The Long Island Railroad’s timetable is a mess. There is too little off-peak service, especially at the urban stations. At the peak, there is more service, but the service pattern is inscrutable. The Babylon Branch runs a skip-stop pattern in which trains make three stops, skip the next three, and then make the three after them. The pattern of which branch east of Jamaica is sent to which city terminal (Penn Station, Flatbush/Atlantic, or occasionally Hunterspoint) is inconsistent; passengers generally get timed cross-platform transfers at Jamaica, but the frequent interlacing of trains introduces a lot of dependency between different branches in the schedule, reducing reliability. Worst, the Main Line runs trains one-way, so for an hour in the peak, there is no off-peak service. As expected, reverse-peak ridership is minimal, even though there’s a fair number of jobs within a comfortable walk of Mineola. In this post, I am going to discuss how to improve the schedules.
The main tool I will use is a map of LIRR line speed zones. This was made by Patrick O’Hara, of the invaluable but now taken-offline blog The LIRR Today. I emphasize that Patrick does not endorse my plan to eliminate one-way service, on the grounds that it would unacceptably add to the travel time for conventional peak trips from Hicksville and points east to Penn Station. However, using the map and some data about rolling stock performance, I am going to show that LIRR schedules are so padded that improvements to reliability via simpler scheduling can reduce trip times significantly, more than making up for additional trip times to the elimination of most express runs.
First, let us compute technical trip times. In Boston, I compute these by looking at the acceleration rate of the FLIRT, but New York has passable rolling stock already, which means that modernization does not require full replacement of the fleet. This means we should use the specs of the M7: 13.9 kilowatts per ton (FLIRT: 21.7 maximum, 16.7 continuous), and an initial acceleration rate of 0.9 m/s^2 (FLIRT: 1.2). Assuming no air resistance, this means the theoretical acceleration penalty to 130 km/h, the speed over most of the electrified LIRR main lines, is 23 seconds. Judging by the difference between theoretical and actual FLIRT acceleration performance, the actual penalty is about 26 seconds. The deceleration penalty is 19 seconds, for a total of 45. Up to a speed of 100 km/h, the acceleration penalty is 17 seconds and the deceleration penalty is 13 seconds, for a total of 30.
Let us take dwell times to be 30 seconds. With reasonably wide doors at the quarter points and level boarding, it should not be difficult for the LIRR to hold to this standard. Actual dwells appear to be about 40-50 seconds, but are in the context of considerable schedule padding, as we will see. I am going to round speeds up from mph to km/h, so 80 mph will be rounded to 130 km/h, and 60 mph to 100 km/h; the numbers are close, and when I compute curve speeds, the total equivalent cant seems very low, such that large speed increases are possible. However, I am going to stick to the speed map, only changing to km/h for ease of calculation. Including dwell time, the stop penalty in 130 km/h territory is 75 seconds, and the stop penalty in 100 km/h territory is 60 seconds.
Of note, the actual stop penalties we see on LIRR schedules are larger, on the order of 100 seconds. Part of it is the padding again, but part of it is that LIRR trains do not accelerate as fast as they can; the LIRR derated its trains, limiting their acceleration to about 0.45 m/s^2 to reduce the electric current. This can and should be reversed. If it is not, the acceleration penalty is 40 seconds to 130 km/h and 31 seconds to 100 km/h, while the deceleration penalty, unaffected by the change to maximum acceleration, remains the same; overall, this slows trains by about 15 seconds per stop.
East of Jamaica, there are almost no slow zones on either the Main Line or the Babylon Branch. Hicksville’s 65 km/h zone slows trains that stop at Hicksville by about 30 seconds (even a few hundred meters from the station, trains could go faster if the line speed were higher). The curve between Bethpage and Farmingdale is worth 15 seconds. The slowdown in the interlocking at the junction with the Hempstead Line adds 5 seconds. The slowdowns in Jamaica add 35 seconds east of Jamaica, and 55 west of Jamaica, both for stopping trains. On the Babylon Branch, there are a few restrictions in the 80-110 km/h range, worth in total about 70 seconds; Babylon itself is in 100 km/h territory, adding another 10 seconds.
It is 63.6 km from Jamaica to Ronkonkoma. An express train from Jamaica to Ronkonkoma stopping only at Hicksville would do the trip in 33 minutes. A limited-stop train that stopped at Floral Park, Mineola, Hicksville, and then all stops to Ronkonkoma would do the trip in 44.5 minutes. A train that made every LIRR stop, even ones that Ronkonkoma trains never stop at today, would do it in 53 minutes. Under the current schedule, limited-stop trains, not stopping at Floral Park (with technical travel time of 43.5 minutes), do the trip in an hour, for a pad factor of 38%. After accounting for the fact that LIRR trains don’t accelerate this quickly because of the derating, we obtain a technical travel time of around 45.5 minutes, for a pad factor of 32%, still immense.
In Zurich, schedules are padded 7%. Rerating the trains to allow faster acceleration, and reducing the pad to 7%, would cut the trip time under the current off-peak stopping pattern from an hour to 47 minutes, which can be taken as either a material speed boost or as an opportunity to make more local stops. As I will argue later, trains should make more local stops – specifically, all from Floral Park east. This is five more stops than trains currently make; taking the 7% pad into account, we get 54 minutes, still a noticeable improvement over the current situation.
It is 17.4 km from Penn Station to Jamaica. Rather than detail the slow zones, I will just give the technical travel time, for a full-acceleration M7 making no intermediate stops: 13 minutes, or 14 with a 7% pad; 1 of those 13 minutes comes from the Penn Station throat and its 25 km/h speed limit, which is one of the reasons I have emphasized the need for simpler interlockings in station reconstruction. The schedule has 19 minutes, which is a 45% pad relative to full-acceleration travel time, and around 40% relative to the derated travel time. This is even worse, which I believe comes from a combination of congestion in the Penn Station area and the timed transfer at Jamaica; these mean that delays on one branch propagate to the others, requiring more slack in the schedule to maintain reliability. However, I will note that Zurich’s 7% pad is in the context of an environment with even more branches sharing a trunk line, and a plethora of timed transfers and overtakes.
It is 44.4 km from Jamaica to Babylon. An all-stop train – counting Saint Albans but not Atlantic Branch-only Rosedale and Valley Stream – would do the trip in 41 minutes. As I’ve argued years ago, the Babylon Branch’s stations all have relatively equal ridership, unlike the Main Line, where a few stations dominate, and therefore, we shouldn’t plan around express trains. The current schedule‘s travel time on all-stop off-peak trains is 53 minutes, a pad of 29% relative to full-acceleration performance and 19% relative to the derated performance. I believe the reason there is much less padding here than on the Ronkonkoma Branch is that the service pattern is simpler: off-peak, all trains make all stops, whereas the Main Line mixes skip-stop and express trains between the Ronkonkoma and Port Jefferson Branches. If all trains make the same stops and there are no overtakes, it’s easier to recover from delays, so there is less need for padding. (A similar principle is that you need less padding on double-track lines than on single-track lines.)
As mentioned before, at Swiss 7% padding, making all Main Line trains all-local from Floral Park east allows 54-minute service from Ronkonkoma to Jamaica. It also allows 69-minute service from Ronkonkoma to Penn Station, with a minute-long dwell at Jamaica. This is two minutes less than the fastest daily train on the current schedule, a nonstop that runs once a day and arrives at Penn Station at 7:30 am, before the greatest rush. Even at the Babylon Branch’s 19% padding, we get 60-minute service from Ronkonkoma to Jamaica and 76-minute service to Penn Station, which compares with 75 minutes for two peak trains with a few intermediate stops, and 82 minutes for off-peak trains with the above-mentioned pattern.
As for the Babylon Branch, going down to 7% padding and rerating the trains at higher speed means all-stop trains, including the three current local stops between Jamaica and Penn Station, would do the trip in 62 minutes. This is competitive with most peak trains: one train stopping only at Jamaica does the trip in 53 minutes, arriving at 7:02 am, but the other morning express trains, with pads varying based on how close to the peak of peak it is, do the trip in 62-65 minutes.
I claim that the solution to the problems of the Main Line is to indeed abolish all express runs. At the peak, there is no excuse for them: current traffic between the Ronkonkoma, Port Jefferson, and Oyster Bay Branches is about 23 trains per hour at the peak, and this means that either all peak-direction trains run local, or trains run one way, with local trains on one track and express trains on the other. The LIRR chooses to sacrifice reverse-peak service, because frankly providing a coherent network is not a priority; the priority is connecting peak-hour suburban travelers to Manhattan, and saving them a few minutes at any cost. This is despite the fact that peak travelers are the most expensive to serve – the peak is what drives capital investment, to say nothing of the crew utilization problems. But in this case, the peak-focused service may be self-defeating, as the above computation of pad ratios shows.
In the morning peak, west of Hicksville, the service pattern should thus be the same for every Ronkonkoma or Port Jefferson Branch train: all stops to Floral Park (where passengers could transfer to the Hempstead Branch), then express to Jamaica and then Penn Station. All trains should be as identical as possible, which means cutting the diesels to shuttles and, in the medium term, electrifying the Port Jefferson Branch to the end, since there is high ridership the entire way, whereas the Oyster Bay Branch and the Main Line beyond Ronkonkoma have low ridership. The dispatching should emphasize headway management rather than the schedule. Since all trains are functionally identical from Hicksville west, it does not matter to passengers if their favorite train left early – the next one will show up in at most 3 minutes. For the same reason, the transfer at Jamaica should not be timed at the peak.
The highest rapid transit capacity in the world is on subway lines that use headway management rather than fixed schedules, including the Moscow Metro and many modern driverless lines, where the limit is 39 tph. I do not expect 39 tph on the LIRR, but there is no demand for that on the Main Line right now; the point is to maintain 24 tph without excessive schedule padding. Off-peak, trains should keep a schedule because the frequency is lower, but the lower frequency is precisely what makes delays not propagate so fast; similarly, off-peak, the Jamaica transfer should be timed. The greatest problem is in the afternoon off-peak, but there, the bulk of boardings are at Penn Station, where delays are less likely since it’s the start of the line.
This pattern also suggests which capital investments the LIRR needs to make: it needs to construct interlockings such that there are no conflicts between Main Line trains and other trains. This means two things. First, grade-separating Queens Interlocking, between the Main Line and the Hempstead Branch, which currently has an at-grade conflict between opposing trains (eastbound Hempstead Branch, westbound Main Line). And second, reconstructing Jamaica’s access tracks from the east in a way that allows the Main Line from the east to continue on the Main Line’s express tracks to the west without interference from other lines. Right now, there’s an at-grade conflict with the Babylon Branch, but only in the same direction, which is less problematic.
This means kicking other branches off the express tracks from Jamaica to Penn Station, the most desirable track pair heading west of Jamaica. This is fine. Passengers on branches that connect to Flatbush, or to the local tracks to Penn Station, could still transfer cross-platform at Jamaica, even if at the peak the connecting train does not wait for them. Besides, as noted above, 7%-padded local trains from Babylon to Penn Station would have the same trip time as all but the single fastest express Babylon Branch train today.
Jamaica’s current track layout is 8 platform tracks, numbered 1-8, north to south. There are platforms between tracks 1-2, 2-3, 4-5, 6-7, and 7-8. This platform configuration allows three-way timed transfers: when a train platforms on track 2, passengers can walk from track 1 to track 3 via the train. Right now, to the west, the Atlantic Branch connects to tracks 3-6, and the four tracks of the Main Line each connects to two Jamaica tracks. But track connections exist to persistently connect tracks 2 and 7 to the express Main Line tracks, making 1 and 8 the local tracks and 3 and 6 the tracks to Flatbush. To the east, the Far Rockaway and Long Beach Branches connect to the Atlantic Branch without conflicting with other trains. Local Main Line tracks connect to tracks 1 and 8 without conflict. The only conflict involves the Babylon Branch, which runs in the middle between the eastbound and westbound Main Line tracks before diverging, and points at tracks 2 and 7. The current service pattern is that most Babylon Branch trains run express from Jamaica to Penn Station, making this track layout desirable. However, if they are switched to the local, single-track flyovers to connect them to tracks 1 and 8 are required, or alternatively a connection to tracks 3 and 6, which can be done without flyovers. In either case, three-way timed transfers would be retained, except at the peak.
Under my through-running proposal, the Atlantic Branch would continue to Lower Manhattan, so its demand would be much greater than today, encouraging a layout in which the Babylon Branch connected to tracks 3 and 6 and went to Brooklyn and Lower Manhattan. The Main Line trains would express to East Side Access and Grand Central, with an additional stop at Sunnyside Junction. The Hempstead Branch, connected to Penn Station and the Empire Connection, would have service increased, with mode-neutral fares encouraging more travel from within New York and Hempstead. I would also propose a new branch of the Hempstead Branch, using the inner Central Branch, going to the East Garden City job cluster. The Oyster Bay Branch would be electrified and its junction with the Main Line grade-separated.
However, I emphasize that none of my proposed schedule changes requires the intensive capital investment associated with connecting Flatbush with Lower Manhattan. Even East Side Access is not required. Queens Interlocking would be grade-separated, and the Oyster Bay Branch would be reduced to a shuttle with an additional track at Mineola (unless electrifying the entire line and grade-separating the junction is cheaper in the short run, which I doubt). Initially, I am not sure the at-grade conflict with the Babylon Branch on the approach to Jamaica would be deadly. The subway has a same-direction at-grade conflict at Rogers Avenue Junction, between the 2, 3, and 5 trains, whose combined peak frequency is higher than that of the Main Line and Babylon Branch’s. Rogers Avenue Junction is a key bottleneck on the numbered lines in New York, which is why the LIRR should not replicate it in the long run, but in the short run, it is fine.
To conclude, here are proposed westbound timetables for Ronkonkoma, Babylon, and Hempstead trains. These assume no new stations and only the minimally required physical infrastructure (that is, grade-separating Queens Interlocking).
|New Hyde Park||7:44|
|New York Penn||8:08|
This is a total travel time of 68 minutes, and not 69 as advertised above. This is because of rounding artifacts.
|Country Life Press||7:33|
|New York Penn||8:12|
The 4-minute difference between local and express travel time between Jamaica and Penn Station comes from the fact that the intermediate stations are for the most part in slower zones than 130 – only at Forest Hills is there enough of a distance to get up to 130, and only west of the station, not east. Erratum: although it is true the stations are in slow zones, I wrote this paragraph thinking there are four intermediate stations, where of course there are only three; 4/3 = 80 seconds per stop, which comes from rounding artifacts.
The Hempstead Branch has a 1.5-km single-track segment starting west of Hempstead and ending east of Garden City. It is quite slow; the 25 km/h curve just north (west) of Country Life Press has geometry good enough for 50 km/h without any superelevation (cant deficiency would be 150 mm), and with 150 mm superelevation would be good for 70. Replacing that entire 25-50 km/h segment with 70 km/h saves about a minute of travel time.
|New York Penn||8:07|
I arbitrarily chose the Ronkonkoma departure time to be 7:00, and then chose the Hempstead Branch schedule to allow a timed transfer at Jamaica. The five-minute offset for the Babylon Branch should be suggestive of the proposed frequency: off-peak, every ten minutes on the Babylon Branch (possibly every twenty but also every twenty on the West Hempstead Branch), every ten minutes on the Hempstead Branch (possibly every twenty but also every twenty on the Central Branch to East Garden City), and every ten minutes on the Main Line, with each of the Ronkonkoma and Port Jefferson Branches getting a train every twenty minutes. The Atlantic Branch trains should run every twenty minutes per branch, with a three-way timed transfer with the Main Line and Hempstead Branch. Off-peak, the Babylon Branch doesn’t transfer to anything else, so there is no need to worry about its at-grade conflict at Jamaica.
I wonder whether 3 minute headways at 80 mph top speeds would even be doable given the existing LIRR rolling stock and signal system, but some quick calculation shows that it’s not completely out of the question, though I’m not sure what Positive Train Control would have to say about trains closing up on their leaders at restricted speed.
Anyway, I think the LIRR should be aiming to increase capacity by simplifying as much as possible. Getting the mainline down to a single service pattern is certainly a good way to get the most capacity out of it, and the junctions around Jamaica really need sorting so that you can get three conflict-free parallel routes through the station in each direction and the sets of branches can run more or less independently without even branching/merging. The same should ideally apply at Sunnyside as well: keep things conflict-free and maybe go as far as assigning the local tracks to one Manhattan terminal and express to the other (with a few Hunterspoint Avenue exceptions).
What about the Port Jefferson branch? Follow the same local pattern?
Yes, exactly. The big change would be that, pending electrification to PJ (which should be pursued as soon as possible), no train would run through at Huntington, to prevent slow-accelerating and unreliable diesels from mucking up the schedule on the Main Line.
I’m trying to get the schedules to be more readable, which means playing with table formatting. I think this looks clearer than before, when the station names were all on the left and the times were all on the right, with a lot of whitespace in between. Let me know if this breaks the table, e.g. on a smartphone.
That Google Map appears to be based directly off of Rich Green’s (sadly also offline) 2007 track maps. I can infill some of the localized speed restrictions within the speed limit zones if that helps refine the numbers. Electric territory listings only. Have at it figuring out what curve straightenings and station approaches can get their restrictions improved.
MP 3 (curve past Harold Interlocking) — 45 MPH
MP 11 (Hall Int., Tracks 2 & 4 underpass of Montauk Br. only) — 60 MPH
MP 31 (Farm Int., single-track switch) — 60 MPH
MP 11 (curved overpass of Main Line Tks. 2 & 4) — 50 MPH
St. Albans station — 60 MPH northerly approach, 50 MPH southerly approach
MP 13 (abandoned Springfield Gardens station) — 60 MPH
MP 13 (curve @ Atlantic Br. approach) — 70 MPH
MP 15 (Atlantic Br. concurrency) — 60 MPH
Lynnbrook station, easterly approach (Montauk side only) — 60 MPH
MP 1 (Flatbush tunnel, easterly approach) — 30 MPH
MP 10 — 60 MPH
Laurelton station — 60 MPH
MP 15 (Montauk Br. concurrency) — 60 MPH
PORT WASHINGTON BRANCH
MP 4 (curve @ Main Line split) — 40 MPH
Murray Hill station — 50 MPH
MP 9.5 (Auburndale station approach) — 45 MPH
MP 12 (curve @ Douglaston station approach) — 45 MPH
MP 17 (curve, Port Wash station approach) — 40 MPH
MP 17 (yard approach switch, Port Wash station) — 40 MPH
OYSTER BAY BRANCH
MP 18 (curve + grade crossings @ Main Line split) — 30 MPH
PORT JEFFERSON BRANCH
MP 28 (curve) — 50 MPH
Syosset station — 40 MPH
MP 15 (S-curve, westerly half) — 45 MPH
MP 15 (S-curve, easterly half) — 60 MPH
Garden City station — 60 MPH
Garden Int. — 15 MPH
WEST HEMPSTEAD BRANCH
MP 0 (curve @ Montauk Br. split) — 15 MPH
Lakeview station — 45 MPH
FAR ROCKAWAY BRANCH
MP 0 (curve @ Montauk Br. split) — 15 MPH
Hewlett station, curve @ northerly approach & W. Broadway grade crossing — 30 MPH
LONG BEACH BRANCH
Lynnbrook station approaches (Long Beach side only) — 45 MPH
East Rockaway station, southerly approach — 45 MPH
MP 5 (curve) — 45 MPH
Island Park station, northerly approach — 45 MPH
The speed limit map was not based directly off his track maps, but the original source was likely somewhat similar. The speed limit map includes all permanent speed restrictions that existed at the time the map was made, including the ones you listed (his track maps did not show all restrictions, and specifically, where those restrictions start and end).
You’d need a current employee timetable. Which would be good until the next employee timetable came out.
Correct, which is why, and subsequently Mr. Levy, noted that the map was accurate at the time it was created, and not necessarily now. Though since the LIRR isn’t straightening curves on a monthly basis, there is little change from timetable issuance to timetable issuance.
Permanent speed restrictions are also signaled by physical signs (black numbers on a yellow diamond) along the right of way, and those can be seen by humans curious enough to look out the window and the satellites and helicopters in the sky.
Passengers on branches that connect to Flatbush…..Jamaica’s current track layout is 8 platform tracks
Service to Brooklyn turns into a shuttle from Jamaica after East Side Access opens with ten platform tracks in Jamaica.
Apparently the contract number is L09219. It’s unclear if anything has happened. For platform F.
“Modifications to existing Jay Interlocking for dedicated Brooklyn to Jamaica Service [existing trks 11 and EWD ATL FRT being reconfigured, including removal of a turnout, to platform tracks 11 & 12 including installation of new diamond crossover].”
… timed transfers…
Rumor on railroad.net is that they move out to the suburbs and none will be attempted in Queens. Rumor is that the split between Penn Station and Grand Central will be 30/20, at peak, with 20 an hour to Grand Central. Ignoring the Port Washington branch, for clarity, that’s one every three minutes to/from Grand Central and one every two minutes to/from Penn Station. Time one transfer and other possibilities aren’t timed.
…. Doing the cross platform transfer in the suburbs means they are cross platform and avoids mayhem in Jamaica. But then most people will spend ten seconds looking at the schedule and just get on a train that is going to their destination.
This pattern also suggests which capital investments the LIRR needs to make:
They are doing all sorts of things. You need a current employee timetable. And a few hours rummaging around in the capital plan.
The Main Line trains would express to East Side Access and Grand Central, with an additional stop at Sunnyside Junction.
It’s unclear where the tracks to Grand Central emerge from their tunnel under Harold Interlocking. It’s not where the proposed Metro North station would be. Stopping at Sunnyside makes it less express-y. For Metro North trains and LIRR trains.
Even East Side Access is not required.
It is required to relieve overcrowding in Penn Station, on the E train, other subway lines to a lesser extent and Metro North’s New Haven and Hudson Lines. And for things like sending Main Line trains to Grand Central.
The substations need to be upgraded. I’m not going to wander the capital plan to see what they are going to upgrade. Eventually you get to the point where you can’t shove more electricity down a rail at 750 volts and you have to build new substations between the existing ones.
Rumor on railroad.net is that the capacity constraint on the Harlem Line is the substations….
M-series trains hit 90 on Metro North, in New York, regularly. Rumor on railroad.net is that the geometry is good enough for 95 but Metro North doesn’t want to maintain the tracks for 110. Additional rumor is that they could hit 90 here and there in Connecticut but CDOT doesn’t want to spend the money to maintain the tracks for those speeds. Rumor also has it that the Turboliners hit 105, back in the day, because the track was maintained for it.
Hudson Line is being upgraded to 110 MPH north of Poughkeepsie; aside from a couple of grade crossings, mainly in places that have curve-related speed restrictions anyhow (cough, Peekskill, cough) there’s no reason that it couldn’t be 110 south of there, aside from yes, M-N’s intrasigence. (yes, the state funds both ES and MN. Don’t get me started). That being said, there’s a difference between 110 mph being *allowed* and it being *comfortable*. Running speed from Hudson to Albany was upped basically instantly to 110 after Amtrak leased the line from CSX, and let me tell you, it was NOT comfortable in those old Amfleets. They’ve put a lot of work in since then, but I haven’t been on a train down to the city in a while, so I can’t report on how it feels now.
The 110 bump on the Upper Hudson was almost entirely result of the re-signaling; Amtrak didn’t touch the running rails or do a resurfacing for that first phase. Now they’re going back and replacing miles of rail and ties to smooth things over, so ride comfort should improve in leaps and bounds as they go along. Impressively massive pile of concrete ties has been delivered to Albany-Rensselaer Yard in the last couple weeks to stock them up for the 2016 construction season.
Since the ideas behind Mr. Levy’s changes are more significant than what the LIRR’s imagination seems to be limited to so far, I wouldn’t bind any of the outcomes to ongoing or planned capital projects or service pattern plans (i.e. Jamaica Capacity Improvements, the Jamaica-Brooklyn shuttles, etc.) or view them differently because of that. For JCI/Brooklyn shuttles, it’s not severing access from the main station to the Atlantic Branch, so through trains will still be possible…the new platform F could just be used to turn supplemental service at Jamaica.
I’ve never heard of any plan to have timed transfers between New York trains east of Jamaica, but instead just connections from diesel trains to electric trains. Having connections between two trains to New York continuing in the same directions would be difficult at all but a small handful of locations, and in nearly all locations would require passengers to climb up and over stairs in at least one direction. I would not expect transfers to become any less popular when “most people will spend ten seconds looking at the schedule and just get on a train that is going to their destination” since the LIRR is both not able and not planning to exactly double service to the New York terminals, there will be some reduction in frequency to the terminal you want to go to. Most people would opt to transfer someplace instead of showing up at work an hour early every day because that’s when the direct train was. Granted, there are some that shift their working times or commuting patterns to better catch those direct trains, but most don’t.
We do know where the Sunnyside Station will go–it’s current planned location (if it does indeed get built) is between where the tunnels to Grand Central duck out of HAROLD and where the Westbound and Eastbound bypass tracks will join them in F. Based on that location, the station can only be used by LIRR trains that are going to or through NY-Penn Station or Hunterspoint Avenue, and that’s it. Trains to NY-Grand Central will turn northwest before then, and the Metro-North trains on the bypass tracks won’t join the tracks to the tunnels until they’re west of the platforms. If moved way further east of where it’s planned to be (over to by 48th Street) you can connect more of those lines, but it’d be a little too cramped to have a full on transfer station with island platforms there.
Electric MU’s do not and have not hit 90mph regularly on Metro-North, in New York. The highest single speed limit in DC territory is 75 mph. All of the 80mph-90mph zones are either on the Hudson Line past Croton-Harmon, or on the New Haven Line in AC territory (though I believe there are no longer any 90mph zones). To my knowledge, the LIRR’s electrical infrastructure is in pretty good shape, there is plenty of redundancy to allow things like the Third Main Line Track and the Ronkonkoma Branch Double Track project to go in without requiring substantial additional spending on substations. The substations on the busy lines are also fairly closely spaced, so derating should not be a significant challenge (phsyically, psychologically, that might be more difficult).
If the M2/4/6/8 is running from the electricity being supplied through the pantographs it’s still an MU.
The derating issue is exclusively one of initial acceleration, rather than power consumption. The power-to-weight ratio is the same as always, as far as I’ve seen on railroad.net and other forums; it’s the initial acceleration that was reduced from 0.9 m/s^2 to 0.45. That said, in the source I gave for this, the explanation given involved current, which is power divided by voltage – it should be about power rather than about initial acceleration, and yet, the LIRR reduced the initial acceleration rate.
Sunnyside indeed would make trains less express… by around 30 seconds, plus the dwell time.
If it accelerates slower it consumes less power at any given instant.
No. Power consumption equals acceleration times speed. At speeds below 110 km/h, the restriction of acceleration to 0.45 m/s^2 indeed reduces power consumption. Above that speed, it is irrelevant. But at the lowest speeds, when high acceleration is the most important, the train’s power consumption would be well below maximum even at full initial acceleration.
And if takes more time, at any given instant you will be using less power at that instant. Circuit breakers don’t care about how much electricity you run through them in a year. They care about how much is running through them at that instant.
No. Just… no. Your power usage at a given time is equal to speed times acceleration, and this is not what the LIRR limited. The LIRR limited absolute acceleration, which means not limiting the amount of power drawn when the train accelerates from 110 km/h to 130 km/h, but limiting the acceleration at 30 km/h, when either way the amount of power drawn would be small.
The amount of power isn’t small, people wouldn’t be doing things like making aluminum rails with steel wear surfaces on them if it was.
Define derate more clearly. If the train is accelerating less rapidly it will take more time to get to a given speed. More units of time imply less units of power per unit of time.
The acceleration capability of the M7 is 0.9 m/s^2 or 13.9 divided by its speed (in m/s), whichever is smaller. When 13.9/v < 0.9, the train is drawing exactly 800 kW per car. When 0.9 is smaller, it is drawing less: namely, it draws 0.9*v. The LIRR derated the initial acceleration to 0.45, so now the M7 draws 0.45 or 13.9/v, whichever is smaller. When 13.9/v 30.89 m/s = 111 km/h, the train draws 800 kW per car again. If the LIRR were interested in limiting power drawn instead, it would derate the motors to accelerate at 0.9 or k/v for some k < 13.9.
I think that Alon is saying that power draw at initial acceleration is much less than the maximum output. It’s also true that acceleration decreases with speed. So increasing the acceleration at very low speed doesn’t impact the maximum power draw (of course it does increase the average power draw).
I’m not sure what Alon is saying; not to say that it isn’t, but as far as I know, the equation ‘Power consumption = Acceleration times Speed’ is not literally a law of physics, but it may nevertheless be a useful generality for some purposes. It’s easy to get mixed up with power and energy, not to mention ‘power usage at a given time’ versus ‘power consumption’ and ‘power draw’ and we haven’t even mentioned Work or Potential Energy.
If you are talking about initial acceleration and problems with current it sounds like the motors want to draw larger amounts of current on startup and low speeds (as motors are wont to do) than can be supported by the infrastructure. If the power to weight ratio was the same as previous motors that presumably means they both went up, thus higher power required and thus maybe more total power during peak times than the system could support. As to why current is referenced, perhaps it is the feeder cables that would max out trying to maintain the nominal power in the face of a too heavy draw.
No, it is actually a law of physics, I’m just eliding mass. Kinetic energy equals , which means that power draw equals . This is why I use 13.9 in the equation: it is equal to the power-to-weight ratio, i.e. .
They don’t accelerate the train with a simple on/off switch.
When an electric train is accelerating, there are two things that can limit how fast it can accelerate: the maximum tractive effort (basically, friction between wheels and rail before the wheels start slipping) and the power consumption limits of the motors. At low speeds, it’s tractive effort that is the limiting factor, and the train is drawing less than its full power, and the power draw increases until it hits the limit, at which point the acceleration starts to taper off and the power draw is the limiting factor. This is also why they make slugs for switcher locomotives: the diesel engine can produce more than enough power at low speeds, but there’s not enough tractive effort, so they add on more wheels to pull the train: https://en.wikipedia.org/wiki/Slug_(railroad)
I can buy the equation with the mass element accounted for; I didn’t really think it was like dropping apples and feathers off the leaning tower. Your source on the ‘derating’ was kind of interesting – do you always range so far to research your posts? I found that checking out this link improved my comprehension of some of the discussion in that thread and furthered my education on the motors themselves; especially interesting how less is more with the field shunting.
Regarding the basic issue of the derating, I guess now that your problem with that is because it looks like the extra resistance (and the possible series connections) used at start up already limit the current draw so that there was no good reason to cut back initial acceleration in order to protect against excessive current draw, I liked it better when I had the simplistic opinion that motors draw more current starting up (I can hope that maybe that theory works for AC motors anyway – that is what happens when the air conditioner’s motor turns on, isn’t it?).
Well what I end up taking from this if those people from the derating thread are correct, the LIRR went with only the P1 setting. Is that because one of those other settings could have drawn too much current if used at startup, or that it could have used too much current if they got ramped up to higher speeds . . . OR . . . is this fix about locking in the most economical profile to save on the electricity bill (if that is even true about this change). What was the original idea with the 3 settings, was the operator supposed to shift through them or did they just pick one and the train automatically went through the proper sequence to get to that state?
Almost no one uses DC motors in railroad cars these days.
East Side Access relieves the E at the cost of dumping more people on the 4/5/6, so as far as subway relief goes it’s kind of a wash.
Many of them will just walk from Grand Central.
How many RR.net “rumors” can one post cram? At least do a search function over there first and be ballpark-precise about what you’re citing. It’s not hard.
— Electrical constraints on the Harlem are for 8 cars @ 6 minute headways on the 1984 electrification extension to Southeast. Not south of there; up to N. White Plains it can take 12-car trains and the craptacular signal system is the ultimate headway limiter. MNRR does a little bit of sleight-of-hand around those substation limits by assigning a lot more M3’s to the line at peak hours and play keep-away with the power-hungrier M7’s, then juggling the headway vs. train length ratio to sneak a long set or closely trailing set into certain slots. Substation upgrades are planned in prep for the M9’s because that M3 segregation option won’t be available any longer to skirt the limits. But that does not end up improving overall service levels or overall train capacity until they upgrade the signals and start lengthening those short 6- and 8-car platforms out to Southeast so platform dwells from over-long trains don’t start becoming their own limiter.
— Similarly, the speed limits below track geometry on the New Haven and Hudson Lines are mostly signaling-related (and obviously some bridge state-of-repair related), not “maintain the track”. Don’t confuse the two. The hardware on the ground is maintained to FRA Class 5. They could maintain the hardware on the ground to FRA Class 6 commensurate with the geometry and it wouldn’t net a single MPH’s improvement without a large-scale investment in a high-speed signal system with the interlocking configurations to suit. That’s how the Upper Hudson is ratcheting up its speed. Not from massive amounts of rail and crosstie replacement; most of the hardware on the ground only needed scattered 1-every-X tie replacement and attention to worn curve/switch rail renewal to pass a Class 6 uprate inspection. That was the cheapest and quickest part of the upgrades. Speeds were garbage and quickly deteriorating because the rapidly failing NY Central-era signal system wasn’t shunting individual track circuits reliably enough above certain speeds, inducing ever-mushrooming number of restrictions. That wholesale replacement is where most of the Upper Hudson improvement is coming from and where the meat of the investment is. And this is where Metro North is the main obstruction to improving diesel territory south of POU.
The Turboliners cracked 100 in revenue service on the same exact Albany-Schenectady track the boring old P32AC-DM’s + AmCans crack 100. Both types of Empire equipment started cracking 100 in-tandem, because that all came from the wholesale mid-90’s re-signaling of that stretch. It wasn’t because Albany or Conrail was feelin’ it or not feelin’ it from one era to the next about “maintaining the track”. That’s not how track classes work.
27 except on the third Tuesdays of months without an R in them. Then 36. Yes there is a search function on railroad.net. Feel free to use it. Amtrak’s historical schedules can be very interesting too.
Some of the more memorable local rumors on railroad,net are that metro Albany is much larger than metro Hartford, CDOT is never ever never gonna let CDOT run trains on the New Haven Line. Metro North, after East Side Access is open and there’s capacity to do this, is desperate to run trains to Penn Station so their passengers can transfer to the LIRR. New York State never spends any money on intercity rail. The ones about how the MTA hates the MTA are especially good. Even better if the specific conflict happened before there was an MTA.
There’s one just outside of the grasp of my memory. That was never ever never gonna happen. Until it did. Oh well…..
90 seconds here, 90 seconds there pretty soon people say “aw fuck it, I’ll just drive all the way”
It might mean loosing a few riders on longer trips, but the number of riders you will gain on shorter trips from more frequent and reliable service should more than offset that. If you want to put in the infrastructure for express trains then fine but that shouldn’t come at the expense of reverse-peak service.
Except it’s a key transfer station and the trip time would still be faster than the fastest train from Ronkonkoma to Penn Station today. If saving 90 seconds on a station is so important, drop Pinelawn. It may have to be closed until there is more double-tracking on that part of the Ronkonkoma Branch anyway.
Of course, there’s an industrial track leading almost all the way to the station from almost all the way to the end of the double track east of Farmingdale… we’re talking about maybe 600 meters of extra track to have continuous double track until just east of Pinelawn, plus about 1.2 km of electrifying the industrial track.
The midday limited stop Ronkonkoma [stopping at only Mineola in between Hicksville and Jamaica, but stopping at every stop east of Hicksville] trains take an hour, and presumably don’t need schedule padding due to trains at different schedules because the line isn’t near capacity. Some rush hour trains are scheduled for one hour three minutes, so the congestion effect on schedule padding isn’t that big. So most of your speed gains are from running trains at closer to the technical maximum rather than increased reliability due to a more consistent schedule. Maybe it’s more of a management / technical choices why the trains aren’t run at their maximum speeds?
All LIRR trains have schedule padding, especially during the off-peak periods, and lots of it. Trains rarely get up to MAS, even on long express runs.
When electrification was extended to Ronkonkoma in the 1980’s, there was a train that was scheduled for 59 minutes from Ronkonkoma non-stop to NY-Penn Station. It was either just barely on-time or slightly late most days it ran, but there’s still nothing that comes close to that now.
Question to the expert… Does LIRR have padding at every stop, or do they pad at every 4th stop or so?
I ask this, because the article mentions the Zürich S-Bahn system. There, they do not pad every stop, but have “Zeitabgleichs-Stationen”. At these stops, the departure times are fixed (and padded). Such stops are at about every 10 to 15 minutes. The stops in between have their published departure times at the technically earliest possible time, meaning that the trains are always a little bit late. But at the next Zeitabgleichs-Station, the train will be on time.
I think that this “grouped padding” is the reason for the small padding percentage, and it also stabilizes the schedules.
There’s only a few places where the LIRR out-and-out schedule pads (adding times between two stops for only a handful of trains). Elsewhere, running times are fairly consistently elongated and applied evenly to all trains over the course of the day. It’s very difficult to quantify exactly how much fat is where since trains seldom stick to the already padded schedules.
Though I can say confidently that cases where trains waiting at particular stations for two or three or more minutes is very rare with the exception of a small few limited-stop runs and trains east of Speonk.
Thanks for the clarification, Patrick.
These are just some theoretical timetables. Lots of things slow down the train. I’ve taken the 7:03 from Deer Park stopping at Wyandanch and then direct to Penn for 8:06 arrival. Typical arrival times were a few minutes after 8:06. The train goes down the reverse direction track and then through the middle platforms at Jamaica before arriving at Penn. The major slowdowns are when the train crawls through Jamaica or when the train crawls in the area before the East River Tunnels or when the train waits for a free platform. So my train takes 63 minutes traveling almost non-stop; the fastest scheduled appears to be 60 minutes. Off peak, the all local train (express Hicksville-Jamaica) makes the same trip in 64 minutes. To the passenger (i.e. me), it just seems that things are too congested for the train to go faster during the peak hours. Now you’re proposing the train can do all the stops between Deer Park and Penn in 56 minutes. It doesn’t seem possible to me.
At least under the current regime, passengers can nap uninterrupted.
Metro-North certainly runs the gamut. I’ve seen express trains leave Stamford on time and show up at Grand Central 7 (maybe even 10?) minutes early, which indicates 16% padding (25% if it’s 10 minutes).
The thing is, a lot of the LIRR crawling is about trying to maintain a very creative schedule, in which trains have to clear stations and interlockings in a certain order. That’s why I’m deliberately coming up with a schedule in which, west of Hicksville, all trains make the same stopping pattern; it means the dispatching can switch to maintaining even headways between trains, so trains might run 2 minutes early or 2 minutes late rather than 0 minutes early or 4 minutes late.
What’s the evidence for crawling resulting from inefficient scheduling / dispatching practices? That may be worth a blog post.
It’s worth noting that Deer Park is 40.2 mi (64.9 km) from Penn. With a rounded travel time of 1 hr, that’s an average 40.2 m/hr 64.9 km/hr. With straight tracks and a top speed of 80 mph, you would think a faster trip time would be possible, at least with peak non-stop trips.
Well, for one, off-peak on the Babylon Branch, where trains have consistent stopping patterns, there’s much less padding. Besides, there are public speed limits, and they’re higher than crawl speed. Even taking into account truly ghastly speeds through the Penn Station interlocking, the trips don’t need to be so slow.
I really wish I’d archived LIRR Today before Patrick took it down.
Was he threatened with a lawsuit by the corrupt management and union employees he exposed, or what?
I really liked having the track diagrams. But the detailed analysis of the work rules was arguably the most valuable. No journalist has been willing to dig into the details of that stuff the way Patrick did.
No I think he didn’t have the time to maintain the website for a period of time, and so the comments were filling with spam. I too hope that the blog can be publicly readable again.
Well, maybe he could reopen it with the comments shut down and no new postings, just as an archive.
I know I’m over 3 weeks late to the party but I completely agree. I loved reading LIRRToday and gained a lot of insight from it. Would love to see Patrick get it back up and running but understand (and really actually appreciated) the time and effort the put into each post.
How does this change with the LIRR Third Track going forward?
I always had this in my mind. I think after the 3rd track is complete. They should to answer better your question. 3 plans. First reopen the Garden City Secondary. The tracks are already there. The train will stop at Nassu Community College, make a station at Uniondale, and revitalize Country life Press Hub. This will be right now with Diesel electric with 2 C3 Bilevel cars. Like they do with Ronkonkoma to Greenport. This train will do country life press to Nassu Community College for the moment. After Country life Press train heads to Floral Park, Jamaica, then Proceed to Penn Station.
Next reactivate Mineola to Valley Stream. Same process Diesel dual electric with 2 C3 level Bilevel Cars. Have the train go from Valley Stream to Oyster Bay. That way people have a choice. Then there will be North South link. Instead of right now going all the way to Jamica then back to Valley Stream which makes no sense. If this works then.
Finally save best for last
Expand the the Garden City Secondary to Bepthpage junction. After the train leaves Nassau Community College. The train will go into a tunnel to Bepthpage Junction. That way you won’t distrupt people’s properties. It will be underground to Bepthpage Junction.
With this take off all the express trains off the mainline. Trains that will not stop at Minola and Hicksville and are going Montauk or Speonk will go on this line. Also maybe have the Greenport train go on this line as well. This will eliminate the bottle neck on the mainline.
This is my idea. Like to see what people think of this idea. Please comment.
The cost of running diesels on a local line is so much higher than that of just extending third rail for a few kilometers.
That way you won’t distrupt people’s properties.
The State already owns the ROW.