Is that double track at golden square ?
I'm not sure exactly where they have put the camera, but there is double track from somewhere south of Kangaroo Flat station, through the old Golden Square station, with the line returning to single track just before the Thistle St bridge. The yard starts on the other side of the bridge.
How many of the yard tracks count as the main line? From the shine or rust on the tops of the rails, trains mostly seem to use a single track through the yard...