So sometime between maybe 1920 and 1950 the bridge has been rebuilt, I would guess at the same time as the embankments were filled in over the arches.
The wisdom of crowds in full force on this thread - superb detective work
Easter Monday c.1929. Temporary scaffolding is in place on the East Lancashire Railway bridge, possibly in connection with the replacement of the cast iron arch bridge spans. These were replaced with steel girders in 1930.
Coming down watling St road and turning onto Garstang road, I think.Winston Churchill in Preston. Which street corner is that in Fulwood??
Watch The Prime Minister, the Right Honourable Winston S. Churchill visits Fulwood and Preston, 27th June 1945 - BFI PlayerWinston Churchill visits Lancashire, in the closing days of his premiership and the last months of the Second World War.player.bfi.org.uk