That’s a Class 81 or 82

We have that here. The 750V DC OLE on the Sheffield Tram Train route to Rotherham over the national network is able to be converted to 25kV AC. The point is converting 3rd rail to OLE is a very different prospect.

Yes but the French are starting to struggle for funding. And GB rail is also being starved of funding. In that landscape the idea of these mass infrastructure works is just not likely. I highly doubt there’ll be any conversions on the Southern in my lifetime.

Absolutely no chance. Converting 3rd rail to OLE is a completely different prospect to converting 1 OLE system to another. Also the French are now struggling with how to fund what to do with the remaining outdated 1.5kV DC system. Some smaller lines are being converted to hydrogen (or diesel)

There’d be an issue anyway as EU gauge stock has different platform heights. But that’s a future future problem, just like the Crossrail platform height problem when they need to replace the Class 345s.

This will never happen. If we’re lucky we’ll get W12 clearance via Maidstone East although more likely is W9a. There is no chance of DC-AC conversion.

Nope.

It has its uses but in terms of relief, it only relieves capacity on the GWML & WCMLs.

Let’s be real, if we really wanted a proper height for HS2 platforms it would be as close to the GB 915mm standard as possible so that we could have level boarding on & off HS2 infrastructure. Given the basic impossibility of an HS1 connection, that would be the better option.

to London Gateway, we can’t use the cross country route from there (only from Felixstowe). With more freight traffic now using the NLL the idea of such a closure is even more fanciful.

Finally, whilst the freight sector would balk at losing the NLL for a considerable period of time, I’m sure TfL would also balk at the prospect of shutting the Mildmay Line for extended periods whilst making their platforms worse. Also, we also can’t lose the NLL because since the switch of volume ⬇️

raise bridges &/or lower track through bridges/tunnels & likely have to rebuild Camden Road & Kilburn High Road bridges as well. The idea of using the NLL is a flight a fancy. The cost & disruption of doing this would be very high where you might as well build a new set of tunnels under Camden.

IIRC HS2 platform heights will provide level boarding. HS2 stock will have 1115mm high floors so completely non-standard. The NLL is a W10 railway so is 500mm too narrow & ~1500mm too low to accommodate a GC gauge train. You’d have to rebuild every platform against the 915mm standard, ⬇️