This photograph was published on Geograph.co.uk by Martin Tester and is shared here under a Creative Commons Licence.
It is dated around 1966-1967 and shows the upper deck of Ashton Avenue Bridge in the process of being dismantled. At this time the lines across the bridge were still double track, the West line was not removed until some time later.
“At one time this bridge over the New Cut was a really extraordinary structure – it had 2 decks, road above rail, & swung, using power supplied from the City Docks hydraulic system. The control cabin was on an elevated structure spanning the roadway. Built by Bristol Corporation & opened in 1906 it allowed the GWR’s line to Wapping Wharf (from Temple Meads) to be extended to serve more wharves, a new goods shed at Canon’s Marsh, & to connect with the Portishead Branch. A swing bridge was needed because the New Cut was used by river traffic to access Bathurst Basin. It was last swung in 1934 & formally fixed in 1951. The roadway & control cabin were removed in 1965-66 as part of major road changes around Cumberland Basin.”
This photo (source unknown) shows the bridge when both decks were in use. Note the tracks crossing left to right to access to other sidings next to A Bond, where the Create Centre car park now is. The diverging line at the bottom of the photo is the one to Canon’s Marsh.