Quote:
Originally Posted by ardecila
Nooo.... the single bore is a bad idea. A bigger tunnel bore needs to be much deeper to avoid surface disruption, so any stations will be many stories deep underground. Several minutes to get from the street level down to the platform. Heavy reliance on elevators and escalators, when most transit agencies don't have the resources to keep them in good working order all the time.
Also there are (or should be) no "station boxes" with this construction type. The sole advantage is that station platforms (and crossovers) can be constructed within the single bore. In theory the tunneling is much more expensive with single bore, but the savings on stations and crossovers outweighs that for a slightly lower cost overall. If Bechtel is planning station boxes, they're doing it wrong! There is a shaft to the side of the tunnel for vertical access, though. |
STP (Bechtel) isn't doing a large single bore like San Jose or Barcelona... its more of like twin plus.... think just a bit bigger than our twin method. They are doing station boxes differently too. I put up the diagram
several pages back (pg 298) on their method and its quite an interesting concept. 2 major things shrink the diameter in this proposal from other single bores.
1. Staggered Platforms
2. Low clearance trains by removing on board rotary propulsion systems
When I go back to the meeting, I will take pictures.
Quote:
Originally Posted by Quixote
Yep. Watch the train pull out of the station at 13:25... 20 seconds later at 13:45 you see another train approaching!
• Video Link |
Whoa. That's crazy! I went back to page 298 to reference the tunnel stuff and realize I never watched this video before. That was
25 seconds between trains. on an automated system. Yeah, this could be LA