typodupeerror

## High Speed Travelator333

Posted by michael
from the umbrella-jousting dept.
Anonymous Award writes "Remember those old Isaac Asimov tales of cities of the future, where everybody walked along on moving sidewalks, sometimes clear across a country? Today's airport travelators have always been disappointingly pale imitations of these, but now in Paris we may be seeing the true birth of this wonderfully dangerous mode of mass transportation. Its already as fast as a bus, but when they can crank them up to motorway speeds... well, lets just say this may have a better chance of having cities designed around it than certain other recent innovations."
This discussion has been archived. No new comments can be posted.

## High Speed Travelator

• #### You know... (Score:4, Interesting)

by Anonymous Coward on Friday July 04, 2003 @08:10AM (#6366583)
When it gets up to a certain speed, the wind resistance against your body will be greater than the friction of the belt against your feet, and you will cease to move forward...
• #### Transition (Score:5, Interesting)

on Friday July 04, 2003 @08:13AM (#6366597)
As mentioned in the article, the most difficult issue is the transition from moving on the walkway and moving on stationary ground.

It seems to me the best solution to this is to have "lanes" in the walkway. The far left lane would move at the maximum speed, whereas successive lanes to the right would be decelerated. When exits were reached, you could easily step to the right to get to a lower speed; the transition between 9km/h and 6km/h is still a transition, but its less than 9km/h to 0km/h.
• #### The problem is for distances _under_ 1 km ?! (Score:3, Interesting)

on Friday July 04, 2003 @08:14AM (#6366611)
----
"The real problem nowadays is how to move crowds; they can travel fast over long distances with the TGV (high-speed train) or airplanes, but not over short distances (under 1km)," he says.
---

How about good ol' walking ?!
• #### Re:Transition (Score:2, Interesting)

<slashdot@joshi.tk> on Friday July 04, 2003 @08:17AM (#6366622) Homepage
Sounds like a nice idea, but people hold on to handrails. You need to have some type of handrails overhead that's short enough for everyone but not too short to be inconvenient for tall people.
• #### Many points of failure? (Score:5, Interesting)

on Friday July 04, 2003 @08:19AM (#6366639)
It would seem to me that the sheer number of moving parts in a kilometre or so of walkway must make the chances of frequent failures pretty high compared to other public transport methods. How fault-tolerant is it? Any French Slashdotters able to answer?

Would be interesting to see some schematics.
• #### Re:The Roads must Roll (Score:4, Interesting)

on Friday July 04, 2003 @08:19AM (#6366640) Homepage
Thanks for reminding me of the title.

What I remember of the story was that they had this rolling road that spanned the USA from east to west, with lanes that went faster and faster. You got on the first slow speed lane, and just walked over to successively faster lanes. The fastest lane was some cool 1950's velocity like 150-300mph.

Some disgruntled workers clipped a lane or two, with expected results.

Nice to see Robert Heinlein's idea making it to reality, now if I could only speak Basic with someone on the moon, or have a farm on Ganymede!

• #### it's mechanical.. (Score:5, Interesting)

on Friday July 04, 2003 @08:22AM (#6366655) Homepage Journal
it's a poor solution..
better would be organic, something like stomach cillia, where the floor doesn't move the length of the journey, but little tiny bits from in place do- not my idea, something I read once.

the individual elements take turns dropping, moving a tiny bit, pushing up again, and moving you a tiny bit... done repeatedly= ya move down the floor- which doesn't move.

less to break down, and spilled drinks and food (as long as they aren't too hot) are actually welcome...

• #### I have been to the future... (Score:2, Interesting)

on Friday July 04, 2003 @08:25AM (#6366670)
...And it's located in the tunnels beneath the Geneve airport. They've got a system like this there, but I'm not sure they run it at the same speed. At least I didn't think it was moving that fast when I used it. Quite fun, atually.
I also use a similar thing in a local supermarket. All you'd have to do is crank up the speed on it to equal the Paris one, but then again, it's slighly elevated and I don't think people like being catapulted from the 2nd floor...

Is this a reinvention of the wheel (Kakakaka! Transportation!) or did I miss something? Prolly the latter, so please releive me of my blissful ignorance.
• #### Expressways (Score:4, Interesting)

on Friday July 04, 2003 @08:27AM (#6366679) Homepage

As an idea, these expressways are a fairly good way of transporting humans. They travel at constant speed, so there should be no obvious difference to the traveller, no matter what the speed is. Of course, in reailty we'd experience air resistence; try sticking your head out of the window on a car going at 70mph. but there may be some way of reducing this in enclosed tunnels, like blowing air at the same velocity as the floor is moving.

In Asimov's vision (I think), the different-speed strips were parallel to each other, not serial like this French version. This meant that you's step to the side to go onto a faster strip, and keep going until you hit the fastest one, which could be several hundred miles an hour. As the differential in speed between the strip you are on and those near is never more than about 1mph, you won't do yourself any serious damage by falling over. see diagram:

---->---7mph->--
---->---8mph->--
---->---9mph->--
etc.

This structure makes them easier to 'network'. The only danger, I suppose, is if a strip breaks then the speed-differential between it and then next one could be massive.

I suppose any serious implementation would use some kind of semiconductor thang to decrease friction, and on a wide scale could be very energy efficient. These things are probably more useful to society than a Segway, but you'd have to design a city around them from the ground up, so I doubt they'll change the way we live just yet.

• #### Re:Expressways (Score:1, Interesting)

on Friday July 04, 2003 @08:32AM (#6366699) Journal
I think the higher speed ones in Asimovs' vision had seats too, for the long distance commute.

Trouble is, I can't see how you get a handrail into these multiple strip senarios, so your chance of causing a pile up increases dramatically.

• #### Re:Transition (Score:4, Interesting)

on Friday July 04, 2003 @08:44AM (#6366751)
Already done, already in Paris, during 1900 universal exposition: a two lanes, two speeds walkway
http://gallica.bnf.fr/scripts/Consultatio nTout.exe ?O=03300029&E=50
• #### Re:You know... (Score:5, Interesting)

on Friday July 04, 2003 @08:47AM (#6366759)
When it gets up to a certain speed, the wind resistance against your body will be greater than the friction of the belt against your feet, and you will cease to move forward...

IANAP either, BUT I just walked to our wind tunnel at university [rau.ac.za], and stood in it. It takes no effort to stay upright up to 50km/h. At 80km/h one has to concentrate on staying upright, didn't go faster than that.
• #### Re:Transition (Score:5, Interesting)

by Anonymous Coward on Friday July 04, 2003 @08:50AM (#6366779)
An easier way to do this woul be to do what they've done recently in Japan to solve this issue. They've got sliding panels as the tread that propels you. Toward the beginning and the end, the panels slide over each other, which slows down the railway. This is because each section of the railway lets a certain number of these sliding panels through per minute, but as they panels lap over each other, the speed needed to let the same number of panels through decreases. This is probably tricky to visualize.

In the middle of the runway, the panels look like this (different numbers to indicate the different individual panels)

11111111111________22222222222________33333333333
________22222222222________33333333333________4444 4444444

(sorry about the multiple _s...I've never had to try and find an alternative for on /. before)
At the ends, they slide together like this:

111111111112222222222233333333333
222222222223333333333344444444444

So that even though the speed slows down, the panels don't squish each other, breaking the machine. I saw it on TV, and the dude was just whipping along the corridor. If they combined this system at a higher pace with the roller system they've got in France, they could probably take the speed up a fair bit.

• #### Re:You know... (Score:3, Interesting)

on Friday July 04, 2003 @09:06AM (#6366850) Homepage Journal
I think you'd actually lose your balance as the friction force would act on your feet whereas the drag force would act on your whole body. Anyway at what speed would the two forces be equal?

drag = 0.5*C*A*D*V^2
where:
C is the drag coefficient
A is the cross section area
D is the density of air
V is the velocity

The frictional force will equal FMg
Where:
F is the coefficient of friction between the walkway and the shoes of the person
M is the mass of the person
g is acceleration due to gravity

Anyway using C = 1, A = 1.4m^2, D = 1.3KgM-3, F = 1, M = 70kg the forces will balance at about 23ms-1 or 51mph
• #### MagLev (Score:2, Interesting)

on Friday July 04, 2003 @09:18AM (#6366946) Journal

Why don't they use something like a maglevel/chairlift. On which individual carriages are propelled (at any acceleration you like :-) down a track that doesn't have the limitation of being flat and straight.

• #### Re:Transition (Score:3, Interesting)

on Friday July 04, 2003 @09:23AM (#6366974)
It seems to me that a better solution would be to have rotating disks at transistion points along the route. This way people could step onto the outer edge of the disk (where the outer angular velocity equals the linear velocity of the belt). They could walk into the center (where the angular velocity is much lower) and then step off into the center hole.

Of course, the problem with this is that the disk would need to be enormously large to make the centripetal force reasonable.

A quick calculation shows that acceleration on the outer edge of a 1000m radius disk that has a angular velocity of 100km/hr is ~130m/s^2. Unfortunately, that is ~13g! To get that down to manageable forces, the disk would need to be at least 10K m in radius (13m/s^2 or ~1.4g).

Since this is just a back of the envelope type of calculation anyway, pehaps someone has a better idea of reducing the forces?
• #### Re:You know... (Score:4, Interesting)

on Friday July 04, 2003 @10:00AM (#6367160)
All the people on the belt should pull enough air along with them so air pumps wont be that necessary.

A basic invention is not dissimilar to a train - you get into a box that has rollers/wheels on the bottom. Internal friction in the wheels/rollers will accelerate the box on the conveyor belt and the box can then be accelerated to whatever speed wanted (extremely fast if in a vacuum). The same effect will slow the box down when it comes off the other end.

Boxes can then be sent back using a travellator that goes the other way, or another idea is to make them collapsible so they can go back under the conveyorbelt.
• #### My idea (Score:2, Interesting)

on Friday July 04, 2003 @10:11AM (#6367222)
A basic invention i just came up with is not dissimilar to a train - you get into a box that has rollers/wheels on the bottom. Internal friction in the wheels/rollers will accelerate the box on the conveyor belt and the box can then be accelerated to whatever speed wanted (extremely fast if in a vacuum). The same effect will slow the box down when it comes off the other end.

Boxes can then be sent back using a travellator that goes the other way, or another idea is to make them collapsible so they can go back under the conveyor belt.

The next question is how to design slip roads and junctions so we can build a whole network of the things.

A sliproad is pretty easy - you just have another conveyor belt going the same speed next to the one you already have and you cross over (either in the box, or in the pedestrian version).

Junctions could be nasty due to the concept of traffic jams. The whole thing would have to be computer controlled with each box knowing its route through the traffic so that traffic jams couldn't happen.
• #### Bahh... Everyone knows Ginger is "IT" ! (Score:3, Interesting)

on Friday July 04, 2003 @10:53AM (#6367476)
[sarcasim]
How can this even get off the ground if future cities are designed around the Segway AKA Ginger? Ginger is the future "Human Transporter" . Ginger is "IT" !. Steve Jobs told me so! There's no place for something like this.
[/sarcasim]

Seriously though, I think the *real* future is in hydrogen fuel cell vehicles (whether they be private cars or public buses) for three reasons. First, that's where all the serious R&D money is going right now. Secondly, they require no great leap of concept and will be more psychologically acceptable to the public (i.e. its just a car with a different engine as opposed to something strange and possibly "dangerous"). Third, other than adding hyrdogen pumps to existing gas stations, they requie no expesive and massive public works project because they can use the current road infrastructure. The gas station problem can be handled by a government regulation on the lines of "if you run a gas station and have more than two pumps, at least one has to be for hydrogen".

Now if they could jack up a fuel cell powerful enough for a jet engine capable of inter-city/cross-country transport, we'd be set.
• #### I try it and it was not a big challenge. (Score:1, Interesting)

by Anonymous Coward on Friday July 04, 2003 @11:15AM (#6367604)
If you follow the instructions it's safe.

Once in the middle part, it's like a normal travelator, and you can walk or don't pay attention.

The accleration phase and the deccelaration is on a carpet of little wheels.
It's like you are on roller and some one pull/retain you by the arm.
If you grip firmly with your hand and your feet flat, there are no problems of stability or any risk to fall.

It's like people who try to drive a bycicle without hand, it's possible but if you bump, the more likely you will fall.

But it was a little bit disapointing, it's not enough speedy, once you are used to the acceleration/decceleration phase, i will like to have a real 30 km/h travelator, that would be fun and more efective to travel quicker.

• #### Re:The Roads must Roll (Score:2, Interesting)

on Friday July 04, 2003 @11:26AM (#6367677)
by Heinlein was one of the first ScFi stories I ever read!

Glad to see it coming to fruition!

Ditto, Although I have not read the book -- this is certainly a major acheivement in the field of trasportation.

Cars should be a thing of past. Think about this: If everyone moved at the same exact speed there would be no accidents. Certainly this travelator uses this principle, but falls a little behind (and thus has to be restricted to certain speeds).

Instead of walking/standing, imagine your personalized bubble (read: no need to keep your feet on ground), being accelerated in to a fast moving pathway (ofcourse motion being calculated in such a way that there will be no collision when entering the fast pathway).

This is what I would like to see come into life.

• #### Re:The Roads must Roll (Score:2, Interesting)

on Friday July 04, 2003 @11:36AM (#6367735)
While I'm at it, one thing that puzzled me about 'The Roads Must Roll' is that the fastest strip (going at 100 mph I think) had restaurants etc. on it.

When I first read the story I assumed they were on massive long looped conveyer belts, which would have made things interesting at the end of the belt when the strip, and all it's attached restaurants etc. would suddenly be hurled round the final drum and spend the return journey upside down, that is if they hadn't been thrown off by the sudden change in momentum (delta V of 200 mph?).

reading it again, heinlein seems to say that the 'Roads' complete a circular circuit - now how in heck would that work?
• #### Re:The Roads must Roll (Score:4, Interesting)

on Friday July 04, 2003 @12:06PM (#6367939) Journal
2 layers. Top layer runs in a circle. The bottom layer looks like our conveyor with hooks to catch the top layer and pull it. It would have to have the capaibility of being pulled back to allow the upper belt to slide incase the conveyor stops.

How is that idea?
• #### Re:Also 'Caves of Steel'? (Score:2, Interesting)

<slas45dxsvadiv.v ... x.com minus berr> on Friday July 04, 2003 @03:12PM (#6368850) Homepage
And Asimov brought up the actual problem you'd run into...not strikers sabatoging the sidewalks, but hot-shot teenagers running around leaping from one to another.

If each strip is only 10 feet wide, and goes up 5 mph each strip...you just know you'd have kids running the 50 yard dash sideways, occasionally causing major accidents.

• #### OW MY FOOT! (Score:2, Interesting)

on Friday July 04, 2003 @03:53PM (#6369050)
If its like the ones at american airports such as detroit, and there are walls on the side that are not moving. I guarentee that eventually your going to run across someone who's foot catches the wall and moving at that speed however fast, is going to break the guys ankle slaming him face first into the crack between the wall and the belt grinding his nose off like a belt-sander.
• #### Toronto has one (Score:2, Interesting)

on Friday July 04, 2003 @04:51PM (#6369295)
There has been one of these at the Spadina subway station in Toronto for years. It works pretty well. They use it between two sections of perpendicular subway tunnel that are extraordinarily far apart. After living in Toronto for 8 years, I would say that the escalators and the moving sidewalk are out of order roughly 30% of the time. They're great when they work, but I have to question the cost affectiveness.

#### Related LinksTop of the: day, week, month.

I have yet to see any problem, however complicated, which, when you looked at it in the right way, did not become still more complicated. -- Poul Anderson

Working...