The canal (and towpath) go under the railway line (notice the cutout in the bridge for the lock gate!) and a footbridge crosses over the top of the line and the canal.
To the right is Mile Marker 56-36 . The mile marker is one of the originals cast in 1819 at Stone by Rangeley & Dixon to replace existing stone markers and is Grade II listed.
SJ8746 : Stoke Top Lock I believe the cover was over a maintenance dry dock that also had a barge weighing mechanism in it. Further corroboration would be welcome.