AlgorithmOfTruth Posted May 5, 2019 Share #151 Posted May 5, 2019 Can someone verify that the timers coming into Broadway Junction on the Manhattan-bound tracks of the / lines as being necessary? 0 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 5, 2019 Share #152 Posted May 5, 2019 It's hard to do that without having access to single line diagrams. A lot of the GTs on (especially older) parts of the signal system are there for stopping distance reasons 0 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 5, 2019 Author Share #153 Posted May 5, 2019 5 minutes ago, RR503 said: It's hard to do that without having access to single line diagrams. A lot of the GTs on (especially older) parts of the signal system are there for stopping distance reasons Adding more insulated rail joints would really help! 0 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 5, 2019 Share #154 Posted May 5, 2019 (edited) 10 minutes ago, Union Tpke said: Adding more insulated rail joints would really help! Yeah, or just more signals — more signals = more granular control of train position, speed, etc. I know you understand this, UT, but for the benefit of anyone who doesn’t: more IJs doesn’t necessarily mean more capacity; the reason that cutting in more here helps is that if you can cut in a new IJ at whatever the today-standard braking distance is from a given signal, there’s no need for a capacity-reducing GT or control line mod. Problem is, new IJs are expensive... Edited May 5, 2019 by RR503 0 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 5, 2019 Author Share #155 Posted May 5, 2019 14 minutes ago, RR503 said: Yeah, or just more signals — more signals = more granular control of train position, speed, etc. I know you understand this, UT, but for the benefit of anyone who doesn’t: more IJs doesn’t necessarily mean more capacity; the reason that cutting in more here helps is that if you can cut in a new IJ at whatever the today-standard braking distance is from a given signal, there’s no need for a capacity-reducing GT or control line mod. Problem is, new IJs are expensive... That is why the NYCT should have bitten the bullet and paid for it in the '90s. Which do you think would make more sense? Also, do you think that there any improvements should be made along with CBTC? 0 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 5, 2019 Share #156 Posted May 5, 2019 2 minutes ago, Union Tpke said: That is why the NYCT should have bitten the bullet and paid for it in the '90s. Which do you think would make more sense? Also, do you think that there any improvements should be made along with CBTC? Yeah, the mods contract was chronically underfunded—which, beyond making IJ mods hard, means that we got a lot more 1 shots than we probably should have (1s GTs are cheaper than 2s). I think your use scenario for more signals vs moved IJs is different. Leading up to interlockings, in areas with difficult geometry or at high dwell stations, you want more signals, while fixing some control line issue in a more average part of the system you’d want a new IJ. I think what’ll be key to good CBTC is a) maximizing speeds and minimizing braking distances wherever possible and b) focusing on installing CBTC, rather than CBTC with a bunch of other junk on top of it. So do max speed profiles, review emergency brake rates and then do work train compliance, etc to eliminate AWS. Because speaking of expensive IJs... 1 Quote Link to comment Share on other sites More sharing options...
R68OnBroadway Posted May 5, 2019 Share #157 Posted May 5, 2019 26 minutes ago, RR503 said: Yeah, the mods contract was chronically underfunded—which, beyond making IJ mods hard, means that we got a lot more 1 shots than we probably should have (1s GTs are cheaper than 2s). I think your use scenario for more signals vs moved IJs is different. Leading up to interlockings, in areas with difficult geometry or at high dwell stations, you want more signals, while fixing some control line issue in a more average part of the system you’d want a new IJ. I think what’ll be key to good CBTC is a) maximizing speeds and minimizing braking distances wherever possible and b) focusing on installing CBTC, rather than CBTC with a bunch of other junk on top of it. So do max speed profiles, review emergency brake rates and then do work train compliance, etc to eliminate AWS. Because speaking of expensive IJs... How much would it cost though to retrofit all the old equipment (work trains, museum trains, etc.) ? If you had to do all of that, wouldn't it be better to just install AWS or is it that expensive? 0 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 5, 2019 Share #158 Posted May 5, 2019 Just now, R68OnBroadway said: How much would it cost though to retrofit all the old equipment (work trains, museum trains, etc.) ? If you had to do all of that, wouldn't it be better to just install AWS or is it that expensive? RPA pegs the cost of full work train compliance at 95 million (if axle counters are not used) or 50-35 million (if they are). Assuming the FTA's estimation of AWS adding a 30% premium onto CBTC installation costs is correct, then AWS added 145 million to the originally budgeted cost of Flushing CBTC. Compliance has been done before, and is actually recommended as -- beyond the upfront savings -- killing AWS means you have many fewer signal components to maintain, and have many fewer points of failure. 1 Quote Link to comment Share on other sites More sharing options...
AlgorithmOfTruth Posted May 5, 2019 Share #159 Posted May 5, 2019 57 minutes ago, RR503 said: It's hard to do that without having access to single line diagrams. A lot of the GTs on (especially older) parts of the signal system are there for stopping distance reasons Do those single line diagrams take into account the route's curvature and topography? The relationship between timers and stopping distance/speed restricted-areas is clear, however, the timers in question appear to be counterproductive in their placement. About 500 FT before you enter Broadway Junction, the slope of the track bed sharpens, naturally reducing speed. 0 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 5, 2019 Share #160 Posted May 5, 2019 Just now, AlgorithmOfTruth said: Do those single line diagrams take into account the route's curvature and topography? The relationship between timers and stopping distance/speed restricted-areas is clear, however, the timers in question appear to be counterproductive in their placement. About 500 FT before you enter Broadway Junction, the slope of the track bed sharpens, naturally reducing speed. Yes, for obvious reasons stopping distance calculations take into account geometric properties. Single line diagrams, btw, don't show stopping distances, but instead the layout of the area signal system. A write up (with examples) can be found here: https://www.nycsubway.org/wiki/Subway_Signals:_Single-Line_Signal_Diagrams 0 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 17, 2019 Author Share #161 Posted May 17, 2019 There seems to be more to come: Screen Shot 2019-05-17 at 2.27.21 PM by Union Turnpike, on Flickr 0 Quote Link to comment Share on other sites More sharing options...
R68OnBroadway Posted May 17, 2019 Share #162 Posted May 17, 2019 Glad to see the push for more TPH on the , I always found it ridiculous that they didn't look to have 30+ tph given CBTC and high ridership. Hope they add tail tracks at 8th and maybe some turnback ones at Atlantic to faciliate this... 0 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 17, 2019 Author Share #163 Posted May 17, 2019 44 minutes ago, R68OnBroadway said: Glad to see the push for more TPH on the , I always found it ridiculous that they didn't look to have 30+ tph given CBTC and high ridership. Hope they add tail tracks at 8th and maybe some turnback ones at Atlantic to faciliate this... We need more trains! The should not be crowded! 28 TPH are possible without tail tracks! 1 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 17, 2019 Author Share #164 Posted May 17, 2019 Screen Shot 2019-05-17 at 7.47.40 PM by Union Turnpike, on Flickr Screen Shot 2019-05-17 at 7.47.45 PM by Union Turnpike, on Flickr 0 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 17, 2019 Author Share #165 Posted May 17, 2019 Screen Shot 2019-05-17 at 7.47.45 PM by Union Turnpike, on Flickr @RR503 How would infrastructure improvements affect the 's OTP? 0 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 18, 2019 Share #166 Posted May 18, 2019 53 minutes ago, Union Tpke said: Screen Shot 2019-05-17 at 7.47.45 PM by Union Turnpike, on Flickr @RR503 How would infrastructure improvements affect the 's OTP? I’m not aware of any infrastructure improvements — just the previously reported sign changes... 0 Quote Link to comment Share on other sites More sharing options...
Lex Posted May 18, 2019 Share #167 Posted May 18, 2019 24 minutes ago, RR503 said: I’m not aware of any infrastructure improvements — just the previously reported sign changes... Did they install CWR? 0 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 18, 2019 Share #168 Posted May 18, 2019 22 minutes ago, Lex said: Did they install CWR? Yeah, but that shouldn’t have any impact on speed — aside from it making a cooler noise, of course. 0 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 19, 2019 Author Share #169 Posted May 19, 2019 @RR503 This shows runtimes between Lexington-63rd and Kew Gardens. 1 is between Lex and Roosevelt Island, 2 is between Roosevelt Island and 21st, 3 is between 21st and Roosevelt Av, 4 is between Roosevelt and Forest Hills, 5 is between FH and 75, and 6 is between 75 and Union Tpke. Look at the extreme variability. The variability at 3 has to do with the merge at 36th Street. RuntimeNorthbound_Train_ by Union Turnpike, on Flickr RuntimeSouthbound_Train_ by Union Turnpike, on Flickr 1 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 19, 2019 Author Share #170 Posted May 19, 2019 Timers on CPW Express between 125th and 59th are clearly a factor here. Six minute variability! RuntimeNorthbound_Train_-1 by Union Turnpike, on Flickr RuntimeSouthbound_Train_-1 by Union Turnpike, on Flickr 0 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 19, 2019 Share #171 Posted May 19, 2019 Yeah, the variability charts are really something. When my friend is done fixing the X axis, I'm going to post some of my favorites -- these are really good at highlighting problem areas. A methodological note: the big range is the 5th to 95th percentile runtimes (not 0-100 to help cull some data failures), and the little box is 25-75. Middle line is 50. The site that makes these will eventually be public. 1 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 19, 2019 Author Share #172 Posted May 19, 2019 1 minute ago, RR503 said: Yeah, the variability charts are really something. When my friend is done fixing the X axis, I'm going to post some of my favorites -- these are really good at highlighting problem areas. A methodological note: the big range is the 5th to 95th percentile runtimes (not 0-100 to help cull some data failures), and the little box is 25-75. Middle line is 50. The site that makes these will eventually be public. Box and whisker plots put to good use! 1 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 20, 2019 Author Share #173 Posted May 20, 2019 @RR503 The program measures runtimes between departures and arrivals, so you cannot easily show delays from merges, as these would be in the form of increased dwell times. The awful switch layout at Jamaica Center really delays service. To show this I showed the running time from one station further west, Jamaica-Van Wyck. The comparison between Southbound and Northbound should show the impact of the lousy switching layout: 1 Quote Link to comment Share on other sites More sharing options...
RR503 Posted May 20, 2019 Share #174 Posted May 20, 2019 Yup! My entry to chartfest is this: look how the GTs from Franklin to Atlantic, the put-ins at Bowling Green, and crappy signalling and long dwells at 14th kill Lex service: 2 Quote Link to comment Share on other sites More sharing options...
Union Tpke Posted May 20, 2019 Author Share #175 Posted May 20, 2019 Last one for tonight. The merge at 50th slows service. Look at the difference here: 1 Quote Link to comment Share on other sites More sharing options...
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