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Comment by lmm | Hacker News Reader

Yeah. London won't allow fully automated trains without platform edge doors, and it would be impractical to put them on the Great Eastern Main Line or the Great Western Main Line with the variety of other trains that share those tracks. AIUI Crossrail is planned to use fully automated signalling eventually (i.e. similar to the Victoria Line, where the driver only pushes the button at each station and speed is automatically controlled between stations) once ETCS in Britain is standardized enough.

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Strange because the DLR is almost completely automated (no driver, but ticket inspector closes the doors) and has no platform edge doors. But they do have emergency stop buttons on the platforms.

Small correction - they can also be driven manually, a flip up panel on the front seat allows the conductor to take control in the case of a complete (or widespread) signalling failure. They're restricted to 12mph though as there are no signals at all and everything must be done by sight.

    > allows the conductor to take control in the case of a
    > complete (or widespread) signalling failure

Or, having ridden that line as part of a regular commute, whenever the conductor gets bored.

I don't think they actually get to drive the train then, just get the press the close door button on the panel. The train still drives to the next station without any human input.

Most automatic trains can't be driven by humans under normal circumstances because signaling information is fed to the train far faster than any human could react to it.

AFAIK It's the lack of a human making the close doors / start moving decision that leads to a need for platform doors.

(The Central, Jubilee, Northern and Victoria lines also use automatic operation to similar levels as the DLR, it's just less obvious as the train operator still has a separate cab).

> AFAIK It's the lack of a human making the close doors / start moving decision that leads to need for platform doors.

There is no such need. Lyon's line D has been running fully automatic since 1992 without platform doors[0], the only major accident has been a drunk falling on the train having jumped from a mezzanine.

[0] https://www.youtube.com/watch?v=ubdJ35NBrbE

Of course there is no such technical _need_, most kinds of these needs are driven by _legal_ requirements founded in fear of full automation. Fully automated systems were realized before your example already in Vancouver's SkyTrain (1986) and even BART was supposed to be specified to be fully automatic.

Same in Copenhagen[0], but they do appear to have LIDAR units monitoring the track edge at stations without doors.

[0] https://youtu.be/R8QvM000uyE?t=151

Copenhagen has since fitted platform edge doors to all stations, above and below ground.

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