Quote:
Originally Posted by milomilo
That's a good point. AFAIK crossovers in subways aren't placed that often so they might not have planned many anyway. There are only 4 underground stations on the Green Line, so worst case scenario is that those 4 stations just act as a single track (maybe a shuttle) during an incident. For the 8km round trip at 30km/h, that would take 16 minutes, not the end of the world.
You're right to be concerned that it didn't even get mentioned though, it speaks to the priorities of those involved. While I'm sure those actually designing the line are aware of the limitations of technology and construction, it seems like the councillors are either oblivious, don't care, or both
|
If you don't think a 16 minute headway during is the end of the world, you've never tried to do it during rush hour - it would almost be worse than no service, as the crowds would be much greater than could ever be moved by the trains running. Plus, the calculation assumes the train is travelling a consistent 30km/h (no acceleration or deceleration), and doesn't factor in station stops and end changes, so would probably be more like 25 minutes. 7th Avenue is less than 3km, with trains running 40km/h, and a headway like that (for both directions) would be a disaster during rush hour.
There were a few crossovers planned for the tunnel, and are critical for maintaining service during a blockage - Calgary Transit's LRT design guidelines stipulate that crossovers need to be placed to maintain a 10-minute headway in single-track operations (including time needed for the actual crossover movements).
It absolutely needs to be in the discussion.