

Clever Chinese trains without stops at stations (concept) - srgseg
http://www.youtube.com/watch?v=DIeRrU4_M3Q

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w1ntermute
This was invented and tested by the British over 150 years ago:
<http://en.wikipedia.org/wiki/Slip_coach>

They stopped using them 50 years ago.

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Semiapies
Slip coaches manage the drop-off, but not the pick-up.

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w1ntermute
_To reverse the journey, the passengers would board the slip coach at the
intermediate station, which would then form part of a local train to the next
station on the line where the express was scheduled to stop, and coupled to
the express train there to be taken to its destination._

The concepts behind the drop-offs and the pick-ups are basically the same.

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Semiapies
You might watch the video. The train in this concept _does not stop_ , unlike
the case you describe above. It is certainly not "basically the same" unless
you think this, slip-cars, car ferries, and modular cargo containers coming
off a ship are all equivalent.

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electromagnetic
Yes, but this is not a dramatic new concept, it's a minor improvement in
implementation because of decreased engineering costs and simply time.

This is nothing more than an elevated rail system and using a linear braking
system to _accelerate_ the stationary vehicle. Beyond that, we're talking
simply precision and as the concept has yet to be implemented, the Chinese are
no way more advanced with the concept than 50 years ago.

For all intent this is a worse design than having a tandem acceleration system
in the trains and allowing the slip-car to simply accelerate itself to rejoin
the express. You wouldn't even have to redesign your fleet, you'd only have to
implement it in the slip-cars initially for the concept to work.

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Semiapies
Whether it's a _good_ concept, I don't much care. It is simply and obviously
wrong to say it's the same as a slip car, just as it's simply and obviously
wrong to say a motorcycle is the same as a draisienne. Whether it's "dramatic"
enough a new concept for someone is not my concern.

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obeattie
Wasn't this on HN a few weeks ago?

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jcl
A couple months ago (among others):

<http://news.ycombinator.com/item?id=1274655>

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WingForward
Wouldn't this destroy a bullet train's aerodynamics?

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dm_mongodb
Perhaps a better solution is to make trains more cell-based. (Think ATM.)

Each "car" holds just 2-4 people. they run on the tracks and switch on and off
at the right stops. Very granular.

But still like a train in that you have tracks and power from the tracks.
There is no conductor then, so everything would have to be computer
controlled.

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Groxx
I've thought of that as well, but you've got _serious_ problems with air
resistance (and associated vibration) at high speeds unless you've got
contoured fronts and backs. So you'd have to drop and add cars in the _middle_
of the train... added complexity and you'd need every unit to be powered
independently (true, many are, but this would be a _requirement_ ).

So picture parallel tracks with a merge-point somewhere ahead (or a few, in
case one doesn't work). You've gotta split the train, merge in the new car,
and merge it all back together, at moderately high speeds. Not much of a fun
engineering challenge, methinks. The top-car probably makes more sense in this
case. At low speeds, where all cars can be the same shape, certainly. Just
remove / add to the front / end as needed.

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macmac
This would make for some quite spectacular accidents...

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astrodust
I can imagine some fussy grandmother disembarking all too slowly on the one
car, and since the next one has to come in, no matter what, they'll have to
launch it, and the old lady, out on to the tracks or risk crashing two of
these cars together at extremely high speed.

This whole concept is insane. It would only work with pre-packaged cargo.

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CountSessine
Looks like a pretty spectacular way to get yourself killed. Am I the only one
thinking about what would happen if the slip coach didn't fully lock and then
came loose while passengers were leaving or entering it from the main train?

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thefool
It seems like it would be very easy for people to get on the wrong mini train
and end up leaving at the wrong place, because it would likely take
significantly more time to get ready for a disembark.

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jonah
Seeing this reminded me of continuous elevators:
<http://www.youtube.com/watch?v=Zx3MHm9WjBE>

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xster
what would happen if half of the train needs to disembark at the same time?

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lincolnq
Then the train stops? This is intended to reduce the time to stop at small
stations.

There is ample time as people are loading onto the slip coach to discover that
the train needs to stop, although I think in practice this would never happen
(the train operators would never be surprised by a large number of people
trying to get off all at once).

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jodrellblank
They wouldn't be surprised that it was crammed uncomfortably full of people;
that doesn't mean they'd do anything about it though.

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yoshiks
what happens if some people still onboarding when next under-bullets comes?

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docgnome
Erm. What if you need to get off 3 stations down the line?

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jrockway
Then you don't take the express train. Just like now.

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docgnome
Sorry, I live in the middle of no where and don't really know anything about
commuter trains.

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cmalpeli
but how does one exit the train?!

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jrockway
The mini-train on top stops at the station, detaches from the main train, the
doors open, and you exit by walking through the doors. Later, passengers
board, the doors close, the mini-train waits for the next main train, and the
mini-train attaches and off you go.

