In other words, we have no idea what this will cost or who is going to pay for it. Anyone care to estimate the likely costs of wiring up a few hundred line-kms in some fairly remote parts of the country?
The more remote, the better, frankly.
Route clearance is the killer, not the masts and wires bit. Electrification shouldn't come in any more expensive per stkm than Edinburgh to Glasgow, where there were all manner of issues - slab tracking and fitting more complex OLE at Winchburgh and Cowlairs Tunnels, rebuilding the canal system at Carmuirs, bridge rebuilding at stations like Polmont and meeting the listed building issues at Glasgow Queen Street.
Urban bridge rebuilding is a particular headache, having to liaise with utilities and have pipework and cabling diverted onto temporary structures whilst a bridge is demolished and rebuilt. When you move into rural areas, overbridges tend to be free from utilities and can be demolished and rebuilt fairly quickly and thus cheaply. They also tend to be fewer in number and of course, in rural areas, a road closure and diversion is easier to organise than in the middle of a busy town, whereas many rebuilt bridges on recent schemes have had to be finished under traffic light control to minimise closure periods.
Tunnels are another issue, but again, they tend to be less prevalent in rural areas - from Dunblane to Perth, there's only Moncrieffe Tunnel at 1210 yards, from Perth to Inverness, there's only Kingswood Tunnel (330 yards), Inver Tunnel (370 yards) and Killiecrankie Tunnel (240 yards), whilst from Edinburgh to Dundee via Fife (both sides of the Fife Circle) there's only North Queensferry Tunnel (460 yards), Inverkeithing Tunnel (410 yards) and Kinghorn Tunnel (260 yards)
The Fife tunnels are tight and will take time to electrify, but should be no worse than Winchburgh or Cowlairs. Moncrieffe Tunnel is a bit tight, but might manage with one or the other - slab track or rigid conductor, Killiecrankie Tunnel on the other hand will be a bit more challenging, with the associated viaduct limiting what can be done. It's also worth remembering that there's now more experience built up in the UK using the OBB-PORR slab track system, with quite a bit of that experience being Scottish in recent years, the use of the F+F rigid overhead conductor system too is something the engineering teams are becoming very familiar with (and there's ROC outside of tunnels now too, which is a useful precedent).
The bridges across the Forth and Tay will be difficult, as I've discussed, but not particularly costly. There will be bespoke steel elements needed and they'll have to be painted to match the Forth Bridge for visual impact, there will also be some additional electrical components needed, but that's all a drop in the ocean compared to rebuilding a major structure, and that itself is a drop in the ocean compared with diverting the Edinburgh City by-pass to fit in an underpass for the Borders Railway.
So in short, I would expect, thanks to a combination of generally easier route clearance, more stable electrification standards, and most importantly, hard fought experience from some really tricky initial projects in Scotland, the average cost per single track kilometre for the proposed works will be somewhere in line with those on the Shotts project and if I had to guesstimate, a bit lower than that.