> I have a NSW signaling question. What does a signal that is RED on RED
> on Green mean???. I have never seen a signal like this before.
That is a "calling on" indication. It means that the track ahead is
NOT clear to the next signal but that the train authorised to enter
the section on the basis that speed is kept low enough to stop clear
of any obstruction sighted.
Automatic "calling on" indications are used in the "City Railway" area
to allow close headways. It is my understanding that most other
"calling on" indications are initiated manually by signallers or other
appropriately authorised safeworking staff.
Cheers,
Bill
Bill Bolton billbolton@acslink.net.au
Sydney, Australia