Places   (Help with places, streets and buildings in Wigan.)

A guy with whom I was at school with, lived on Ashton Heath, from where he could see the trains, tells me that the lines were NOT both used for same direction, only those in and adjacent to the Station.

That makes sense, on the photo, you can see the crossover just beyond the station to allow the outgoing train from the 'wrong' platform to regain its appropriate track. This would permit one train to be despatched whilst another is loading, and the next train to be moving from the storage sidings West of A49 into the free slot at the station.

Signalling requirements for that are conventional, as it is how they operate at terminal stations.