 The South Wales Railway (a subsidiary of the Great Western Railway) bought the Forest of Dean Railway in 1849; their main line was opened in 1851 between Gloucester and Chepstow, and sidings were built at Bullo Pill for transfer of goods.The Forest of Dean line was surveyed by Isambard Kingdom Brunel in 1851 with a view to constructing a single-track broad gauge (7 ft 0¼ in) steam railway from the main line up to Churchway, with a branch to Whimsey.Although it approximately followed the line of the earlier railway, it was more heavily engineered with embankments, cuttings and tunnels, which tended to straighten out the earlier somewhat meandering course.