Re: Waterloo & City Line Extension Jun 6, 2012 21:39:26 GMT
Post by anthonyfendall on Jun 6, 2012 21:39:26 GMT
Isn't the central line right next to it, at exactly the same level (give or take a yard or so). Its so close that you could straighten the westbound central line platform by putting the tracks and platform the other way round, and accessing the new platform by just stepping through a new door in the existing waterloo & city interchange corridor (but I'm not saying do this - the corridor is probably too narrow to cope with the extra traffic).
If it was extended, it would need to dive immediately.
It can't go due east, because it either hits the northern line concourse, or the northern line itself, or the northern line escalators. Remember, when you walk from the central line to the northern line, you go down about 1.5 floors, and then there's a corridor and concourse, then there's the northern line right beneath that - there isn't enough room to thread the waterloo and city under the central line.
It can only really dive quite steeply, and turn north (there's enough distance for this, provided it cuts under the building on the corner of princes street - the one opposite the bank of england), going under the west end of the central line platforms.
I don't think it can go over the central line, because it would probably be to close to the old emergency stairs (from the central line).
So the only way to extend the Waterloo & City east, rather than north, would be to completely abandon the existing platforms and take a new route entirely from as far back as mansion house station.
And to thread through to the east, you'd still need to either go so deep that you're under the DLR (which would be a very sharp dive, and difficult to reach - escalators would be huge, emergency stairs would be of hampstead sorts of height, and geologically risky), or cut through the piled foundations of the rothschild skyscraper (which is admittedly ugly enough to be demolished despite its newness), and other buildings.