Section 2 finished in 2007 (just within your 20 year cutoff!)
It links the channel tunnel with London St Pancras. Much of the London part is in tunnels and it is 100% grade separated.
The uk High Speed 2 route was also going to do this and build a new high speed rail line and station into London, but the exact issues you describe seem to mean that it will be halting at a point outside London instead possibly using existing tracks.
Overall though, High speed rail doesn't need new tracks into cities unless all the existing lines are full (or they are too slow)
It's much easier to build high speed line in the countryside and link it to the existing lines that run to existing stations in cities.
(Also the Elizabeth line in London, but's more like a metro really, even if it is 'heavy' rail)
It is pretty impressive and they're looking at building an extension. however oddly its operation speed has been significantly reduced from 268mph to 186mph.
The basic problem is that Maglev is on average more expensive to build and operate
and cannot (unlike ordinary high speed rail trains) ever operate on ordinary (non high speed) rail track.
It's also still pretty experimental, the Shanghai one is operational and high speed, all other operational systems are either low speed or experimental test beds.
Section 2 finished in 2007 (just within your 20 year cutoff!) It links the channel tunnel with London St Pancras. Much of the London part is in tunnels and it is 100% grade separated.
The uk High Speed 2 route was also going to do this and build a new high speed rail line and station into London, but the exact issues you describe seem to mean that it will be halting at a point outside London instead possibly using existing tracks.
Overall though, High speed rail doesn't need new tracks into cities unless all the existing lines are full (or they are too slow)
It's much easier to build high speed line in the countryside and link it to the existing lines that run to existing stations in cities.
(Also the Elizabeth line in London, but's more like a metro really, even if it is 'heavy' rail)