The track far right is triple gauge, were they 4'8½" (British standard), 5'3" (Irish standard) and 7'¼" (Great Western broad) gauges?A print of Curzon Street , Titled ‘The First Railway Passenger Station in Birmingham (1838) source Historicengland.org.uk
Forget it ! I was looking at an enlarged version which hid the fact of two tracks crossing in the foreground! All are normal 4'8½" gauge tracks.That is the only conclusion that I could come to, but cannot find any evidence that the GWR, ever ran Broad gauage into Curzon St. There were parliamentary bills to this effect, and the Duddeston viaduct was built with this in mind, but never completed. I wonder if this was artist's licence
Can you give us more details please as this sounds as if it might be the viaduct from Bordesley which was never completed.In the Science Museum of images of Curzon Street there is one captioned Curzon Street Viaduct. Not all the plans there were carried forward and this one seems not to have happened and the London & Birmingham Railway build a level crossing instead to reach their goods yard