Re: Three Position Signalling

[David Langley <del@ancc.com.au>]

Tony Gatt wrote and Chris Gordon added -

> : I also know that on the S/G, the arrival signals on the loops (no's x/2 and x/8)
> : can not show top yellow.
>
> : If it is necessary to enter the loop on No 1 road with the departure signal at
> : Stop, you will get R/R/Y (same as if you were going into No 2 road in the loop. Has
> : it always been like this?

Yes.

> Also on loops on the BG.
>
> The only way to get the signal off for a movement into no.1 road and not
> have the departure signal off is to reverse the points at the far end.
> The after the arrival signal is off then the points at the far end are still
> free to move (ie you can move them back).

Are you sure? AFAIK once you set up this move the points at the far end are locked until
you either put the home arrival back to stop or the train passes the home arrival at low
speed caution and enters the "yard" area either main or loop.

> You can't just pull off the arrival signal into No.1 (it will stay at stop)

Yes.

The other way is to pull off the arrival and departure signals for No.1

> road and once the arrival signal is at proceed put back the departure signal.

I think you'll find some interlocking here preventing that. This interlocking is probably
in the Office equipment and thus field circuits do not show it but that is how I
understand it would work. It always did when I worked on the system.

David Langley (having recovered from F317)