A common type of mass transit is the "Light Rail" car, such as a trolley. This is an independent vehicle, carrying as many passengers as a bus, following a particular route along the rail lines. Now, one significant expense of installing a rail system is the perceived need for two separate tracks, so that trolleys can go two directions along the mass transit route, without colliding. This idea can get around that!

We need specially designed trolley cars. These will be low-slung, maybe only a meter high, with gull-wing doors. Chairs are aligned at a steep angle; passengers will be leaning backwards very comfortably, although entering and leaving may be a bit of a stretch. On the ROOF of these special trolley cars are embedded rail tracks! The front and rear of these trolleys have long sloping angles. When two trolleys approach each other in opposite directions, or one has stopped to pick up passengers while another, behind it wants to pass, well, passing takes place in the 3RD dimension. One trolley literally drives right over the other!

Yes, I know that the trolleys will probably have to have rubber tires on the rails, to have the traction needed to climb over each other. So?

But we get instant "hills"! Instant fun roller coaster effect! No two rides are ever the same, because the hills move around! All this with only half the rail track to build in the city! And no delays caused by broken-down trolleys blocking the tracks!
-- Vernon, Mar 08 2003

Roly Poly Cars http://www.halfbake.../Roly_20Poly_20Cars
like this on the highway [FarmerJohn, Oct 04 2004]

Chinese straddling bus http://www.youtube....watch?v=Hv8_W2PA0rQ
[pashute, Feb 23 2011]

Yay!
-- thumbwax, Mar 08 2003


Overlapping trains that are actually trains? Croissant.
-- Shz, Mar 08 2003


i'd die before getting in one of these. how about suspending the cars from the track(cable-car style). then you can raise or lower the car to allow another to pass.
-- sambwiches, Mar 08 2003


It's going to be quite a squeeze fitting wheels, engines, passengers and ground clearance into 1m. Worse, city use requires rapid turnover of many passengers at each stop: hard to achieve that with reclining seats and gull-wing doors.

But a wonderfully half-baked idea. Maybe it could work in industry, or some other place where un/loading could be achieved smoothly.
-- DrCurry, Mar 09 2003


FarmerJohn, I did not know about the Roly Poly Cars idea when I wrote this down. Also I'm pretty sure I hadn't heard of it elsewhere, as indicated by ravenswood. It's just that I live in a city where some hullaballoo is going on about using some regular old railroad track lines as a starter unit for a Light Rail system. But the existing tracks are only single, not double. So, how to let trains go both ways on one track, without lots of additional construction (even ordinary railway sidings)? Thus I had this wild idea....

DrCurry, I would not say that this is such an engineering challenge as you suppose. These trolleys don't have to have full-size railroad wheels, for example, and since railway tracks are notoriously level, ground clearance shouldn't be any kind of big problem. I figured that the engines for these independent trolleys could fit in either or both of the sloping ends of the vehicles. And, there is NO hurry about loading/unloading passengers, because with appropriate gull wing doors, they would not interfere with the passage of the next trolley that hasn't stopped for passengers. (Yes I know most gull wing doors swing quite a ways upwards, but that is more for looks than need.)
-- Vernon, Mar 09 2003


Vernon, no problem, I'm sure. Another way, with special wheels and seats, would be to tilt each trolly 60 degrees up from the track, to balance on one rail when passing the other.
-- FarmerJohn, Mar 09 2003


Hate to say it but have thought of this before for cars. This is more practicle because you can inforce a rule that all trains can be driven over. If the trains are long enough then the angle of ascent can be reduced to something workable.

If it works it will eliminate the risk of head on collisions. I think that all the bridges and tunnels will need to be double height (just in case).

I think that there will have to be some discipline at stations though.. So that the platform doesn't move when grandma is getting off..
-- madness, Jul 31 2004


//I know that the trolleys will probably have to have rubber tires on the rails, to have the traction needed to climb over each other//

Or enough momentum to make it all the way over. This would help prevent the more boring low speed passing.

Also, would there be windows so you can see the other trolleys? Or would you just get sudden bumps and noises?
-- caspian, Nov 22 2004


[drivel], these trolleys are intended to be low-height -- I specified "maybe only a meter high" in the main text. That would pretty much make them "half-height", and so no need to build double-height tunnels/bridges. Also, I did intend them to have moderately long tapering ends, so it would not be too steep a climb for one trolley going over another. I figure the ends could hold the engines and other stuff, while the central area is for reclining passenger seats.

[caspian], I didn't say anything about windows because all passenger trolleys/trains currently have windows, and it didn't occur to me to NOT have them on these things. Regarding momentum, somewhat cool notion! :) especially when WANTING that "roller coaster" effect. On the other hand, it doesn't hurt to do things on the safe side. One alternative is to use ordinary steel wheels on the rails, and arrange that the rails which are mounted on the trolleys to be rubber-coated! Then any slow-climbing trolley will still be able to get over the top.
-- Vernon, Nov 22 2004


Congratulations [Vernon] - I have finally read one of your ideas in it's entirity. And it's a goody!
-- wagster, Nov 22 2004


About the windows: you probably can't see the other train through side windows. I'm not sure I'd be willing to ride these at high speed, but nice idea. Croissant.
-- caspian, Nov 22 2004


[caspian], since I was describing a one-track system, it would indeed be kind of tough to see the other trolley through side windows. However, video is fairly cheap these days, so cameras mounted front and rear, with a screen or two onboard could provide such a view.
-- Vernon, Nov 22 2004



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