It is quite clear to me that on the old British rail infrastructure there will be difficulties to install overhead power for electrification.
Vast swathes of the network are however pretty straightforward. (No pun intended)
Install gantries at trackside and the hang wires and trackside transformers etc.
The thread diversion (sorry Mick) started because of the word "vision".
Vision is not short term gain and profit for shareholders and bigwigs, but rather (especially in this instance) an attempt to see into the future in a way that will benefit all of the next generation(s)of our society.
Electrifying the rail network fulfills that ideal because of it's many advantages; low pollution at source, simpler maintenance, quiet, high speed and acceleration capabilities and last but not least, the ability to use many diverse sources of power.
With the new renewables now ever more on stream and advances in digitalized management of power this is as future proof as it gets.
A Vision of a low carbon efficient rail system serving us all.
Nothing fancy but good solid tried and tested overhead wire technology for which everything is already in commercial production in Europe.
These last Tory Govts have been more short term in their thinking than many others,and that really is saying something!
Self serving and dogmatic.
Visionless and greedy.
They undid much of the proposed infrastructure investment after the 2008 crash by Darling (an underrated Chancellor IMV), immediately on gaining office, knee jerk stuff and poorly thought through.
HS2 was lauded by Osbourne as a saviour of rail, while the broader network was allowed to stagnate.
I am not an expert but the upgrading and widening of pinch points on the existing infrastructure, plus full electrification would, I feel, have been probably better use of the money.