Telegraph, control the way to send a message

[Charles123]

I was watching “Hell on Wheels” (nice series by the way), and with a train stopped they connected their telegraph terminal to the telegraph cable, and decided to send a message in a particular direction. How was this done? How is the direction for sending the message controlled?
Thank you
Regards

 

[davenn]

1) They chose the cable that went in that direction ? ... would be the obvious reasoning,
not having seen the series I can't elaborate any further

2) all stations were connected on the common line and sender would send an identifier for the receiving station he wanted to reach...
The operator at that station would recognise his identifier code and start listening to the morse code message coming through.

I would expect it to be one of those 2 methods... maybe some one else on here can offer another suggestion :)

ahhhhh the good ol' days of single wire and Earth return ;)Dave

 

[Charles123]

I think it was a single cable, so first option is excluded.