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RR503

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Posts posted by RR503

  1. On 7/12/2021 at 7:56 PM, darkstar8983 said:

    Some of the main problems with ANY de-interlining plain I see is that

    1. The current subway system (even with rebuilding of Rogers Av Junction) has inefficient terminal operations that cap the number of trains that can run on the entire line.

    2. If we try to circumvent issue 1, then interlining begins, either through merges, or short-turn trains. With short-turns, you are forcing a station that typically doesn't operate as a terminal to operate as one. If there are going to be merges, then it defeats the purpose of de-interlining, which would just add confusion

    3. You would be forcing the subway to YES operate at near max capacity, yet MORE riders will not be taken to their destination on a single line. This would force transfers, or additional walking time to get to/from their destination, which could re-shape the rush hour (making it start earlier and ending it later). The problem with transfers is that within the system there are some stations (even in popular complexes) that have narrow pathways that wouldn't be able to handle the foot traffic.

    4. De-interlining the system would drive up the cost of providing daily service because many more train crews would be needed to operate each line - which would therefore translate into needing government grants to make up the deficit because you can be sure that doubling the subway fare will be a non-starter.

    Pretty much all of these issues boil down to "we'd need to run more trains to implement plan x." That isn't always true! Let's run through the common proposals:

    - (F)/(M) swap: you really should bump up (M) service by 1-2tph given how popular the connection at Lex-63 has become with the (Q), but you don't have to, and the running time differences btwn the two routes are like 1 minute.

    - CPW: again, you should increase service, but it's totally feasible without that. Assuming (B) - 168 local, (D) - BPB local, (A) - 207 exp and (C) - 205 exp, essentially swap (C) and (D) service levels for the CPW peaks (so s/b AM and n/b PM). The (C) is about 10 mins shorter than the (D) (comparing 59-EUC to 59-STL), but some of that is made up for by the fact that (C)s relay and (D)s don't. Either way, minimal changes in overall service-hours spent 

    - Dekalb: all of the S. Brooklyn Manhattan Bridge routes have, to a first approximation, the same service profile in the Brooklyn peaks. So that's an easy one. 

    Now for the harder ones:

    - 34 St: you basically need to add 7.5tph of (W) service to make up for lost (N)s. Some of the service-hours you need for that can come from the fact that 96 St is 11 mins closer to 34 than Astoria, but you'll end up spending money there. 

    - Rogers: Peak hour (3) service levels are close enough to the (5) that you could probably get away with not adding service here, but the whole point of this investment is that the IRT express routes run well below need, especially for Brooklyn peaks and on the West Side. 

    - Something more extensive in Queens: I think the need to add service when you do (E)(K)(F)(M) and (R) to Astoria is pretty self evident? 

    Also note: for most merges, you'll likely achieve some running time savings through merge elimination. Nothing earth shattering, but with knock on effects in reduced OT, dispatcher workload, switch maintenance...it's money!

  2. FWIW: in the world where we don't have 10 car (M)s or an express station at 36 St, I think the best QBL deinterlining plan is the light touch (F)/(M) swap. Lex-63 is an awful place to merge services -- you're making a 34 St copy at the beginning of the 30+ tph QBL trunk -- and you can realize a good bit of reliability and speed benefits by fixing CPW and Dekalb while you wait. 

  3. On 7/10/2021 at 7:19 AM, jammerbot said:

    My understanding is that 179  was initially designed to be the terminal for four services on the QB, so this 30 each figure makes sense. My natural doubtfulness would lower this number a bit, but I think the M could afford to turn around there to relieve congestion at 71 Av.

    179 is likely to be limited by the same problems that afflict Forest Hills: train clearing, and poor coordination of recrewings. It'll likely run a bit better because there's no diverging move immediately after the inbound platform (and CBTC is still something of an X factor in all of this) but we're talking about the difference between 20 and 22 or 23, not 20 and 30. 

    Also: take those terminal capacity estimates with a (small) grain of salt. A lot of them look about right, but, for example, Utica sees hours where it turns 15tph on its two relay tracks. Really the best way to figure out this sort of question is to go and time train movements during peak hours...

  4. On 6/20/2021 at 5:18 AM, Trainmaster5 said:

    The mistake that many people are making is that CBTC speeds up the system when actually the premise is that trains can operate closer together with the newer system. The trains aren’t going any faster it’s just the spacing of the signals making it appear that way. In my experience it’s the variants that I mentioned that determine the running times of the intervals throughout the day. Hope this makes sense. That’s why specifically mentioned the Lexington Avenue line.  Carry on.

    You actually do get sped up! The NTTs come programmed with two acceleration curves: the "cold curve" for use on fixed block portions of the system, and the "hot curve," for use in CBTC territory. During peak hours, you're going to be gaining as much from higher quality close-in operations as you are from faster speeds, but the difference is significant. 

  5. To the curvature point: I think the precedent that most thoroughly puts the lie to the whole "curvature and length compromises OPTO" argument is Paris's RER. Many of its lines have been OPTO since the 1990s, and some run ten car trains of bilevel EMUs through stations which are packed and often quite curvy. Successful implementation obviously requires good investments in CCTV infrastructure (some of which the L already has), but it's really not impossible. 

    (London's Thameslink is another good one)

  6. On 6/22/2021 at 9:41 AM, paulrivera said:

    What I would do is run those (D) trips in service up Brighton. The (B) stops running between 7 and 9 depending on what's going on that night anyway, and those empty (D) trains are a waste when they're actually needed elsewhere.

    This is a good question. The reason (D)s are sent up Culver is because the weakest link in the entire "everything up the wall after 7:30" GO is Dekalb. North of 36 St, there isn't any way of getting (D)s and (N)s back onto the express tracks, so you have a few hours every evening where the (B)(D)(N)(Q) are all sharing A2 track through Dekalb Avenue station. That can get *quite* messy quite quickly, so reducing train volumes there is a must -- hence Culver. 

    My big question about the (D) via Culver, fwiw, is why those intervals don't run via B4 track. Sending them up the local -- which seems to be the norm -- seems a waste of time and money, to say nothing of delay around Church. 

    Not going to touch the Wally proposal, because self care summer

  7. 5 hours ago, R10 2952 said:

    Either that or accused of being tone-deaf to the political realities.  Convincing the MTA and local leaders to allow wholesale deinterlining is a pipe dream and politically DOA.  They won't sign off on it; even the proposals that do make sense would result in the community boards, councilmember offices, and borough halls getting bombarded with letters by outer-borough riders pissed off at losing their one-seat rides.  Persuading these folks on whatever benefits they could incur would be a tough sell.  Without the support of management and the local pols, many of these proposals will simply be unable to move forward. The whole Bronx (2)/(5) fiasco from the mid '90s is case in point.

    This, IMO, speaks more to a need for advocates to get better at speaking the pols' language rather than just quitting. Totally agree that it's a hill (and a half) to climb, but there are some spots of hope in recent history. The way Oddo worked _in coalition_ with MTA to push the SI Exp redesign through, for example, seems a great precedent -- albeit one from a rather marginal political figure in the grand scheme of NYC politics. 

    Anyway, my point in posting was more to inform the technical conversations.

  8. On 4/19/2021 at 8:00 PM, Trainmaster5 said:

    Let me try to sort out your complaints somewhat. Some of us were promoted from the Conductor title back in the prehistoric days. On the older SMEE equipment the Conductor was told to ride outside of the cab in passenger view between the station stops.  On a northbound (4) or (5) leaving Brooklyn Bridge the consist makes a series of curves before reaching Union Square itself. We actually had "C" signs affixed to the pillars advising the M/M to coast from about Spring St, through Bleecker, to south of Astor Place

    Great post, TM5. Despite all the signal mods made since your time, the "don't risk flying into a red home @ 108-ball" is still the cause of much slowing at the Astor Curve. If I may make one little correction, though: the "C" signs are now gone, and if you're operating totally textbook you're good for MAS from the "R10" sign beyond the curve leaving BB to the 35mph sign entering Spring, and then from when clear of those curves to wherever you choose to slow for Astor (there is no sign there, so you're not technically doing anything wrong if you go MAS)

  9. 11 hours ago, bulk88 said:

    QBL CBTC != 7/L train CBTC. QBL CBTC has automatic blocks/track circuits triggering "location updates" of fake CBTC-enabled (bypass/AWS) trains, IRT ATS style. 7/L did hard cut overs in 1 weekend. no going back without another GO. QBL CBTC allows FULL operation of the legacy track circuits (bypass) and CBTC trains interleaved at 2-3 minute headways. Double the equipment, double the maintenance, double the failures, and EXACTLY the same timers. QBL CBTC is just "cab signals" (PRR pulse code) the way its implemented, not CBTC.

    This is how it's operating *now*, not how it's planned to operate forever. AWS on QBL will not support much more than a 5 min headway (like the (7)), speeds will increase, etc. 

    And FWIW, the (7) did tons of off peak section-level testing until full cutover -- not unlike the overnight periods seen on QBL. There wasn't such an extended mingling period, yes, but it wasn't a hard transition either. 

  10. Not to state the obvious here, but: congestion pricing is most fundamentally a means of internalizing an externality. When car n + 1 enters the Manhattan highway network, it imposes costs on other drivers (congestion) and society (increased traffic accidents, emissions, road wear), which it does not have to pay for. Extremely for this serving broader goals of road capacity and VMT reduction -- which are critical to keeping Manhattan, much less the Rockaways above sea level by the end of the century -- but you need not go far beyond basic economics to prove the worth of the cordon pricing scheme. 

  11. 3 hours ago, T to Dyre Avenue said:

    It’s true. But without some serious additional infrastructure (starting with 2nd Ave), we have no choice but to interline across the B-Division once the (T) train enters the picture. Interlining has been a part of NYC subway operations almost right from the start. Getting transit planners and to see that in a different light would require breaking with more than a century’s worth of city transit planning. 

    I think modern day transit planners are all too aware of the dangers associated with interlining. Just because we don’t hear deinterlining proposals doesn’t mean that the agency doesn’t want them — politics are a critically important mediating force here. And at any rate “this is how it’s always been done” =/= “this is how it should be done,” with the qualification that you need to be cognizant of adaptive infrastructure changes when shifting paradigms. 

  12. Yeah, all credit to Vanshnook for that idea (which is great and I still support)

    I see the fundamental issue with SAS 3/4 as being that they cement interlining across the entire B division and don't actually add any core capacity. Any comprehensive route simplification scheme requires routing the (N) to 96; there is not space for the (N)(Q) and (T) to run up SAS today at full service levels. Similarly, there is no way to fill lower SAS (assuming (Q) continues to upper SAS) without interlining a train onto 63 St -- which blocks an (M) reroute there. 

    This is all a fancy way of making the capacity point. Today, there are 6 B division track pairs in Manhattan's core (8th local/express, Bway local/express, 6th local/express), and 6 track pairs leaving the core to the north (CPW local/express, 53, 60, 63, SAS). Thus, any addition of capacity in the core without addition of other northern routes constitutes a redistribution of capacity away from tracks which already exist -- this is what SAS does today. I have yet to find a fix for this problem which I really love, but I think it's fair to say that as proposed, SAS 3/4 have low-to-negative network ops value. 

  13. On 3/11/2021 at 9:52 AM, T to Dyre Avenue said:

    I just wish there was a quicker, easier way to go from five to four cars in a set, so if the Eastern Division is short cars again, they’d be able to send sets of cars from elsewhere in the system to ENY to address the shortage. Maybe it’s just me, but I feel like ENY frequently finds themselves with car shortages and there seems to be no easy way to address it, like there was in the past when it was mostly 60-foot single and paired cars in the B-Division (outside of the leftover BMT cars and the R44/46 cars that came later).

    You only need that flexibility when you make major fleet planning mistakes. Shortages of late have been the result of the aberrantly tortured introduction of the R179 class in conjunction with the R44's early retirement. Better planning and better contract management can make up much of the difference here -- and what it can't can be solved by relinking sets if you absolutely must. As the saying goes, organization > electronics > concrete.

  14. On 3/8/2021 at 12:42 AM, Around the Horn said:

    If I had a nickel for every time you've shared that presentation, I'd be rich! lol

    More seriously, has transit done anything about equipping work trains since that came out?

    I wish I knew. I imagine the 255s are being spec'd with provisions for conversion given that the 156s were, but not sure whether we have firm info on that front. @Union Tpke?

  15. 10 hours ago, Lex said:

    Sure, under current guidelines, frequencies should increase, but let's not kid ourselves.

    Yeah, I think the most likely outcome is that they just use the 160 seated capacity figure for the 211s as if there's no difference. Point being: there may be peak cuts, but I would be quite surprised to see the 211s causing off-peak reductions. 

  16. Worth noting that while the additional square footage is going to mean R211s will have more peak capacity than previous fleets, the reduced seating capacity (bc wider doors) should actually net out to increased headways based on a strict interpretation of NYCT loading guidelines. Whereas peak service is calculated on a seated capacity + passengers/available sq ft basis, off peak service is adjusted up from 10 min headways where loads exceed seating capacity +25%, a figure which will be lower on the 211s than on (say) the 160s. 

  17. 2 hours ago, Lawrence St said:

    Those (5) trips to/from Utica all depend on the traffic conditions of both Nostrand & New Lots.

    Even though there's a scheduled outbound trip from New Lots, most of the time during the AM rush because the (4) gets delayed from Lexington Av, some of those Utica Av (5) trains will instead run to New Lots Av and get stored at New Lots until the PM rush or turn back around to go to Dyre Av.

    Now in terms of the PM rush, and @Trainmaster5 correct me if im wrong, the (5) can be all over the place. Especially if Lexington Av is ridiculously overcrowded. Most of those scheduled (5) trips end up doing something completely different then what they're suppose to. A (5) thats suppose to come out of Flatbush can instead originate out of New Lots or Utica, a (5) thats suppose to operate to Dyre can get sent to Neried and then end at Gun Hill Road, a (5) thats suppose to come out of Bowling Green ends up running via 7th Av. 

    Now the main point of this post (sorry for going off track lol), is the fact that despite on public schedules those trips are listed as (N) trains, on countdown clocks and trains they are shown as (Q) via Sea Beach. This bring me to the point that (MTA) has no organizational skills when it comes to scheduling. I understand that they don't want riders getting confused along Broadway, but either sign those trains up the correct way or fix the scheduling to be accurate.

    I think you're overestimating the degree to which the (5) is a flexible operation. It just has a really complicated schedule! Here's a string chart of scheduled southbound 5 service in the AM and PM rushes. Utica, Bowling Green and Flatbush all get trains, and there's not much of a pattern to it (or rather, the pattern is difficult to see without looking at (2)(3)(4) schedules simultaneously).

    tms3vP2.png

    PS6dBDC.png

    Changing a train's terminal can be done, but is avoided wherever possible. Remember, most of transit service management is crew management rather than equipment management. A train is a train and can basically run wherever you want whenever you want it, but moving crews around a lot can rapidly lead to service issues as the fabric of the timetable comes apart and you end up with intervals on the stand with no available crew to take the train out, crews missing lunches, crews deadheading everywhere, or the like. There are ways to deal with these things, but there's a reason we have timetables and work programs, and it's not to generate performance metrics. 

  18. 2 hours ago, Storm said:

    Ok, so:

    1. The shuttle would run from 96th-57th/7th. The reason why I am mentioning this is because sometimes the (Q) runs in two sections and SAS service runs every 20 mins.

    2. This shuttle is only going to run on weekends.

    Also, why does the (N) sometimes run up 2nd ave? Is it for additional service? Or is it because of a switch problem? Fill me in.

    If it is for additional service, then that is proving my idea about a shuttle.

     

    The (Q) runs every 20 on 2 Av when they need to do single tracking. A shuttle will not help there, for obvious reasons. 

    There are some rush hour (N) trips to/from 96 to provide additional service to the corridor + to slightly reduce the load on 60 St and Astoria. It's a common rerouting terminal as well (for everything, really), so it may be you saw an incident diversion. 

  19. As a general rule, I try to stay out of rolling stock discussions on here, but some quick points:

    - Having married pairs or single units actually decreases reliability. Because you can't spread systems across the set, and because you have more coupling points, you end up with significant duplication and more points of failure. In isolation, the flexibility is nice, but NYCT's experience with the fleet in recent years -- to say nothing of the experiences of other countries -- should vindicate the perspectives of those who see linked sets as the way to go here.

    - The "more capacity" point is one that I think is getting too little stress here. More standing room/car will obviously help smooth peaks, but OGs likely will also shorten dwells. If you're more able to move throughout the train, the chronic end-loading seen on some lines should moderate. Even if this affect is only slight, it counts for something. 

  20. On 3/4/2021 at 1:45 PM, Vulturious said:

    How would it be cheaper? If it's running local on 4th Av during the weekends, that's just going to add more wear and tear on the switches. You also have the issue of interfering with the (Q) further since it's running along the bridge and then splitting up to run local and interfering further with (R) service. It's not like before where it interferes only once when it runs local on Broadway, but express on 4th Av, it has to cut it off twice. I'm assuming when you say "cheaper" you mean less (R) service to deal with? I could be wrong but that doesn't make it any cheaper and just useless. The only bright side to come from this is the (D) trains don't have to deal with the (N) only deals with the (A), but that's pretty much it. 

    It's about 10 minutes slower to go via tunnel from Canal to Dekalb. That's a 20 minutes of additional train cycle time, which means you need as many as two additional equipment sets (and crews) to run service, assuming 10 min headways. That's real $$$, to say nothing of real time losses for riders. The added merges are annoying and certainly do contribute to this system's chronic weekend reliability issues, but I think they made the right choice. 

    20 hours ago, Vulturious said:

    (F) trains couldn't operate through Rutgers Tunnel. It was easier to swap them entirely because at least the stations south of West 4 St along the (F) would've been missed. Although, personally I would've just extended the (E) and cut the (F) since it was basically the (E) extended, just signed up as an (F). Sure it would've confused riders in Brooklyn, but at least people in Manhattan wouldn't have any issues. Then again that's just my opinion.

    Not necessarily. You could have run the plan they have now ((E) to Delancey, (F) to Brooklyn via Cranberry) with the swap taking place at West 4 rather than at 36 St. Two issues, though: 

    - A W4 swap would have created a relatively complex junction operation there. On 8th local, you'd have (F)s, (E)s and (C)s all trading places. At 5tph apiece, it's certainly possible to schedule this to work, but weekend junction ops need to be basically bulletproof given the generally variable operating environment + NYCT's reluctance to trust operators to punch correctly when operating GO routes. This latter problem is, in fact, one which disadvantages this service plan above and beyond the potential for delay: GOs which require diverges northbound at W4 generally are staffed with a 'spotter' whose job it is to confirm train identities to Tw/Os who then issue routes. 

    - 8th Avenue CBTC is already creating a number of GOs, which would further complicate the W4 operation. On weekends where (A)s are local, you'd be dealing with an additional 6tph through the merge at W4. On weekends when the local is out of service, you'd have to compose some alternate service plan, as neither A3 nor A4 track has direct access to 6th Avenue at W4. So to make the service plan more resilient to GOs, it's better to swap at 36.

  21. On 3/6/2021 at 1:45 PM, bulk88 said:

    Isn't ATS non-vital or in my words "advisory"? No countdown clocks, and all interlockings require TOs radioing OCC to ID their train and OCC moves switches manually. IIRC ATS and remote towers/IRT CTC interlockings are unrelated systems in NYCT.

    Sorta. If you lose comms between ATS and the interlocking, you'll lose your fleeted routes => all signals within interlocking limits will drop to red, compromising the railroad. This is exceedingly rare. The fix is to man each tower, which requires a) qualified TSSes and Tw/Os to be present and b) for them to know what they're doing. 

    On 3/4/2021 at 10:02 PM, R10 2952 said:

    @RR503 The key words being well-operated and catastrophic-but-rare.  Most North American systems I've ridden on are not the former, and the latter, by definition, wreaks havoc anytime it does happen.

    Having been caught in that ATS failure on the A division as well as two separate system failures on the (L), as a passenger I'm not enthusiastic about a future prospect of trading a twice-monthly, short-circuited signal in one fixed block for a twice-yearly software glitch or malware attack that brings down an entire line or even the system.  That day when the IRT crapped out, Atlantic Avenue was chaos and much of nobody was able to board a BMT train on the first attempt.  As to Canarsie, that was no picnic either.

    Twice monthly versus a few times per decade is probably a more accurate comparison of the risks that you get caught up in type of signal failure, once CBTC is fully cut in on a line. As bulk88 notes, it's really quite a reliable system. 

    To the broader point: thank you for illustrating how mediocre institutional ops competency increases capital costs! Don't design for bad organizational practices. Fix those, and design your system to a higher standard. And regardless, the primary reason NYCT designs auxiliary waysides is for work train movements, not CBTC failure recovery. Equipping work trains is a solved problem, and is something we should absolutely be aiming to do in the medium term. 

  22. 1 hour ago, R10 2952 said:

    Several years ago there was an incident where ATS went down on the IRT, caused the entire A Division to be f**ked for all of afternoon rush hour.  It's got me thinking, do the current CBTC systems being brought online across NYCT have any fail-safes to prevent that type of shit from happening again down the road?

    I mean, suppose the system crashes or even gets hacked- then what? Seems like that would be a much bigger operational disruption than a single fixed-block signal going dark, if you ask me.

    On the (L)(7) and QB, there exist auxiliary wayside signals which allow some basic service to be run when CBTC is down, or when you have non-equipped trains. The (L)'s allow about a 10-12 min headway, the (7)'s and QB's allow about a 5. Thing is, those waysides are expensive to install and maintain, and really aren't that useful if CBTC shits the bed in the middle of rush hour -- it's not like you can magically thin out (E) and (F) service by 60% to make service operable with AWS. So, IMO at least, they really should be engineered out of future designs. CBTC failures are operationally catastrophic but exceedingly rare, and actually the additional complexity introduced by auxiliary waysides can reduce overall system reliability. Everything is about tradeoffs, and the one most well-operated subway systems make is cheaper/more simple signals with fewer backups. 

  23. On 1/26/2021 at 3:04 PM, T to Dyre Avenue said:

    They really can’t turn 8 tph of the (R) at Whitehall? SEPTA is able to turn their Broad-Ridge Spur trains at single-tracked 8th-Market while running 7.5-minute headways (8 tph). If they can do it, then we also should be able to.

    Normatively, we should be able to turn up to 15 tph on a single pocket -- HY does 29 on two, after all. However, the slow entrance speeds at Whitehall + the inconvenience of the narrow platforms for crew movements + the operations risk that comes with a single point of failure on that high frequency of a pipeline means we don't and probably shouldn't. The (W), fwiw, maxes out at 6tph turning. Some of that is a function of upstream scheduling constraints that make it impossible to take turn headways down from, say, 10 to 8, but some of it is just the limitations of the operation there. And even now, that terminal operation sucks. 

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