Engineers have uncovered wartime plans to build a replacement for the iconic Forth Bridge.
The blueprints, found by Arup staff in a microfiche file among a box of historic documents, show a ‘reconstructed’ crossing just east of the existing rail bridge.
Dated 22 January 1945, the documents are attributed to the ‘Engineers Department Edinburgh’. The alternative alignment suggested would have seen the railway deviate through historic parts of Dalmeny and North Queensferry.
The ambitious design – said to represent the equivalent of building three Sydney Harbour Bridges back to back – shows arches standing at 110m high, leaving the track at the same height as it is now, and four masonry towers.
Network Rail and Visit Scotland have called for anyone with information about the plans to get in touch. One theory is that the design was a contingency measure in case the world-famous Victorian structure was destroyed during the Second World War.
Network Rail senior project manager Ian Heigh said: “It’s amazing that a 125-year-old structure like the Forth Bridge can still offer us new mysteries. These plans date from early 1945, towards the end of the Second World War, so we think they may have been drawn up as a contingency plan in the event of a V2 rocket strike.
“To be honest, even Network Rail’s longest serving railway engineers seem to be a bit perplexed by the true purpose of these proposals. If this bridge had been built, the entire character of the area would have altered, not just the famous landmark. We’d love to know more about these plans, so I’d encourage anyone with more information to get in touch.”
Arup was appointed more than a year ago to develop detailed designs for two visitor facilities at the Forth Bridge.