Here's a bonus view which may or may not make it easier - I posted the side-on shot as it shows the piers which are the only railway feature remaining. The deck was replaced or widened in the 1970s, judging by the style of guard railing used.
and the original image
The piers of this bridge were built to carry a railway line but they never carried a train to the best of my knowledge. It has since been used for a highway.