All the 25Kv electrification hardware, and its associated costs, being installed over fractions of already electrified and working 3rd rail, or not infilling gaps like that being discussed (which quite possibly will then end up so expensive that it won't be worth doing at all).
Given the difficulties that the North London Line ran into (apparently unexpected) where there were two systems installed, we can doubtless look forward to all sorts of issues at the new changeover points. Do I hear that the Farringdon supply changeover is regarded as the Achilles Heel of Thameslink?
I see that today all round Birmingham is grossly disorganised because the wires are down again, while the southern 3rd rail networks seem to be rolling along, which in all fairness they normally do, at least on the power supply side.
Still not sure how that is a waste if you get an electrified route at the end. By that logic, surely electrifying at 3rd rail is a waste due to the much higher frequency of substations needed?
I doubt they were unexpected, the problems on the NLL I believe were more to do with signalling than the two electrification types interfering with each other. Of course the two run very merrily alongside each other along the Southern WCML.
The changeover will always be the achilles heel but the alternative was 3rd rail up the MML or OHL down to Brighton so....
The changeover points will gradually reduce and of course modern stock is much more adept at switching power supply.
So the wires are down? Okay. Well sometime the 3rd rail fails? Not really a point. Sometimes a diesel engine fails too, we shall electrify everything with OHL. But wait the OHL falls down? Right well lets do 3rd rail, but that fails too. Shall we use diesel (and the circle continues).
Let us add in the 3rd rail risks to staff working on the tracks too as a big plus point for removing it.
It is all a balance, which after numerous years of experimentation, usage and study, has come down on the side of OHL not just the UK but around the world.
--- old post above --- --- new post below ---
It's not petty name calling, at least not directly, and he's perfectly right. Why replace perfectly capable & functioning 750vDC with 25kV AC? An infill would certainly be cheaper!
Nitwits at Network Rail is most certainly petty name calling. Considering there are many Network Rail employees on this forum.