Extracts from
Wikipedia[url] on the complex history of trains from Exeter to Plymouth via Okehampton and Tavistock
Lidford was chosen as the terminus because from there a connection with the SDR's Tavistock branch line could give LSWR▸ trains access to Plymouth via Tavistock. However it was only on 17 May 1876 that the connection was made and trains could run through to Plymouth. This was a broad gauge line so, as at Crediton, a third rail was added to create a mixed gauge route
Running over the SDR line, the trains of the LSWR entered Plymouth from the east.
Access to Plymouth was inconvenient as LSWR trains had to run over the GWR▸ 's lines from Lidford to Plymouth and Devonport, most of which was just a single-track where GWR trains were given precedence.
The PD&SWJR line opened on 2 June 1890 and this changed Devonport into a through station. The new west-facing connection to Friary was brought into use on 1 April 1891. Trains to London now started from Friary, ran through Plymouth from east to west, called at North Road, and continued westwards through Devonport before heading north alongside the Tamar.
Trains between Exeter and Plymouth via Okehampton were withdrawn from 6 May 1968. The 20-mile (32 km) section between Meldon Quarry and Bere Alston was lifted, and between Meldon and Okehampton the line was only retained for freight trains. Okehampton to Exeter passenger services were withdrawn on 5 June 1972.
Proposals were made in 2008 to reopen the line from Tavistock to Bere Alston for a through service to Plymouth. In the wake of widespread disruption caused by damage to the mainline track on the south coast at Dawlish by coastal storms in February 2014, Network Rail considered reopening the Tavistock to Okehampton and Exeter section of the line as an alternative to the coastal route. The line was listed in 2019 by Campaign for Better Transport as a 'priority 1' candidate for reopening.