Track occupancy using balls?

General Forum to discuss anything you like. No religious topics please.
Post Reply
User avatar
Scrat
Fat Controller
Posts: 99
Joined: Fri Feb 11, 2011 4:18 pm

Track occupancy using balls?

Post by Scrat » Sun Jun 22, 2014 7:17 pm

I just read "signalmans morning" and "signalmans twilight". There was a short description of track occupancy display using metal balls that would be either in sight or out of sight in the track diagram to show if the track is occupied or not.
Can anyone give me an idea on how this worked?
Post Reply