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BrooklynIRT

How do we know terminal capacities?

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Where do people find this information? Like how do people know that 179 Street-Hillside Ave can turn 63 trains per hour or that Jamaica Center (E) level can turn 15 trains per hour? Or that Flatbush & Nostrand Aves can turn 20 trains per hour (if that is even correct)? how can 63 trains per hour even be turned if there are only two tracks per direction at 179 and the system can only take 30 trains per track per direction in an hour? seems like the capacity could only be 60 trains per hour for 179 terminal.

 

I know wikipedia has some of this info. I would like to know how wikipedia and/r others know this information or if there is/are some mathematical formula or formulas that can be used to determine terminal capacities.

Edited by BrooklynIRT

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The MTA has scheduling information on their website, so regular turn rates are easily assessed. However, even with CBTC, I doubt any terminal that is not a loop terminal has a capacity greater than, at most, 30 trains per hour. 

 

Current turning capabilities are highly dependent on signalling just outside the terminal. The reason I suspect that the (E)'s Queens Terminal's capacity is lower is because perhaps the signal blocks outside the station are longer than most of the rest of the system due to being built more recently than the rest of the system. Theoretically, since the signal blocks are longer, trains waiting to use the double x-over to enter the new terminal must wait farther away from the station while a train departs, and therefore the trains coming in take a longer time to enter and terminate, thus drawing out turn around times. But that's just my theory.

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It depends on switching, and tail tracks. A loop technically has as much capacity as the signalling on a straight piece of track. Terminals without tail tracks are limited to a theoretical 24 TPH given the switch capacity, and the fact that trains have to enter stations at reduced speeds so they don't crash into a wall. If I remember correctly, a station like Main St could also have reduced capacity, since the switching takes so long.

 

The thing about the (E) station is that the crossover isn't ideally situated - the (E) was never supposed to end at Parsons/Archer, so the crossover wasn't designed to support actual terminating services - the longer distance to the crossover means more time to negotiate said crossover, and it thus takes longer for a track to clear.

 

Keep in mind that before the days of MTA, trains used to run a lot more frequently, and faster. Was it safe? Probably not. But, safety comes at a price.

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It depends on switching, and tail tracks. A loop technically has as much capacity as the signalling on a straight piece of track. Terminals without tail tracks are limited to a theoretical 24 TPH given the switch capacity, and the fact that trains have to enter stations at reduced speeds so they don't crash into a wall. If I remember correctly, a station like Main St could also have reduced capacity, since the switching takes so long.

 

The thing about the (E) station is that the crossover isn't ideally situated - the (E) was never supposed to end at Parsons/Archer, so the crossover wasn't designed to support actual terminating services - the longer distance to the crossover means more time to negotiate said crossover, and it thus takes longer for a track to clear.

 

Keep in mind that before the days of MTA, trains used to run a lot more frequently, and faster. Was it safe? Probably not. But, safety comes at a price.

 

The new IRT South Ferry Station would be a perfect example of the point on loop vs straight track terminals with conditions relating to it such as tail track distances for lay ups, and switches installed at the correct locations for operation flexibility. It was designed to allow for turnarounds @ 24 TPH. However, the previous 107 year old IRT SF loop can only support turnarounds @ 20 TPH, which was why the new station was constructed by the MTA, and opened for business in 2009. Nethertheless, of course, reality trumps operations planning many times concerning the new SF station in terms of TPH, pre-Sandy.

 

Ditto on the (E), and the (J) for that matter, the fiscal crisis of the 70's during it's construction killed any extension of IND QBL/BMT Jamaica service from Archer to SE Queens via LIRR ROWs. So as you were saying about terminal capacities on that segment of the QBL/BMT Jamaica @ Jamaica Center, it was not intended to be a terminal, either level.

Edited by realizm

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was Flatbush/Nostrand Aves a 24 TPH terminal before the GT-10s were replaced by GT-5s there? or was it 20 TPH even when the GT-10s were there?

 

by the way there is at least one GT-10 sign (just the sign, no GT-10 signals) at Flatbush that they have yet to remove.

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The new IRT South Ferry Station would be a perfect example of the point on loop vs straight track terminals with conditions relating to it such as tail track distances for lay ups, and switches installed at the correct locations for operation flexibility. It was designed to allow for turnarounds @ 24 TPH. However, the previous 107 year old IRT SF loop can only support turnarounds @ 20 TPH, which was why the new station was constructed by the MTA, and opened for business in 2009. Nethertheless, of course, reality trumps operations planning many times concerning the new SF station in terms of TPH, pre-Sandy.

 

Location, location, location.

 

If the platform was located on the section of straight track immediately before, or after, the loop, it would've been able to handle as high a capacity as the (6) at Brooklyn Bridge. However, because of gap fillers (which reduce capacity a lot, since those things take forever), a position on the loop itself is actually very disadvantageous.

 

In practice the (1) has never really done more than 19TPH without problems.

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Yeah, they should've put those gap fillers on the trains under the doors, like on the Siemens/Bombardier SLT's. Takes only a 1-2 seconds to slide 'em out and back in. That wouldn't have been possible way back when but they could've implemented that on the R142s.

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Yeah, they should've put those gap fillers on the trains under the doors, like on the Siemens/Bombardier SLT's. Takes only a 1-2 seconds to slide 'em out and back in. That wouldn't have been possible way back when but they could've implemented that on the R142s.

Money money and more money, not to mention maintenance. It's much easier to maintain one set of gap fillers at the few stations that need it rather than retrofit an entire fleet of 1000+ cars when only a fraction of them run on lines that even have stations that need the gap fillers.. 

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179 St has the capacity of 63 trains per hour because of the layup yard and relay tracks north of the station.

 

 

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What about Utica on the 4.anyone know the official number of trains for that station?

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179 St has the capacity of 63 trains per hour because of the layup yard and relay tracks north of the station.

 

 

 

Makes sense. As for Utica, rush hour sees trains approximately every 5 minutes. And considering the unique station and relay layout, I would estimate a maximum of 12-15 tph.

http://www.mta.info/nyct/service/pdf/t4cur.pdf

Edited by Fan Railer

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@Fan Railer (or anyone else who wants to answer)

 

But the (4) gets backed up at Utica Avenue so often at rush hour, so bad that the (3) constantly beats it there at times. I've been seeing the (4) and those Utica  (5) dropouts held on the express tracks between Nostrand and Utica. Sometimes if this occurs, the crew is told to remain in service to New Lots and switches to the local track right after Franklin, which delays the (3) (if its like say 2-3 minutes away).

Edited by RollOverMyHead

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Church Avenue on the IND Culver Line should have a big capacity because of the relay yard south of it.

And also is it possible to find out wht Smith-9 Sts capacity when the (G) stupidly terminated there.

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Like how do people know that 179 Street-Hillside Ave can turn 63 trains per hour or that Jamaica Center (E) level can turn 15 trains per hour?

 

Where did you get the idea that 179th can turn 63 tph? It certainly can't, at least not practically.

 

Jamaica Center can't turn 15 tph. If it could, then all E's would run to Jamaica Center. The reason some E's go to 179th is that not all 15 tph can fit at Jamaica Center.

 

Location, location, location.

 

If the platform was located on the section of straight track immediately before, or after, the loop, it would've been able to handle as high a capacity as the (6) at Brooklyn Bridge. However, because of gap fillers (which reduce capacity a lot, since those things take forever), a position on the loop itself is actually very disadvantageous.

 

In practice the (1) has never really done more than 19TPH without problems.

 

They only add a few seconds to the dwell.

 

The 1 is only scheduled to run at 19 tph, and it hasn't been scheduled for more than that, at least not in recent history.

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Where did you get the idea that 179th can turn 63 tph? It certainly can't, at least not practically.

 

Jamaica Center can't turn 15 tph. If it could, then all E's would run to Jamaica Center. The reason some E's go to 179th is that not all 15 tph can fit at Jamaica Center.

 

not my idea. blame wikipedia and itmaybeokay (just joking). =) but itmaybeokay did state on these forums that 179 could turn 63 TPH.

 

how much can Jamaica turn and how many TPH does the (E) run in rush hour?

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not my idea. blame wikipedia and itmaybeokay (just joking). =) but itmaybeokay did state on these forums that 179 could turn 63 TPH.

 

how much can Jamaica turn and how many TPH does the (E) run in rush hour?

The (E) runs about the same frequency as the (4) does during rush. Once again, mta.info is your friend.

http://www.mta.info/nyct/service/pdf/tecur.pdf

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Where did you get the idea that 179th can turn 63 tph? It certainly can't, at least not practically.

 

Jamaica Center can't turn 15 tph. If it could, then all E's would run to Jamaica Center. The reason some E's go to 179th is that not all 15 tph can fit at Jamaica Center.

 

 

They only add a few seconds to the dwell.

 

The 1 is only scheduled to run at 19 tph, and it hasn't been scheduled for more than that, at least not in recent history.

 

179th can, due to the upper and lower level relay tracks. Trains can enter at speed, drop everyone off, and head into either level of relay track without conflicting movements from other trains. However, trains also have to be cleared of passengers, and that takes time. But if that wasn't the case, 179th St could handle a lot more (as could Forest Hills, removing the one constraint that prevents (G) service to Forest Hills.)

 

The subway system used to run much more frequently during its heyday than it does today. Various factors, including speed timers installed to prevent speeding derailments (a bit overzealously, i might add), wear and tear on trains and subway tracks, and the passenger fumigation requirement all mean that the only way to regain this aggressive scheduling would be to install CBTC. (Chicago's Red Line once ran at headways of a staggering 105 seconds - that's an example of how aggressive train scheduling could be with the right set of experienced hands.)

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Money money and more money, not to mention maintenance. It's much easier to maintain one set of gap fillers at the few stations that need it rather than retrofit an entire fleet of 1000+ cars when only a fraction of them run on lines that even have stations that need the gap fillers.. 

 

What the hell did you read? I never talked about retrofitting. I talked about ORDERING. As in: they should've ordered the R142's with the gap fillers under the doors.

And the gap fillers under the doors from Bombardier/Siemens on their SLT model are maintain-free so maintaining isn't really the problem. If they can make that so perfect on the SLT model then they sure can do that on new R1xx subway cars as well. I actually do know a lot about those gap fillers on the SLT fleet because their are a few hundred SLT's running here and I know about the low, low needed maintenance of the fleet due to people I know from the maintenance team.

Edited by Vistausss

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What the hell did you read? I never talked about retrofitting. I talked about ORDERING. As in: they should've ordered the R142's with the gap fillers under the doors.

And the gap fillers under the doors from Bombardier/Siemens on their SLT model are maintain-free so maintaining isn't really the problem. If they can make that so perfect on the SLT model then they sure can do that on new R1xx subway cars as well. I actually do know a lot about those gap fillers on the SLT fleet because their are a few hundred SLT's running here and I know about the low, low needed maintenance of the fleet due to people I know from the maintenance team.

 

Keep in mind that the New York subway system is the same transit system that put at least two or three (don't remember the exact number) highly regarded American railcar manufacturers out of business because their products couldn't deal with the abuse the system gave them and they had to fork over money for repairing their inadequate products.

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Where did you get the idea that 179th can turn 63 tph? It certainly can't, at least not practically.

 

 

The E and F each run 15 tph, but only 12 tph run to Jamaica Center.

 

 

 

I would like to know myself how it is remotely possible that dispatchers @ 179th Street can send trains out at a theoretical 63 trains per hour.

 

I calculated this too. As of now in 2013, during the AM rush according to the current timetable, (F) trains run at 15 TPH with two (E) trains departing 179th Street on the approximate 8 AM rush for a total of 17 TPH. I guess they are going on the assumption that a train can be sent off on its run about every minute or so.  Even with the BMT Canarsie line with CBTC signaling, (L) trains are scheduled to run @ 15 TPH, 17 TPH max according to the timetable during the approximate 8 AM hour on the rush.

 

At one time, pre Archer Ave Line, before December 1988 when the line opened and (E) trains were rerouted, (E) and (F) trains were dispatched and departed from 179th Street @ 15 TPH for a grand total of 30 TPH according to transit workers via subchat on a thread I've read a long time ago, I remember this to an exact.

 

However dispatching 60 TPH *is* possible with other more modernized subway systems. The Moscow Metro system can have trains arrive and depart at 1 minute intervals according to a documentary which means at some terminals it can dispatch 60 TPH, technically. 

 

Well in short, really we need a transit worker to confirm this.

Edited by realizm

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What the hell did you read? I never talked about retrofitting. I talked about ORDERING. As in: they should've ordered the R142's with the gap fillers under the doors.

And the gap fillers under the doors from Bombardier/Siemens on their SLT model are maintain-free so maintaining isn't really the problem. If they can make that so perfect on the SLT model then they sure can do that on new R1xx subway cars as well. I actually do know a lot about those gap fillers on the SLT fleet because their are a few hundred SLT's running here and I know about the low, low needed maintenance of the fleet due to people I know from the maintenance team.

My point still stands, regardless of whatever wording you prefer; point being, go sell your idea to the (MTA).

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Keep in mind that the New York subway system is the same transit system that put at least two or three (don't remember the exact number) highly regarded American railcar manufacturers out of business because their products couldn't deal with the abuse the system gave them and they had to fork over money for repairing their inadequate products.

 

True, but the Bombardier/Siemens SLT fleet is running for a few years in regular service now without any problems with the gap fillers under the doors so I'd say: that's well tested. And Bombardier/Siemens has also made railcars and subway cars for NYC. So it's only a matter of implementing 'em on new subway cars. They are controlled software-wise so they can be enabled/disabled at request (although I've never seen 'em disabled because they need to be enabled here because of the large gaps; we use 'em as railroad trains over here). It's fairly quick. It takes 1 second for 'em to pop out and then the doors unlock.

 

But alright, maybe the suway isn't the place to use 'em. But how about LIRR and MNRR? They have quite some stations with gaps. Even up to the point where Charlie announces at most stations that you have to step over the gap.

 

 

 

 

 

I would like to know myself how it is remotely possible that dispatchers @ 179th Street can send trains out at a theoretical 63 trains per hour.

 

My thought is that he misinterpreted the information from the always *cough* reliable Wikipedia.

http://en.wikipedia.org/wiki/Jamaica_%E2%80%93_179th_Street_%28IND_Queens_Boulevard_Line%29

 

"This underground station opened on December 10, 1950, has four tracks and two island platforms. To the east (railroad north) are two levels of four relay tracks each extending out to 185th Street. This total of eight storage tracks gives 179th Street the highest peak terminal capacity of any station in the New York City Subway: 63 trains per hour, or one train every 57 seconds, although the station currently operates at a far lower throughput (only 20 trains per hour during peak hours)."

Edited by Vistausss
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My thought is that he misinterpreted the information from the always *cough* reliable Wikipedia.

http://en.wikipedia.org/wiki/Jamaica_–_179th_Street_(IND_Queens_Boulevard_Line)

 

"This underground station opened on December 10, 1950, has four tracks and two island platforms. To the east (railroad north) are two levels of four relay tracks each extending out to 185th Street. This total of eight storage tracks gives 179th Street the highest peak terminal capacity of any station in the New York City Subway: 63 trains per hour, or one train every 57 seconds, although the station currently operates at a far lower throughput (only 20 trains per hour during peak hours)."

True, the anonymous writer provided no accurate source link providing proof of that claim of 63 TPH output in that that citation from the Wikipedia article. Meanwhile Andrew JC and myself simply did the math to determine the TPH at max, today, (including (E) put-ins during the AM rush) and before 1988 when (E) and (F) trains used the same terminal. It simply sounds impossible.

Edited by realizm

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True, the anonymous writer provided no accurate source link providing proof of that claim of 63 TPH output in that that citation from the Wikipedia article. Meanwhile Andrew JC and myself simply did the math to determine the TPH at max, today, (including (E) put-ins during the AM rush) and before 1988 when (E) and (F) trains used the same terminal. It simply sounds impossible.

 

Four tracks and each pair linked to a dedicated relay area with four storage tracks? 63 TPH could've very well been the level of service in the 50's, when subway usage was at an all time high and both the (E) and (F) (or their predecessor services) terminated at 179th St. I myself do not have schedules from this era, but it seems entirely possible in the age before heavy federal regulation of rail transport, and in a time where trains were regularly doing 110+ MPH service on single track that today is limited to 79MPH operation.

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