Signals for Shunting
Posted: Wed Oct 27, 2010 9:02 pm
I am trying to get a better understanding of shunt/ground signals.
In the simple situation of a siding making a trailing connection with a uni-directional running line, a ground signal is often used to ‘give permission’ for a train to shunt into the siding. There is some variation in which side of the track to place the signal, but that is not my main concern.
Consider a goods train wishing to pick up or drop wagons in the siding. Assume it would initially stop before the siding and uncouple its brakevan and perhaps part of the train. It would then move forward over the siding turnout and, once clear of the turnout, stop, whistle and wait for the turnout to be reversed and the ground signal to be cleared. It would then enter the siding, couple up (or drop) the appropriate wagons and move forward onto the running line, clear of the turnout. What happens then? How is permission to back onto the rest of the train, couple up and set off given? Does the ground signal get used also for backing along the running line... or is a second ground signal (alongside, or ‘stacked’?) needed?
I have a rather separate question about ground signals on facing points. In this case, a train running along the running line would effectively ignore the ground signal - is that right. And, although I’m mostly thinking about disc ground signals, what happens with position light ground signals on facing points? Having red lights on the running line is confusing.
There are several trailing ground signals planned for my layout at Welwyn. A screen shot of part of the control screen is attached (I hope - it’s an experiment!), from which it can be seen there are three trailing shunt signal positions on the running lines. Basically, I want to figure out how these should be used.
[The circles on the screen are buttons to operate the turnouts - white when available, black when locked; the boxes with numbers are the block/track circuit numbers]
Andrew Jukes
In the simple situation of a siding making a trailing connection with a uni-directional running line, a ground signal is often used to ‘give permission’ for a train to shunt into the siding. There is some variation in which side of the track to place the signal, but that is not my main concern.
Consider a goods train wishing to pick up or drop wagons in the siding. Assume it would initially stop before the siding and uncouple its brakevan and perhaps part of the train. It would then move forward over the siding turnout and, once clear of the turnout, stop, whistle and wait for the turnout to be reversed and the ground signal to be cleared. It would then enter the siding, couple up (or drop) the appropriate wagons and move forward onto the running line, clear of the turnout. What happens then? How is permission to back onto the rest of the train, couple up and set off given? Does the ground signal get used also for backing along the running line... or is a second ground signal (alongside, or ‘stacked’?) needed?
I have a rather separate question about ground signals on facing points. In this case, a train running along the running line would effectively ignore the ground signal - is that right. And, although I’m mostly thinking about disc ground signals, what happens with position light ground signals on facing points? Having red lights on the running line is confusing.
There are several trailing ground signals planned for my layout at Welwyn. A screen shot of part of the control screen is attached (I hope - it’s an experiment!), from which it can be seen there are three trailing shunt signal positions on the running lines. Basically, I want to figure out how these should be used.
[The circles on the screen are buttons to operate the turnouts - white when available, black when locked; the boxes with numbers are the block/track circuit numbers]
Andrew Jukes