third rail

[rail10]

What type of third rail configuration system is used in the nyc subway?

[pennsy]

Hi,

Third rail power is provided by a raised track, insulated above and below, carrying 600 volts, DC. The rail can be on either side of the tracks, since each MU truck has an over running pickup on either side. The pickup rides along the top of the third rail.

[devbeep2]

Correct me if I'm wrong, but only one rail on the system is used for traction return, while the other rail is used for track circuits (the train being the shunt over an insulated joint), thus enabling the usage of DC traction energy and track circuits and thus eliminating the need for expensive and complicated AC track circuits. Just walk through a station and check out the rails.. only one will have insulated joints separating the track circuits, the other will be straight rail.