Half a croissant, on a plate, with a sign in front of it saying '50c'
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The nonstop train

Okay, it does stop. Just not at stations
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Trains waste a lot of energy overcoming inertia when stopping and starting. The whole mass has to come to a halt even if nobody's getting off. So start and stop the passengers instead. Each station has a few miles of paralell LSM tracks either side of it. You get in your personal pod or drive onto a car pallet. The pods and pallets are lined up in a special order. When the computer detects a train approaching, it starts the line of pods and pallets off. The timing is just right so when they reach the speed of the train, they are running alongside it. The line of pods and pallets clamp onto the side of the train and lift themselves aboard just as the pods and pallets getting off detatch themselves and decellerate. For the length of the trip you have your own personal space to do as you please in without strangers looking over your shoulder.
Cats Whiskers, Oct 06 2003

Non stop train. http://www.taiwanhe...tem=79655&CtNode=39
(found via Boing Boing) Apparently somebody has now 'invented' this concept for real. There really is no gratitude is there! [DrBob, Jun 19 2008]

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       This would use even more energy than stopping and starting the train.
WikdWaze, Oct 12 2003
  

       interesting idea, but as wikdwaze points out, this would waste more energy than the train stopping and restarting. i thought you were going to suggest a pipelined train schedule, infinitely repeating
screwtape, Oct 12 2003
  

       Waste energy in what way? It takes more energy to accelerate and decellerate a larger mass than a smaller one. That's simple physics.
Cats Whiskers, Oct 12 2003
  

       But it takes more energy to accelerate many small objects than one large one.
WikdWaze, Oct 18 2003
  

       The total mass of the all the small objects will be less than the train. Simply Newton's law of reaction. Unless you mean that they will have greater frontal area, in which case they should all be accelerated a few inches away from each other.
Cats Whiskers, Oct 23 2003
  

       Assuming I follow, you, passangers will sit in the pods, and the pods will go along for the ride too (rather than being used simply to load/unload passengers to conventional seating).   

       In which case, the loaded pods will form a decent fraction of the total train mass; your system only wins with the mass difference - ie, the locomotive and the presumably flat rolling stock - but it loses with having to accelerate the pods alongside the train.   

       So I don't see how you'll do better than break even.
benjamin, Oct 24 2003
  

       It is not possible to have 50 self-propelled, single passenger pods weigh less than a 50 passenger car. By the time you add up the basic structure of the pod, the power source, the drive mechanism, and the latching mechanism, you've easily exceeded the weight of a single passenger car. There's also the matter of the extra rolling resistance of all the wheels on the pods when hooked together. A regular 50 passenger car has 8 wheels, each pod would need 4 to be stable, which means 200 wheels on the track when 50 pods are hooked together.
WikdWaze, Oct 25 2003
  

       I had assumed that the pods that were boarding the train would be coupled together and accelerated to train speed by the tug of a stationary engine at the station, rather than being self-propelled. The extra rolling resistance would only present itself up until the pods were lifted and clamped to the train - ie, alongside the station; a very small part of the trip.   

       You still lose in terms of efficiency, cost, weight etc. Now, if the original problem was not stated as "trains waste a lot of energy overcoming inertia when stopping and starting" but instead "trains waste time stopping and starting" then I'd be more supportive of the idea.   

       In fact for passengers, lose the pods. Instead, combine a regular train/subway/etc with the multi-speed moving walkway idea - to bring you up to speed before boarding the train.
benjamin, Oct 25 2003
  

       What if a long hill was used to help get the pods up to speed before they became attached to the train?
spiraliii, Oct 26 2003
  

       spiraliii, you'd still lose efficiency overall because at some point you'd have to get all those pods back to the top of the hill.
WikdWaze, Oct 28 2003
  

       Cats Whiskers, I am giving you a scone because no one else can understand what you and I can see.   

       There will be a saving in energy if there are only a few people getting off or on at each station. The example of the 50 seat car is only valid if there are 50 people to get on or off.
KiwiJohn, Dec 22 2003
  

       ( linky )
DrBob, Jun 19 2008
  

       Does each pod have its own toilet?
coprocephalous, Jun 19 2008
  

       forget the train and only consider the PODs the train is the issue mass transit with only the PODs
canadian_boy, Sep 15 2009
  

       I think there was something a little like this proposed in the Foundation series by Isaac Asimov. It was a number of side by side belts that ran slower the closer to the curb you walked. you got on the slow one and walked over to the "express lanes" to speed along to your destination, where you debarked in a similar manner.
Sparkyplugclean, Sep 15 2009
  
      
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