[SauronOfMordor]

(Whatever a '3rd rail' is! Tracks around Texas only seem to have 2!)

Subway systems in NYC and elsewhere have trains running on two rails, with a third rail off to the side which carries the high-voltage power for the train. Touch it, and you get several hundred volts passing through you. Every once in a while in NY, some homeless guy gets killed by urinating on the third rail

[supercat]

Subway systems in NYC and elsewhere have trains running on two rails, with a third rail off to the side which carries the high-voltage power for the train.

At least some of London's trains put it in the middle, as do 3-rail electric sets. I wonder what advantage there is, if any, to having it on the side? I wouldn't think arcing to the car's axles would be a problem.