I've noticed just outside Armidale (towards Uralla) there is a sign for trains approaching Armidale that says "Armidale - End Train Order Working - STOP" or something similar.
I'm just wondering why trains have to stop at the sign? The Xplorer only seems to stop for a couple of seconds before it continues to the station.
It is a change of Authority for Safeworking systems. Werris Creek to Armidale is Train Order Working, and Armidale Yard is not in Train Order Territory, and is just worked as Yard Working. Because A Train order only authorises a train to travel up to that End Train Order Working sign. Permission must be seeked from the Network Control Officer to enter, and operate in Armidale Yard.
There is a similar arrangement at Canberra, where it is not in Train Order Working Territory either.
To keep it simple, it is to make it easier for both Network Control and the Train Operators this way, as only verbal authority (as opposed to a dictated, computer generated Train Order) is required to work under yard working, and multiple trains can work in the same yard in an easier to manage way when compared to multiple movements in a Train Order Location.