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Train doors require GPS signal to open despite stations being underground (2014)

ciras.org.uk

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Re: Train doors require GPS signal to open despite stations being underground (2014)

#81

Post by lttlrck »

hlandau wrote: post #76

There are a few issues here. SDO, CSDE: Firstly, some platforms are too short to fit all of the doors on, especially with the lengths of trains being extended. Thus at some platforms it is necessary to ensure that the first or last doors of the train, or both, are not unlocked. The London Underground has its own system to do this ( https://en.wikipedia.org/wiki/Selective_Door_Operation ). Here it appears they decided…

Edge triggered sounds safer to me. It protects against stuck switches due to failure or leaning)

Re: Train doors require GPS signal to open despite stations being underground (2014)

#82

Post by manicdee »

Hello71 wrote: post #80
blibble wrote: post #10

Earlier quoted context omitted.

it's more common that the driver opens the doors on the wrong side, or at a short platform opens all the doors instead of, say the first 8

Why would it be an issue if you opened more doors than necessary? I'm assuming that the edge of the platform will always match the edge of a car, and that it is not possible to board off-platform cars (otherwise they wouldn't be off-platform), and that there will be no people in the "off-platform" cars. Otherwise, how would they get off? It seems extremely inefficient to start the train just to move it half its lengt…

Some trains will have 8 cars but stop at some stations with only 4 cars worth of platform. The passengers heading to those station usually knowmto board the first four cars.

The difficulty arises when doors are accidentally opened for all cars at 4-car platforms.

No, the train does not move forwards by 4 cars, it simply stops, passengers board and alight from the front four (including a rush of passengers frommthe back four cars who forgot that their station is a four-car stop), then the train leaves.

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