https://peninsularailtaskforce.files.wordpress.com/2016/11/prtf-closing-the-gap.pdf
Capacity and comfort - Long Term Strategy 2030+
Extract from the above.
Dartmoor Northern Route Phase 3. Completion of the northern route through
a 90mph predominantly single track route between Coleford Jn and Tavistock
including a North Cornwall Parkway station.
Provide passenger services to an area of poor accessibility and rural deprivation. Improves connectivity to northern Cornwall. Improves resilience through provision of a
diversionary route.
Inclusion in the long term rail industry electrification programme to the South west
peninsula, building on partial electrification that has taken place.
Improved resilience, performance benefits, fuel savings and environmental benefits.
Notes: * Assumed similar cost to the Tavistock reopening to cover upgrade of the Okehampton route (GSM R and linespeed etc), creation of long dynamic loop around Crediton by converting and upgrading the parallel single lines to Coleford divergence and extending the existing loop eastwards.
**Capacity between Westbury and Reading for mix of passenger and freight was identified as the prime constraint on capacity by the Western Route study. Resolving this is essential to provide reliable journey times.
****Costs taken as approximates from ARUP 2013 study for DfT.
So, it is official or at least the intention is official. A 90mph line via Okehampton and Tavistock, presumably by slewing across curves to allow higher speeds. No doubt the Gov will delay and prevaricate for ages. Also mentioned.....
Part re-doubling from Castle Cary to Yeovil and beyond to Exeter
Hungerford diversion (?)
Westbury platform 4 reopening
Selective electrification over Dainton, presumably not in the tunnel.