SUBWAY - Random Thoughts Topic

[Jemorie]

9 hours ago, MysteriousBtrain said:

Look, I admit I sometimes overreact over certain things, but do you really think I give a rat's ass about anyone disagreeing with me? Don't know where the hell you got that from. All I said was that you can't expect everything to come to you no matter who you are. You want to tell me how I "disagreed" with others, send a PM.

I think P3F is referring to the downvote you gave GojiMet86, so I believe that's why he called you out on that matter. But overall, I'm mostly on your side and plus you said what you had to say anyway.

@bwwnyc123, the SMEEs all had their field shunting removed a while back. Hence why they take off slower than the NTTs when leaving a station together at the same time. However, the NTTs are specifically programmed not to go at certain speeds past the 45-50+ mph mark and tend to struggle as soon as they reach around the 40s, compared to the SMEEs which performed better in that regard. Also, a full 600 feet long train of an R160 weights more than a full 600 feet train of a 75 footer. The R32s and R42s are the lightest cars in the entire B Division alongside the now retired R38s and R40s, Overall, the max is 50-55 mph on all cars in the present day.

Edited July 8, 2018 by Jemorie

[RR503]

I think the difference in 160 vs 68 speeds (and someone with better knowledge of car equipment please correct me here) has to do with the way traction is managed in the two cars. 68 are simple cars. You tell them to put x amount of power and they do exactly what they say, regardless of whether that actually accomplished the desired acceleration or not. 160s have brains. They manage horsepower and therefore acceleration to output the maximum possible without exceeding their traction curve (while also not allowing wheel slip etc), allowing them to more reliably reach higher speeds. At those higher speeds, again, the 160s may struggle, but it’s programmed struggling versus uncontrolled struggling, making it all the easier for the train to continue — however slowly — to accelerate. 

[Rick44]

3 hours ago, bwwnyc123 said:

R68s are more sluggish than R160s.

It's okay to be wrong, don't get in your feelings.

 

1 hour ago, RR503 said:

I think the difference in 160 vs 68 speeds (and someone with better knowledge of car equipment please correct me here) has to do with the way traction is managed in the two cars. 68 are simple cars. You tell them to put x amount of power and they do exactly what they say, regardless of whether that actually accomplished the desired acceleration or not. 160s have brains. They manage horsepower and therefore acceleration to output the maximum possible without exceeding their traction curve (while also not allowing wheel slip etc), allowing them to more reliably reach higher speeds. At those higher speeds, again, the 160s may struggle, but it’s programmed struggling versus uncontrolled struggling, making it all the easier for the train to continue — however slowly — to accelerate. 

What you're describing in a basic sense is torque. When it comes to a train, torque doesn't have an enormous effect on speed, however there would be a slight difference, yes, especially when the effect on a new tech is programmed and not natural.

[KK 6 Ave Local]

Does anyone else think a budget cut is near? I somewhat do.

[AlgorithmOfTruth]

Correct, torque has an influence on a train's acceleration, as it is a consequence of RPM, but top speed can be manipulated by various factors, such as propulsion output, aerodynamics of the car body design, and weight. An additional factor to these is known as field shunting, which caps the top speed of an arbitrary piece of equipment by use of resistors, increasing the duration that current takes to complete circuits within the traction system—it's physics at work.

[Lance]

If anyone's wondering why three pages of content is missing, it's because some of you don't know how to move on. You could've left it alone after the first couple of responses, but a few of you chose not to. We strive to be a welcoming community of transit enthusiasts here some of the recent posts in this thread do not give off that vibe. It was a dumb idea, I'll give you that, but it did not require over 30 posts to convey that message. And it certainly did not require rehashing the same points and counterpoints after the initial discussion was finished. We have to be better than that. There's one rule everyone should follow both on this forum and offline: don't be an a**hole.

And on a side-note, guys, it's just trains. Don't let it rule your lives.

[bwwnyc123]

51 minutes ago, Rick44 said:

It's okay to be wrong, don't get in your feelings.

 

What you're describing in a basic sense is torque. When it comes to a train, torque doesn't have an enormous effect on speed, however there would be a slight difference, yes, especially when the effect on a new tech is programmed and not natural.

I'm not wrong you all just don't understand R68 cars are heavier than R160s that why R68 and R46 are more sluggish it happens ALL the time R160 outrun the R46 and R68s.

[Jemorie]

1 hour ago, Rick44 said:

It's okay to be wrong, don't get in your feelings.

It’s like talking to a brick wall. What can you do? Sometimes you just can’t get through to some people like him and in the end just gotta accept their opinions on the subject matter. Let’s just move on and let him talk out his ass all he wants lol.

RR503, the thing is, people in general shouldn’t be comparing the NTTs and SMEEs because there’s a major difference between the two. The R160s are like an actual computer because like you said they were built specifically for that purpose. I don’t know how to put it, but that’s just how I see it.

Edited July 8, 2018 by Jemorie

[trainfan22]

R160s outrun ALL B div SMEE cars. The 32s are lighter than 160s and the 160s still accelerate faster than 32s.

 

IIRC, it was explained that NTT hold their 2.5 MPH acceleration longer than the SMEEs do. Hence why they seem faster.

Edited July 8, 2018 by trainfan22

[bwwnyc123]

41 minutes ago, Jemorie said:

It’s like talking to a brick wall. What can you do? Sometimes you just can’t get through to some people like him and in the end just gotta accept their opinions on the subject matter. Let’s just move on and let him talk out his ass all he wants lol.

RR503, the thing is, people in general shouldn’t be comparing the NTTs and SMEEs because there’s a major difference between the two. The R160s are like an actual computer because like you said they were built specifically for that purpose. I don’t know how to put it, but that’s just how I see it.

Because you all are blind as a bat so R160 and R46 or R68 Express and Local would start to leave station at the same motion then R160 would start to move up ahead quicker than the older cars.

[Lawrence St]

Can. We. STOP. For the love of Christ MOVE ON!

[jon2305]

Sigh, this whole thing just seems like a dumb game of "mine is bigger and better than yours".

[KK 6 Ave Local]

18 hours ago, P3F said:

Maybe it's an illusion, but in the past week I've gotten the feeling that R160s move faster via Brighton Express than R68s. I know the R68s accelerate more slowly, but is there any reason for the NTTs to be running faster on the line after getting up to speed?

The comment that started it all (somehow)

Edited July 8, 2018 by KK 6 Ave Local

[RR503]

7 hours ago, Rick44 said:

What you're describing in a basic sense is torque. When it comes to a train, torque doesn't have an enormous effect on speed, however there would be a slight difference, yes, especially when the effect on a new tech is programmed and not natural.

Not exactly, no. What I'm trying to communicate is that the SMEEs always provide the amount of tractive effort required to achieve 2.5mphps acceleration on flat, tangent, dry track without any load. NTTs do not. They calibrate tractive effort to the environmental/physical characteristics of the situation they're in, and adjust accordingly. This, for example, allows them to mitigate wheelslip in wet rail/leafy conditions, and also allows them to accelerate relatively well with a full load of passengers. I'm suggesting this may be the cause of the observed discrepancy between NTT and SMEE speeds on Brighton -- though I can't say for sure. 

[AlgorithmOfTruth]

1 hour ago, RR503 said:

Not exactly, no. What I'm trying to communicate is that the SMEEs always provide the amount of tractive effort required to achieve 2.5mphps acceleration on flat, tangent, dry track without any load. NTTs do not. They calibrate tractive effort to the environmental/physical characteristics of the situation they're in, and adjust accordingly. This, for example, allows them to mitigate wheelslip in wet rail/leafy conditions, and also allows them to accelerate relatively well with a full load of passengers. I'm suggesting this may be the cause of the observed discrepancy between NTT and SMEE speeds on Brighton -- though I can't say for sure. 

That's a very compelling observation of the NTT's. If a set of R32s were compared to a basic run-of-the-mill bike, a set of R179s would be a cyclist's dream in relative regard, consisting of a traction system operating off various gears to compensate for weight contributed by passengers, rail grade, and even weather conditions that cause tracks to be slippery. I would think it's easier to program the electronics of a system to execute some function than having to overcome these factors with just a mechanical beast with no "brains."

[Rick44]

15 hours ago, RR503 said:

Not exactly, no. What I'm trying to communicate is that the SMEEs always provide the amount of tractive effort required to achieve 2.5mphps acceleration on flat, tangent, dry track without any load. NTTs do not. They calibrate tractive effort to the environmental/physical characteristics of the situation they're in, and adjust accordingly. This, for example, allows them to mitigate wheelslip in wet rail/leafy conditions, and also allows them to accelerate relatively well with a full load of passengers. I'm suggesting this may be the cause of the observed discrepancy between NTT and SMEE speeds on Brighton -- though I can't say for sure. 

I don't know the science to it, but I'd say this and the other post are really interesting breakdowns that make a lot of sense. I'm upvoting lol.

[Yankees4life]

For f**ks Sake, its irrelevant really. As long as it's gets me from A to B. I could really give two shits about "speed".

[KK 6 Ave Local]

Ok, I'm reposting because the whole "R160S ARE FASTER !11!1!!!1!11 NO R68S ARE FASTER!11!!1!11!!1" thing managed to continue on: Because the  falls short in money on EVERYTHING, I honestly think some kind of budget cut is to happen in the near future. Just my thoughts. 

[Yankees4life]

38 minutes ago, KK 6 Ave Local said:

Ok, I'm reposting because the whole "R160S ARE FASTER !11!1!!!1!11 NO R68S ARE FASTER!11!!1!11!!1" thing managed to continue on: Because the  falls short in money on EVERYTHING, I honestly think some kind of budget cut is to happen in the near future. Just my thoughts. 

Hmm...I don't know. With the SAS coming along and the L shutdown, what are they gonna cut? The ?

[Amtrak706]

DC motor cars use resistor banks as well as series and parallel relay configurations to manage acceleration. For example, if a T/O releases the brakes and immediately wraps the controller around to the "parallel" notch (full power) the train will not actually start in parallel. It will initially apply power in series configuration, and depending on the type of car this might be complemented with resistor banks to gradually increase current.

Around 10mph the car makes transition, which means the power control relay flips to parallel. This is that second "push" you may feel after a train takes off initially. Again, resistor banks may be used to manage the increase of current. Once the last resistor bank shuts off and the motors have full parallel current, the acceleration starts falling off from 2.5mph/s  at around 20mph and eventually stops at "balancing speed" between 35-45mph on level track.

Back in the day when field shunting was still enabled, several stages of field weakening or "shunting" (look this up online if you want a full electrical engineering description) would kick in to basically trade torque for speed by introducing a resistance to weaken the current in the field winding and ultimately the back EMF of the motor. This would allow a train to gradually reach its top design speed of 55mph, assuming level track.

The series notch on the controller will start a train out with the same resistor banks, but won't make transition to parallel. The first notch will start a train the same way except it leaves a few resistor banks on so the train never gets full series current. This notch is not used for more than a few seconds, as it could burn up the resistors.

All this is to explain that it makes no sense to advance gradually through the controller notches to manage acceleration. It is the same electrical process regardless of notch, you are just telling the controller where, or if, to pause the process.

For NTT trains with AC motors, none of this applies. Instead, the computer manages acceleration by modulating the AC current and frequency into the motors to stay at 2.5mph/s without wheelslip. The dropoff from this rate of acceleration does occur a bit later than on DC equipment, which is why R160s appear to "pull away" from R68As on Brighton. This took me a damn while to type so congrats if you are still reading.

[Calvin]

A 5-car reburished R160 is coupled to a regular 160 on the  . Just one-set with the artwork. 

Edited July 10, 2018 by Calvin

[bobtehpanda]

On 7/8/2018 at 1:54 PM, KK 6 Ave Local said:

The comment that started it all (somehow)

 

8 hours ago, Yankees4life said:

For f**ks Sake, its irrelevant really. As long as it's gets me from A to B. I could really give two shits about "speed".

 

3 hours ago, KK 6 Ave Local said:

Ok, I'm reposting because the whole "R160S ARE FASTER !11!1!!!1!11 NO R68S ARE FASTER!11!!1!11!!1" thing managed to continue on: Because the  falls short in money on EVERYTHING, I honestly think some kind of budget cut is to happen in the near future. Just my thoughts. 

No one gives a shit about your snark. At least some people here can manage to have an interesting conversation.

On that note, how hard would it be to extend the Eastern Division to ten cars? Most of the line dates from the Dual Contracts era.

Edited July 10, 2018 by bobtehpanda

[OIG119]

7 hours ago, bobtehpanda said:

On that note, how hard would it be to extend the Eastern Division to ten cars? Most of the line dates from the Dual Contracts era.

There are a number of places where adjacent infrastructure limits station length to 480 feet, like Essex Street, Chambers Street, or Broadway Junction, for example. There are other places where stations would end up too close together. At Marcy Avenue due to the curve to the WBB the station an extension would have to be built to the east, and the station would get too close to Hewes Street. Of course in that case Hewes Street would likely have to close, and maybe a new Union Avenue station could be built to transfer to the .

[officiallyliam]

8 hours ago, bobtehpanda said:

On that note, how hard would it be to extend the Eastern Division to ten cars? Most of the line dates from the Dual Contracts era.

1 hour ago, OIG119 said:

There are a number of places where adjacent infrastructure limits station length to 480 feet, like Essex Street, Chambers Street, or Broadway Junction, for example. There are other places where stations would end up too close together. At Marcy Avenue due to the curve to the WBB the station an extension would have to be built to the east, and the station would get too close to Hewes Street. Of course in that case Hewes Street would likely have to close, and maybe a new Union Avenue station could be built to transfer to the .

Bear in mind, though, that many of the stations on the Eastern Division once accommodated 8-car trains of BMT Standards, which are 67' long - meaning that a lot of platforms are actually about 540' long rather than 480'. That's why the idea of having 9-car trains for the Canarsie shutdown had been suggested. So extending to 600' would only involve - for most stations - an extension of about 60', or one car length. Moving switches back a few feet should be relatively easy on elevated sections (like at Broadway Junction, or Metropolitan on the ) but might not be possible at Chambers or Essex, which also have track grade issues to deal with. Even in these cases, though, the amount of the train not on the platform would be 1 car length or less, so we could simply employ selective door opening as was done in London when they found themselves in a similar situation extending platforms to fit the S Stock.

The point about station spacing is still important: extending platforms along the Eastern Division will call to attention the already-very-close spacing of stations around parts of the network. Consolidating some of the closer stations, like Hewes and Lorimer, or several of the stops between Broadway Junction and Crescent, might be more worth it than lengthening all those platforms.

[P3F]

28 minutes ago, officiallyliam said:

The point about station spacing is still important: extending platforms along the Eastern Division will call to attention the already-very-close spacing of stations around parts of the network. Consolidating some of the closer stations, like Hewes and Lorimer, or several of the stops between Broadway Junction and Crescent, might be more worth it than lengthening all those platforms.

Except for the fact that completely demolishing two stations and building a new one from scratch is in a completely different league from adding 60 feet to a platform, in terms of scope and cost. And is it even necessary to consolidate these stations? Absolutely not. Any time saved by trains would be minimal, and cost savings from less required maintenance are laughable as well. It's simply a ridiculous proposal.

Regarding the transfer, build a passageway from Hewes & Broadway to Montrose & Union. That will connect the eastern end of Hewes Street to the center of Broadway , and the distance covered is fairly manageable.