High Quality Content by WIKIPEDIA articles! The Exeter to Plymouth line is a central part of the trunk railway line between London Paddington and Penzance in the southern United Kingdom. It is a major branch of the Great Western Main Line and runs from Exeter, to Plymouth, from where it continues as the Cornish Main Line. It was one of the principal routes of the Great Western Railway which in 1948 became part of the Western Region of British Railways and are now part of the Network Rail system.