briman94 Posted February 15, 2015 Report Posted February 15, 2015 There was nothing that you or Busjack cited that would lead a person to come to an idea that the 7000s would have "air brakes." Alternative 4 shall be a pneumatic disc brake system I'm really having a hard time believing your statement. Quote
Komplex Posted February 15, 2015 Report Posted February 15, 2015 When are they going to add new train cars on Blue line? Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 When are they going to add new train cars on Blue line? The blue line is staying with 2600s (and hopefully 3200s eventually) until the 7000s are delivered in 2019-2020 and later. Quote
chicagopcclcar Posted February 15, 2015 Report Posted February 15, 2015 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. 1 Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
chicagopcclcar Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
chicagopcclcar Posted February 15, 2015 Report Posted February 15, 2015 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? Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 Do you hear anything when our 5000s release? They're hydraulic. Quote
sw4400 Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 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 Quote
Brandon93 Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
4CottageGrove95th Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
4CottageGrove95th Posted February 15, 2015 Report Posted February 15, 2015 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: Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 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: How long until those are in service? I haven't been to D.C. since before they were announced but they look amazing. Quote
chicagopcclcar Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 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? Quote
chicagopcclcar Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
briman94 Posted February 15, 2015 Report Posted February 15, 2015 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. Quote
chicagopcclcar Posted February 15, 2015 Report Posted February 15, 2015 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. But you never drove a "L"....I did. Quote
Kevin Posted February 15, 2015 Report Posted February 15, 2015 Hi folks, just a reminder to please keep things civil. Sometimes it's just best to agree to disagree. 2 Quote
Busjack Posted February 16, 2015 Report Posted February 16, 2015 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. Quote
4CottageGrove95th Posted February 16, 2015 Report Posted February 16, 2015 How long until those are in service? I haven't been to D.C. since before they were announced but they look amazing. Well, right now the D.C 7000 series prototypes are in the testing stage. As best I can tell, they will probably go into rev service around early to mid spring. Quote
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