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# Non-Stop Subway.

Keep the trains moving all the time.
 (+26, -6) [vote for, against]

Stopping and starting subway trains takes a lot of energy, it also reduces the total throughput of the system. This system keeps the trains moving at full speed and just accellerates and decellerates the passengers.

The train station is a large horizontal rotating disk. Customers enter and exit through escalators and elevators at the center. Around them they see a circular room with doors around the edge marked with all the destinations available on that line. The passenger passes through the door into a small capsule with four seats and a small standing/ package space.

When a train approaches the station, the doors to any occupied capsule close and the capsule slides outward on the disk. The outer rim of the disk is travelling at the same speed as the train, so as the train passes, the capsule is slipped into a slot. When the destination for the capsule is reached the capsule slips out to the rotating disk of that station, and is cranked into the center where the doors open into the central room.

The passenger then walks to the elevator and rises up to the street.

 — Galbinus_Caeli, Apr 20 2006

Scientific American 1905 http://www.endex.co...8/SciAm19050318.htm
...the train shall not stop, and we are forced to use a slowly-rotating loading-platform... [xaviergisz, Apr 20 2006]

US patent 3,727,558 http://patft.uspto....558&RS=PN/3,727,558
transport system with continuously moving platform [xaviergisz, Jul 09 2006]

Non-Stop train http://www.carectom...in-that-Never-Stops
[MisterQED, Jul 02 2008]

I like this. Assume that the station is 1/4 mile radius, or 440 yards and revolving at 1 revolution/minute. Then the outside rim is moving at 2x440xpi =2764 yards/minute, or 94mph - a decent speed for an underground train.
 — hippo, Apr 20 2006

Cute idea. [+]
 — st3f, Apr 20 2006

We still have a lot of els (where the subway runs above ground on an elevated track) in the outer boroughs here. I have visions of one of these capsules coming unglued and flying across the Bronx rooftops.
 — DrCurry, Apr 20 2006

 This idea is already in use at the small-scale at least for loading water-based amusement park rides, and works well.

Centrifugal force will likely be an issue at those speeds, but you could deal with this by shaping this platform like a bowl.
 — Worldgineer, Apr 20 2006

 "Odd as it may seem, we have subways for our convenience, not that of the engineers." Well, the passengers do get shorter travel times as the train does not have to stop.

I think Worldgineer is right about the forces and I don't think a bowl is sufficient for hippo's example. A quick back of eyelid calculation is telling me that the outside of the platform would be pulling about 5g.
 — st3f, Apr 20 2006

Passengers also get to enter their capsule as soon as they enter the station, and don't have to pay any attention until the doors open at their destination.
 — Galbinus_Caeli, Apr 20 2006

 [st3f] I think hippo is a bit optimistic about the speed. 30mph is probably more realistic.

And the platform itself would not have to be a bowl, the capsules could be on davats instead.
 — Galbinus_Caeli, Apr 20 2006

 And the energy saved could be used to power the rotating discs.

Oh, wait...
 — egbert, Apr 20 2006

The power requirements might not be as bad as it seems. The disk rotates at a constant rate, and the trains run at a constant rate, so fewer losses from starting and stopping.
 — Galbinus_Caeli, Apr 20 2006

As a New Yorker I like any idea that means a faster train ride.
 — Goceph, Apr 20 2006

 [xaviergisz] My idea is different because it is computerized.

 Actually it is a bit different because different capules would go to different stations.

Thanks for the links though. It is interesting that the Brooklyn Bridge was considered antiquated over a century ago.
 — Galbinus_Caeli, Apr 21 2006

 //affect poeple panhandling or muggers waiting for you in the train?//

Yeah - think of people's careers here!
 — Letsbuildafort, Apr 23 2006

 A while ago I did a project on trains, and in a book I have I found a curious side-box said that an experiment had been made in which a train never actually stopped, it just slowed to a crawl so as that passengers could get on and off. The experiment was never repeated.

 It does not elaborate the reasons as to why it was never repeated, whether it was proven to be too dangerous, a lack of funding or interested parties, or just that it was a Bad Idea.

I shall endevour to find the book which printed this, so for now I shall remain neutral.
 — froglet, Apr 23 2006

This actually all seems entirely feasible if hippo's calcs are right. This should only cause .45 horizontal Gs.
 — mastermindmortal, Apr 23 2006

 //Stopping and starting subway trains takes a lot of energy//

 //water-based amusement park rides//

High speed waterslide subway entrances/exits.
 — AfroAssault, Apr 23 2006

 [zevkirsh] The pod is going to stop at one and only one station. You walk into your originating station look for a capsule with your destination marked on it, and climb in.

 If you see a shady person in that capsule, look for another one with the same destination, and use that instead.

Also at times other than rush hour I think that someone inside the car should be able to control the door. So if you are the only person in the car, just close the door to keep the muggers and panhandlers out.
 — Galbinus_Caeli, Apr 23 2006

This works until some bum holds the door open, hoping for a tip, as the train pulls away from the station, and fall out of the train at 94mph.
 — sninctown, Apr 23 2006

The capsule will not load onto a train unless the door is securely closed. A couple Electronic "Something is blocking the door" announcements and an announcement to a central security/repair depot if that does not work.
 — Galbinus_Caeli, Apr 23 2006

[bigsleep] Costs \$.50 extra.
 — Galbinus_Caeli, Apr 24 2006

 I had a similar idea that it looks like i deleted. My idea was an S shaped station where you would transfer from a fast train to a slow train.

 I think I deleted the idea due to the calculations some other baker smarter than me did showing me the actual diameters and speeds possible for such a thing.

I'm very much impressed w/ all of your success! (+ on being the one thing interesting & possibly feasible enough to make me break down & post when I've banned myself from that for awhile (I have no self discipline do I?)).
 — Zimmy, Apr 24 2006

Make the wheel big enough, say 10km, and you don't need the train...
 — Ling, Apr 24 2006

The cost to retrofit every station into a giant wheel would be crazy. How about installing 2-3 moving sidewalks on the station platform. They run parallel to the train and each "layer" of moving sidewalks would be progressively faster as you get closer to the train. The train only needs to slow down to match the speed of the fastest sidewalk, which people can get in and out of in about the same 15-20 sec that the doors normally stay open (at least the DC metro). That should be enough time to exchange passengers before the fastest sidewalk makes it from one end of the platform to the other.
 — phrancis, Apr 24 2006

a) Here at the halfbakery, inconcievable expense has never stopped us before.
b) Disappearing on us [Zimmy]?
 — hidden truths, Apr 24 2006

phrancis : that's a much nicer improvement on the idea. Takes less space, even more cool :-) ... especially when you think of all the grandmas who were not able to make it to the train in time and are "conveyed" into a wall at the end of the platform at 100 km/h ... unless there is some kind of a safety net that picks up the people who have reached the danger zone.
 — ixnaum, Apr 25 2006

seems like no one has realised the major advantage this system brings: since there are only 4 passengers per cart, it means there won't be any terrorist attack threats on subways. [+]
 — sweet, Apr 25 2006

Not so fast: a little damage at the centre bearing should do the trick...
 — Ling, Apr 25 2006

<semi-drunken passenger>"Picadilly Circus? I wanted Charing Cross... damned Coriolis effect."
 — RayfordSteele, Apr 25 2006

Yeah, coffee cups would need to be designed with a sloping top edge.
 — Ling, Apr 25 2006

 ixnaum: Well, yeah the moving sidewalk wouldn't just go straight into the wall at the other end of the station. That would just be some cruel/funny form of darwinism. There would just be a decelerated sidewalk and padded wall at the end.

How about just one sidewalk that gently accelerated to the speed of the slowed train. You would just signaled to get onto that sidewalk if you wanted to catch that particular train. Its like "catching your sidewalk" instead of catching the train - hence the train would never have to stop and the sys would move more commuters in a given time.
 — phrancis, Apr 25 2006

I love it! One of the many great ideas that would improve the nyc system yet won't be implemented in our lifetimes because they're still working out how to keep the existing system half functional...
 — allterrainbrain, Apr 25 2006

wasn't the accelerating-sidewalk idea baked by the japanese ?
 — sweet, Apr 25 2006

 What Galbinus_Caeli has added to this old idea is the use of small carts to accellerate up to train speed. If you combine that with phrancis' modifcation of using conveyors instead of a wheel, then people can accellerate onto and off the train in a deterministic path and no one can fall off and get hurt.

Really, since you're using carts, you don't need a wheel or a conveyor belt. A single accelleration rail curving from the boardwalk to the moving train would do the trick. Each cart should be as small and hold as few people as possible.
 — jcatkeson, Apr 26 2006

Part of the idea of the giant wheel is that everything keeps moving at a near constant velocity (expect for the passengers). Plus its cool.
 — Galbinus_Caeli, Apr 26 2006

"Professor Einstein, does New York stop at this train?"
 — land, Jul 09 2006

I just had the same idea today. [+] One issue though, even if the g's were bearable on the edge of the rotating platform, something would need to be done about the wind... At 94mph (150km/h) you'd need at least a pair of safety goggles for stepping on and off!
 — placid_turmoil, Apr 25 2007

 If starting and stopping and energy lost during is the only problem.. why not use regenerative braking? the conductors know when they have to start applying the brakes, so it need not be as sophisticated as for with street vehicles.

no new tunnels built, although I like the capsules idea.
 — twitch, Apr 26 2007

Regenerative braking is only about 30% efficient. Then storing that energy is no more than 75% efficient. Then converting that stored power back to movement is no better than 50%. All of which means you only get about 10% back from regenerative braking. Better not to slow down in the first place.
 — Galbinus_Caeli, Apr 26 2007

You could just go with hills. Trains drive up a high hill that's been designed to absorb all of the kinetic energy into potential energy. People get on/off, then the train zooms down the hill.
 — Worldgineer, Apr 26 2007

 I like the hills idea. It would allow the train to stop, but still store the kinetic energy, efficienty, only losing out to friction, but only little energy i suppose.

Although I've never been on a train before. Hawaii no more trains.
 — twitch, Apr 26 2007

Most subways are usually pretty much flat. They just make the stations deeper as needed.
 — Galbinus_Caeli, Apr 26 2007

So, not a 24/7 sandwich shop?
//wasn't the accelerating-sidewalk idea baked by the japanese // Dunno about Japan, but I think there was an accelerating travelator at Schipol in the 80s.
 — AbsintheWithoutLeave, Jul 02 2008

This reminds me of that fine film, Dark City. There was a train in that one. Poor Keefer was much misused, but the atmosphere and creepy premise made for a fun watch.
 — bungston, Jul 02 2008

Great idea, but we need to add one thing. The stations and "trains" have air locks, and the whole tube is de-pressurized to eliminate air resistance.
 — kevinthenerd, Jul 02 2008

Install a paternoster so that you can have a non-stop elevator as well.
 — theleopard, Jul 08 2009

[+] Would be nice if we had a service capsule.
 — danman, Jul 08 2009

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