English Heritage is seeking views on the historic and architectural significance of a number of historic railway buildings, bridges and tunnels along the 116 miles of track of the Great Western main line, which runs from London^s Paddington Station to Bristol^s Temple Meads.
The pioneering Great Western route was built 176 years ago by the eminent engineer Isambard Kingdom Brunel, to open up new trade routes between London and Bristol.
Network Rail^s 10-year improvement plan, which is due to be completed by 2017, includes electrifying part of the historic line.
In response to this major project, English Heritage, with the support from Network Rail, is consulting on the histories and descriptions of 50 buildings and structures which have been identified, as deserving closer attention.
These include bridges and other structures in or around Maidenhead, Reading, Oxford, Newbury, Bath and Bristol.
The consultation, which runs from now until May 9, will help confirm the part these played in the development of the line and provide evidence of their significance.
Following the consultation, English Heritage will recommend to the Department for Culture, Media and Sport which should be designated.
Network Rail has been carrying out a comprehensive survey of the parts of the Great Western main line that will be modernised.
A gazetteer of all the structures along the route has been produced by their consultants, Alan Baxter and Associates, as well as a detailed Statement of History and Significance.
Read together, the documents provide a detailed history of the development of the line as well as identifying significant structures.
Local authorities, the Victorian Society, amenity groups such as the Railway Heritage Trust, Steam Museum and National Railway Museum are some of the bodies being consulted as well as railway enthusiasts and the general public.
Emily Gee, Head of Designation at English Heritage, said: "While the whole Great Western Railway is historically remarkable, statutory listing is warranted for its buildings of special architectural or historic interest.
"After carefully examining the documentary evidence and the structures themselves, it is likely that certain further bridges and other railway buildings will merit listing, and others might be upgraded to better reflect their importance.
"English Heritage is working closely with Network Rail and their professional advisers ^ and now the public ^ to fully understand and protect the most special aspects of this significant Victorian railway achievement, to help prepare it for its next exciting phase."
Patrick Hallgate, Route Managing Director for Network Rail Western, said: "The Great Western Railway is undergoing the biggest investment since it was built by Brunel to deliver faster, greener, more reliable services with additional seats for passengers.
"Electrification will improve links between towns and cities and, critically, help stimulate economic growth across the region. "We recognise the historical and heritage significance of this railway, which is why we^re working closely with English Heritage now to make sure that any sensitive structures are safeguarded ahead of construction."
The consultation is on-line at
www.english-heritage.org.uk/gwml-consultation 
