How come the M3s dont make a noise when they start up?

[lilbluefoxie]

How come the M3 cars dont have a woooooo noise like the older subway cars or the M7s when they start up, do they have a different style power chopper? All you hear when the M3s start moving is this loud hummmm.

[Joel Up Front]

I can't remember what it was with the M7s... I think it was the conversion from AC to DC or something like that. INDman would have a much better answer.

 

That same noise is why I hate the M7 so much. The touted it as "quieter and more comfortable" when those things buck like a mother and hearing that noise whenever the train goes over a switch or slows down at a terminal is enough to keep me awake.

[INDman]

The M3s for the LIRR are DC cars so there would be no chopper. The whine you hear with the M7s and NTT subway cars is due too the DC power from the 3rd rail being converted to AC power for thr traction motors. Also that "wooo" noise that you hear with the R1/9s and Low-Vs is from the style of gear box they have.

[lilbluefoxie]

The M3s for the LIRR are DC cars so there would be no chopper. The whine you hear with the M7s and NTT subway cars is due too the DC power from the 3rd rail being converted to AC power for thr traction motors. Also that "wooo" noise that you hear with the R1/9s and Low-Vs is from the style of gear box they have.

 

not that wooooooo, im talking about the wooooooooo when the R32s and R46s accelorate, its a higher pitched wooo

[lilbluefoxie]

I can't remember what it was with the M7s... I think it was the conversion from AC to DC or something like that. INDman would have a much better answer.

 

That same noise is why I hate the M7 so much. The touted it as "quieter and more comfortable" when those things buck like a mother and hearing that noise whenever the train goes over a switch or slows down at a terminal is enough to keep me awake.

 

the M7s suck, they squeak and bounce and are noisy, the M3s pull into the stations and leave quietly and the only noise they make is the brakes squealing a bit

[INDman]

not that wooooooo, im talking about the wooooooooo when the R32s and R46s accelorate, its a higher pitched wooo

 

I think that's just the sound the motors make, I mean they are moving. I think you don't hear it on the M3s because they have alot of sound insulation since they are railroad cars, not subway cars and the ride quality is expected to be higher.

[Vistausss]

I think that's just the sound the motors make, I mean they are moving. I think you don't hear it on the M3s because they have alot of sound insulation since they are railroad cars, not subway cars and the ride quality is expected to be higher.

 

But according to posts above, the M7's make that noise and they're newer than the M3's and also railroad cars.

But you're right though that it's just the sound the motors make.

[4P3607]

Actually, Jon, now that you pointed it out I never noticed any propulsion on the M3A's (or M3, the ones that are on the MNRR). I would think that the M3/A's have it since they were based off the R46. I caught an R46 departing Queens plaza the other day going very slow, it made the same exact sound that an M2/4/6 does.

 

And yes, I agree with the others about the M7A's. They are sh!t. at least MNRR doesn't have ~800 M7's like the unfortunate LIRR does...

[lilbluefoxie]

Actually, Jon, now that you pointed it out I never noticed any propulsion on the M3A's (or M3, the ones that are on the MNRR). I would think that the M3/A's have it since they were based off the R46. I caught an R46 departing Queens plaza the other day going very slow, it made the same exact sound that an M2/4/6 does.

 

And yes, I agree with the others about the M7A's. They are sh!t. at least MNRR doesn't have ~800 M7's like the unfortunate LIRR does...

 

they have about 300 M7As, they dont need that many of them since only two lines use them vs the 8 lines that use electric trains on the LIRR. At one point the LIRR had about 800 M1s

[Amtrak7]

the M7s suck, they squeak and bounce and are noisy, the M3s pull into the stations and leave quietly and the only noise they make is the brakes squealing a bit

 

How are M7's squeaky and bouncy? They have a pretty smooth ride, IMO. The M3 are bouncy, and boy are the M2's bouncy. I was bouncing around the whole 2 hour ride NYC-NHV. Coming back on an M6, it was better, but of course not as good as an M7. Need to ride an M8 someday.

[Rutgers Tube]

For the record, here are is the information that I'm familiar with regarding the propulsion types and various traction motors for the aforementioned equipment:

 

Propulsion:

 

All pre-M7 equipment have the GE DC cam controller type (I'll have to check on the exact specifications). The M1/3 resistors are also DC-controlled, while the M2/4/6 have DC-controlled resistors in when running on third-rail power and have AC-controlled thyristors when using overhead catenary power. The M4's and M6's were equipped with thyristors when delivered, while the M2 series were initially equipped with ignitrons, which were later changed over to thyristors at some point.

 

The R46 uses the GE DC SCM 17KG327A1.

 

Traction motors:

 

R46 - GE1257, 115 HP x 2 per truck (460 HP per car);

M1 - GE1255, 150 HP x 2 per truck (600 HP per car);

M2 - GE1259, 162 HP x 2 per truck (648 HP per car);

M3 - GE1251, 140 HP x 2 per truck (560 HP per car);

M4 - GE1259, 162 HP x 2 per truck (648 HP per car);

M6 - I'm not sure, but they may very well have the same traction motors as the M2 and M4 equipment.

 

I can go into a fair amount of detail about the various noises and the inner workings of the various propulsion and traction motor types, but I'm rushed for time right now. Perhaps I will later.

[Vistausss]

And yes, I agree with the others about the M7A's. They are sh!t. at least MNRR doesn't have ~800 M7's like the unfortunate LIRR does...

 

What others? I never said anything about the M7's in this topic.

I agree with Amtrak7 that the M7's give you a smooth ride. Not as smooth as the M8's, but they're hell of a lot better then what we have here (except for the SLT). I love the M7's and M8's

[Matt91]

I hate the m7s with a passion, ill go out of my way to get a diesel set or m3s. The M7s are more squeaky and bouncy if you're in the ends of the car. They're definitely noisy between that, the motors, the creaking when they go over switches, and especially the damn bing bong announcements every minute. I'll take a quiet but beat up m3 over that any day, but even that doesn't beat the fact that you can hear a pin drop in a smooth riding c3

[Joe]

M3s have been noted for having an exceptionally smooth ride on concrete-tie track.

[Joel Up Front]

The only time I like being on an M7 is if it at speed and nowhere near anything that would require it to slow down.

 

Of course, I was meaning to find an M3 into Penn but when it did come up I had no interest in going into Manhattan....

[Rutgers Tube]

Two corrections on my previous post regarding propulsion systems:

 

The M2 series are equipped with GE 1259A traction motors, providing 160 HP each at four per car, yielding 640 HP.

 

The M3 series are equipped with GE 1261 traction motors, also providing 160 HP each at four per car, yielding 640 HP.

 

M3s have been noted for having an exceptionally smooth ride on concrete-tie track.

 

Couldn't that statement apply to just about any railcar? Concrete-ties and CWR are probably the most integral railroad infrastructure components necessary in order to provide smooth, quiet high-speed travel.

 

FYI: both the M2 and M3 series are outfitted with the same General Steel Industries Model 70 trucks.

[INDman]

 

Couldn't that statement apply to just about any railcar? Concrete-ties and CWR are probably the most integral railroad infrastructure components necessary in order to provide smooth, quiet high-speed travel.

 

 

 

Not really since the M7s that use the same track don't have as good of a ride as the M3 cars.

[Joe]

Not really since the M7s that use the same track don't have as good of a ride as the M3 cars.

 

Exactly. I mean, ride an RT car at BERA and it's a fairly bumpy ride but a trolley like 2001 will be pretty graceful.

[metsfan]

Because they (M3) use DC motors.

 

The whine you hear on M7 etc is due to magnetostriction within the traction power circuit(s).

 

- A