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by mschuster91 2993 days ago
> Both metros should have barrier between platforms and tracks since they know where the doors will open.

This only works for environments with one type of rolling stock only. It's not uncommon that you take a ride in a decades-old train (e.g. the oldest trains in the Munich subway hail from 1971, they are expected to run for essentially over 50 years!), switch lines at a station and end up in a train that rolled off the factory line 2 years ago. Each new train generation has, for example, different door widths, door positions, even the number of doors per wagon can change.
2 comments
borne0 2993 days ago
That's true. Montreal just upgraded their rolling stock: (The MR-73 didn't owe them anything https://en.wikipedia.org/wiki/MR-73) but the new cars (https://en.wikipedia.org/wiki/MPM-10) have the doors in the same place as the MR-73 cars.

Admittedly I hadn't thought of that, but I don't think there's that much variety in rolling stock for a given location, and when speccing out replacements I don't think it's too much to ask that the doors are in the same place (cars are purchased in dozens...), maybe I'm wrong. Montreal is a much smaller network than New York.

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gruez 2993 days ago
>when speccing out replacements I don't think it's too much to ask that the doors are in the same place (cars are purchased in dozens...)

that pretty much only works if you have 1 generation of rolling stock currently in use, and you know (or forsee) that you want to install platform doors. considering that the new york subways were built before platform doors were a thing, I can totally see how door location wasn't even a concern when purchasing rolling stock.

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loufe 2993 days ago
Exactly. The generations don't HAVE to have different dimensions. There's no worldwide metro standard across all dimensions leading to "common" models, every subway system requires custom made. Of course they can work them in, like they do in Montreal (where I see them working harmoniously)
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innocenat 2993 days ago
Japan accomplished that though. They just use a very wide barrier door, or (still in development) movable barrier.
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