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5000-series - Updates


greenstreet

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I'm really having a hard time believing your statement.

Rereading I SEE the discussion with "hydraulic assist, but pneumatic." Fortunately, a another discussion stated the continuation of electric brakes.

"Normal service stops shall be made with electric brake which shall maintain the rate to approximately three miles per hour (3 mph), there shall be no friction brake blending at speeds over 6 miles per hour. As the electric brake fades, the friction brake shall be smoothly blended in to complete the stop and hold the train."

No service braking using air. I'm going back to my nap.

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Rereading I SEE the discussion with "hydraulic assist, but pneumatic." Fortunately, a another discussion stated the continuation of electric brakes.

"Normal service stops shall be made with electric brake which shall maintain the rate to approximately three miles per hour (3 mph), there shall be no friction brake blending at speeds over 6 miles per hour. As the electric brake fades, the friction brake shall be smoothly blended in to complete the stop and hold the train."

No service braking using air. I'm going back to my nap.

The hydraulic (or air) brakes will still have to be applied for every full stop, and released every time the train accelerates again.

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The hydraulic (or air) brakes will still have to be applied for every full stop, and released every time the train accelerates again.

Hydraulic parking brakes don't make noise, like the one we have already on 5000s. I don't know what a pneumatic parking brakes would sound like. Remember, the sounds we hear in other systems are releasing the tread, disc, etc. that braked the entire train.

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Hydraulic parking brakes don't make noise, like the one we have already on 5000s. I don't know what a pneumatic parking brakes would sound like. Remember, the sounds we hear in other systems are releasing the tread, disc, etc. that braked the entire train.

Pneumatic disc parking brakes would probably still be audible...I'm pretty sure WMATA uses the same sort of system that CTA does for braking except with pneumatic brakes and their trains make an audible brake release sound similar to a bus or truck. I'd have to do more research on their system to verify, but they don't make their specs as open as the CTA does it seems.

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Pneumatic disc parking brakes would probably still be audible...I'm pretty sure WMATA uses the same sort of system that CTA does for braking except with pneumatic brakes and their trains make an audible brake release sound similar to a bus or truck. I'd have to do more research on their system to verify, but they don't make their specs as open as the CTA does it seems.

Do you hear anything when our 5000s release?

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Do you hear anything when our 5000s release?

The only sound I hear is when these trains pull into/leave stations... best I can describe it is like a whistling sound. I imagine it's the A/C motor on the trucks slowing down and accelerating. I know the D/C powered trucks on the older equipment don't make the whistling sound.

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The only sound I hear is when these trains pull into/leave stations... best I can describe it is like a whistling sound. I imagine it's the A/C motor on the trucks slowing down and accelerating. I know the D/C powered trucks on the older equipment don't make the whistling sound.

That would be the inverters for the A/C motors, yes. D/C motors have no "frequency" so they don't make noise unless PWM is used, which it's unfortunately not on the CTA.

Sometimes I use that sound to tell if a train pulling into Adams is a Green line or Brown line...my friends think I'm some sort of incredible nerd magician because I can tell which train it is without seeing it ;)

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That would be the inverters for the A/C motors, yes. D/C motors have no "frequency" so they don't make noise unless PWM is used, which it's unfortunately not on the CTA.

Sometimes I use that sound to tell if a train pulling into Adams is a Green line or Brown line...my friends think I'm some sort of incredible nerd magician because I can tell which train it is without seeing it ;)

I can relate because I can tell the difference btw the buses especially back when the TMC's and Fixibles were around.

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Supposedly they'll have air brakes.

The 7000s with air brakes???? Outer-sliding or plug doors??? I'm not saying those radical changes can't be implemented. But they would seem out of character with the L equipment most of us have been accustomed to. And, as with the 5000s, they would definitely be an "exclusive" series in that they could not train with any other existing equipment.

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The 7000s with air brakes???? Outer-sliding or plug doors??? I'm not saying those radical changes can't be implemented. But they would seem out of character with the L equipment most of us have been accustomed to. And, as with the 5000s, they would definitely be an "exclusive" series in that they could not train with any other existing equipment.

I believe that's actually slightly intentional...it almost seems that the CTA is trying to move onto a new generation of railcar (eventhough the 5000s were supposed to do that...) while still maintaining at least a little bit of consistency.

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I can relate because I can tell the difference btw the buses especially back when the TMC's and Fixibles were around.

I don't really pay attention to busses, but back when I was in high school I could tell the difference between the diesel and gas engines (anybody could...), but also the newer diesels (super quiet) and older ones.

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I believe that's actually slightly intentional...it almost seems that the CTA is trying to move onto a new generation of railcar (even though the 5000s were supposed to do that...) while still maintaining at least a little bit of consistency.

Air brakes huh?

Maybe the 7000s will use the combination air / disc brake operation similar to that used on Washington D.Cs newest 7000 series subway cars:

8074260940_cb89d22b4d_z.jpg

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7000s will NOT USE AIR BRAKES. I feel you, briman94 have been playing your computer games too long. Read

my lips....Plans for 7000s..."Normal service stops shall be made with electric brake which shall maintain the rate to approximately three miles per hour (3 mph), there shall be no friction brake blending at speeds over 6 miles per hour. As the electric brake fades, the friction brake shall be smoothly blended in to complete the stop and hold the train."

CTA, no service braking using air. Washington, Atlanta, MTA New York, Boston, etc, etc, use air brakes for service. That is the sound you hear.

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7000s will NOT USE AIR BRAKES. I feel you, briman94 have been playing your computer games too long. Read

my lips....Plans for 7000s..."Normal service stops shall be made with electric brake which shall maintain the rate to approximately three miles per hour (3 mph), there shall be no friction brake blending at speeds over 6 miles per hour. As the electric brake fades, the friction brake shall be smoothly blended in to complete the stop and hold the train."

CTA, no service braking using air. Washington, Atlanta, MTA New York, Boston, etc, etc, use air brakes for service. That is the sound you hear.

I don't think this is a productive discussion, but if the 7000s use pneumatic brakes like the spec says they might, the pneumatic brakes will have to be applied once the regenerative brakes lose effectiveness at low speeds. Then they'll obviously have to release to let the train move again, which, if they're air brakes, will make a sound as the air leaves the cylinder. It's not a big deal though, so why don't you just accept it and move on and I'll do the same?

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I believe that's actually slightly intentional...it almost seems that the CTA is trying to move onto a new generation of railcar (eventhough the 5000s were supposed to do that...) while still maintaining at least a little bit of consistency.

I don't think this is a productive discussion, but if the 7000s use pneumatic brakes like the spec says they might, the pneumatic brakes will have to be applied once the regenerative brakes lose effectiveness at low speeds. Then they'll obviously have to release to let the train move again, which, if they're air brakes, will make a sound as the air leaves the cylinder. It's not a big deal though, so why don't you just accept it and move on and I'll do the same?

The spec do NOT say they might. You are misreading the spec. I quoted what the spec says: ""Normal service stops shall be made with electric brake which shall maintain the rate to approximately three miles per hour (3 mph), there shall be no friction brake blending at speeds over 6 miles per hour. As the electric brake fades, the friction brake shall be smoothly blended in to complete the stop and hold the train." No service braking using air.

Where do you think I got that from? The specs.

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The spec do NOT say they might. You are misreading the spec. I quoted what the spec says: ""Normal service stops shall be made with electric brake which shall maintain the rate to approximately three miles per hour (3 mph), there shall be no friction brake blending at speeds over 6 miles per hour. As the electric brake fades, the friction brake shall be smoothly blended in to complete the stop and hold the train." No service braking using air.

Where do you think I got that from? The specs.

If the friction brake is an air brake, an air brake will be used to stop the train! Reread the spec if you're confused. I'm done discussing this.

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The 7000s with air brakes???? Outer-sliding or plug doors??? I'm not saying those radical changes can't be implemented. But they would seem out of character with the L equipment most of us have been accustomed to. And, as with the 5000s, they would definitely be an "exclusive" series in that they could not train with any other existing equipment.

That's what the specs have as options, and since CTA indicated that bids conforming to the prior spec that the 7000s had to be compatible with the 5000s were thrown out, and prices were requested on such things as the brake alternatives briman mentioned, the doors, automatic third rail deicers, Tomlinson couplers, and the like, one has to assume that those options are on the table, and while it certainly isn't certain that CTA will accept them, it isn't that it won't either.

In that the specs say that if Tomlinson couplers are offered, each car needs an adapter for Ohio Form 5 couplers, it becomes obvious that something can be incompatible with the 5000s but consistent with the specifications.

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