The line was first proposed in 1837 but it took until 1844 before an Act of Parliament authorised its construction. The broad gauge line and viaduct at Ivybridge was opened on 5th May 1848 as part of the Totnes to Laira (Plymouth) line. This line consisted of the last extension of the Great Western Railway from Bristol to Plymouth.
To celebrate the opening of the South Devon Line, a special train carrying invited guests, many connected with its construction, left Laira near Plymouth on the morning of 5 May. The train consisted of one first class carriage, two second class and two third class and was drawn by two engines, named Pisces and Cancer.
Shortly after leaving Laira the journey took in the grounds of the Earl of Morley at Saltram and Colebrook Station at Plympton before continuing through open countryside. Entering a deep cutting at Ivybridge, the train passed the yet to be completed railway station. From there the track crossed the Exeter to Plymouth turnpike road via a skew bridge near Bittaford and then on to the 800-yard Marley tunnel through the grounds of Lady Carew. After an “exceedingly pleasant trip”, passengers alighted the train at Totnes just 42 minutes later.
At Totnes everyone enjoyed a breakfast at the Seven Stars and Seymour Hotels before re-boarding the train which was decked in flags and evergreens for the return journey. Arriving back to Plymouth the guests were met and transported to the Royal Hotel for a déjeûner á la fourchette and the prosperity of the South Devon Railway was toasted.