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RR503

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RR503 last won the day on March 15

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About RR503

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  1. Yeah, of course they don’t want to. But we aren’t getting new Manhattan<>Queens tunnels anytime soon, and the only way you can extract more capacity from Queens boulevard is by getting more people to ride locals west of Roosevelt, sooooo... As anyone who rides QB can tell you, the incentives to stay on the local today are mighty weak. Ever been to Roosevelt during the AM rush? Wall of lining the express, that grows whenever a local pulls in.
  2. Yes! This is exactly what I’d do. People underrate the capabilities of WTC (look at 8th or SF ) as well as the operational convenience of having your QB-53 service be a short line.
  3. This effectively limits 8th local and 6th local to a _combined_ 30tph. Have the decency to give the its own trunk! It seems I'm fighting a losing battle here on convincing folks that interlining 36 St is a bad idea, but I'll make one last pass at it. As I mentioned upthread, 59 St -- whose merge configuration is exactly the same as 36 -- is a bad merge. It is, in fact, a _very_ bad merge. It causes a massive amount of runtime variability on the routes that pass through it, and is in fact so limiting of B division performance that the entire division is scheduled backwards from it. Here are variability charts for the and to help attach numbers to the issue: The merge performs badly not because it's cursed with slow switch speeds or poor signalling, but because of its design and its position on the routes that transit it. 59 St is what I like to call a 'conflicting merge,' where a merge delay can ripple backwards through the pipeline and cause a delay on a different service (think: ). Here, this effect is especially pernicious because a delaying a or vice versa can further complicate things by messing up the merge of the second service -- if a is delayed by an and delays a behind it, that may end up delaying (or being delayed by) a . Worsening its impact is the fact that it's positioned immediately before a high-dwell station, meaning delays from a merge get followed by a nice dose of NYCT close-in fixed block ops, which are...bad. Finally, the merge in both the north and southbound directions is downstream of at least one other merge, making consistent operation through it that much more difficult. 36 St would be all of this, but worse. While there isn't a high dwell station to aggravate things, switches at 36 are slower and train volume is higher. With _current_ throughputs (before you up service levels, which sorta is the whole point of this exercise) Jackson Heights (closest measure point with all services passing through) sees 4tph more trains (in both peaks) than 59 St does in the AM. Both charts show n/b train volumes: vs Given that merge delays are proportional to throughput (see chart below of runtimes through a day), you've got a problem. I am _extremely_ skeptical that you'd be able to hold the PM peak railroad together through 36 St, what with the lines having passed through merges and a bunch of high-dwell Midtown stops on their routes to 36. I think as throughputs went towards 50 or 60tph, you'd end up with trains stacking up through 63 St and into Queens Plaza, which really just...isn't a way to run the trains. This operational logic alone should be enough to convince folks that this may not be the wisest of ideas. In case you don't feel this way, let's talk about O/D. Sure, QB local loses direct 6th local access, and QB express gets cut off from 53/8. But express riders can easily transfer at Jackson Heights to recapture that O/D, and local riders can get the at 7-53 for 6th; neither of those losses should be dealbreakers. The O/D argument that _should_ give pause is that interlined 36 St would mean there is zero incentive to stay on the local past Roosevelt (or Woodhaven, if that gets built out). On the ? Take the . On the ? Take the . That would likely make the Queens Boulevard dwell time issue -- which already produces peak hour runtime increases as pronounced as this: ...to say nothing of the fact that it'd further reduce the efficiency of the Queens subway network by reducing loads on the one part of said network that has significant room for growth: QB local. I really don't suggest this course of action.
  4. Yes, internal schedules schedule put ins, layups etc. They are not random operations. This. A bunch of new operators on a line with tons of gnarly GTs and poorly signed (if signed at all) STs is really not a recipe for consistent runtimes and service delivery. I do not mean to belittle the work those crews do, of course. It’s just they could benefit from better infrastructure, better training and a more nurturing supervisory environment.
  5. The other horrible one is the , especially during GOs or rush hours. A 2 hour round trip without leaving the cab PEL-BBR-PEL + adjacent track flagging or rush hour delays can really do a number on you. And if you're late, and your layover gets cut at Pelham...
  6. I don't think it did... 1) Maybe the switches connecting City Hall yard with the mainline north of Fulton. The diverging move north of BB is awful. 2&3) Yes. Deinterlining CPW is an extremely worthy policy objective in and of itself. 59 St is a terrible merge -- so bad, in fact, that the entire IND is scheduled backwards from it.
  7. WTC honestly...isn't that bad. It's a stub, but you could (esp. post-CBTC) probably get >>20tph out of it, if we use 8 Av and SF as our reference points. The issue with interlining 36 St is twofold. The first problem is that it eliminates any incentive to stay on the express beyond Roosevelt -- riders can use the and riders can use the . The worked largely by giving ridership beyond Roosevelt a one seat ride across the peak load points into the CBD (thus relieving the ) and picking up nontrivial LIC-6th Ave ridership that used to use the . Very, very few people through rode beyond Roosevelt when the express was an alt for their destination. Second problem is, of course, ops. I don't think I need to explain just how garbage 59 St is. Its peak throughput is about 43tph across two tracks. Imagine running it at 50-60tph. It's simply an operational non-starter.
  8. Something to be thankful for here is that the T/O got the train to 110. Tunnel fires are scary; tunnel fires in deep bored tunnels built to 1900s egress standards and with little fire protection could have been even more catastrophic. My heart goes out to the family of the deceased; he's a hero.
  9. Gonna disagree that it's a great idea in theory -- it's a great one in practice as well. It was just designed obtusely, so that you have to LR the entire train vs a zone, which means you can't use it in normal door operation or outside of an autorecycle sequence bc just pressing the button may recycle a door you're not looking at.
  10. When the signal contract went out for Culver, Church was never supposed to be a real terminal -- it was just a place to squirrel away trains. When presented with the opportunity to save maintenance $$$ on 4 switches, then, the agency went for it....et voila. I'm not either. But it's certainly something worth looking at IMO.
  11. Church certainly could use a little help on the policy side, but there are real infrastructure constraints there -- especially if NYCT ever lengthens Gs to >300'. The ramp down to the lower level is timed to 10mph, making the diverging move down to the layups S L O W. The ramps themselves are also quite short, so if you get downstairs and don't have a lineup into a relay, a long train will overhang onto the main. Once you're at the yard, things don't improve. Some aspiring engineer decided to mess with the switch config in the yard durin the resignalling, so instead of having this: We now have this: Which reduces flexibility and forces the installation of annoyingly restrictive signalling. The relays themselves are also only 600' long and have AK signals on them, so if you're a long train you're gonna c r e e p in, reducing turning capacity. These problems, with the exceptions of the ramp and relay length are fixable, but would require a decent bit of investment. When the alternative is good for ops, good for the budget (because of the amount of time it takes to relay a train, doing the 8m + layover time trip to 18th would be approximately cost neutral but ridership-positive), and good politics....why not? The 4th Avenue corridor has 3 branches and 2 tracks in each direction. You're stuck with a merge kinda however you want to slice the pie, so to speak. The move off of West End is nasty, so I'd imagine that new xovers south of 36 could only be an improvement. Free yard space! Also overflow for whatever you can't turn at 18. If you move the crossovers, you could definitely do more than 15tph. Both levels have tail tracks (albeit ones that are normally occupied), so with good switch geometry I don't see any reason why we shouldn't be looking at capacity figures that begin with a 2 or a 3.
  12. Ah, sorry--CBTC can fix all of these areas, but they're only installing on 8th and Fulton.
  13. See my original response. CBTC fixes this 100% because your speed profile is the lower of maximum allowed speed for geometry and maximum safe speed for following. This, plus the acceleration benefits that come with CBTC ops are why you see such big runtime gains when you turn CBTC on. The whole point of my reply is these aren’t exactly physics (curve speeds etc) problems: they are choices made relative to a very specific set of constraints inherent to fixed block installations. FWIW, CBTC fixes operator variability but not conductor variability, which can be punishing in high ridership segments.
  14. If I were a betting man, I would be willing to wager that a majority of timers exist for control line safety (ie making sure trains are going slow enough that, given a certain distance ahead of a signal which makes it red/maximum attainable speed, there's sufficient stopping distance) rather than to protect nutty track geometry. Most CPW timers are there for that reason, or were baked into the resignalling they did there in the late '80s because controlling train speeds actually can help _increase_ capacity (this is the primary motivation behind many timed areas on downgrades: it's not so much that we don't want trains doing 65 as it is we don't want to have the control line lengths that'd come with that).
  15. Yes, West End loves express. But this gets you yard access for the and doubles their frequency or allows express. I'd say that's a viable trade-off, no? Because Stillwell can't handle that many s. Absent some rebuild plan, you need KH as a relief for s, which forces the to 18 or Church. Of those two, I'd take 18th with the equivocation that at tph >10 you should split between the two terminals as you really don't want to be running a single pocket at those frequencies. Ah, I see. That makes sense, though you could easily use Crescent or 111 St to short turn. Much less pretty of an operation, but doable enough. I see on your map that you moved the crossovers on the UL at Parsons -- why not do the LL too?
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