Jump to content


Attention: In order to reply to messages, create topics, have access to other features of the community you must sign up for an account.
Deucey

MTA: You mean we built tunnels already??

Recommended Posts

13 minutes ago, CenSin said:

It would help clear out a conga line of trains when things like this happen on a daily basis. I heard the 125 Street terminal was being reduced to 2 tracks? :rolleyes: What would replace that?

A conga line is not a literal billion-dollar problem.

Share this post


Link to post
Share on other sites

10 minutes ago, bobtehpanda said:

A conga line is not a literal billion-dollar problem.

How do you measure the cost of a problem or value of a solution? Man-hours saved? Economic output? Time efficiency?

Share this post


Link to post
Share on other sites

Three track terminals help with train storage and with mitigating outages of a terminal track. Otherwise they actually reduce terminal efficiency -- because you need more switches, the distance (and therefore the time) it takes for a train to pass through the terminal interlocking is increased, so less capacity. 

  • Upvote 1

Share this post


Link to post
Share on other sites
36 minutes ago, RR503 said:

Three track terminals help with train storage and with mitigating outages of a terminal track. Otherwise they actually reduce terminal efficiency -- because you need more switches, the distance (and therefore the time) it takes for a train to pass through the terminal interlocking is increased, so less capacity. 

In any case, any discussions of that matter are probably moot, seeing that tail tracks are planned...

Share this post


Link to post
Share on other sites
21 minutes ago, Lex said:

In any case, any discussions of that matter are probably moot, seeing that tail tracks are planned...

I don't think Phases 1 and 2 are getting third tracks. Phases 3 and 4, however, still have possibility...

Share this post


Link to post
Share on other sites
On 4/16/2019 at 11:39 PM, Deucey said:

 

On 4/17/2019 at 12:58 AM, HenryB said:

Thank goodness they came to their senses on these two things!

Share this post


Link to post
Share on other sites
18 minutes ago, T to Dyre Avenue said:

 

Thank goodness they came to their senses on these two things!

I just hope that the structure's stability won't be significantly impacted by this (unless it's made more stable, in which case, great).

Share this post


Link to post
Share on other sites
On ‎4‎/‎17‎/‎2019 at 11:10 PM, RR503 said:

They also didn't want to have columns on the platform, which will be the case now. 

I'll take the columns and get the line to Harlem sometime before 2100 over the alternative. I mean, it won't be like the Contract I stations where the pillars eat up significant walking space on the ends of the platforms.

  • Upvote 3

Share this post


Link to post
Share on other sites
3 hours ago, Lance said:

I'll take the columns and get the line to Harlem sometime before 2100 over the alternative. I mean, it won't be like the Contract I stations where the pillars eat up significant walking space on the ends of the platforms.

Exactly. Make the platform wide enough so   there’s still walking room between the platform edge and the support pillars or stairway bases if someone is standing next to them.

Share this post


Link to post
Share on other sites

So the columns are what are already there, and the rebuild would have removed them, I take it. But then columns in tunnels are 5 feet apart, while on platforms they are generally 15 feet apart (every third column, basically). So did this section of tunnel built happen to have columns 15 feet apart?

Share this post


Link to post
Share on other sites
On 4/18/2019 at 5:09 PM, CenSin said:

How do you measure the cost of a problem or value of a solution? Man-hours saved? Economic output? Time efficiency?

The other developed Anglophone countries use business cases with cost-benefit ratios, similar to our environmental analyses but with predetermined benefit values. But that's mostly because they're functioning developed countries where half the political system isn't focused on totally crippling government function, and are instead focused on delivering value for taxpayer dollar.

There's also

  • no-build; there are costs to obtaining a billion dollars of deployable capital; overhead for applying for grants, the cost of taking out debt, etc.
  • opportunity cost; a billion on this particular third track is a billion dollars not being used for Fast Forward, or bus improvements, or increasing schools capacity, or attacking NYCHA's investment backlog, etc.

Given that we have historically run more trains without issues on today's subway network, I highly doubt the necessary solution is a billion-dollar third track segment.

Share this post


Link to post
Share on other sites

Wow! So this center track already has it's own catwalks on both sides, on the curtain wall (basically; a "benchwall/curtainwall" hybrid!). 😲 Don't really see anything like that anywhere else! 

So it's much more space than just the trackway itself. (Wish I knew this; I would have definitely been pushing for using this space, all along). So a platform there wan't be so narrow after all!

 

Still, there are the five foot apart columns I mentioned. Will they have to remove two out of three (which then will require structural modification, to shift the load onto the remaining columns)? As I said, it would be very awkward to have columns on a passenger platform that close. 

Share this post


Link to post
Share on other sites
On 4/17/2019 at 8:10 PM, R68OnBroadway said:

Are they still doing bellmouths to the Bronx? Dropping the third track isn’t a problem given that extensions should be across 125th up 3rd; but removing the bellmouths seems like a mistake given the potential of a line up 3rd  ((N)) and another on 125th  ( (Q) ).

Since the 125th Street terminus is being reduced to two tracks, we need those bellmouths more than ever so they can serve as two additional trail tracks aiming up to the Bronx.

3 hours ago, Eric B said:

Wow! So this center track already has it's own catwalks on both sides, on the curtain wall (basically; a "benchwall/curtainwall" hybrid!). 😲 Don't really see anything like that anywhere else! 

So it's much more space than just the trackway itself. (Wish I knew this; I would have definitely been pushing for using this space, all along). So a platform there wan't be so narrow after all!

 

Still, there are the five foot apart columns I mentioned. Will they have to remove two out of three (which then will require structural modification, to shift the load onto the remaining columns)? As I said, it would be very awkward to have columns on a passenger platform that close. 

Yeah, there's definitely ample platform space, thank heavens, but I worry about structural load shifts since two out of every three columns will have to be (re)moved. My solution would be to pull back every two columns out of three towards the center of the new platform to take on the weight. Then again, you have sections of this tunnel that are completely column-free from wall to wall, so...

Share this post


Link to post
Share on other sites
6 hours ago, Eric B said:

Wow! So this center track already has it's own catwalks on both sides, on the curtain wall (basically; a "benchwall/curtainwall" hybrid!). 😲 Don't really see anything like that anywhere else! 

So it's much more space than just the trackway itself. (Wish I knew this; I would have definitely been pushing for using this space, all along). So a platform there wan't be so narrow after all!

 

Still, there are the five foot apart columns I mentioned. Will they have to remove two out of three (which then will require structural modification, to shift the load onto the remaining columns)? As I said, it would be very awkward to have columns on a passenger platform that close. 

Doing a load shift isn't *that* difficult, especially given that those columns are just supporting the street. I'd expect they'll remove enough to make it look like your average NYC station and call it a day. 

I will be interested to see how they outfit the columns. I'm quite partial to the minimal aesthetic treatment stations like 57/6 got; I'm hoping they go for that instead of some column version of those godawful panels. 

Share this post


Link to post
Share on other sites

So I see the exit ladders; are they going to squeeze the exits into those spaces (which might be between those narrow columns in the ceilings, which would require more column shifting). Or is that illustration with the additions to the lower side indicating the exit will do down from the platform, and cross under the tracks? (like 34th Penn Sta. and Atlantic Ave)?

Share this post


Link to post
Share on other sites

Wouldnt removing the middle track beams result in the structure failing since the tunnels werent built like the new SAS ones?

Share this post


Link to post
Share on other sites
13 hours ago, Lawrence St said:

Wouldnt removing the middle track beams result in the structure failing since the tunnels werent built like the new SAS ones?

Pretty sure they will reinforce the size walls + add new columns in the middle of the "platform" before removing any old sturctures

Share this post


Link to post
Share on other sites
13 hours ago, Eric B said:

So I see the exit ladders; are they going to squeeze the exits into those spaces (which might be between those narrow columns in the ceilings, which would require more column shifting). Or is that illustration with the additions to the lower side indicating the exit will do down from the platform, and cross under the tracks? (like 34th Penn Sta. and Atlantic Ave)?

It seems they're going to demolish some sections of the structure to get the exits/related mezzanines in. That'll come from above, so the structural angle should be easier to work out. 

Share this post


Link to post
Share on other sites
On 4/23/2019 at 7:17 AM, Eric B said:

So it's much more space than just the trackway itself. So a platform there won't be so narrow after all!

It looks like all the existing tunnels are built to IND specifications, with the exception of the middle trackway. The width of the maintenance platforms, the addition of the narrow stairways leading up to the ceiling, and the slight shift in the columns as they approach the maintenance area - they all indicate that the transverse distance between columns is greater than the typical width of 13.5 feet, which also means the island platform will end up being wider than 16.7 feet. In addition, the island platform can gain an extra 2 feet of space if the bench walls along the northbound and southbound trackways are removed (any remaining space must be reserved for wayside signals and other equipment).

 

On 4/23/2019 at 7:17 AM, Eric B said:

Still, there are the five foot apart columns I mentioned. Will they have to remove two out of three (which then will require structural modification, to shift the load onto the remaining columns)? As I said, it would be very awkward to have columns on a passenger platform that close. 

On 4/23/2019 at 10:41 AM, Porter said:

Yeah, there's definitely ample platform space, thank heavens, but I worry about structural load shifts since two out of every three columns will have to be (re)moved. My solution would be to pull back every two columns out of three towards the center of the new platform to take on the weight. Then again, you have sections of this tunnel that are completely column-free from wall to wall, so...

If the MTA chooses to do so, they can - but not in the way you two described. The modifications, in general, can be boiled down to 1) removing all existing lightweight columns spaced 5 feet apart and 2) using heavier columns spaced 15 feet apart to hold up spans of heavy longitudinal beams that will support all the transverse roof beams and transfer all the roof's load to the new columns. There is no need to worry about the feasibility of this procedure as it has been done many times before; the numerous platform extensions that were carried out on the IRT and BMT stations to accommodate longer trains, and even Bleecker Street's new uptown platform (for a more recent example) all use the exact same column and beam design.  Add Times Square (S) to the list as well; official drawings show that its columns will be modified in the same manner as part of its upcoming reconstruction.

It is very likely that there will be two rows of columns due to how the tunnel was originally designed. Its design also limits how close the column rows can be placed near each other; by comparison, constructing the station so that there is only one line of columns running down the center of the island platform will most likely require replacement of all transverse beams with heavier sections since the original beams may not be strong enough to hold up the ground above.

It will be interesting to see how the engineers will handle the tunnel's roof design. It is hard to see in the tunnel's current state, but this blog has a photo taken during construction (courtesy of NYTM) showing that the roof beams over the maintenance track are situated above the beams over the northbound and southbound trackways. This could change the way they will modify the structure; most stations with platform extensions have transverse roof beams whose flanges are aligned from one end of the beam to the other.

 

On 4/23/2019 at 1:36 PM, RR503 said:

I will be interested to see how they outfit the columns. I'm quite partial to the minimal aesthetic treatment stations like 57/6 got; I'm hoping they go for that instead of some column version of those godawful panels. 

In addition to the plain steel columns, I hope 116th Street takes on a look that is like a nod to the design of older IND stations. I share sentiments with someone who asked the MTA during a public Q&A session for Phase 2 to make their new stations look more like the old, as the Second Avenue Subway stations have nothing in common with the rest of the system. Of course, the IND does not exist anymore, so I would understand if the MTA prefers to move on from the past and go with the new design they've been using thus far.

 

On 4/24/2019 at 7:11 AM, Eric B said:

So I see the exit ladders; are they going to squeeze the exits into those spaces (which might be between those narrow columns in the ceilings, which would require more column shifting). Or is that illustration with the additions to the lower side indicating the exit will do down from the platform, and cross under the tracks? (like 34th Penn Sta. and Atlantic Ave)?

Depends on where it is located. If it is not within or near the mezzanine locations, then it is possible the openings may be sealed up if the room is not repurposed in some way.

Just saying stairways by itself will require column shifting is not entirely accurate; there are other factors to consider before deciding where columns should be located, such as the overall width of the platform and the clearance between the stairway and the platform edge.

I can't make any sense out of the second part of your question, but on the topic of underpasses I'll mention that they might not be necessary since there is enough room for a mezzanine; the station is about 40 feet below street level, according to the FEIS (Chapter 2, pg. 16 of pdf). Another photo taken during construction (courtesy of NYTM) shows the constructed tunnel behind the light rays and the empty space between it and the scaffolding at street level.

 

On 4/24/2019 at 9:07 PM, RR503 said:

It seems they're going to demolish some sections of the structure to get the exits/related mezzanines in. That'll come from above, so the structural angle should be easier to work out. 

I wonder if they could cut costs even more by constructing the mezzanines over the existing tunnel instead of demolishing what was already built. Since they are only planning to excavate certain portions to create entrances, it gives them a perfect opportunity to build onto the existing structure.

The passageway connecting the north and south mezzanines at 14th Street-Union Square on the Broadway Line is one example where such construction was done. It was definitely constructed after the station's opening; besides the columns not being riveted, its higher floor level and the ramps at both ends of the passageway are due to the fact that the original transverse roof beams remain and are deeper than the beams used to support the mezzanines.

  • Thumbs Up 1
  • Upvote 1

Share this post


Link to post
Share on other sites

As long as they go through with the conversion from maintenance track to station platform, I'm sure they'll find a clever way to do it reasonably.

If they keep the spirit of saving costs, why not just build phases 3 and 4 as originally envisioned, making use of existing tunnels?

Share this post


Link to post
Share on other sites
Posted (edited)
16 hours ago, Gong Gahou said:

In addition to the plain steel columns, I hope 116th Street takes on a look that is like a nod to the design of older IND stations. I share sentiments with someone who asked the MTA during a public Q&A session for Phase 2 to make their new stations look more like the old, as the Second Avenue Subway stations have nothing in common with the rest of the system. Of course, the IND does not exist anymore, so I would understand if the MTA prefers to move on from the past and go with the new design they've been using thus far.

I'm kind of surprised that they haven't bothered to print any designs on the panels used for SAS Phase I. It's 2019, we have printers and crap.

Not to mention, you can do some pretty interesting stuff with panels. Compare New York to, say, Munich:

maxresdefault.jpg

Munich_subway_GBR.jpg

A splash of color would do a lot to make the platform level feel less depressing.

Edited by bobtehpanda

Share this post


Link to post
Share on other sites
6 minutes ago, bobtehpanda said:

I'm kind of surprised that they haven't bothered to print any designs on the panels used for SAS Phase I. It's 2019, we have printers and crap.

Not to mention, you can do some pretty interesting stuff with panels. Compare New York to, say, Munich:

maxresdefault.jpg

Munich_subway_GBR.jpg

A splash of color would do a lot to make the platform level feel less depressing.

One thing that bugs me is how all the artwork was kept in the mezzanine only (which are already oversized) while the platforms were left drab. At the least they should try and put up some fake decal mosaics to make it look better... 

Share this post


Link to post
Share on other sites

The MTA is still stuck in the millennial minimalism phase that everyone else has long-since gotten past. It's much easier to maintain, I'll give them that, but it looks absolutely clinical.

Share this post


Link to post
Share on other sites

This is something I’ve always disliked about the new stations. None of them have any color. Even in some of the ESI stations, they removed the color that was there (specifically the ones on 4th Avenue, which are good otherwise). The reason I dislike this is that it makes it harder to tell at a glance what station you are at, by looking at the color of a column or the tiles. They all look the same. Also, white stations are getting boring.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.