Leo_Chan
Senior Member
I don't think it would be. Platforms width, stairways, etc. are all sized for fire. Specifically, they assume there is a station fire and both trains are forced to empty at the station.
It would probably require a triple platform setup for both levels as the people traffic would be insane. Getting people exiting one platform and to another platform on the other level and opposite side efficiency would be a logistical nightmare. The circulation from the centre platforms to the surface would require insane capacity.
So, with 4 tracks they'd need to assume that 4 trains need to empty at the station on fire. This would double the amount of platform space and stairway required. So in addition to double the tunnel cost, station cost would also increase more than a trivial amount (station box needs to be wider to allow for much bigger exits from the upper floor).
If need be, a split platform setup could work, but it would require a lot for vertical space and 4 level stacking of tracks.
Like this but doubled:
I'm pretty sure neither St. George or Bloor/Yonge would meet modern fire code if built today.
100% not to modern standards. Not enough vertical circulation, horizontal circulation, nor platform width.
That said, it is an interesting suggestion.
One that would never happen unless the demand was through the atmosphere.