Double Decker els and tunnels?

[YungMarxian]

From a purely engineering perspective, could it be done? By it, I mean building either another deck of tracks on top of existing el's (e.g. West End, brooklyn Broadway), open cuts (Sea Beach, Brighton), and a lower deck on underground tracks (e.g. Nostrand).

[trainfan22]

Yes, that can be done.

[Sparen of Iria]

The real question is, how much does it cost? Because if it's not budget-shattering expensive, it may still be possible to build a Queens Blvd bypass...

[YungMarxian]

The real question is, how much does it cost? Because if it's not budget-shattering expensive, it may still be possible to build a Queens Blvd bypass...

You mean a tunnel underneath the current QBL? Must be expensive as hell as all tunnels are.

 

I'm curious of the feasibility of double-decking el's. Can old structures like the West End support another el on top of it? You'd probably have to heavily reinforce the old pillars as well as have some new pillars go straight down to the ground.

[Kamen Rider]

short version: No.

 

Long version: the costs, the weight loads, the nessecity, none of it makes it worthwhile. Does the West End need to be more than three tracks? Basicly the only line that could use this method is the Canarsie, it REALLY needs express tracks.

[YungMarxian]

short version: No.

 

Long version: the costs, the weight loads, the nessecity, none of it makes it worthwhile. Does the West End need to be more than three tracks? Basicly the only line that could use this method is the Canarsie, it REALLY needs express tracks.

The West End doesn't even need to use it's express track for service, I was just using the West End as an example. I doubt the West End will get that type of ridership for AGES. 

 

But in the example of Canarsie Line, two express tracks could be bored and laid underneath and two express tracks a deck above the current Canarsie Line past Broadway jct., ASSUMING it would be feasible. That's my main question. Costs aside, I think with some major engineering, it could work. I'm not sure if there's a fatal flaw to it though.

[bobtehpanda]

Decking over a line that is currently in service with more tracks is asking for trouble; tunneling under active stations is even more so. If you new-build a double deck line, it's technically possible, but doing so on existing lines is ill advised. You can get capacity improvements on the through a variety of means, some less crazy than others; you can length train platforms, you can upgrade the power supply to move from 20 to 26 TPH (CBTC on the allows up to 26 TPH, but power supply issues prevent this from being run), you can even technically cascade the (L)'s cars to other lines and order a new class of articulated cars just for the , if it is really necessary. All of those options are significantly cheaper than building new track, and if you're going to build new track, it would be better to do so on a parallel alignment close by rather than do it directly underground and disrupt existing service.

The West End doesn't even need to use it's express track for service, I was just using the West End as an example. I doubt the West End will get that type of ridership for AGES. 

 

But in the example of Canarsie Line, two express tracks could be bored and laid underneath and two express tracks a deck above the current Canarsie Line past Broadway jct., ASSUMING it would be feasible. That's my main question. Costs aside, I think with some major engineering, it could work. I'm not sure if there's a fatal flaw to it though.

 

Even with "major engineering", things will screw up. The SR 99 Tunnel project is stuck despite all of the engineering that went into it because the TBM hit a pipe, and before that the TBM was causing entire neighborhoods to sink.

[YungMarxian]

Decking over a line that is currently in service with more tracks is asking for trouble; tunneling under active stations is even more so. If you new-build a double deck line, it's technically possible, but doing so on existing lines is ill advised. You can get capacity improvements on the through a variety of means, some less crazy than others; you can length train platforms, you can upgrade the power supply to move from 20 to 26 TPH (CBTC on the allows up to 26 TPH, but power supply issues prevent this from being run), you can even technically cascade the (L)'s cars to other lines and order a new class of articulated cars just for the , if it is really necessary. All of those options are significantly cheaper than building new track, and if you're going to build new track, it would be better to do so on a parallel alignment close by rather than do it directly underground and disrupt existing service.

 

 

Even with "major engineering", things will screw up. The SR 99 Tunnel project is stuck despite all of the engineering that went into it because the TBM hit a pipe, and before that the TBM was causing entire neighborhoods to sink.

 

 

You right, you right. I think the options you mentioned are more elegant and simple anyway. I guess if lines get so congested in the future (probably a century from now, if NYC isn't in rubble by then  ) they can use eminent domain and expand horizontally.

[Wallyhorse]

The only existing place I could think of that would need any double decking at all would be in the area of the Culver Line around Ditmas Avenue, and that would be specifically if you rebuilt what was the old connection to the Culver line from 4th Avenue (most likely if so with single tracks on two levels at some parts of that section being rebuilt).  The section would be on the northbound side, where a new track would jut out south of Ditmas on the northbound side and go to an upper level there (while the southbound platform is re-converted to an island platform as it was in the shuttle days, EXCEPT such goes the full length of the platform and merges with trains coming from Park Slope south of the station).  

In this scenario, northbound trains from Culver via 4th Avenue would cross above the existing Culver line tracks and would be on the upper of two single-track levels that can make up a rebuilt Culver El, especially in areas where the old Culver El ROW no longer exists.  

Otherwise, I don't see where such is justifiable. 

[Sparen of Iria]

With Canarsie, all they *really* need to do besides upgrading the power supply is find some way to make 8 Av a more effective terminal or construct a western extension with a proper diamond crossover and tail tracks. More than anything, the lack of effective terminals on the Canarsie Line places a very brutal hard cap on how many trains can be run.

[YungMarxian]

With Canarsie, all they *really* need to do besides upgrading the power supply is find some way to make 8 Av a more effective terminal or construct a western extension with a proper diamond crossover and tail tracks. More than anything, the lack of effective terminals on the Canarsie Line places a very brutal hard cap on how many trains can be run.

I was always wondering if the ran up 10th or 11th avenue (this was before the extension) and then terminated at a station connecting with 72nd street on the IRT Broadway.

[Wallyhorse]

With Canarsie, all they *really* need to do besides upgrading the power supply is find some way to make 8 Av a more effective terminal or construct a western extension with a proper diamond crossover and tail tracks. More than anything, the lack of effective terminals on the Canarsie Line places a very brutal hard cap on how many trains can be run.

And as I've said before on the , I would do that as a 10th/Amsterdam Avenue Line as follows (with three tracks once the line gets to 10th Avenue):

 

23rd Street (two island platforms, can be used for short turns or a peak-direction express)

31st-33rd Streets (same as 23rd)

41st Street (same as 23rd and 31st-33rd, transfer to if that is ever built)

49th-50th Streets (local only, two side platforms)

58th Street-Roosevelt Hospital (local only, two side platforms)

65th Street-Lincoln Center (local only, two side platforms)

72nd Street-Broadway (two island platform terminal, transfer to with an exit at 75th and Amsterdam and tail tracks extending to at least 81st Street or so, allowing for a future extension along Amsterdam Avenue).

 

That would solve that issue and provide a 10th Avenue line. 

[Sparen of Iria]

And as I've said before on the , I would do that as a 10th/Amsterdam Avenue Line as follows (with three tracks once the line gets to 10th Avenue):

While your plan is great and all, short-turning trains right next to Midtown is a bad, bad idea. Keep your plan simple and within budget by using two tracks and all Island Platforms.

[Wallyhorse]

While your plan is great and all, short-turning trains right next to Midtown is a bad, bad idea. Keep your plan simple and within budget by using two tracks and all Island Platforms.

The idea is if the line is extended beyond 72nd Street in the years after, it likely would continue as three tracks with possibly a peak-direction express (and possibly such being short-turn trains that would begin at 23rd Street before heading north).  Potential stops going uptown after 72nd might look like this:

 

86th Street (local only, two side platforms with exits at 83rd or 84th and 86th Street)

96th Street (local only, two side platforms with exits at 94th and 96th Street)

110th Street-Cathedral Parkway (express with two island platforms, exits at 107th and 110th Street)

116th Street-Columbia University (express with two island platforms, exits at 116th and 118th Street) 

125th Street (possible terminal with two island platforms, exits at 125th Street and to be determined) 

 

There would be provisions to expand the line even further up Amsterdam in a later phase.  

[Ramirez1523]

If your question is can it be done the answer is Yes....Double El's can be found at Coney Island with the on top of the from Coney Island to West 8th at which point the makes a sharp turn North and the continues west and slowly descended into Ocean Parkway. 

[YungMarxian]

If your question is can it be done the answer is Yes....Double El's can be found at Coney Island with the on top of the from Coney Island to West 8th at which point the makes a sharp turn North and the continues west and slowly descended into Ocean Parkway. 

Well yes I know that lol I live in Coney Island, my question was more of can they be built now on top of structures already built decades ago.

[Fresh Pond]

Well yes I know that lol I live in Coney Island, my question was more of can they be built now on top of structures already built decades ago.

Probably not as most are near/over 100 years old, and the cost to strengthen them to handle another load would be too much