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RR503

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Everything posted by RR503

  1. Most of Lex's current day issues are related to overlong dwell times, long control lines and issues closing train spacing via ST. Eminently fixable with CBTC, especially if NYCT fixes CBTC's interlocking compatibility issues. FWIW, dwell times southbound at USQ aren't as bad as northbound. The GFs suck -- if for no other reason than ADA -- but they're not the biggest ops impediment to improved service on the corridor.
  2. So you do realize that running more trains to the Bronx will reduce average load/train, right? While also allowing IRT West's express tracks to do more than their measly 22tph peak. This notion that you need to put in s because trains from the Bronx will always be full is just...wrong. Induced demand exists, yes, but a) it's weak during peak times, and b) this would allow a nontrivial increase in service level down the express there. There are also, I might add, ways to redistribute loads away from the , for ex by running more . That said, I agree that deinterlining 149 is a bad idea in the short run -- the platforms/stairs that'd absorb the transfer loads there are waaaay too narrow for the volumes that'd be transiting them. I'm really amused by the suggestion that 59 St is a good junction. It isn't. It sucks -- so badly, in fact, that the entire IND is scheduled backwards from it. Regardless, you cannot easily reconfigure Rogers to look like 59. You'd basically have to reconfigure the entire Eastern Parkway line east of Franklin to do so, as preserving the stacked config makes it impossible to deconflict the interlocking (the best configurations the '90s and '00s studies on the issue could come up with were ones that put 3 services on one track through Franklin, the issues with which should be self evident). And, of course, I do not see any logic in spending an order of magnitude more money to build something with a _lower_ operational/travel time return than simply deinterlining the area. Tail tracks would be really nice, but it's worth keeping in mind that the majority (IINM 16/22) of AM put ins come out of 148. Running a few early-AM put ins from New Lots wouldn't be that hard, nor would be skewing the balance of IRT West express service more towards s to allow more put ins from the Bronx's yards -- remember there'll be more space up there for put-ins given that the would have some of its fleet transferred to Livonia.
  3. And, of course, low service frequency is inextricable from problem of interlining. Re: the and yard access, much of the reason this was an issue in the past is because the rampdown in passenger volumes after the PM peak was extreme, so running trains north from Flatbush to yards in Manhattan/the Bx was financially inefficient. That's not the case today, and as has been noted in past discussions on the issue, it'd be trivial to run some s or s as put-ins from Livonia.
  4. Once again, the logic of Dekalb deinterlining is that said transfer really wouldn't have to be used all that much. If you're on the , you can use the to almost exactly the same destinations in Midtown, or transfer to the to get further east/west/closer to 14 St. Vice verse for Broadway: transfer to the to move your final destination around if necessary. And, of course, Herald Square exists. I don't disagree that some of the proposals here are tending towards...the extreme, but I do think it's worth pointing out -- and I'm sure you understand this -- that transfers aren't the only contributor to trip time. Merge delays from poorly designed service pattern, dwell delays from unbalanced loads, etc, all lengthen trips as well, and generally have ramifications for the entire system vs people in some rel. limited submarket. This is about balance.
  5. - If you’re going to interline 11 St, you may as well give Bay Ridge the yard to simplify equipment moves - Phasing out Whitehall as a terminal should be a long term planning goal given its severe negative impacts on through service - City Hall Curve can’t handle >21tph with existing signaling, which would leave you with just 6tph of WHL-CTL after filling Astoria Reforming punch treatment may get you +1tph, but beyond that deinterlining is needed. It alone is likely the most impactful step you could take towards upping capacity, but you’d probably run into other topological constraints if you tried to push tph above, say, 24. Not only is the signal system within the junction quite gnarly (lots of timers, long control lines, etc), but many of the corridors feeding the junction have constraints of their own, ex 36 St merge and long control lines on the NB express for the , the sharp curve entering Dekalb NB on the , Whitehall terminal, 95 St terminal and City Hall Curve on the , 59 St on the , etc etc etc. This isn’t to say deinterlining isn’t useful, you just have to take a system perspective when doing it.
  6. ...Bleecker St, Barclays Center transfer to the ... Hardly separating them. FWIW, I think the most convincing argument against deinterlining Dekalb is that it'd make it difficult for West End riders to get to 8th Ave. You'd be looking at either an xfer to the for Jay, a ride crosstown on the , or substitution using the from Barclays for areas south of 42, at which point are only a block from 8th. Do I think that that's sufficient reason not to deinterline Dekalb? No, both because 8th Avenue below 42 St has, by Manhattan standards, very low job density, and because Dekalb has huge operational ramifications for the system...including 8th Ave. But it's interesting food for thought. I'm sure some do through ride. But the peak load point for the is, last I checked, between Roosevelt and Elmhurst -- ie the sum of through riders and passengers boarding west of Roosevelt isn't enough to replicate loads east of Roosevelt. Re: O/D I'd strongly challenge the notion that the primary destinations are Broadway and 53. trains gather most of their loads at 1 stop (Lex-59), trains leave 47-50 packed, and SRO s north out of there in the PM are the norm. 53 is certainly a draw, but let's not forget that 6th Ave is damn near the median midtown job.
  7. 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.
  8. 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.
  9. 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.
  10. 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.
  11. 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...
  12. 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.
  13. 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.
  14. 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.
  15. 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.
  16. 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.
  17. 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.
  18. Ah, sorry--CBTC can fix all of these areas, but they're only installing on 8th and Fulton.
  19. 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.
  20. 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).
  21. 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?
  22. CBTC will take care of 8th and Fulton, but you can't really do anything about the timers on CPW. Whatever you may think of their implementation, they do indeed serve real safety functions!
  23. They stopped turning 10s into 8s or 6s for that reason. Splitting a train in half isn't nearly as annoying an operation as doing some uneven cut, as you end up with some stump when you're done. Lefferts , Dyre , Myrtle do this every night. Shortened trainsets would free up CRs and reduce ABDs related to CR availability, but you wouldn't save that much $$$. Remember, a work program is a work program -- whether you run what's in it or not, those called on a given day still have to show up.
  24. So I guess my question is why you chose not to do things like to 18 and to West End? Those things have clear operational (and ridership) upsides, which have been talked through in the past/in this current discussion. There certainly are counterarguments to be made, but "I didn't feel like it" isn't really one of them. Also am wondering what your reasoning with the is. At 16tph, the schedules for express allow a merge at Bway Jct without too much pain, and there's nonzero demand between Bway Jct and points east. Why short turn locals?
  25. On the short term map, express/ local allows you to deinterline 59, 50 and Canal without touching Queens and helps keep the to a decent length. Once you've done that, you're somewhat forced to do to Brighton -- to 4th would mean you either end up with 4 weekend services on CPW (the two expresses, and then two locals because you need one for each branch of 4th exp), more local than express service on CPW, or one of West End/Sea Beach without weekend service to Manhattan. On the long term, I figure a) continuity is good, b) the logic rel. the still holds, c) the as an overlay Brighton Express/Concourse Local service is legible and really pretty to operate (clear hierarchies of primary/secondary services makes disruption management easier because it's easy to thin out/suspend a train without messing up some branch's service).
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