Timers timers timers!

[GreeneggsnPelham]

Hey all!

 

I had a few questions about timers that I've been wondering about for awhile. Here goes.

 

1) In Peter Dougherty's book, "Tracks of the NYC Subway", he mentions that prior to the introduction of the 1-shot, 2-shot GT, and ST signal aspects on the subway there were Station & Grade time controls in effect on the subway in the early 60s (correct me if I got the date wrong). What were these controls and how did they work if their now universally accepted signal aspect(s) hadn't been "invented" yet?

 

2) What is the purpose of some signals having both 1- and 2-shot GT controls? I was looking over some diagrams the other day and saw that this is very prevalent on the IRT (I was looking at the area between 66 & 86 Sts on the IRT West Side). Also, Peter's book mentions that J2-234 just before Myrtle Av has 1- and 2-shot GT controls that will display differently based on what track you enter from. Again, what's the logic behind this?

 

3) Slightly less technical: What are the highest and lowest speeds (to anyone's knowledge) on the subway that clear GT and ST signals? I know that some ST's are as low as 10 and as high as 30, and that some 2-shot GTs are as high as 45mph (the Queens-side entrance to the 60 St tubes).

 

Thanks again for viewing/answering my crazy technical questions!

 

-A 

 

 

[AndrewJC]

Hey all!

 

I had a few questions about timers that I've been wondering about for awhile. Here goes.

 

1) In Peter Dougherty's book, "Tracks of the NYC Subway", he mentions that prior to the introduction of the 1-shot, 2-shot GT, and ST signal aspects on the subway there were Station & Grade time controls in effect on the subway in the early 60s (correct me if I got the date wrong). What were these controls and how did they work if their now universally accepted signal aspect(s) hadn't been "invented" yet?

 

2) What is the purpose of some signals having both 1- and 2-shot GT controls? I was looking over some diagrams the other day and saw that this is very prevalent on the IRT (I was looking at the area between 66 & 86 Sts on the IRT West Side). Also, Peter's book mentions that J2-234 just before Myrtle Av has 1- and 2-shot GT controls that will display differently based on what track you enter from. Again, what's the logic behind this?

 

3) Slightly less technical: What are the highest and lowest speeds (to anyone's knowledge) on the subway that clear GT and ST signals? I know that some ST's are as low as 10 and as high as 30, and that some 2-shot GTs are as high as 45mph (the Queens-side entrance to the 60 St tubes).

 

Thanks again for viewing/answering my crazy technical questions!

 

-A 

 

1) The typical indications are a lunar white aspect for one-shot GT, a lit-up letter "S" (or "D") for two-shot GT, and a lit-up number (the speed) for ST. I think there still are some GT's and ST's without indications (I can't remember where) - they just look like regular signals, and the train operator doesn't know if they're going to clear on time.

 

2) Two-shots are less stressful for the operator, so the resulting operation is smoother (and faster). But if the safety objective requires that the train operate slowly through a very specific area, a one-shot may be required.

 

3) Off the top of my head, I believe there are one-shot GT-5's between Marcy and the Williamsburg Bridge.

[RestrictOnTheHanger]

Aren't there a bunch of 5 mph timers in other places along the ?

[RTOMan]

No they aren't give mph timers eight is a better number. It's the area from Cypress Hills to Crescent street both directions. It's not that bad actually.

*Five I meant five.

[BrooklynIRT]

There are GT-5s at Flatbush/Nostrand Aves; I think they used to be GT-10s. There is at least one GT-10 sign there that has yet to be removed (but no signals associated with any GT-10s remain there).

 

I suspect Queens Plaza westbound express track has GT-5s.

[itmaybeokay]

There are GT-5s at Flatbush/Nostrand Aves; I think they used to be GT-10s. There is at least one GT-10 sign there that has yet to be removed (but no signals associated with any GT-10s remain there).

 

I suspect Queens Plaza westbound express track has GT-5s.

 

I'm not sure if the westbound (Technically railroad Southbound) express track (D3) has timers, but if they do, I bet they're 10mph timers. 

 

The Northbound (or Eastbound if you want to get cardinal about it) Local track (D2) has 10mph Wheel Detectors all the way up the platform. 

[AndrewJC]

Aren't there a bunch of 5 mph timers in other places along the ?

 

I may be wrong, but I believe the worst speed restrictions elsewhere on the J (Crescent Street curves, Alabama Avenue curve) are GT-10.

[GreeneggsnPelham]

@Andrew: I understand the need for 1 and 2 shot GT control. I was asking about the reasoning behind placing both on the same signal. If safety was an issue, the 1-shots would be more obvious, but if smooth operation was the goal, then use the 2-shot. Why both would be needed on the same signal is what is throwing me off.

[RTOMan]

@Andrew: I understand the need for 1 and 2 shot GT control. I was asking about the reasoning behind placing both on the same signal. If safety was an issue, the 1-shots would be more obvious, but if smooth operation was the goal, then use the 2-shot. Why both would be needed on the same signal is what is throwing me off.

 

In that area your train is still going around the Curve..

 

Hence the Green Resume Sign we see after the Second Home signal.. Thats a tight curve and you can throw People...

[AndrewJC]

@Andrew: I understand the need for 1 and 2 shot GT control. I was asking about the reasoning behind placing both on the same signal. If safety was an issue, the 1-shots would be more obvious, but if smooth operation was the goal, then use the 2-shot. Why both would be needed on the same signal is what is throwing me off.

 

Sorry, I misunderstood the question.

 

M trains come around a sharp curve, where strict speed control may be necessary to avoid a potential derailment. J trains don't - whatever speed control may be necessary isn't nearly as severe. So the type of speed control depends on the setting of a switch (just as some GT's are only in effect for diverging moves).

 

I'm not aware of anything like that on the West Side IRT. Most of the territory you describe isn't near an interlocking, so what is the GT type conditioned on? That is, when is the one-shot in effect and when is the two-shot in effect? It can't be conditioned on the setting of a switch if there's no switch in the area.

[FriedChikkin]

Depends on the situation. Station Time, by definition, allows you to approach a train sitting in or moving out of a station. With a train right in front of you there are many, usually 2-shot GT signals that change to single shot Station Time before changing to their usualy, 2-shot yellow over S.

 

Off hand the only grade time signals I can remember that operate as such but give no indication that they are GT signals are the automatics coming into Dyre.

[GreeneggsnPelham]

Thanks to Andrew & Chikkin for your helpful responses!

 

@Andrew: Not a problem on misunderstanding--I should've worded my question more clearly. And I misspoke in my OP--the area around the West Side IRT between 66 & 86 had ST & GT signals, but FriedChikkin just answered my query about that.

 

Thanks again guys! I will definitely keep this post open as I encounter more interesting tidbits when building the subway in Trainz!

 

-A 

[AndrewJC]

Thanks to Andrew & Chikkin for your helpful responses!

 

@Andrew: Not a problem on misunderstanding--I should've worded my question more clearly. And I misspoke in my OP--the area around the West Side IRT between 66 & 86 had ST & GT signals, but FriedChikkin just answered my query about that.

 

Thanks again guys! I will definitely keep this post open as I encounter more interesting tidbits when building the subway in Trainz!

 

-A 

 

Glad to see I'm not the only one who finds this stuff fascinating.

 

Off hand the only grade time signals I can remember that operate as such but give no indication that they are GT signals are the automatics coming into Dyre.

 

Before CBTC, the Canarsie line had lots of GT's without indication. The ones in the tube, at the hands of a skilled train operator, were thrilling.

[GreeneggsnPelham]

@Andrew: the signalling completely fascinates me which is why it's such an honor to be doing NYCTA routes for the Trainz Railroad Simulator series. A lot of good people (who shall be kept anonymous) have contributed their expertise and talents to helping me with this route!

 

Also, another timer question I just thought of. What would be the indication on a "combo signal" (as I call the GT-ST hybrids), if it was a 2-shot GT displaying a caution display, but also fell into the ST category (while the GT indication was "live", the train ahead also cleared the tail end of the block, which would normally display a "20").

 

I only see two possibilities:

 

Option A: 

Yellow/S/20

 

Option B:

Red/S/20

 

Or maybe I'm completely off!

 

-A 

[FriedChikkin]

I can't think of any 2-shot ST "hybrid" signals in the system (where both operational rules are to be obeyed at once). The most important factor for MTA is Safety—if Station Time exists to allow one train to close in on another [then] a signal more "perilous" than a yellow has to be displayed to the Train Operator of the oncoming train.

[SubwayGuy]

Good question...lots of good responses so I'll try to add on:

 

There are GT-5s at Flatbush/Nostrand Aves; I think they used to be GT-10s. There is at least one GT-10 sign there that has yet to be removed (but no signals associated with any GT-10s remain there).

 

I suspect Queens Plaza westbound express track has GT-5s.

 

Flatbush's final approach, on each track, has a one shot GT 15, one shot GT 10, and one shot GT 5 on each track. The GT 10 sign is there, but the signals have been slowed down such that they clear at about 5-6. The GT 5 signals clear comfortably at 3, 4 max. While the GT 10 signals are not true GT 10, they are still faster than the GT 5 signals.

 

As far as fast signals go, in the A Division, the fastest are two shot GT 40's (3 in a row) on the Lexington Avenue express - 3 track north of 86th (heading towards 125).

 

Sorry, I misunderstood the question.

 

M trains come around a sharp curve, where strict speed control may be necessary to avoid a potential derailment. J trains don't - whatever speed control may be necessary isn't nearly as severe. So the type of speed control depends on the setting of a switch (just as some GT's are only in effect for diverging moves).

 

I'm not aware of anything like that on the West Side IRT. Most of the territory you describe isn't near an interlocking, so what is the GT type conditioned on? That is, when is the one-shot in effect and when is the two-shot in effect? It can't be conditioned on the setting of a switch if there's no switch in the area.

 

There are no such signals on the West Side IRT. However, there are plenty of conditional timers. Most will not have a time aspect at all unless a diverging route is set up ahead, in which case there will be a timer in effect only when that route is established. There are many examples of this - entering Times Square spur from the south on the IRT Broadway line, Pelham expresses crossing to the middle north of Parkchester in the morning, 3 trains going to or returning from the wash using the spur at 135/Lenox middle...to name a few.

 

There is only one signal I know of in the IRT that has a conditional 1 shot or 2 shot approach, and that's the third automatic north of Buhre Avenue on the Pelham line on 3 track (since it's the controlling signal for both the 1 shot and 2 shot aspects a train will see approaching the switches south of Pelham). It's a complicated signal so I'll try to explain it as best as I can, which is probably in more detail than most here care for...but why not?:

1)The caveat to this signal is that it's an approach signal also, so if it's not cleared off, you won't be able to approach it - you'll usually be stopped at the second automatic north of Buhre before it will be cleared off, although you can be brought up to it without clearing it off also.

2)This signal can also be cleared off without clearing the home signal behind it. A full lineup into Pelham, or even just to south of the station, does not need to be established for the signal to be cleared off and thus have one of its grade time aspects in effect. In this case, the signal displays the aspect associated with the current switch position of switch 1015, associated with 1018 home signal.

  2a)Therefore if the switch is set for the main route (regardless of whether or not the homeball is clear), a two shot GT 25 aspect will be in effect, with the approach signal at danger, and the preceding signal (the 2nd automatic north of Buhre) displaying a yellow with illuminated "S".

  2b)If the switch is set for the diverging route (regardless of whether or not the homeball is clear), a one shot GT 20 aspect will be in effect, with the approach signal at danger with a lunar white, and the preceding signal (the 2nd automatic north of Buhre) displaying solid yellow.

3)Therefore the relevant grade time aspect being displayed depends entirely on switch position. It is possible to approach 1018 home signal and have to clear the one shot GT 20 generally associated with the diverging route, be stopped at the homeball while the switch is moved, and then receive a main route to enter Pelham on 3 track. Likewise it is also possible to approach 1018 home signal and have to clear the two shot GT 25 generally associated with the main route, be stopped at the homeball while the switch is moved, and then receive a diverging route to enter Pelham on 2 track. The key point is that the timer does not exist to protect the switch during the move over it. The timer exists to protect the approach to the switch at the time the approach is being made. Principles of interlocking require switches that are not being used to be moved in such a way as to prevent a collision when conflicting moves are being made. The timer is intended to protect on the approach during the present condition of a train's approach.

 

For example: 2 track is empty at Pelham and the next southbound is leaving from track 3 at Pelham. A northbound at Buhre is next to arrive. The dispatcher decides that the southbound ought to leave the station first, then the northbound will be brought in on Track 2. The southbound is given the lineup, and the northbound receives a lineup up to the home signal 1018. In order for this to happen, 1015 switch must be set for the main route since it provides greater protection against a collision should the northbound run the signals at full speed (greater stopping distance before a fouling point). Therefore as the northbound approaches 1018 home signal, it will have to comply with the two shot GT 25. Once satisfied, the third automatic north of Pelham will clear from red to yellow, and the northbound will be held behind 1018 homeball until the southbound has completely left the interlocking area. Once the southbound is clear of the switches, 1015 switch will be set for a diverging route (along with the rest of the switches to complete the move to Pelham), and the homeballs will have routes established. Thus it is possible to operate through the area seeing the GT aspects associated with the main route, but yet receive a diverging route (or vice versa).

 

Depends on the situation. Station Time, by definition, allows you to approach a train sitting in or moving out of a station. With a train right in front of you there are many, usually 2-shot GT signals that change to single shot Station Time before changing to their usualy, 2-shot yellow over S.

 

Off hand the only grade time signals I can remember that operate as such but give no indication that they are GT signals are the automatics coming into Dyre.

 

There's also the automatics north of Parkchester on M and 3 which clear on time provided the home signal behind them has the diverging route established.

 

I'm 50/50 on whether or not X742 at the north end of Hunts Point is also...seems once you clear the two timers entering Hunts Point, if you come up on the automatic kind of fast, the homeball takes a really long time to clear...and there are GT 15 signs in the area but no indication if the signals are on time. It's either a GT signal with no indication, or ATS approach locking enforcing the train staying on the circuit for a given time before it clears off the homeball (like coming into Bowling Green northbound from the river tube).

 

@Andrew: the signalling completely fascinates me which is why it's such an honor to be doing NYCTA routes for the Trainz Railroad Simulator series. A lot of good people (who shall be kept anonymous) have contributed their expertise and talents to helping me with this route!

 

Also, another timer question I just thought of. What would be the indication on a "combo signal" (as I call the GT-ST hybrids), if it was a 2-shot GT displaying a caution display, but also fell into the ST category (while the GT indication was "live", the train ahead also cleared the tail end of the block, which would normally display a "20").

 

I only see two possibilities:

 

Option A: 

Yellow/S/20

 

Option B:

Red/S/20

 

Or maybe I'm completely off!

 

-A 

 

ST is the more restricting aspect always, so if both were in effect, the ST aspect would be the one you'd see. Signals that have combined ST/GT may have identical speeds for both, or the ST will be lower than the GT. The GT will never be lower than the ST since that doesn't make any sense ("approach this signal at 20 regularly, but you can approach 25 if there's a train directly in front of you" doesn't make any sense!) Since an ST signal is a conditional one shot GT, let's use a two shot GT with an ST function for our example (remember ST is ALWAYS one shot!):

 

4 scenarios would occur:

-Signal is red due to train movement and it is not safe to allow a train to pass the signal: Signal is red and will not clear until the preceding train advances.

-Signal is red due to train movement, but it is safe to allow a train to pass the signal to come one signal closer to the preceding train: ST in effect: Signal is red. If available, the speed is illuminated on the signal (many ST signals do not have illuminating number plates)

-Signal clear, next signal at danger due to train movement: Signal is yellow, but has no illuminating "S" or "D" since if grade time is complied with, the next signal will not clear (because it is red due to train movement). This is still true even if the next signal has an ST aspect.

-Signal clear, next signal at danger, no train traffic immediately ahead: signal is yellow with illuminated "S" or "D", two shot grade time is in effect.

 

Other interesting combinations could occur: If the preceding train was stopped, then moved out quickly, a following train could approach a red signal with GT function operating on ST, satisfy the ST, clear the signal to yellow, witness the "S" illuminate as the preceding train moved out to a distance safe enough for the grade time function to take over, and see the signal clear on grade time to green.

 

So lots of things are possible.

[Around the Horn]

Speaking of illuminated Ds I saw one yesterday what do they mean?

[RTOMan]

Speaking of illuminated Ds I saw one yesterday what do they mean?

 

The Next Signal will Clear with a Diverging route..

[GreeneggsnPelham]

@SubwayGuy: Wow! Thanks a whole bunch for this! I wasn't expecting a response this detailed, and this definitely is something I'll have to re-read a few times to get the gist of it! Thanks for taking the time to explain it in detail, and to answer all of my questions! These questions are half motivated by my interest in the signaling and half motivated by my development for the Trainz Simulator series and coding the signals just right. As I'm working on the IRT right now, your examples are an excellent source for when I get to the Pelham branch.

 

Thanks again!

 

-A 

[FriedChikkin]

Approach said signal at allowable speed and...

The Next Signal will Clear with a Diverging route..

[FriedChikkin]

There's also the automatics north of Parkchester on M and 3 which clear on time provided the home signal behind them has the diverging route established.

 

 

I'm 50/50 on whether or not X742 at the north end of Hunts Point is also...seems once you clear the two timers entering Hunts Point, if you come up on the automatic kind of fast, the homeball takes a really long time to clear...and there are GT 15 signs in the area but no indication if the signals are on time. It's either a GT signal with no indication, or ATS approach locking enforcing the train staying on the circuit for a given time before it clears off the homeball (like coming into Bowling Green northbound from the river tube).

I haven't been on the Pelham line for awhile but, from what I remember, the North end of 3TK at Parkchester is a single shot Red over Lunar White. M TK uses out-of-whack Wheel Detectors—they're constantly blinking as if you aren't operating within the speed limit. The same of the Wheel Detectors in the Steinway tube when Wrong Railing from 2TK Vernon-Jackson to 1TK Grand Central (stay blinking).

 

For Bowling Green I simply don't push the GT15 speed limit. There's the two Yellow over Greens then the Red automatic that clears before hitting the station. If I'm in the Bowling Green loop and maybe the road is jacked up I'll see them set the approach to Yellow (the approach that new guys are warned to never key or they'll lock out the switch), after I bridge the Approach's IJ the homeball clears.

 

Talking about ATS kicking in—entering Utica 4TK and 157 St SB on the Broadway line to name two where I see the signals all go from Red to Green ahead of me.

 

Dyre's still the only spot where I recall no signs (miscellaneous or otherwise) and they operate as timers and don't look like them.

[SubwayGuy]

I haven't been on the Pelham line for awhile but, from what I remember, the North end of 3TK at Parkchester is a single shot Red over Lunar White. M TK uses out-of-whack Wheel Detectors—they're constantly blinking as if you aren't operating within the speed limit. The same of the Wheel Detectors in the Steinway tube when Wrong Railing from 2TK Vernon-Jackson to 1TK Grand Central (stay blinking).

 

At Parkchester, the wheel detectors are in bypass, but they continue blinking as if in effect anyway. Come to think of it I can't actually remember if 3 track has a lunar white on it or not, but I know for a fact that M track doesn't. The leaving signal at the north end of the station is yellow, the approach automatic is red, and the homeball will be yellow over yellow for a Pelham express (assuming of course you have the lineup). If you never leave Parkchester, the approach will never clear off for you. 8-10 MPH clears it comfortably, so it's probably a GT 15...but the signal does not have a lunar white.

 

For Bowling Green I simply don't push the GT15 speed limit. There's the two Yellow over Greens then the Red automatic that clears before hitting the station. If I'm in the Bowling Green loop and maybe the road is jacked up I'll see them set the approach to Yellow (the approach that new guys are warned to never key or they'll lock out the switch), after I bridge the Approach's IJ the homeball clears.

 

Talking about ATS kicking in—entering Utica 4TK and 157 St SB on the Broadway line to name two where I see the signals all go from Red to Green ahead of me.

 

Dyre's still the only spot where I recall no signs (miscellaneous or otherwise) and they operate as timers and don't look like them.

 

That's exactly how I operate Bowling Green also, and I do the same thing coming into Chambers S/B around the curve on 2tk on the west side (since the lineup takes forever to come into the homeballs south of Franklin St.), and the first homeball is "supposed" to be on time but usually is on ST since the lineup isn't established all the way in (the yellow automatic is always solid as you approach, and if you take it slow enough it will add the "S", but usually you'll pass it first).

 

4tk entering Utica is strange. Half the time I come around the curve entering the portal, and the signals are clear up to the entering automatic, and the signals clear off as I approach. The other half of the time I don't even have the lineup at the homeball yet, so I hold two points into the portal after clearing the timers until I get clear signals to the south end of the station (so the signals are set up as the first way), then I'll wrap. In this second instance I'll get the lineup all the way in before I reach the yellow automatic approach. I just find it strange how inconsistent the timing of these signals being cleared off is.

[GreeneggsnPelham]

Love the discussion guys! It's so interesting to hear all of this stuff. Any B-Division motormen want to drop in their two cents about interesting timers they come into contact with on a regular basis? @Fried & Subway Guy, I'll show some videos of the areas you mentioned once I get them signaled and you can tell me how authentic they are.

 

-A 

[Around the Horn]

Green,I would gladly report any interesting timers I see during my railfanning "excursions" if you want of course.

[GreeneggsnPelham]

Absolutely--anything anything! 

 

In particular, to the motormen who've posted--any interesting anomalies with the timers/homeballs approaching Coney Island from either the or ? I saw a RFW video of the nostalgia train running via Sea Beach Exp to CI, and those timers at the Creek Interlocking were really interesting to see in action.

 

-A