I'm sorry, I thought the 24tph after mentioning RR, but TM has thoroughly covered this.Either the second one was supposed to be an edit to the first, or these two posts are two of the most ironic pieces of a back-and-forth I've seen in a while.
It's not entirely clear what your "24 tph, tops" number is referring to, but it is entirely clear that if there's a source for it, you didn't cite it in your post (if it was cited previously in the thread, I must have missed it) Even if that number is accurate (which it might be; I know TransitMatters had a significantly-higher number for Southside regional rail, but that is the busier side), while I agree with you that two tracks can generally accommodate 24 tph, I don't know if that figure applies to tracks feeding pretty much directly into a terminal (and at present each two-track bridge only serves half of NS; will the crossing-over needed to go from a two-track bridge to the ten-track terminal screw with capacity for one or both?). It bears repeating that these are moveable bridges, meaning there's a risk of them getting stuck (it's happened with the current ancient ones; new ones should be more reliable, at least for a while, though eventually they'll get old too), meaning there's value in redundancy that ensures a single failure doesn't completely cut off access to the terminal.
This is an ideological statement, not an argument. If you want to present argument and data showing how a Regional Rail north side CR system can operate through the NSRL with absolutely no need for the surface terminal, such would be welcome. (Though it's an option not without risk of waking a slumbering F-Line, who's been very vocal about NSRL not being able to eliminate the surface terminals altogether.)
Problem is, even if such data exists, and supports the argument that North Station would be rendered completely obsolete by the NSRL (and I suspect that at minimum it would require NSRL + OLX to Reading because trying to pair-match Reading through the NSRL without wreaking havoc on scheduling is probably going to be excruciatingly difficult), even then it requires that the NSRL be built. There is no prospect of it being built anytime soon. None whatsoever. We don't get to let the surface terminal become unusable because its bridges have rotted away because we're unhappy that the politicians have sandbagged a better option for so long. Your analogy is fallacious because the "meteor" here (NSRL) doesn't exist.
I'm all in favor of electrifying the Commuter Rail, and of getting rid of nasty, nasty fossil fuels as swiftly as possible, but, uh, if you're going to complain about people's lack of data, maybe don't put things like "we have 20 years" to do X without some kind of explanation?
This does pre-suppose a non NSRL Reading service of some kind.
For the purpose of of this discussion there will be three lines.
Because in part of the GLX, TM has suggested a max of 15 min service on each branch ........ 8 tph
This has more potential of increased frequency due to density and lack of alternatives past Alewife............ . ................................................8tph
Some combination of services involving a maximum 8tph to Nbypt, Rkpt, possibly Danvers and short turns................................................... 8tph.
Amtrak,might, at maximum, run 1tph to Portland, and 1tph to Concord. These are the only likely users in NSRL world.