Bordeaux Trams

[puff o'wind]

This might be too far off topic, but...In Bordeaux the trams there run on 750v DC which is fed from a live rail in the ground. But this is all open to the public so they have engineered it such that the live rail is only live at the time and in the part the tram is actually over the track. Now, clever yes...but how do they do it? How do they make only PART of a live rail live? Anyone know??

[ha_banos]

I was thinking the only way to do this is to have sections! I think that's what they are saying here...

APS uses a third rail placed between the running rails, divided electrically into ten-metre rail segments with three-metre neutral sections between. Each tram has two power collection shoes, next to which are antennas that send radio signals to energise the power rail segments as the tram passes over them. At any one time, two consecutive segments under the tram will be live.

Ref. https://en.m.wikipedia.org/wiki/Grou...l_power_supply

[puff o'wind]

Ah, well researched. Thanks. I had to dash out earlier so couldn't do this but wanted to know because my daughter is over there and she asked. Frankly I was surprised she asked, she's a smart girl but a girl nevertheless*. I'm quite impressed!

*not usually observant of techie things like the absence of catenary wires... She works in fashion...now, drop a sequin...