Graham
In Smoggy Land
I have this mad idea of fitting sprung bumpers onto the back walls of the loco shed and installing micro switches. One switch to toggle a red green LED maybe on a small post just before the shed to show that a loco is in and at the end of the track and a second to isolate the track section in the shed to stop the little engine drivers (grandkids) recreating that scene of a loco hanging over the edge of the track