

Show HN: Tube Map Live for iOS - andydrizen
https://itunes.apple.com/gb/app/tube-map-live/id665729837?mt=8

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staticfish
I made something similar for Philadelphia

[https://play.google.com/store/apps/details?id=com.staticfish...](https://play.google.com/store/apps/details?id=com.staticfish.septainstant&hl=en)

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kokey
Wow, I knew they rolled out some access to countdown from the ibus system, but
I thought hell would freeze over before they'll allow people to track tube
locations.

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10dpd
Its probably not the actual location of the tube, but a guestimate based on
the departure time, arrival time and the distance between stations.

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diroussel
It depends on the line. The more modern lines, have induction loops every 3
meters that allow precise measurement of current position, and also data for
voice comms to the line controller.

On older lines, they can only detect when a tube changes power circuit and the
resulting blue/white spark sends a measurable pulse down the power system. In
this case, yes, they have to just count trains into and out of a section.

I learnt this by chatting to a TFL engineer in a pub, he designed the
signalling systems equipment.

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kosei
Used the tube map app while visiting London and it was incredibly helpful.
Great to see this new improvement.

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diroussel
Very cool. Free app tried, paid app bought!

