That's the Great Western main line on top of the bridge (see signal gantry on left), but why that curious structure beneath? That was an underbridge for the direct line from the Blaenavon collieries to ships on the wharves on the River Usk. see image 39348 Newport station is to the right (West) of this view. Mill Street station was just North of this bridge; it was open to passengers from 1853 to 1880, and had standard gauge track; as opposed to the broad gauge High Street station, and the 4 foot 4 inches Dock Street!
Location: Newport
Original line: South Wales Railway
Photographer: Ken Strachan
Contact photographer: Ken Strachan
Photosets: South Wales, ancient and modern
Date: 20/06/2012
Image number: 39372