Not a chance of turning a train like that around in 4 hours. It is going to have a "home" during these works which it will need to get back to and from the work site. The HOBC and TSR4 need 8 hours minimum between shifts.
Ok, so no 16-hour days. My figures above didn't consider being able to run two shifts though, so let's see how much wiring can actually be achived if we are going to make the most of the electrification train.
Going with the two electrification teams I listed above (a High Output train for GWML and a much slower system in the north West), and assuming both teams start Jan 2013 and anything after Dec 2019 is too late for replacing IC125s and Pacers without granting temporary Equality Act / DDA exemptions there is 7 years of wiring.
The GWML team, at 150 miles per year, can electrify 1,050 route miles of railway in those 7 years. The slower NW team, 25 miles a year, could do 175 miles in that time. I've read on here that Network Rail are looking at buying a second Hugh Output train for the TPE north project. Assuming that also gets going in 2013, that would be another 1,050 miles of electrification by the end of 2019.
Personally, I think there should also be a third rail electrification team to rid Southern of diesels and free up most of SWT's Sprinters. As a wild guess that'd manage 25 miles per year like the NW team.
So, which 2,275 miles of railway (plus perhaps 175 miles of 3rd rail) would you like electrified? What's the total present mileage of electrified lines and other lines?
P.S. Does anyone know what electrification plant was used for the new rail line (Bathgate being one end) in Scotland, and is/will be being used on Edinbrough - Glasgow electrification (and what the timescale for said project, and TPE for that matter, is)? Maybe the Scotish OHLE team could be used to increase the 2,275 mile total even higher by wiring to, say, Aberdeen?