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| How much ballast remains? (1585511) | |
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| (1585530) | |
Re: How much ballast remains? |
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Posted by R46 5636 on Fri Sep 17 14:49:31 2021, in response to How much ballast remains?, posted by gbs on Fri Sep 17 03:20:46 2021. Some parts of the Express tracks along BMT Broadway seem to be ballast still. The entire (or at least parts of the) Dyre line is too I believe, even the "underground" Pelham Pkwy Sta.The Brighton line along Flatbush (7 Ave to Prospect) seems to still be mostly ballast, as well as the Prospect Park Station itself. Interesting mention of the 7 along Queens Blvd, as the section between 33rd and 46th is still all jointed rail from the last installation probably from the 80s despite being on concrete. Still interesting to hear the click-clack of jointed rail along that section when so many others of the same have been replaced by CWR. The NB Local track at 34 Herald Square (6 Ave) was distinctly all jointed rail until a weekend or two ago, now all CWR (although concrete, this was one of the last spots in the system with no extra space between the rails on the trackbed which was an original 30's IND feature. Forest Hills - 71 was the only other spot I can think that used to be the same). |
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| (1585557) | |
Re: How much ballast remains? |
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Posted by Steve B-8AVEXP on Fri Sep 17 20:10:23 2021, in response to Re: How much ballast remains?, posted by R46 5636 on Fri Sep 17 14:49:31 2021. IMHO it's a mystery why the BMT Broadway express tracks were never upgraded to a ties-in-concrete roadbed. After all, they were out of service for a decade while the south side tracks of the Manhattan Bridge were closed. |
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| (1585565) | |
Re: How much ballast remains? |
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Posted by randyo on Sat Sep 18 02:27:49 2021, in response to How much ballast remains?, posted by gbs on Fri Sep 17 03:20:46 2021. Although most of the dual contract construction was type 1 ballast, the stations were type 2 concrete and is specifically mentioned in a PSC report from that era. |
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| (1585566) | |
Re: How much ballast remains? |
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Posted by randyo on Sat Sep 18 02:31:25 2021, in response to Re: How much ballast remains?, posted by Steve B-8AVEXP on Fri Sep 17 20:10:23 2021. It depended on what thr priorities for tk maintenance were at the time. As MOW gets around to it, eventually all the ballast will be changed to concrete. Also, in the past even though90% of the IND was type 2, special work (switches and Xovers) were on ballast. As new special work is being installed, it is done on concrete. |
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| (1585575) | |
Re: How much ballast remains? |
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Posted by Avid Reader on Sat Sep 18 09:11:28 2021, in response to Re: How much ballast remains?, posted by randyo on Sat Sep 18 02:31:25 2021. Also, in the past even though90% of the IND was type 2, special work (switches and Xovers) were on ballast.Because rail replacement in the Future was considered. |
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| (1585586) | |
Re: How much ballast remains? |
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Posted by R46 5636 on Sat Sep 18 12:04:55 2021, in response to Re: How much ballast remains?, posted by Steve B-8AVEXP on Fri Sep 17 20:10:23 2021. I used to think it had something to do vibrational issues and for structural reasons the tracks had to be ballast, although obviously that's not the case as some sections have been replaced with concrete by now, and the apparent issues along 4 Avenue a few years ago:4 Avenue between 86th and Bay Ridge Ave is or used to be all ballast... Until a church around 77 Street complained about vibrations from the tunnels below causing cracks and structural concerns in 2014. The result? An R32 (R) test train for "vibration testing" along 4 Ave. Shortly after the 77 Street station became entirely concrete with CWR. That R32 (R) in May of 2014 was supposed to ONLY run the night shuttle from 36th to 95th, but either crews refused to pull it out during the night or the vibrational testing was assigned during the day and the result was two full round trips from 95th to Continental despite being laid up all night between 86th and 95th signed as 36 Street - 95 Street "Shuttle". I still remember going down to 95th to check up on it after hours of it sitting there and witnessing the signs being scrolled to "71-Continental" going ohhh shittt... Very interesting times indeed. |
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| (1585629) | |
Re: How much ballast remains? |
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Posted by gbs on Sat Sep 18 21:16:02 2021, in response to Re: How much ballast remains?, posted by R46 5636 on Sat Sep 18 12:04:55 2021. Spend some time in the Broadway branch of the Queens Library (on Broadway just east of Steinway St in Astoria) and you'll feel the vibrations of the M and R trains below. The library is built directly on the tracks, as this is where they turn from Steinway St onto Broadway under private property, including the library. The sidewalk grate is on 41 St south of Broadway, not on Broadway itself, since the tracks haven't yet reached there. You can hear the clickety-clack of the track joints, and you can easily tell if the train is slowing down (Manhattan-bound, entering Steinway St) or speeding up (Forest Hills-bound, leaving Steinway St). Those tracks are embedded in concrete. |
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| (1585630) | |
Re: How much ballast remains? |
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Posted by gbs on Sat Sep 18 21:18:31 2021, in response to Re: How much ballast remains?, posted by randyo on Sat Sep 18 02:27:49 2021. I recall seeing the express tracks that ran through the local stations embedded in ballast, though the local tracks at the stations were in concrete. |
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| (1585687) | |
Re: How much ballast remains? |
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Posted by randyo on Mon Sep 20 00:20:05 2021, in response to Re: How much ballast remains?, posted by gbs on Sat Sep 18 21:18:31 2021. That’s correct. The PSC report commented that the type 2 roadbed on the lcl tks in stations made keeping the roadbed in the stations cleanere and neater looking but it wasn’t deemed to be necessary on the exp tks. |
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| (1585688) | |
Re: How much ballast remains? |
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Posted by randyo on Mon Sep 20 00:21:43 2021, in response to Re: How much ballast remains?, posted by Avid Reader on Sat Sep 18 09:11:28 2021. Rail replacement is no different for type 1 or type 2 roadbed. It’s the actual tie replacement that becomes problematic. |
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| (1585741) | |
Re: How much ballast remains? |
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Posted by BLE-NIMX on Mon Sep 20 15:03:14 2021, in response to Re: How much ballast remains?, posted by randyo on Mon Sep 20 00:20:05 2021. I thought it was for safety in having a trough for falling passengers to have a chance at surviving a 12-9 |
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| (1585772) | |
Re: How much ballast remains? |
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Posted by randyo on Mon Sep 20 19:29:32 2021, in response to Re: How much ballast remains?, posted by BLE-NIMX on Mon Sep 20 15:03:14 2021. That wasn’t the main purpose of it but it certainly was a positive side benefit. As I recall the PSC report said that it made the station areas easier to clean and presented a neater appearance. By the way, the initial type 2 installations had the ties bolted into the concrete whereas the IND and even newer sections of the BMT like the 14 St Line did not. Certain portions of the IND on sharp curves not only had the ties bolted in but those areas had every 5th tie fully across like the later installations of what is called “modified type 2” which is also how the Philly Broad St subway is done. I recall reading an article in sone one of the trade magazines from the late 1920s that mentioned that it was found that bolting the ties into the concrete was not really necessary as the concrete was sufficient to hold them in place without the bolts. What I have noticed in recent installations of type 2 is that horizontal pieces of rebar are inserted into the ties which basically replicate the function of the bolts in the older dual contract installations. There were also a few places where an additional pouring of concrete was done on the inner side of the ties to stabilize their position in the concrete. |
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