The Race to Create Elon Musk’s Hyperloop Heats Up(wsj.com)
wsj.com
The Race to Create Elon Musk’s Hyperloop Heats Up
http://www.wsj.com/articles/the-race-to-create-elon-musks-hyperloop-heats-up-1448899356?mod=e2tw
79 comments
Then don't be. There is room for one more transportation system. Money is not a single pot which gets distributed to a number of things. It's a fallacy to think that if hyperloop didn't happen more money would go to other transportation systems.
> And decently fast (200km/h) intercity trains.
Surely you mean 200mph? 200km/h barely qualifies as high-speed rail on old lines in europe, new lines require 250, 350 lines are being rolled out and plans are being drawn for 400 lines in the UK and Russia.
Surely you mean 200mph? 200km/h barely qualifies as high-speed rail on old lines in europe, new lines require 250, 350 lines are being rolled out and plans are being drawn for 400 lines in the UK and Russia.
200km/h would be smoking fast in the US. Sadly.
Almost all Dutch intercity trains run 140km/h, and that's fast enough (it's faster than cars, and goes city center to city center). Of course cities are close together here, but we are in Europe.
I'd certainly call 200km/h "decently fast".
I'd certainly call 200km/h "decently fast".
> Almost all Dutch intercity trains run 140km/h, and that's fast enough
When it's hard to find cities more than 100km apart, sure. And the US already have passenger trains in that range.
> Of course cities are close together here, but we are in Europe.
I quoted what's considered high-speed rail in Europe, I'm sorry that offends you.
> I'd certainly call 200km/h "decently fast".
Not when your cities are 500km apart or more.
When it's hard to find cities more than 100km apart, sure. And the US already have passenger trains in that range.
> Of course cities are close together here, but we are in Europe.
I quoted what's considered high-speed rail in Europe, I'm sorry that offends you.
> I'd certainly call 200km/h "decently fast".
Not when your cities are 500km apart or more.
New high speed railways in Germany are built only for 250km/h: https://en.wikipedia.org/wiki/Wendlingen%E2%80%93Ulm_high-sp...
A specific 80km rail section with a long tunnelled ramp is only built for 250 (which does qualify as high-speed anyway). Germany also has 300km/h rail: https://en.wikipedia.org/wiki/Erfurt–Leipzig/Halle_high-spee...
The trains almost never go that fast, and even if they do, it's for short periods of time. Average speed is the key thing.
Why are we only impressed by megafast trains? They aren't really cost efficient and probably won't be built at all. The best train is the one that exists! 200km/h is already probably reaching. Even 150km/h means you could go Chicago to Cincinatti in 3 hours (vs 4.5 by car) or San Francisco to LA in under 5 hours (vs 6 hours by car). At 5 hours, that beats the hassle of an airplane, IMO.
Why are we only impressed by megafast trains? They aren't really cost efficient and probably won't be built at all. The best train is the one that exists! 200km/h is already probably reaching. Even 150km/h means you could go Chicago to Cincinatti in 3 hours (vs 4.5 by car) or San Francisco to LA in under 5 hours (vs 6 hours by car). At 5 hours, that beats the hassle of an airplane, IMO.
> The trains almost never go that fast
Sure they do. Worldwide, Acela is a peculiar exception, not a rule (and no if you're going to put your train on old low-speed rails and give priority to freight you definitely don't need high-speed trainsets, I'm not going to disagree with that one, turns out only in the US do people do that, go figure)
> Average speed is the key thing.
And the average speed is higher if the train can reach a higher top speed. All of the top average service speeds are high-speed trains: https://en.wikipedia.org/wiki/Land_speed_record_for_rail_veh...
> Why are we only impressed by megafast trains?
Because megaslow trains are pointless for long distances?
> They aren't really cost efficient and probably won't be built at all.
Considering the US's love for trains, I just assume you guys won't build any either way, that's usually a pretty safe bet.
> Even 150km/h means you could go Chicago to Cincinatti in 3 hours (vs 4.5 by car) or San Francisco to LA in under 5 hours (vs 6 hours by car). At 5 hours, that beats the hassle of an airplane, IMO.
When the flight is 1h15~1h30, you'll be a very small minority, the general annoyance of transport and loss of the whole day means flight pretty much always win. Lower that to ~2h30 city center to city center, however, and train might become competitive, especially without security check and with better cabin comfort.
Sure they do. Worldwide, Acela is a peculiar exception, not a rule (and no if you're going to put your train on old low-speed rails and give priority to freight you definitely don't need high-speed trainsets, I'm not going to disagree with that one, turns out only in the US do people do that, go figure)
> Average speed is the key thing.
And the average speed is higher if the train can reach a higher top speed. All of the top average service speeds are high-speed trains: https://en.wikipedia.org/wiki/Land_speed_record_for_rail_veh...
> Why are we only impressed by megafast trains?
Because megaslow trains are pointless for long distances?
> They aren't really cost efficient and probably won't be built at all.
Considering the US's love for trains, I just assume you guys won't build any either way, that's usually a pretty safe bet.
> Even 150km/h means you could go Chicago to Cincinatti in 3 hours (vs 4.5 by car) or San Francisco to LA in under 5 hours (vs 6 hours by car). At 5 hours, that beats the hassle of an airplane, IMO.
When the flight is 1h15~1h30, you'll be a very small minority, the general annoyance of transport and loss of the whole day means flight pretty much always win. Lower that to ~2h30 city center to city center, however, and train might become competitive, especially without security check and with better cabin comfort.
Well, you specifically mentioned trains in Germany. I've ridden quite a few, and I can tell you, they almost never go that fast, and not for long periods of time. With all the stop and go, all the slow tracks, quiet areas, and whatever else, the average speed isn't that high. So in general the US should probably not focus on superfast trains, since they don't pan out usually, but just getting some decent trains that are on-time and reasonably fast.
I will give up my car when the people driving the subways, lightrail, buses, and trams promise not to strike.
The day the subways, lightrail, buses, and trams are run by private enterprises and are not subject to the political whims of the unions and elected officials, then I might consider giving the concept a test run.
The day the subways, lightrail, buses, and trams are run by private enterprises and are not subject to the political whims of the unions and elected officials, then I might consider giving the concept a test run.
In the US in general, strikes are NOT the problem. I do not recall a single strike in the past 20 years or so (In the Boston area).
There are tons of other problems (like outdated cars, frequent equipment issues, etc) - but I doubt a private enterprise would improve things much by itself.
Introducing competitive environment, on the other hand, would.
Introducing competitive environment, on the other hand, would.
Because the transit systems do not have that as a tool. Look at other countries and see that where the system is used by more hostages, the number of times a ransom is demanded anecdotally appears higher.
In the last 15 years for U.S. transit:
* 2005 New York City transit strike
* 2007 Orange County transit strike
* 2010 Spirit Airlines Pilot Strike (U.S.)
What does private enterprise need to improve as it currently stands? The government subsidizes transit to such an extent that private players stay out and any hint of a profitable line is look unfavorably upon by government players that they ban it or try to robustly oppose it; examples include Google Bus', and Jitney's in New York.
In the last 15 years for U.S. transit:
* 2005 New York City transit strike
* 2007 Orange County transit strike
* 2010 Spirit Airlines Pilot Strike (U.S.)
What does private enterprise need to improve as it currently stands? The government subsidizes transit to such an extent that private players stay out and any hint of a profitable line is look unfavorably upon by government players that they ban it or try to robustly oppose it; examples include Google Bus', and Jitney's in New York.
Tl,dr: If the US is going to give up personal driving, it needs fast intercity connects and ubiquitous in-city transportation.
- Subways and light rail are high cost, high visibility, negative return investments for most municipalities.
- Intercity could be trains or a hyperloop, given hyperloop developers' projected cost structures.
- In-city should be buses and, eventually, self-driving quasi-taxi fleets.
----
On the in-city transportation:
Subways are very expensive to build, very expensive to move, and a deficit on their community if the areas in which they're built don't have very high population densities.
See: almost any city in the US with a subway, many cities elsewhere.
----
Light rail, if the tracks are built into existing roads, is a little less expensive to build and move but suffers the same population and planning issues as subways, as well as being an added impediment to traffic and imposing the same commuting inefficiencies on the rider as if they were in a car.
If they're instead given dedicated space, they become much more expensive as extra road lanes must often be built (or easements otherwise negotiated and purchased by municipalities), and they end up much harder to move for want of further easement & road expansion.
The light rail requiring expansion of paved traffic surfaces would also make them less environmentally friendly from the perspective of urban surface radiance.
See: The Arlington/Alexandria, Virginia light rail project most quickly comes to mind.
I'm looping "trams" in here as well because I'm assuming they're electric-line-driven mass transport boxes of some sort. If they're not track-dependent then cost is installation and maintenance of a whole bunch of tram power lines, so cheaper than light rail but still slow to respond to population growth and change.
----
Buses require no tracks, no tunnels, no $5 million train cars, and a route can be switched in a day by putting up a couple new bus stop posts. Bus systems can actually be profitable if local governments don't try to make political wins by drawing expensive bus routes in distant, low-volume rural areas. Buses suffer from traffic like most light rail does.
As an answer to urban congestion, buses are cheap, require almost no new infrastructure, can carry a ton of people, and with kinetic recovery and alternative fuel systems can be very low-impact. When used in higher density areas where personal car parking would be onerous, bus commuting can be quicker than private driving.
See: Lots of bus systems. Stuttgart, Germany's SSB has hybrid buses with kinetic recovery systems improving efficiency by 18%, for example.
Self-driving cars or crowd-shared cars (e.g. Car2Go) provide gap-filling where bus routes don't conveniently link up.
- Subways and light rail are high cost, high visibility, negative return investments for most municipalities.
- Intercity could be trains or a hyperloop, given hyperloop developers' projected cost structures.
- In-city should be buses and, eventually, self-driving quasi-taxi fleets.
----
On the in-city transportation:
Subways are very expensive to build, very expensive to move, and a deficit on their community if the areas in which they're built don't have very high population densities.
See: almost any city in the US with a subway, many cities elsewhere.
----
Light rail, if the tracks are built into existing roads, is a little less expensive to build and move but suffers the same population and planning issues as subways, as well as being an added impediment to traffic and imposing the same commuting inefficiencies on the rider as if they were in a car.
If they're instead given dedicated space, they become much more expensive as extra road lanes must often be built (or easements otherwise negotiated and purchased by municipalities), and they end up much harder to move for want of further easement & road expansion.
The light rail requiring expansion of paved traffic surfaces would also make them less environmentally friendly from the perspective of urban surface radiance.
See: The Arlington/Alexandria, Virginia light rail project most quickly comes to mind.
I'm looping "trams" in here as well because I'm assuming they're electric-line-driven mass transport boxes of some sort. If they're not track-dependent then cost is installation and maintenance of a whole bunch of tram power lines, so cheaper than light rail but still slow to respond to population growth and change.
----
Buses require no tracks, no tunnels, no $5 million train cars, and a route can be switched in a day by putting up a couple new bus stop posts. Bus systems can actually be profitable if local governments don't try to make political wins by drawing expensive bus routes in distant, low-volume rural areas. Buses suffer from traffic like most light rail does.
As an answer to urban congestion, buses are cheap, require almost no new infrastructure, can carry a ton of people, and with kinetic recovery and alternative fuel systems can be very low-impact. When used in higher density areas where personal car parking would be onerous, bus commuting can be quicker than private driving.
See: Lots of bus systems. Stuttgart, Germany's SSB has hybrid buses with kinetic recovery systems improving efficiency by 18%, for example.
Self-driving cars or crowd-shared cars (e.g. Car2Go) provide gap-filling where bus routes don't conveniently link up.
Having lived for a few years in Europe now, I can tell you that thoughtful city planning is totally possible at critical densities, and highly worth it. The quality of life for citizens is highly improved by having first of all, walkable cities. Every bus station, 4-lane road, and parking lot within a city makes it less walkable. Since many European cities were already quite large well before automobiles, they inherit their walkability through their centuries of necessity. It is going to be hard to push many US cities towards that density threshold with just buses and taxis. I'll respond to some of your points.
<quote>Subways and light rail are high cost, high visibility, negative return investments for most municipalities.</quote>
That's absolutely fine. The government and public infrastructure is not really meant to turn a profit. They are funded through tax dollars since they have positive externalities for all citizens. It's just usually the case that pay-per-use is just too expensive to bootstrap effectively. We need to rid ourselves of this mental model. The government needs to spend money to make the public system work, hands down. And that means taxes. And even if you don't use the subway, you benefit that other people do (because they don't have their huge cars taking up your road space and parking space!)
<quote> Subways are very expensive to build, very expensive to move, and a deficit on their community if the areas in which they're built don't have very high population densities. </quote>
So what. It works in NYC and in pretty much every major European city. These are old, well-established cities where digging is fraught with peril. As I mentioned before, the problem is that US cities usually aren't dense enough.
<quote> If they're instead given dedicated space, they become much more expensive as extra road lanes must often be built (or easements otherwise negotiated and purchased by municipalities), and they end up much harder to move for want of further easement & road expansion. </quote>
Well, considering that public transport is generally more space efficient than autos, replacing a lane with a tram or light rail track should actually increase capacity. Why do we keep thinking that it has to be additive (i.e. in addition to existing roads)? No wonder people balk.
<quote> Buses require no tracks, no tunnels, no $5 million train cars, and a route can be switched in a day by putting up a couple new bus stop posts. Bus systems can actually be profitable if local governments don't try to make political wins by drawing expensive bus routes in distant, low-volume rural areas. Buses suffer from traffic like most light rail does. </quote>
That's great, let's have more buses! (Although I disagree that routes into rural areas are for political points.) But buses won't be enough. Subways are unbelievably efficient once they are in place (you can fit literally 500 people in one train!), and again, they require critical density. We need to get there, and buses are step along the way.
Also, BIKES and BIKE lanes. Nothing really beats walking or riding a bike to work on a nice day. Hands down! Try Copenhagen.
<quote>Subways and light rail are high cost, high visibility, negative return investments for most municipalities.</quote>
That's absolutely fine. The government and public infrastructure is not really meant to turn a profit. They are funded through tax dollars since they have positive externalities for all citizens. It's just usually the case that pay-per-use is just too expensive to bootstrap effectively. We need to rid ourselves of this mental model. The government needs to spend money to make the public system work, hands down. And that means taxes. And even if you don't use the subway, you benefit that other people do (because they don't have their huge cars taking up your road space and parking space!)
<quote> Subways are very expensive to build, very expensive to move, and a deficit on their community if the areas in which they're built don't have very high population densities. </quote>
So what. It works in NYC and in pretty much every major European city. These are old, well-established cities where digging is fraught with peril. As I mentioned before, the problem is that US cities usually aren't dense enough.
<quote> If they're instead given dedicated space, they become much more expensive as extra road lanes must often be built (or easements otherwise negotiated and purchased by municipalities), and they end up much harder to move for want of further easement & road expansion. </quote>
Well, considering that public transport is generally more space efficient than autos, replacing a lane with a tram or light rail track should actually increase capacity. Why do we keep thinking that it has to be additive (i.e. in addition to existing roads)? No wonder people balk.
<quote> Buses require no tracks, no tunnels, no $5 million train cars, and a route can be switched in a day by putting up a couple new bus stop posts. Bus systems can actually be profitable if local governments don't try to make political wins by drawing expensive bus routes in distant, low-volume rural areas. Buses suffer from traffic like most light rail does. </quote>
That's great, let's have more buses! (Although I disagree that routes into rural areas are for political points.) But buses won't be enough. Subways are unbelievably efficient once they are in place (you can fit literally 500 people in one train!), and again, they require critical density. We need to get there, and buses are step along the way.
Also, BIKES and BIKE lanes. Nothing really beats walking or riding a bike to work on a nice day. Hands down! Try Copenhagen.
Reminders about the initial criticisms of the Hyperloop plan, which I do not see rebutted anywhere in this article:
* It's riotously expensive, far more so than the white paper indicates; simply building the elevated track overpasses at the costs listed in the white paper would imply a revolution in civil engineering.
* Door-to-door transit times are within the same ballpark as HSR, because it's not possible to terminate Hyperloop tracks downtown in LA or SF; ROW issues put them roughly an hour outside each city.
* Hyperloops will have approximately the same security concerns as airplanes --- they fail more dangerously than normal trains --- and so will have TSA-style security checks, further slowing travel.
* At the speeds Hyperloop advocates claim, there is virtually no tolerance for bends on tracks without inducing nausea.
* It's riotously expensive, far more so than the white paper indicates; simply building the elevated track overpasses at the costs listed in the white paper would imply a revolution in civil engineering.
* Door-to-door transit times are within the same ballpark as HSR, because it's not possible to terminate Hyperloop tracks downtown in LA or SF; ROW issues put them roughly an hour outside each city.
* Hyperloops will have approximately the same security concerns as airplanes --- they fail more dangerously than normal trains --- and so will have TSA-style security checks, further slowing travel.
* At the speeds Hyperloop advocates claim, there is virtually no tolerance for bends on tracks without inducing nausea.
Great! I can't wait to see the pieces of this puzzle that turn out to be much harder than they first appear, and the pieces that turn out to be much easier.
No matter the final outcome, we'll learn tons, which is a win.
No matter the final outcome, we'll learn tons, which is a win.
I know Hyperloop has a ton of naysayers -- partly because the initial price tag of $6 billion is most likely a severe underestimation -- but...
It has the potential to make a tremendous impact on society, much more so than self-driving cars in my opinion. Just as a simple example, imagine what would happen to the Bay Area housing market if people could live in a ~300 mile radius and still get to work in downtown SF in less than 30 minutes.
It has the potential to make a tremendous impact on society, much more so than self-driving cars in my opinion. Just as a simple example, imagine what would happen to the Bay Area housing market if people could live in a ~300 mile radius and still get to work in downtown SF in less than 30 minutes.
I think the only game changing thing about the hyperloop is that it is getting rich people excited about public transit. I mean, my guess is that we're never going to get a SF <-> LA transit path that is faster than a airline with a "skip the security" pass; I don't believe that the hyperloop as envisioned will never be built.
I know that sounds trivial... but it's not. Public transit is a failure in America in large part because wealthy people, even wealthy people who support public transit in general, don't want public transit near them.
I know that sounds trivial... but it's not. Public transit is a failure in America in large part because wealthy people, even wealthy people who support public transit in general, don't want public transit near them.
> even wealthy people who support public transit in general, don't want public transit near them.
This seems very odd to me. Here in the Netherlands, housing prices actually increase when there's good public transport. In the north of Amsterdam a new metro line is being built, which is already causing an increase in housing prices there.
This seems very odd to me. Here in the Netherlands, housing prices actually increase when there's good public transport. In the north of Amsterdam a new metro line is being built, which is already causing an increase in housing prices there.
It's odd but true.
For instance, biking to school or work in the US means you are kinda poor or a cheapskate (not for everyone, and not in densely populated cities such as DC/Arlington, SF, NYC and Perhaps Boston)
On the other hand, in Europe I've seen deans biking to school and the feeling is exactly the opposite ("wow that's so cool!")
Sorry for generalizing, but that was what I saw, having lived on both sides
For instance, biking to school or work in the US means you are kinda poor or a cheapskate (not for everyone, and not in densely populated cities such as DC/Arlington, SF, NYC and Perhaps Boston)
On the other hand, in Europe I've seen deans biking to school and the feeling is exactly the opposite ("wow that's so cool!")
Sorry for generalizing, but that was what I saw, having lived on both sides
A reference for Toronto: http://www.metronews.ca/views/toronto/condo-trends/2015/02/1...
Really? Have you ever tried to get from the train station of, say, Blaricum or Bloemendaal to anywhere else there? 'Wealthy' people don't live in houses whose prices are affected by availability of public transport, in the Netherlands. (OTOH I wouldn't say that they 'don't want PT near them', but then again that's not really true for other places either).
This is true, but we're talking SF & LA here, metropolitan areas. Blaricum is better compared to something like the Hamptons. There is no public transport because there's space to park cars, so public transportation is not necessary and it's impractical since the population is spread out.
The Apollobuurt in Amsterdam is also full of rich people and yet there's a lot of public transportation. The people living there are not against public transportation though.
The Apollobuurt in Amsterdam is also full of rich people and yet there's a lot of public transportation. The people living there are not against public transportation though.
Yep. Here in SF, housing is more expensive when it's near a subway station.
Public transit is not a failure in the US, it's just very uneven and it's a big country. Moreover, the US especially suffers from the "lost decades" of urban decay through the mid 20th century. There was a sweet spot for initial public transit infrastructure investment around the turn of the 20th century and a lot of cities in the US missed it, with a much bigger hill to climb today.
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Public transport in the US is generally a failure because we try to build static systems in low-to-moderate density areas with dynamic population change.
I.e. putting a $30 million light rail system in a "business corridor", then watching market forces move businesses away from it 5 years later and wondering why no one rides the trams.
I.e. putting a $30 million light rail system in a "business corridor", then watching market forces move businesses away from it 5 years later and wondering why no one rides the trams.
I should say hundreds of millions. This[1], for example.
Munis sell these projects on the "expectations that the corridors will attract much economic growth," but the finished product has shown not to be a reliable multiplier of community investment and development.
1: https://en.wikipedia.org/wiki/Pike_Transit_Initiative
Munis sell these projects on the "expectations that the corridors will attract much economic growth," but the finished product has shown not to be a reliable multiplier of community investment and development.
1: https://en.wikipedia.org/wiki/Pike_Transit_Initiative
Hyperloop doesn't solve that problem. You can't have a hyperloop station in every town in a 300 mile radius.
5 years ago you probably would have said "we can't have a self driving car... there is <problem1> that we can't surmount." Yet, now we are on the brink of it. Hell, even at the start of this year I would have laughed if you said we will have aerial drones delivering amazon goods. Yet, here we are with a pretty impressive POC from amazon. we can merge onto a freeway why can't we merge these hyperloop pods so we can have many stops?
Because deceleration takes time, unless you want to be flattened to the front of the vehicle. The more stops you have, the lower the overall speed will be at which this thing operates. High-speed trains in Germany that can drive up to 350 km/h often only average around 120 km/h over their total distance because with stops in between you spend a lot of time accelerating and decelerating. And where stops are more frequent you can't even reach the full speed since you have to start breaking already before you're done accelerating.
There's nothing inherent in physics that prevents self-driving cars, but unless you want to jump out of a moving hyperloop pod, it has to come to a stop and accelerate again; and it does so slowly enough not to kill its passengers.
There's nothing inherent in physics that prevents self-driving cars, but unless you want to jump out of a moving hyperloop pod, it has to come to a stop and accelerate again; and it does so slowly enough not to kill its passengers.
I think we can tolerate about 0.5g of deceleration, which shifts the direction of gravity by 30 degrees. So, about 5ms⁻². To get to interesting speeds such as 500ms⁻¹ (about mach 1.5), it would take 100 seconds, and 25,000m (25km, or about 15 miles). Assuming maximum acceleration and deceleration, it would take 3 minutes and 20 seconds to travel over 50km. At first approximation, separating stations by 50km looks doable.
But that's not the whole story. If we have intermediate stations at all, we need to ensure all cars have the same speed when they get to share the same main tube. We need acceleration tubes the same way we need acceleration lanes in regular roads. (How to plug those tubes to the main one is left as an exercise to whoever builds this.) Anyway, those tubes need to be 25km long.
But that doesn't mean they have to be separated by that much. You could have a station every 5km if you're willing to run 5 acceleration lanes in parallel (and pay for them).
This gets even easier once you get close to the destination: even in the main tube, cars need to decelerate, starting at 25km from their destination. 10km away for instance, the speed is already down to a little over 300ms⁻¹. To join the lane at that point, you need only 10km to accelerate. Likewise, if you need to join 5km before the destination, you need to accelerate for 5km as well.
In other words, you could very well have stations as close as 5, 10, or 20km from the urban centre. You won't go very fast, but remember that at those speeds and accelerations, it's going to take less than 5 minutes anyway.
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If trains didn't have to stop at every station, and used acceleration and deceleration rail-roads where appropriate, their average speed would be much higher. First, they can't for 2 reasons: rail-roads are expensive and take land (so does an Hyperloop tube). Second, passengers need to go in and out. This means many stops for the same train. Hyperloop's uses individual, so it doesn't have that problem.
But that's not the whole story. If we have intermediate stations at all, we need to ensure all cars have the same speed when they get to share the same main tube. We need acceleration tubes the same way we need acceleration lanes in regular roads. (How to plug those tubes to the main one is left as an exercise to whoever builds this.) Anyway, those tubes need to be 25km long.
But that doesn't mean they have to be separated by that much. You could have a station every 5km if you're willing to run 5 acceleration lanes in parallel (and pay for them).
This gets even easier once you get close to the destination: even in the main tube, cars need to decelerate, starting at 25km from their destination. 10km away for instance, the speed is already down to a little over 300ms⁻¹. To join the lane at that point, you need only 10km to accelerate. Likewise, if you need to join 5km before the destination, you need to accelerate for 5km as well.
In other words, you could very well have stations as close as 5, 10, or 20km from the urban centre. You won't go very fast, but remember that at those speeds and accelerations, it's going to take less than 5 minutes anyway.
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If trains didn't have to stop at every station, and used acceleration and deceleration rail-roads where appropriate, their average speed would be much higher. First, they can't for 2 reasons: rail-roads are expensive and take land (so does an Hyperloop tube). Second, passengers need to go in and out. This means many stops for the same train. Hyperloop's uses individual, so it doesn't have that problem.
> I think we can tolerate about 0.5g of deceleration
Untrained human beings can handle minutes of linear deceleration (perpendicular to the spine) at 12 g, and at least a second at 25 g. Strapped, mind you. And the limits are higher in backwards-facing seats (eyeballs-in is ~17 g untrained) with the additional advantage that very little strapping is needed.
Untrained human beings can handle minutes of linear deceleration (perpendicular to the spine) at 12 g, and at least a second at 25 g. Strapped, mind you. And the limits are higher in backwards-facing seats (eyeballs-in is ~17 g untrained) with the additional advantage that very little strapping is needed.
to be fair the test that showed a lower bound on survive-ability caused the fellow eye damage. (wikipedia says it was measured at a peak "eyeball out" g-force of 46.2g and 25g for 1.1 seconds.)
I'd say 1-2g over a span of a few min might be tolerable by the general population but might not be need to be researched for suitability for children, the elderly, and the disabled.
I'd say 1-2g over a span of a few min might be tolerable by the general population but might not be need to be researched for suitability for children, the elderly, and the disabled.
Yeah, but that's quite rough. I picked 0.5g because that's close to what you get during an airliner take off.
> Yeah, but that's quite rough.
Even that's a bit of an understatement.
> I picked 0.5g because that's close to what you get during an airliner take off.
You don't get any more than that even during landing?
Even that's a bit of an understatement.
> I picked 0.5g because that's close to what you get during an airliner take off.
You don't get any more than that even during landing?
Not that I recall, though I wouldn't bet on it. Maybe it goes up to 0.7. Definitely less than 1g, though.
For reference, I can easily decelerate harder than that in my car.
For reference, I can easily decelerate harder than that in my car.
There are a lot of strategies for handling this. One of which is, accelerate the pods on a separate, shorter (semi-circular?) track before merging into the main "pod stream". Similarly, decelerate on a separate, shorter (semi-circular?) track. There was some prototype (or theory) of this discussed in a link on HN several months ago in which a Chinese train station accelerated (or decelerated, I forget) a car to match the speed of a passing train to append that car to the train as it went by.
Just because you need to accelerate and decelerate doesn't mean you need to do it on the same shared track as the main line.
Just because you need to accelerate and decelerate doesn't mean you need to do it on the same shared track as the main line.
In the same spirit, small pods allow far more flexibility than a bus. With small enough pods, i stop at my destination only, rather than every destination that anyone needs. I'd guess 4 or 6 is a useful size, about the same as cars.
Just to point out that there have been solutions to the acceleration/deceleration problem in the past:
https://en.wikipedia.org/wiki/Slip_coach
Not sure if something like that would be practical in this instance, but never count out human ingenuity.
https://en.wikipedia.org/wiki/Slip_coach
Not sure if something like that would be practical in this instance, but never count out human ingenuity.
4 years ago I was telling people we would have self driving cars in 5 years. So I'm very pleased with the progress.
It remains to be seen how effective pumping can be, but as envisioned hyperloop is a point to point system. Switches are very difficult and must be done at low speed a) because of the slipstream disruption and b) because branching greatly increases the interior volume of an enclosed tubeset. It can be done.. but it's a level above the basic infrastructure.
It remains to be seen how effective pumping can be, but as envisioned hyperloop is a point to point system. Switches are very difficult and must be done at low speed a) because of the slipstream disruption and b) because branching greatly increases the interior volume of an enclosed tubeset. It can be done.. but it's a level above the basic infrastructure.
You can't have it in every town, but you could hit a bunch. And probably not 30 minutes, but maybe 1.5 hours.
Chicago's train system has 241 stations and carries 300k people a day. The furthest station is 62 miles from Chicago.[1] Takes more like 1hr 40 min. New York's train system has to be more more active.
1-Motorola was dumb enough to build a campus out there and then never used it.
Chicago's train system has 241 stations and carries 300k people a day. The furthest station is 62 miles from Chicago.[1] Takes more like 1hr 40 min. New York's train system has to be more more active.
1-Motorola was dumb enough to build a campus out there and then never used it.
I'd say Hyperloop is like normal high-speed rail; you have a few main stations, and then supplement links to those with metro and light rail services.
300 miles in 30 minutes is extremely challenging to do with a spoke-and-hub model. Anyone who rides transit regularly will tell you that waiting at transfer stations can easily overwhelm actual in transit time.
So, changing the Bay area housing market is a "much more tremendous impact" than self driving cars?
Maybe you haven't thought this through. Self driving cars are likely to create world wide significant changes to mass mobility. The bay area is a drop in the bucket in comparison.
Maybe you haven't thought this through. Self driving cars are likely to create world wide significant changes to mass mobility. The bay area is a drop in the bucket in comparison.
I doubt it will be like current rail systems with multiple stops. There will probably be a very few stops, likely once every hundred miles or so. Getting to downtown SF within 30 minutes is unlikely for the vast majority of people within that 300 mile radius, Hyperloop or not.
Too bad I can't think of anywhere within 300mi that is both (a) large enough to justify a hyperloop stop and (b) isn't an awful hellhole (Fresno). Maybe east of Sacramento?
Look at the history of the rail network and see how cities were made (or undone) by where rail stations were placed.
hyperloop will not solve this problem just as any FIXED point transportation system cannot. Autonomous driving will serve far more people where they want and when they want than any fixed point system. Autonomous buses can move people in large numbers and is infinitely adjustable to changes in usage patterns
Now it might be possible that something like this could reduce the need for short hop flights. Even if it did not I would put both end points onto existing airports to take advantage of the existing infrastructure that already serves them.
tl;dr fixed point to point fails long term
Now it might be possible that something like this could reduce the need for short hop flights. Even if it did not I would put both end points onto existing airports to take advantage of the existing infrastructure that already serves them.
tl;dr fixed point to point fails long term
I don't think it matters which one is better - each has a niche to fill. I would much rather hop on a train and be in LA or Seattle in an hour, than get a self-driving car and be there in 6+. But for short distance, cars or a slower, more traditional public are the better option (mainly because you can't have high-speed lines to carry people a few blocks at a time)
> "The pod has been pressurized to minimize the G forces effects on a passenger"
Anyone's got an idea what they meant with that?
Anyone's got an idea what they meant with that?
They're are trying to communicate, in a humorous way, that they have absolutely no grasp of physics and will report anything that sounds cool, and thus are best ignored if you're looking for actual news and facts about a project like this.
That's my take, at least ...
That's my take, at least ...
Most interviews I've seen with project leads on the Hyperloop, they explain that they pressurize the pods to counter the vacuum in the tube, and relate it to how airplanes are pressurized. I imagine the author mixed that and a discussion of acceleration mixed together.
That Markov's chains are almost ready to take over this journalist's job ...
> Suprastudio’s students suggested pods pressurized like airplanes to reduce G forces
They even put it in there twice.
They even put it in there twice.
They could put it in as many times as they like, it doesn't make any sense.
You would feel less airsick if the pressure in an airplane cabin was the same as on ground. I think they mean that Hyperloop will maintain the outside pressure inside the pod (not a smaller one), and that will reduce acceleration sickness compared to airplane travel.
https://en.m.wikipedia.org/wiki/G-suit
I guess it's the same concept.
I guess it's the same concept.
That makes no sense, the point of pressurising a G-suit is to physically press on the pilot's lower body and drive blood towards the upper body, think adaptive high-pressure compression stocking.
Pressurising the cabin can have no such effect.
Plus the point of G-suit is high-G manoeuvres, not linear acceleration or deceleration: untrained humans can handle 17g eyeballs in and 12g eyeballs out for several minutes versus instants of 4~6 g along other axis, Stapp's work demonstrated that properly restrained humans could walk away from 46G eyeballs out (decelerating while facing forwards)
Pressurising the cabin can have no such effect.
Plus the point of G-suit is high-G manoeuvres, not linear acceleration or deceleration: untrained humans can handle 17g eyeballs in and 12g eyeballs out for several minutes versus instants of 4~6 g along other axis, Stapp's work demonstrated that properly restrained humans could walk away from 46G eyeballs out (decelerating while facing forwards)
But we actually may use a G-seats. You enter the seat, it wraps around you. It may break your neck on sudden deceleration though.
> But we actually may use a G-seats.
For what purpose? A souped up train isn't going to do high-g manoeuvres.
> It may break your neck on sudden deceleration though.
The only deceleration for which that'd happen is an explosive one where you'd dismantle the carriage into a wall (and even then it's unlikely to break your neck), and a broken neck would be the least of your worries.
For what purpose? A souped up train isn't going to do high-g manoeuvres.
> It may break your neck on sudden deceleration though.
The only deceleration for which that'd happen is an explosive one where you'd dismantle the carriage into a wall (and even then it's unlikely to break your neck), and a broken neck would be the least of your worries.
With rail - particularly these days when it's practical to work on trains - it's not really the speed, it's the capacity. And Hyperloop's capacity advantage seems to come solely from the assumption that their cars will be allowed to run as close as buses or trams or lorries.
We allow lorries to run at 56mph less than a meter nose-to-tail, with a human at the controls. Yet we require signalling blocks that put miles of clear air between two successive trains even when automatically operated. We could make rail vastly more economic overnight if we simply allowed it to operate at the same safety levels that we accept for road traffic.
We allow lorries to run at 56mph less than a meter nose-to-tail, with a human at the controls. Yet we require signalling blocks that put miles of clear air between two successive trains even when automatically operated. We could make rail vastly more economic overnight if we simply allowed it to operate at the same safety levels that we accept for road traffic.
The mass and stopping distance of trains is what dictates the length of the space, so we are already operating at the 'same safety levels that we accept for road traffic'.
It's all based on the friction between the vehicle and the surface, in road vehicles that's typically asphalt and rubber and stopping distances are relatively short because of reduced mass. In trains the materials are steel and slightly harder steel and stopping distances are much larger, especially when the rails are wet.
A loaded freight train running 55 Mph will take more than a mile to come to a full stop. A passenger train doing 100 Mph takes 750 meters to stop with emergency brakes applied. This will lead to lots of people being wounded due the fact that trains don't normally have seatbelts, unsecured overhead luggage and people standing if the train is relatively full.
Trains also can't evade, they're tied to the rails.
It's all based on the friction between the vehicle and the surface, in road vehicles that's typically asphalt and rubber and stopping distances are relatively short because of reduced mass. In trains the materials are steel and slightly harder steel and stopping distances are much larger, especially when the rails are wet.
A loaded freight train running 55 Mph will take more than a mile to come to a full stop. A passenger train doing 100 Mph takes 750 meters to stop with emergency brakes applied. This will lead to lots of people being wounded due the fact that trains don't normally have seatbelts, unsecured overhead luggage and people standing if the train is relatively full.
Trains also can't evade, they're tied to the rails.
It's not the same level. You're quite right that stopping distances are longer but we don't require road traffic to be its full stopping distance apart (you have to be much much closer before you'll get stopped for tailgating), and we do see much higher accident rates for buses and other road traffic than for trains as a result.
Exactly, buses and road traffic have higher accident rates than trains (and aircraft) and this has everything to do with how those means of transportation are being operated. Rail and aircraft operators are companies that take responsibility for the lives of a large number of people and that typically have a long term view, as in, they'd like to be in business in half a century or more.
Tourbus operators (not the same as public transport) are responsible for a large number of the road traffic accidents involving buses, public transport involving buses is involved in accidents at a much lower rate. The reasons are: tourbuses tend to go faster, drive much longer distances (exhaustion), drive routes that are less safe to begin with and so on.
The way the rail industry deals with a capacity problem on a line is not to send more trains with a decreased train-to-train spacing but simply to send longer trains.
You can't really make longer buses beyond a certain maximum length due to the fact that the minimum turning radius of roads is a very small fraction of the minimum turning radius of a train.
Tourbus operators (not the same as public transport) are responsible for a large number of the road traffic accidents involving buses, public transport involving buses is involved in accidents at a much lower rate. The reasons are: tourbuses tend to go faster, drive much longer distances (exhaustion), drive routes that are less safe to begin with and so on.
The way the rail industry deals with a capacity problem on a line is not to send more trains with a decreased train-to-train spacing but simply to send longer trains.
You can't really make longer buses beyond a certain maximum length due to the fact that the minimum turning radius of roads is a very small fraction of the minimum turning radius of a train.
Thinking about it I guess the more relevant question is: can the "hyperloop" stop faster than a train? If not, why should we let them run at anything like the capacity Musk claims?
A train is not constrained in the same way that the hyperloop is. This is both a good thing and a bad thing depending on what happens. Presumably the remaining air between two hyperloop capsules will be compressed prior to impact reducing the deceleration to something more manageable.
Why do we insist on character worship. Hyperloop is not his idea - it's a totally obvious idea that has popped up many times since the 1800s:
https://en.wikipedia.org/wiki/Hyperloop#Historical
Compressing the air in front of the capsule is not some fantastic stroke of genius - it's trivially obvious.
All he has done is drawn our attention to a really good idea.
All he has done is drawn our attention to a really good idea.
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The political implications tied to self-driving cars are all scary.
The political implications tied to self-driving trains are not.
The difference being the rails that bind and inhibit true autonomy.
An internet of two-ton things hurtling at 60+ MPH should not be an idea tossed about dismissively. It should at least be locked into track systems, or loops as training wheels, for baby's first sentient AI.
The political implications tied to self-driving trains are not.
The difference being the rails that bind and inhibit true autonomy.
An internet of two-ton things hurtling at 60+ MPH should not be an idea tossed about dismissively. It should at least be locked into track systems, or loops as training wheels, for baby's first sentient AI.
Those 'two-ton things' are already hurtling at 60+ MPH with human drivers, who are distracted by cell-phones, radio, birds, etc. or are under the influence of something. I find the thought of human drivers being replaced by AI very comforting to be honest.
You know what's really scary?
Humans driving two-ton things at 60+ MPH.
Humans driving two-ton things at 60+ MPH.
But we don't need hyperloop. We need decent subways, lightrail, buses and trams. And decently fast (200km/h) intercity trains. We don't lack the technology or the engineering, we lack the political will. Pissing away billions on more techno fantasy is just a distraction while the number of cars and parking lots and freeways just keeps on growing, accreting ever more, little by little, like it has for the past 60 years in the US. The layout of and density of US cities is already profoundly inefficient due to streets, parking lots, and freeways.
A lot of comments here seem to be betting big on self-driving cars, like somehow magic chariots will appear from the sky and whisk us away to fairy land where we never have to look at a stranger or sit in a seat next to someone we don't know, or god, touch a railing! And they'll just as easily disappear into the ether where they require neither maintenance nor upkeep, storage, or cleaning. Apparently these self-driving cars will also run on magic engines that are somehow going to be more efficient than electric light rail or subway, or god forbid, a bike.