost of the project now sits at $68 Billion (and is still climbing): http://www.latimes.com/local/california/la-me-bullet-train-cost-final-20151025-story.html

Re:other enormous challenges not considered.

[Grishnakh]

1. the majority of americans outside a handful of cities still consider public transportation to be a mark of poverty and avoid it at all costs. others cant be bothered to even consider a greyhound to the next state, let alone a train, and once they arrive the local public transit infrastructure based on their destination is either so poor as to be unusable or nonexistent through legislative fiat.

Have you ever taken a Greyhound, or even investigated a ride on one? They're ridiculously impractical; that's why no one uses them except poor ex-cons. The only reason anyone uses Greyhound is because they have some kind of problem (like lack of proper ID) which prevents them from taking a plane, or they're so broke that the meager savings over airfare is worth it to them. Greyhound isn't all that cheap, and worse, it takes forever to get there because they take horribly meandering routes on backroads through every little village they can. It's an awful way of traveling, so only people on the fringes of society bother with it. No one in their right mind wants to spend 24 hours on a bus when they can do the same trip in 3 hours on a plane. And all that is overlooking the kind of company you'll have on the bus....

And local public transit infrastructure sucks mainly because of the laws of physics, and the lack of high density in most American cities. Public transit works pretty decently in very dense places like Manhattan, but other places just don't have the density necessary,

If you want people to use public transit, you need to make public transit systems that actually work well and perform well. The only way you're going to get that is with high-speed, fully-automated PRT (personal rapid transit). Go read about SkyTran. Nothing else will work: light rail and other trains cost an absolute fortune to build and interfere with all the roads, and they only go in a line; buses are too slow and stop too much; and everything goes according to a pre-set schedule so you end up wasting a lot of time waiting on the next ride instead of moving. SkyTran fixes all those problems. The Wikipedia page explains it all.

Re:other enormous challenges not considered.

[Grishnakh]

I will say however that your lack of confidence in the American government (at every level) is very rational. It does seem that our government would just bungle any kind of transportation technology, Hyperloop, SkyTran, etc. I guess that's why SkyTran is first being built in Tel Aviv, Israel. Maybe after it's deployed across Europe and parts of Asia and finally it's the norm in places like El Salvador, we can get it here in the US.

Re:other enormous challenges not considered.

[Grishnakh]

It doesn't have the density to make 19th-century public transportation technology viable. But SkyTran would be perfectly suited for suburban US cities and urban ones not as dense as Manhattan.

Re:other enormous challenges not considered.

[Anonymous Coward]

Riding public transportation saves money and time!

Unless you live close to your destination or busy bus hubs, public transportation saves money but wastes a lot of time waiting for the next bus.

Re:other enormous challenges not considered.

[MachineShedFred]

And yet there are transportation modes that continue working fantastically, because the advantages far outweigh the costs and horseshit. People don't have issues with air travel, even though the experience is as close to public transit as you can get - you go to a big government paid-for terminal called an 'airport' where you get in a big metal tube filled with strangers, where you then sit for a non-trivial amount of time until it gets to another government paid-for terminal. Then you pack up your shit and leave.

The only difference between air travel and public transit is that the airplane is owned and operated by a private entity, and that airplanes get you where you're going way faster than just about any other viable alternative.

Re:other enormous challenges not considered.

[Anonymous Coward]

Yeah, but you're forgetting that many of the public transportation advocates think that everyone should live in a super-dense city, so that public transportation actually lives up to it's expected usage and efficiency rates.

The thing that so-called Smart Growth advocates always forget, is that people don't just sit in their "livable walkable" neighborhoods for their entire existence - they need to actually leave the city every once in a while, and then they are totally fucked.

Re:other enormous challenges not considered.

[Dog-Cow]

Americans with PT that actually saves time are in the minority.

Re:other enormous challenges not considered.

[MachineShedFred]

Don't forget that most mass transit projects end up being pork for property developers and public employee unions, and aren't actually designed to be cost-efficient or efficient from a passenger-miles traveled perspective. Projects usually go over-budget, and no attention is ever paid to operating costs after the thing is built, causing transit agencies to cut services elsewhere to keep it running, because the fare box doesn't even come close to paying for operations.

Urban Streetcar projects in the 1990s were sold as a way to circulate people around a district. That turned out to be horseshit, so now they are sold as an inflator of property value, because tracks can't be moved as easily as a bus stop.

And why do bus stops move? Because they can pay a guy to move a bench and a sign, and the route gets more efficient, moving the bus to where people actually are, or where they want to go. And this is seen as a bad thing, for some reason.

Re:other enormous challenges not considered.

[MachineShedFred]

There's actually some things that the US Government gets right with transportation.

The freight rail system in the US is the envy of Europe. We move billions of tons of cargo untold miles incredibly efficiently, over massive mountain ranges. Air travel, for all the annoyances it creates through security theater and companies that want to siphon every last nickel from your wallet for checked bags and seats that aren't akin to torture, is more affordable then ever, with traffic control and airports that are operated by insane numbers of government authorities.

The problem is that rail network isn't designed with passengers in mind, and the rails are owned by the freight companies - so while it's fantastic at moving freight, the passenger trains get second priority to freight trains, and the rails lay in parts of town where people aren't so you have a 'last mile' problem.

Re:other enormous challenges not considered.

[Archangel Michael]

The HSR system was a joke from the beginning. It was a "make work" program for Unions designed to keep middle class Democrat voters from fleeing the state. It never made economic sense. The routes went to places nobody wants to go. Didn't use existing Highway pathways. Had too many stops to be useful. And OneWay Ticket prices were expected to exceed the average round trip in state airfare from the beginning.

But typical liberalism doesn't care about actual facts, they only care about what "feels" good. And HSR is one of those liberal ideals that simply require ongoing expensive taxes in order to subsidize perpetual economic drain.

The fact is, we do have HSR, that is much more flexible and capable of hauling people around. The Liberal elites just want it reserved for those going to Global Warming Symposiums. They are called Airplanes.

Re:other enormous challenges not considered.

[Ichijo]

most jobs are far from the stations

Is that true where employers aren't forced by cities to overbuild their parking lots? Or where freeways pay for themselves 100% from gas taxes and other user fees instead of less than half?

Or is the fact that "most jobs are far from the stations" a result of the kind of Big Government authoritarianism favored by the right?

Re:other enormous challenges not considered.

[Archangel Michael]

Just so you (or maybe not you, but others) know, the USA lower 48, would span from UK to Israel if overlayed on a map. People not in the USA, having never been here, have no idea how big it actually is. They love to tell us, how we should be, comparing us to little Scandinavian Countries with Monolithic cultures. I can assure you that Miami Florida is nothing like Seattle Washington, or Casper Wyoming, or Boston Massachusetts or Phoenix Arizona or Chicago Illinois or Memphis Tennessee ....

The only thing that is intriguing about Hyperlink is that it is capable of providing personalized transportation with High Speed. If I could get into a Hyperlink unit in LA and end up in NYC without getting out of the car (or minimal stops/transfers), with anything approaching Airline speed, that would be awesome. But if Government is involved, there is no way that it becomes viable, because there are too many people who will cry about some "unfair" reality that needs to have some SJW involved to make it fair.

Re:other enormous challenges not considered.

[Anonymous Coward]

Because there's no other country on earth that doesn't depend on public transport systems to function?

No other cities even...

Re:other enormous challenges not considered.

[hey!]

Unless you live close to your destination or busy bus hubs, public transportation saves money but wastes a lot of time waiting for the next bus.

Assuming you use your downtime doing stuff like playing Candy Crush. Oddly enough this ability to fill every available moment with distraction I think is changing attitudes toward alternative forms of transit which free your attention up from driving. But you don't have to fritter the time away; you can put it to productive use. I used to take the Amtrak from Boston to Lynchburg VA to visit a client, even though flying would have been somewhat faster. I prepped for the visit on the way down, wrote up my report on the way back, and when I stepped off the train in Boston South Station I had my report and invoice all ready to send. Yes, it was somewhat more expensive than flying and yes, it took a few more hours, but they were billable hours.

Re:other enormous challenges not considered.

[Anonymous Coward]

1. the majority of americans outside a handful of cities still consider public transportation to be a mark of poverty and avoid it at all costs.
 

Luckily the majority of the rich have made the vast majority of Americans relatively poor.

Re:other enormous challenges not considered.

[Anonymous Coward]

If there is a market for air travel between LA and San Francisco, then this is the same thing except potentially cheaper. This isn't about commuting to work every day.

Re:other enormous challenges not considered.

[bigpat]

Hyperloop isn't a replacement for buses or city cars. It's a replacement for airplanes. Supersonic travel with high initial but low unit cost - airplanes are very wasteful because they need to use a lot of energy just to prevent falling. Hyperloop train, once running, keeps running with only minimal friction losses and can recuperate most of energy used on acceleration during braking.

That still needs to be proven out, but yes it could be theoretically more efficient and therefore less expensive than air travel.

Re:other enormous challenges not considered.

[Rinikusu]

Well, the big thing is living in a city where the mass transit density is enough to make it worthwhile. Memphis, TN? I hope you like looking for a job because depending upon mass transit will cost you yours. Los Angeles, CA? I can find several different routes to get me where I need to go at regular intervals. Not nearly as fast as cutting through traffic on my motorcycle, but I like to spend the hour so in commute (compared to 35-40 minutes on bike) reading/studying, etc/ I "salvage" an extra 1.5 hours on average doing something I want to do anyway vs commiting my active mind to dealing with assholes in traffic. Except when we get the crazy homeless guys on the bus. That's entertainment (loosely) that you just can't find anywhere else. For "free."

Re:other enormous challenges not considered.

[dpidcoe]

That's nice you had a job that lets you bill those kinds of hours, but you seem to be falling into the trap of assuming that what worked for you will work for everyone else also. That's clearly not the case, unless you can explain to me how someone like a welder is going to be able to bill his hours spent commuting over public transportation.

Re:other enormous challenges not considered.

[Grishnakh]

The only thing that is intriguing about Hyperlink is that it is capable of providing personalized transportation with High Speed.

SkyTran can do the exact same thing, only on a much smaller scale (like being able to transport you a few miles that way, station-to-station, with stations all over the place in a grid, not a line). However, it's not that fast: maybe 100mph in-city max, and up to 150mph for longer routes. That's a lot faster than a car of course (esp. considering the lack of congestion, stops, etc.), but still not nearly as fast as an airplane. Hyperloop would compete directly with that, and in fact be quite a bit faster than airplanes, plus probably safer too.

But if Government is involved, there is no way that it becomes viable, because there are too many people who will cry about some "unfair" reality that needs to have some SJW involved to make it fair.

It does seem like things are completely broken in this country. I think we should outsource our governance to Denmark. We're just too stupid to do it ourselves.

Re:other enormous challenges not considered.

[nukenerd]

1. the majority of americans outside a handful of cities still consider public transportation to be a mark of poverty and avoid it at all costs.

Aren't airlines public transport? I thought Americans loved them.

Re:other enormous challenges not considered.

[hey!]

I'm addressing the point that time spent waiting for the bus equal time wasted. That's not the case any longer, even if you aren't being paid for the time. The hedonic calculus of driving vs. public transit isn't what it used to be in the pre-mobile Internet days. It used to be a choice between spending say 45 minutes doing something you didn't want to do (driving) vs. spending 90 minutes doing something you didn't want to do (riding transit). Obviously shorter was better.

Now on your transit commute (and some day soon in your computer-driven car) you can be doing a lot of the stuff you'd have been doing if your were sitting around your house: reading, shopping, blogging, playing games. That's just as true for a welder taking public transit as it is for a consulting software engineer. It is true as a consultant I have the option of doing paid work, and that's nice. The flip side is people expect you to work all the time.

Re:other enormous challenges not considered.

[Gavagai80]

airplanes are very wasteful because they need to use a lot of energy just to prevent falling.

It's not as if airplane engines are on the bottom providing upward thrust. Air pressure + speed keeps them aloft. The hyperloop does theoretically help the wind resistance slowing problem though.

Re:other enormous challenges not considered.

[dave420]

Density doesn't need to be a problem if it's covered by transport links. An integrated local/regional tram system works wonders for sparsely-populated areas.

Re:other enormous challenges not considered.

[dave420]

The EU is larger than the US and still manages to get decent public transport. And "monolithic culture"? Are you kidding? That would have nothing to do with anything, if it ever existed, which it doesn't. You are trying to find excuses for shitty policies and a lack of basic infrastructure the rest of the developed world seems to have figured out decades ago. "SJW"? Get a fucking grip - you are embarrassing yourself. You sound like a bitter, unloved old person.

Re:other enormous challenges not considered.

[dpidcoe]

Now on your transit commute (and some day soon in your computer-driven car) you can be doing a lot of the stuff you'd have been doing if your were sitting around your house: reading, shopping, blogging, playing games. That's just as true for a welder taking public transit as it is for a consulting software engineer.

No it isn't. You're falling into the same trap that every public transit advocate does and thinking that everyone is similar to you and a one size fits all solution will work. People with the kinds of jobs that require a physical presence often don't have hobbies or pasttimes that are conducive to working on while riding a bus, unless the bus makes accommodations for tieing fly's, reloading ammunition, or working on cars while in transit. There are plenty of people who don't shop online (at least not to the point of spending 2 hours a day doing that), don't play games, don't blog, and don't read (at least not 2 hours a day worth of material). Spending half of that transit time driving themself would be significantly more productive.

That's great public transit works for you, but you're doing your viewpoint a disservice by insisting it's great for everyone.

Re:other enormous challenges not considered.

[Grishnakh]

How does monolithic culture not have anything to do with anything? It's plainly self-evident that Danish culture, for instance, is far more homogeneous than American culture. It's a small country, roughly 5M people IIRC, about the size of one US state. They all speak the same language and have pretty much the same culture. So politics in a place like that are much easier: everyone's mostly going to agree on things. How many right-wing, "god and guns" Danish are there in Denmark, who hate public transit and don't want to pay taxes for it but are happy to pay taxes for a giant military? Not many, I suspect. So public transit and projects like that have little trouble getting funding there. Here in the US, we don't speak the same language (there's a huge contingent of Spanish speakers), and the culture varies pretty widely from place to place, so we can't even agree on very basic things, like whether the government should have any social services at all. There's a huge contingent of people here who don't think it should. We can't agree on whether guns should be all banned, or there should be strict gun control, or there should be zero regulations on guns altogether. We can't agree on whether abortions should be fully legal, legal in exceptional cases, or completely illegal. I could go on and on. Denmark doesn't have these problems; neither does Norway, or insert any other small European nation here. Even a big one like Germany doesn't have internal strife approaching what we have.

Yes, the EU is larger, but the public transit is mainly done by the individual member nations, not at the EU level. The EU is basically a confederation, with very little centralized power, so the nations enjoy a lot of sovereignty but agree on matters of trade and currency, and that's about it. There's strife between the EU members however (since their cultures really are very different), but they're not all stuck together voting against each other in a single big government like us. And even so, they're threatening to tear their union apart just because of differences over monetary policy and now immigration laws in the face of a huge wave of refugees. I think they'll probably figure things out (even if they lose a member here or there for a while, or have to "demote" them to returning to their own currency), but it's a good case study in how hard it is to get different cultures to work together and agree on things. It's no wonder places like Iraq simply don't work: there's too many groups fighting each other and completely unable to agree and work together; democracy simply cannot work in a place like that, which is why they either need to be broken up into separate nations, or they need a strong dictator like Saddam to run the place.

The only reason things aren't that bad here is because our regional cultures aren't *that* different, and there's been a lot of homogenization thanks to various things like a largely shared language, TV, and the fact that we grew by expansion and settling rather than a bunch of existing, long-time nations deciding suddenly to try to join forces rather than having constant wars like they did in centuries past. Also, many of our cultural differences are between urban and rural areas more than between different states or regions. People in rural California and rural Virginia both complain about the people in urban California, and would probably get along pretty well together.

Re:other enormous challenges not considered.

[hey!]

People with the kinds of jobs that require a physical presence often don't have hobbies or pasttimes that are conducive to working on while riding a bus, unless the bus makes accommodations for tieing fly's, reloading ammunition, or working on cars while in transit.

You have a strange ideas about people's hobbies. I'm an engineer but I work on cars and fish. And plenty of people who do manual labor play videogames.

Re:other enormous challenges not considered.

[dpidcoe]

I'm an engineer but I work on cars and fish. And plenty of people who do manual labor play videogames.

That's the entire point. If you were a construction worker you couldn't bill your commute time, you couldn't work on your car, and you couldn't fish. So then what, you play candy crush the entire train ride and consider it a good use of your time?

The key thing here is that many people do things in their down time that aren't possible to do on a bus or train, and the productive things they have on their list that are possible to do on a bus or train don't take up anywhere near the entire duration of the trip. As such, your assertion that they can just do other things while commuting so as to not "waste" the time is laughable unless applied to a very specific subset of people.

Musk's idea?!

[Anonymous Coward]

Larry Niven's book World Out of Time has a "hyperloop" system in it. And I can't help but think other SF writers may have come up with something similar before that.

The notion that Musk came up with this 'idea' is ludicrous.

Re:Musk's idea?!

[Anonymous Coward]

I remember playing with this as a kid. Maybe Elon had one as a kid and wants one as an adult?

https://www.youtube.com/watch?v=Pj_QsAdh4MI

Micronauts Rocket Tubes!

Re:Musk's idea?!

[Matheus]

Not to mention Futurama!! :)

Re:Musk's idea?!

[westlake]

Larry Niven's book World Out of Time has a "hyperloop" system in it. And I can't help but think other SF writers may have come up with something similar before that.

The sci-fi writer isn't obliged to demonstrate that his system is technically feasible or economically viable.

In film and video "instant" transportation by tunnel or teleportation makes for fast transitions between scenes and is dirt cheap to animate.

Re:Musk's idea?!

[Rei]

What's ludicrous is that you're commenting about the topic without even realizing what Hyperloop is.

Sci-Fi (Niven, Heinlein, Clarke, Bradbury, and countless others) love vactrains. Hyperloop is not a vactrain. It wouldn't even work in a vacuum. It's an extreme version of a ground-effect aircraft - at pressures as if it were at extreme altitudes, and very small ground effect clearances. Unlike with a vactrain, the tube does not hold a hard vacuum - while pressure is greatly reduced, it still has more than enough air to pose resistance to the vehicle (this is necessary for the capsules to gain lift). To avoid the wind resistance, the capsules use battery-powered compressors to shunt it to behind them (and assist the lifting surfaces). The compressors however do not provide propulsion - that's done by magnetic accelerator segments. To get rid of the heat from the compressors, the capsules contain onboard water supplies into which they dump the heat; the water gets swapped out and the batteries recharged before a given capsule relaunches. The use of air for lift enables the vehicle to avoid all of the costs associated with maglev (at low speeds, such as at stations and during emergencies, they settle down onto wheels).

Show me a single sci-fi novel you've read that's proposed such a system.

Re:Musk's idea?!

[chispito]

Larry Niven's book World Out of Time has a "hyperloop" system in it. And I can't help but think other SF writers may have come up with something similar before that.

The notion that Musk came up with this 'idea' is ludicrous.

Musical analogy: Musk did not compose the vactrain, he merely arranged it under the name "hyperloop."

Re:Musk's idea?!

[Altus]

Musk has done neither. He isn't even directly involved with the people who are actually trying to see if this is technologically and economically viable. This is an old idea. It almost certainly could work but the engineering and economics are the hard part and musk has had nothing to do with those.

Re: The pod has been pressurized to minimize the

[Anonymous Coward]

Some of them are just really misguided due to their superstitions. I have relatives that are mostly normal people, just superstitious, so they fall for the religious nonsense that Republicans sell.

Solution In Search Of A Problem

[Phil06]

Add this to the list with self driving cars as a solution in search of a problem.

Re: Solution In Search Of A Problem

[Anonymous Coward]

Like lasers.

Re: Solution In Search Of A Problem

[Big Hairy Ian]

Like lasers.

Just add Shark

Re: Solution In Search Of A Problem

[Anonymous Coward]

The problems solved by self-driving cars will include elderly drivers, drunk drivers, and distracted drivers. Not enough for you?

Re: Solution In Search Of A Problem

[Anonymous Coward]

All of which can be solved through other means, without spending billions of dollars on research and development. And, without introducing new unanticipated problems.

Re:Solution In Search Of A Problem

[hey!]

Add this to the list with self driving cars as a solution in search of a problem.

Which is usually the case for new technologies that aren't simple refinements of things that people are already doing. I've been through this multiple times -- introducing managers to desktop computers; LANs; Internet; and the Web. These were all in the very earliest days solutions in search of a problem as far as pragmatic managers were concerned. They knew how to do their job without a computer on every desk connected to almost every other computer in the world, so why would they need such a thing? Well, you don't need it until you figure out how to use it.

That said, the two examples you allude don't fall into that category of tech that accomplishes unfamiliar things. The Hyperloop is a straightforward replacement for other modes of intercity travel: plane and rail in particular. Self-driving cars are an alternative to driving yourself. If you imagined either of these things existing and being competitively priced, you'd have no difficulty in picturing how you'd use them.

Re: Solution In Search Of A Problem

[JazzLad]

Same could (may) have been said of cars themselves.

Dumb article is dumb ...

[BarbaraHudson]

Why would Elon Musk open-source an idea this valuable, while also leaving the door open to step in himself?

Because the idea has been in the public domain for decades, including the whole depressurized tubes bit, maglev, and electric propulsion via external coils.

For now Elon Musk, it seems, is calling his invention home to see what it’s become.

Not his invention ...

Re:Dumb article is dumb ...

[Rei]

The fact that you think that Hyperloop is a maglev vactrain shows how you shouldn't talk about a topic of which you don't even know the most basic aspects.

Re:Dumb article is dumb ...

[Anonymous Coward]

As much as you like sucking Musk's dick, the Hyperloop is still a vactrain.

Re:Dumb article is dumb ...

[Rei]

A device that physically cannot work in a vacuum by definition cannot be called a vactrain.

Re:Dumb article is dumb ...

[BarbaraHudson]

I never said it was a "vactrain." Also, you don't want any physical contact with the walls, and the best way to do that (and supply boost at the beginning and regenerative braking at the end) is with electromagnetic fields. All this is more than a half-century old.

Re:Dumb article is dumb ...

[Rei]

But that is not what Hyperloop does. Hyperloop is not maglev, and for good reason - maglev is expensive. Hyperloop capsules are close ground-effect vehicles, relying on air bearing skis at high speed (at low speed they settle onto wheels).

Show me a single - single - example in history from before Hyperloop Alpha - of a design involving evacuated but not vacuum tubes containing an effective ground-effect aircraft with battery-powered compressors to shunt the sparse air behind them, but propulsion coming from the occasional short coilgun segment, not the compressors.

Re:Dumb article is dumb ...

[BarbaraHudson]

Nobody bothered with GEVs because of their obvious problems - one of them being that they are going to have the equivalent of "head crashes" from vibration it high speeds. Earth tremors, frakking, rock slides ... air bearing skis cannot self-center as well as coils, nor can they react as fast. Plus, the less air, the less air resistance, meaning boost stations can be further apart and use less energy. Also allows for higher speeds, which translates into more carrying capacity per unit of time. The proposed hyperloops are not much different from today's subways, which have strategic air shafts to shunt the air that builds up ahead of the train to the outside. Almost the same complexity as a vacuum system, but nowhere near the same advantage wrt top speeds and energy usage.

LOL... There's a race all right

[Anonymous Coward]

A race for whatever money either the government or gullible millionaires will hemmorhage for a pipe dream.

How's that 1997 space hotel coming along? How's that Solaren space solar-power station coming along? 2016 is in three weeks!!

Re:LOL... There's a race all right

[sexconker]

2016 is in three weeks!!

Can you give me the Powerball numbers for the December 5th drawing?

Re:LOL... There's a race all right

[Anonymous Coward]

You don't take the last week off in December? What god awful third world backwater banana republic slave-owning dictatorship are you hailing from?

I wonder if it can aid in space launches.

[SharpFang]

Imagine a section of tube going splitting away from the main network. It has an airlock shortly after the split, then gently curves up a tunnel through a mountain, and exits at a rather steep angle upwards. Then there's a quick-acting airlock at the opening.

A special train is loaded - a rocket adapted to travel through these tubes. It speeds up to the regular Mach 1 in the "civilian" section of the tunnel, then goes down the branch and gains another 2-3 Mach. The airlock at the end opens right before the rocket reaches it, then the hyperloop propulsion module drops on a parachute while the rocket ignites its engines. We've just shaved off first 1.5km/s out of the required 9 or so needed to reach orbit - and with the tyranny of rocket equation, that's quite a bit of savings!

Re:I wonder if it can aid in space launches.

[frnic]

Thew airlock would need to be long enough so that the pressure could be normalized before the outer door is opened, while the rocket is traveling at Mach 3. Probably in the neighborhood of a mile or two if you pressurized the airlock in one second.

Constant/repetitive cycling of the pressure would certainly be very stressful to the structure.

Re:I wonder if it can aid in space launches.

[careysub]

We've just shaved off first 1.5km/s out of the required 9 or so needed to reach orbit - and with the tyranny of rocket equation, that's quite a bit of savings!

No you haven't. The Earth's surface is not in a vacuum. The initial launch of a rocket is just spent climbing out of the atmosphere . The Space Shuttle traveled at a constant, subsonic velocity (slower than a commercial airplane) until it reached 10 km, above most of the atmosphere, before it started to accelerate and acquire its actual launch velocity.

Re:I wonder if it can aid in space launches.

[Rei]

You plan to have a capsule emerge from a near vacuum at several times the speed of sound straight into atmospheric pressures? That's going to be like hitting a brick wall. "Opening an airlock" will send in a shockwave down the tube to meet the capsule. And then to boot, its lift surfaces, designed for providing lift in a near-vacuum, are suddenly going to be facing huge amounts of air.

It's actually better to have hypersonic (relative to atmospheric air) projectiles moving through vacuums or near vacuums literally break through whatever "airlock" is sealing off the end (this is done in several types of hypersonic guns) - it's better to hit a literal (as thin as possible) wall than to hit the shock of air flooding into a near vacuum.

There is no such thing as a "hyperloop propulsion module". Hyperloop capsules are not self-propelled.

Note that you can't reach "mach anything" greater than 1 in such a tube relative to the internal gases. But you can increase the speed of sound several times over by using sparse hydrogen and/or very hot gases in the tube instead of sparse atmospheric air.

Re:I wonder if it can aid in space launches.

[MachineShedFred]

A lot of the energy of a space launch is spent getting above atmospheric thickness - this is why launches are vertical on the ground, and then perform a "gravity turn" after getting above 10km. Getting out of the atmosphere is fairly easy - they proved that with the X-25 rocket plane and the initial Mercury launches. It takes a whole shitload more energy to stay up there, because you need horizontal velocity, which you're not going to get in the scheme you suggest.

Also, instantly transitioning from less than half of an atmosphere of pressure in a tube to a full atmosphere of pressure while at supersonic speed sounds like a fantastic way to destroy anything / anyone you're attempting to launch.

Re:I wonder if it can aid in space launches.

[ceoyoyo]

Gravity turns are not performed after getting above 10 km. Reality isn't KSP, and those things in KSP aren't gravity turns anyway. Gravity turns usually begin as soon as possible after launch (some rockets actually launch at a slight angle). The idea is that gravity will naturally bend your trajectory over into a curve and aerodynamic pressure will keep you pointed along that trajectory. Gravity turns are also called "zero-lift turns."

The space shuttle initiated it's turn quite early on, despite having to perform a roll maneuver. You can see it in this picture:

http://upload.wikimedia.org/wi...

Re: I wonder if it can aid in space launches.

[Namarrgon]

You might be interested in the Launch Loop.

Re:.. pressurized to minimize the G forces effects

[Anonymous Coward]

Speed has nothing to do with G-forces. Acceleration. Also, pressurizing a "pod" means the atmosphere, and that isn't doing anything for or against g-forces. Like the above poster said, you can put some air bladders in a tight-fitting suit but that's for like 5+ Gs, which would probably kill the ordinary American civilian these days.

Re:Funny me

[Anonymous Coward]

Congrats, you're a deranged RWNJ. Now that you've been diagnosed, it's time to get help. Start by removing all hate-radio, wingnut blogs, and Fox "News" from your life. Spend some time with people outside your cult until your ignorance and hate fade away and you gradually move toward sanity.

The Bank!

[JimSadler]

Go to a bank at the drive- in teller station and you have proof of concept immediately. They only need to use a vacuum but the air removed from the front of the carrier could easily be pumped in behind the carrier and a bit more added as well if speed or distance requires the added boost. There is no question that it works the only question is the expense balanced against the benefits.

Re:The Bank!

[Rei]

Hyperloop is not a pneumatic tube system. And pneumatic tube systems unfortunately don't scale well.

Literally

[bravecanadian]

a pipe dream..

Re:Literally

[Anonymous Coward]

That's funny. I hope you get modded up.

I can't help but think of Futureama.

Re:Literally

[Anonymous Coward]

And plumbing and sewage systems are a pipe nightmare. It's not sexy so doesn't get funded by billionaires so much, unless Bill Gates is throwing some money in that direction for developing nations, which is conceivable.

To demonstrate the technology, transport cargo

[mykepredko]

I'm probably being Toronto, Canada centric but when I look at the number of 18 wheelers travelling between Windsor, Toronto and Montreal (520 miles a bit longer than LA to San Francisco) I would think that a hyperloop with the 401 highway, eliminating big rigs, would make a lot of sense in terms of reduced traffic, wear on the road and truck/driver costs.

According to http://www.thetruckersreport.c... it costs $1.38 USD/mile and let's assume that each truck is carrying 100,000 lbs of cargo. Along with that, there are 10k trucks travelling the route (https://canadaalive.wordpress.com/2014/01/18/highway-401/) for a total cost of $7,280k per day or more than $2.6B per year.

Going back to Musk's estimate of $6B for LA to SF, I think that the Windsor to Montreal route could be done for a similar amount (ie quite flat with no mountains and no earthquakes) which means that a 5 year ROI could be conceivable for putting a hyperloop between Windsor and Montreal (with a stop at Toronto) with the bonus of less traffic jams.

Why isn't somebody this analysis for LA to SF or other city pairs where's there's lots of commercial truck traffic to validate the hyperloop process and demonstrate a track record and demand for passengers?

Re:To demonstrate the technology, transport cargo

[wonkey_monkey]

I'm probably being Toronto, Canada

Can I be Peculiar, Missouri?

Re: To demonstrate the technology, transport cargo

[Anonymous Coward]

You could also put all the truck traffic on regular rail...there is a reason there is not more rail traffic now. Rail companies. Hyper loop is just a fancy rail system.

Re:To demonstrate the technology, transport cargo

[Rei]

I'm sure there are lots of people running the numbers for various routes. The LA/SF route was chosen to introduce the concept in the Hyperloop Alpha document, but it's hardly the only route possibility (personally I think they should have started with a LA/Las Vegas proposal so as not to earn the ire of the HSR people and the "but you won't stop at my town on the way" people, but anyway...)

If you want to roughly estimate tube costs in your area, your best comparison would be not roads or rails, but large oil pipelines (which also run for thousands of kilometers). Because Hyperloop tubes basically are large pipelines. It has some some advantages and disadvantages vs. an oil pipeline, of course.

1) Oil pipelines are usually raised, but not as high as Hyperloop. On the other hand, they bear far higher loadings (being full of oil rather than vacuum), so it's probably a wash.
2) Oil pipelines face much harder right of way / environmental approval issues than Hyperloop, due to the potential of spills. It's often a large chunk of their total construction costs.
3) Hyperloop faces far tighter tolerances, and has to ensure that it stays within these tolerances at its support columns. The inside of Hyperloop requires a pass with a circular polishing machine before it can come into service to ensure the necessary level of smoothness.
4) Oil pipelines face corrosion issues not faced by Hyperloop.
5) In both cases, small leaks are problematic and need to be fixed but not world-ending; giant holes are a Bad Thing that will take your tube out of service and cost you money.
6) Both require pumping, although of very different types. Hyperloop's pumping is probably a bit easier and cheaper, although still significant. Oil pipelines also have more thermal management issues (oil usually comes up from the ground hot, and its viscosity changes as it cools).
7) Hyperloop requires periodic emergency exits - although oil pipelines have a variety of periodic hardware as well.
8) A few percent of Hyperloop's length is accelerator segments (think "coilguns"). These are a cost not present in oil pipelines
9) Oil pipeline storage terminals are probably a lot more expensive than Hyperloop stations.

So, balance out those factors as you will.

Re: To demonstrate the technology, transport cargo

[Anonymous Coward]

It's not really a fancy rail system... it differs in a fundamental way: it is on demand. If you are into computers, it's a real time system versus a batch system.

Re:To demonstrate the technology, transport cargo

[turp182]

Add in the savings for the state with regards to road wear from semi trucks. Those can become tax incentives and other benefits to get it built that can reduce that 5 year ROI (for all parties excepting truck drivers, they would be reduced in number and transitioned to end-point work).

Great idea, by the way.

Re:To demonstrate the technology, transport cargo

[currently_awake]

How would the use of light rapid transit (hyperloop) reduce wear and tear on roads from heavy trucks? Heavy trucks are not normally used for bulk people transport.

Re:To demonstrate the technology, transport cargo

[turp182]

The parent specifically mentioned 18 wheelers, which are probably non-person cargo (I hope so, otherwise it would be terrible).

Re:To demonstrate the technology, transport cargo

[ceoyoyo]

Existing trains are even cheaper. The reason they use trucks is because the trucks can do local delivery.

Re: To demonstrate the technology, transport cargo

[Rei]

That really is a big part of it. By splitting up the passengers into many smaller, frequently launched capsules rather than fewer numbers of large, heavy, proportionally increquent vehicles, they greatly reduce the peak loadings on the track. Which significantly reduces the costs to elevate it. The peak loadings are more like what you'd see with the Disney Monorail than a HSR viaduct.

Re: To demonstrate the technology, transport cargo

[Anonymous Coward]

so in other words it is just a batch system with more frequent smaller batches.

Re: To demonstrate the technology, transport cargo

[Anonymous Coward]

True when you look at it as a people transport, about 30-40 per capsule. But here we are talking about freight. And for freight it would likely be one shipping container per capsule. When you compare the effort that it takes to assemble a freight train, the hyperloop (freight version) is fundamentally different from a train.

There are actual plans for this, I'm not making it up. Hyperloop Tech plans to build a route for freight b/w LA and Las Vegas.

Re: To demonstrate the technology, transport cargo

[nukenerd]

That really is a big part of it. By splitting up the passengers into many smaller, frequently launched capsules rather than fewer numbers of large, heavy, proportionally increquent vehicles, they greatly reduce the peak loadings on the track.

With microprocessor control, you could do that with conventional rail, which currently is still generally based on electro-mechanical line-side signalling systems.

In fact there have beeen moves in the past to "break" trains into smaller faster units, such as the Flying Hamburger https://en.wikipedia.org/wiki/... and the UK's GWR railcars https://en.wikipedia.org/wiki/... - for their time, fast and light rail vehicles. However, like the Hyperloop they were confined (in their original roles) to the upper end of the market. To move people in mass, nothing beats heavy rail.

Re: To demonstrate the technology, transport cargo

[Rei]

To be fair to rail, they've had to deal with a much harder problem. Hyperloop, as proposed, involves no intersections, no switching. Rail has intersections and switches all over the place. If Hyperloop ever gets built and starts to expand from unbranched direct routes to an actual network like rail, their task will become a lot harder, it's a much more difficult scheduling problem.

Re:.. pressurized to minimize the G forces effects

[Rei]

The author doesn't know what G-forces are, that's all. They were trying to say that the person isn't exposed to a vacuum.

Re: The pod has been pressurized to minimize the

[Anonymous Coward]

All he cares about is money.

Re: The pod has been pressurized to minimize the

[Anonymous Coward]

Money is all he cares about

Seattle Tacoma would be ideal place for this

[Anonymous Coward]

A hyperloop between Seattle, Seatac and Tacoma would be perfect. Rather than it take 45 minutes to get downtown on slow old Link Light Rail it might take 5 minutes. People that commute from Tacoma to Seattle on the Sounder commuter rail could do the trip in a few minutes vs 55 minutes. Build it next to the existing BNSF rail corridor.

Re:Seattle Tacoma would be ideal place for this

[MachineShedFred]

You really need to adjust your idea of timing. You can't instantly accelerate and decelerate without liquefying your passengers internal organs. You would have a maximum acceleration rate, as well as a maximum braking rate in order to not kill people.

Also, you can't just build this next to existing freight rail lines - the US freight rail system was designed for a maximum straight-line speed of 69 MPH. The route you suggest has a HUGE turn in it from headed east-southeast towards Puyallup, to due north towards Auburn. Even if you could take that thing at the speeds talked about with these Hyperloop systems, the centrifugal forces would cause severe "distress" on the passengers.

They chose the I-5 corridor through central California for a very good reason - it's very flat (except for when you get to the San Gabriel mountains right before LA), and very VERY straight.

Re:Seattle Tacoma would be ideal place for this

[Anonymous Coward]

i believe it is a lot more difficult than you think to liquefy someone from extreme acceleration alone.

Read about John Stapp and the human rocket sled tests

he used to hold the land speed record.

Stapp demonstrated that a human can withstand at least 46.2G. (In the forward position, with adequate harnessing.) This is the highest known acceleration voluntarily encountered by a human.

Re:Seattle Tacoma would be ideal place for this

[nukenerd]

The GP was talking about instant acceleration (meaning in this context going instantly from 0 to 760mph). I think that merely liquifying is being optimistic: they'd probably be vapourised.

Nevertheless, Strapp showed that we should be OK with 46g (let's leave the last 0.2, as a safety margin) - as long as we ae Strapped in.

Re: The pod has been pressurized to minimize the

[Anonymous Coward]

That's how they be.

Re:.. pressurized to minimize the G forces effects

[Anonymous Coward]

G-forces have little to with speed. G-forces are caused by *acceleration*. F=ma, after all. So it really isn't about the top speed, it is about how fast you get to that speed, and how gentle the curves in the tube (if any) are.

What about vertical acceleration rates ?

[Anonymous Coward]

So far, I have not seen any discussion of how much vertical acceleration or ascend / descend passengers can tolerate. A hyperloop tube which follows terrain would be like riding a fighter plane at treetop height as it crosses hills and valleys. So viaducts need to be constructed. How many viaducts? How high?

Re:What about vertical acceleration rates ?

[Rei]

It's discussed in the Hyperloop Alpha document, although I can't be bothered to dig it up right now - I recall that the numbers were what I'd call "a bit roller-coaster-ish", but nothing too bad. Note that there is no "lateral acceleration", as the craft is not locked into a fixed orientation with respect to Earth - "down" is always the direction where G-forces are the most intense. Passengers face acceleration/deceleration forces and vertical (downward) forces.

G-forces are the main limiting factor to Hyperloop velocity in most places - the more the track has to bend in order to follow roads, avoid mountains, etc, the slower it has to move. So bends are the biggest factor in determining trip times. Technically Hyperloop is also limited by the speed of sound in the tube, but it's not as big of an issue as curves, at least over routes like LA/SF. And it's an issue that can be avoided - with more pumping, one could inject a sparse light gas, which can support dramatically higher speeds of sound. Elevated temperatures also raise the local speed of sound, and given how sparse the gas in the tube is, it's probably not going to be very good at ditching the heat imparted to it by the passing craft - so its equilibrium temperature may be well elevated over ambient without any extra effort.

Bothered? Greyhound?

[Anonymous Coward]

I suppose the parent is right. I can't be bothered to take a Greyhound bus anywhere, in much the same way I can't be bothered to gouge out my own eyes so I don't need glasses, or how I can't be bothered to electrify my testicles to wake me in the morning.

Yeah, not gonna happen

[Anonymous Coward]

We can't seem to build high-speed rail in the US, which is a proven technology.

But somehow we're going to build a tube-based transport system, which is unproven and probably an order of magnitude more difficult (considering you need a tube and pumps and still need some sort of rails or maglev to support the vehicle inside the tube).

Re:Yeah, not gonna happen

[Rei]

You know, rather than speculating, you could actually read how it works before talking about it (hint: no, it uses neither rails nor maglev)

Re:Yeah, not gonna happen

[MachineShedFred]

they're not building 1950's style switched telephone systems in Africa either - they're building cellular networks because it's the modern way to do things.

The so-called 'high speed rail" that has been proposed in the US is a fucking joke, and a very expensive one at that. I'll give you a hint - the majority of the proposed high speed rail corridors are a whopping 20 mph over what Amtrak currently does.

Re:Yeah, not gonna happen

[Anonymous Coward]

Ok, ok, according to Wikipedia it uses "air bearing skis" driven by a compressor powered by on-board batteries.

I don't see how that invalidates my basic point, it's not gonna happen.

Re:Yeah, not gonna happen

[hey!]

We can't seem to build high-speed rail in the US, which is a proven technology.

Well you put your finger on the problem right there. We Americans have a novelty fetish; we're the only country that could go from putting our first man in orbit to landing a man on the Moon in seven years, then totally lose interest in manned spaceflight. The fact that other countries have done high speed rail successfully makes tackling all the complicated and expensive things you need to make it work profoundly uninteresting to the average American.

That said, they are building a high speed rail link between LA and San Francisco, but while that's an eminently practical project, particularly when you consider the impact on places in between on the line like Bakersfield and Fresno, it's boring. The train won't be the fastest in the world; until we're talking the fastest train or train-like system, Americans won't like the idea.

Re:Yeah, not gonna happen

[Rei]

My basic point is that you're criticizing a system that you don't even know the most fundamental details about. Start with actually reading the Hyperloop Alpha document, then come here. I'm obviously not going to sit here and debate the finer points of a topic with someone who is just now learning what the thing even is.

Re:Yeah, not gonna happen

[nukenerd]

Yes, building a track/road/ski-run/railway/sliding-surface (I'll give you the honour of chosing the terminology) in a vacuum tube sounds much cheaper and easier than building in the open air.

Re:Yeah, not gonna happen

[Rei]

None of the above. And it's not a vacuum tube. Hyperloop wouldn't work in a vacuum.

Again, if you want to actually have a discussion of the plan, you're going to have to actually read the plan first. I'm not sure what's difficult about this concept for you.

Re:Yeah, not gonna happen

[nukenerd]

I was going by Wikipedia, and just took another look.. Perhaps Wikipedia has got it wrong (if so, perhaps you will edit it as you are obviously up on the subject), but :-

[Wikipedia] The Hyperloop ... operates at approximately one millibar (100 Pa) of pressure. .......is proposed to operate by sending specially designed "capsules" or "pods" through a continuous steel tube maintained at a partial vacuum.

No-one has ever created a perfect vacuum*, so the word "vacuum" tends to mean something close to it. One thousand of atmospheric pressure is pretty good going as a "vacuum" in for a mega-structure 100's of miles long. I work in heavy engineering - we would call that a "vacuum" and and would be quite pleased to maintain one as low as that in a vessel much smaller.

But you are right to emphasise the "vacuum" being partial here as some air is essential to the air film aspect.

Nevertheless, my point still stands that this is a staggeringly large "vacuum" vessel from an engineering design point of view (the point of view I am seeing from) which will be staggeringly expensive to build, whatever Elton Musk and his followers might believe.

*Nearest thing was behind a parasol dragged behind a space vessel in very high orbit, and even that was not perfect.

Re:Yeah, not gonna happen

[Rei]

First off, stop reading Wikipedia. You can read the actual concept design document, Hyperloop Alpha, if you actually want to learn about the proposal.

No, "One thousand(sic) of atmospheric pressure" is not "pretty much as good as a "vacuum". Hard vacuums operate at around a trillionth of atmospheric pressure. At a thousandth of atmospheric pressure, even if you weren't in a tube you'd face relevant wind resistance at those sorts of speeds. Inside a tube, you build up a dense column of air in front of you while dragging hard vacuum behind you. This column of air would rapidly slow the capsules. The old concept - vactrains - was to operate in hard vacuum to prevent this. In order to coast at high speed in Hyperloop, the capsules have to shunt the air to behind them via compressors. However, unlike an airplane, the magnitude of air being moved isn't huge (it's non-propulsive), so battery-powered water-cooled compressors are sufficient to handle it.

The reason for Hyperloop choosing not to operate in hard vacuum is severalfold. One, it's much cheaper to maintain low pressures than a hard vacuum - it requires dramatically lower pumping costs (both capital and operating) to operate at a thousandth of atmospheric pressure than a trillionth. Two, the cost needed to deal with the low pressures on the capsules (the compressors) is not unreasonable. And three, they make use of the air in the tubes to provide lift, avoiding expensive maglev options. Basically, they took a look at the old maglev vactrain concepts, found what made them expensive, and found a way to eliminate those things by making it not maglev and not a vacuum.

Their design parameters make the tube itself not much more complicated than an oil pipeline (see above in the thread for a comparison between the two). And oil pipelines are not unreasonably expensive to build.

But you are right to emphasise the "vacuum" being partial here as some air is essential to the air film aspect.

A basic aspect which you should have known before you even started talking about the concept.

Re:Yeah, not gonna happen

[nukenerd]

"One thousand(sic) of atmospheric pressure" is not "pretty much as good as a "vacuum". Hard vacuums operate at around a trillionth of atmospheric pressure. At a thousandth of atmospheric pressure, even if you weren't in a tube you'd face relevant wind resistance at those sorts of speeds.

My original and subsequent comments have not been about the propulsion, suspension or air resistance; they have been about the cost and challenge of building the tube. No, I have not read the concept design document (we are not the design committee here), but I have got the point that it is in a tube kept at a near vacuum.

From the structural point of view it does not matter whether the internal absolute pressure (I'm trying hard to avoid the word "vacuum" as it seems to give issues) is a millibar, microbar, 10 millibars, 100 millibars or even a perfect vacuum - the structural design of that tube will be the same.

No it will not be as simple or cheap as an oil pipeline.

Oil pipelines have internal pressure (ie above atmospheric) which makes them structurally simpler because the pipe walls are in tension - which most structural material is very efficient at holding. OTOH, the Hyperloop tube walls will be in compression so there is the additional failure mode of wall buckling to consider - unstable implosion of the pipe in other words. With a tube 4m diameter (I got that from Wikipedia too) this is likely to be the dominant structural consideration. To avoid implosion buckling, steel walls will need to be either uneconomically thick, or will need to be copiously re-inforced with circumferential flanges and longitudinal ribs - unlike oil pipelines. One solution would be to make the tube of concrete which is far cheaper than steel, so the walls could be thick and hence more stable against implosion buckling - but then there would be far more self-weight to consider, negating the "advantage" of light pods/capsules/cars/whatever-they-are-called.

A further difference from oil pipelines is that the latter can make relatively abrupt changes of direction. Eg, to cross a small valley, the oil pipes can simply dive down into it and rise up the far side, on relatively low and normally-spaced pedestals all the way. The Hyperloop could not do this - it would need a high viaduct like any conventional railway - in fact it would be far fussier than a conventional railway to keep the lateral and vertical accelerations within passenger tolerance at its high speed. Maybe the landscape is featureless where the Hyperloop is going (I don't know); otherwise some very serious civil engineering is going to be required on its route.

Re:.. pressurized to minimize the G forces effects

[Anonymous Coward]

I love how the guy you replied to is modded at 3 and you're at 0.

Re:Funny me

[Coren22]

But if we remove Fox "News", should we also remove all the left wing propaganda "News" organizations at the same time? I guess than we are left with BBC?

Re: The pod has been pressurized to minimize the

[Anonymous Coward]

About money is all he cares.

Re: The pod has been pressurized to minimize the

[sexconker]

His cares are all about money.

Elon Musk's Idea?

[Anonymous Coward]

I didn't even know Elon Musk was that old. I already learned about this when I was a kid in the 80's. I never knew Saint Elon was a child entrepreneur who already developed this train system at a very young age. Why didn't my teachers tell me it was Elon Musk's idea? I could have worshipped him for so much longer...

Re:Elon Musk's Idea?

[Rei]

I didn't even know that there are so many people here on Slashdot who see fit to criticize Hyperloop without understanding even the most basic concepts of what Hyperloop actually is

For the fourth time this thread: it's not a maglev vactrain. It wouldn't even work in a vacuum.

Re: The pod has been pressurized to minimize the

[Anonymous Coward]

Forgot to post anon again, cow.

Alon Levy's analysis: barf ride

[call -151]

Alon Levy, transit expert (particularly about costs of construction,) has this recent update about the proposal. His earlier analysis brought up a number of concerns about cost and how it would actually work. Basically, at the speeds that are claimed, the required gentleness of the curves means expensive construction. Or just going fast and cheap and thus having barfing passengers.

Re:Alon Levy's analysis: barf ride

[Rei]

Apparently this "transit expert" is following up to his humorously bad** G-forces post by commenting on the G-forces on a deliberately small test track, as if that's relevant to what actual passengers on actual public tracks would experience. And his complaint is about a vertical 0,2g? Seriously? That's the vertical G-force of a passenger jet taking a 30 degree bank. Oh my god, we're all going to die.

Also, I'd like to see his credentials on the topic of pipeline construction. Because we're not talking about the construction of road or rail, we're talking about the construction of a long steel tube. Given that he keeps acting like pipeline and rail costs are directly comparable. Also humorous is his concept that building a small-scale test track gets the same economies as building a full-length track.

** - In his post he calls the maximum G-forces experienced by Hyperloop "lateral" G-forces. As if they're going to install giant magnets under the track to keep the pods vertical during curves in order to torture the passengers rather than just letting them bank as all of the forces on the capsule will be pushing them to do. The bad math on curve radii is icing on the cake. The "financial" comments are a hoot too. I could do a complete breakdown if you want, although since it's such a long post it'd take a while. I have to wonder whether he just skimmed the document or chose to ignore it. Like the comments about elevation changes not being covered, when large portions of the document were dedicated to the importance of varying the tower heights to smooth the vertical curve radius, the need for tunnels in certain points to avoid excessive vertical acceleration, etc.

Re:.. pressurized to minimize the G forces effects

[nukenerd]

The author doesn't know what G-forces are, that's all.

This is the root of problem with schemes like this. They are hyped up by people who don't have a technical clue, and decided upon by politicians ditto.

Re:.. pressurized to minimize the G forces effects

[Anonymous Coward]

F = V^2 / r is the problem at hand. Get a tight corner and high speed and you'll be squished. Sounds fun to me. I would pay more for a 3G ride... for a few minutes. One hour? They might need to have a "No eating 8 hours before hand" like with surgery.

Leaky pod?

[Legal.Troll]

No concerns.

Re:.. pressurized to minimize the G forces effects

[gweihir]

You just failed Physics 101. Speed has no relation to g-forces, unless you are going in a curve.

Re:.. pressurized to minimize the G forces effects

[Crowd Computing]

Yes, I know it's about acceleration. But I'm curious why the hyperloop can't speed up gradually. After all, the G-forces in a jet plane are pretty much bearable unless we're talking about fighter pilots.