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Fix & Fortify - 14th Street (L Train) Tunnels Closure

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The best option is the one that Transit is being strong-armed into not considering. The second-best would be to suspend off-hours service entirely and run a modified contingency service plan with boosted service on the appropriate lines to compensate.

This is a perfect case of having your cake and eating it too. Everyone wants service to run unimpeded across the river but the work still has to be done as they do not have the opportunity to punt this down the road. These half-assed measures are the end result. Now that they are forced to go along with the bad option, they have to work around it to avoid an incredibly dangerous situation in stations not even remotely equipped to handle the crowds expected under such a reduction of service. There's a reason why Transit painted this partial closure idea as the worst option when presented back in 2016 and it wasn't just to piss riders off.

Transit knows they will feel the full brunt of the criticism when this all comes to a head once this partial shutdown begins, hence the pushback to the article. Riders aren't going to blame Cuomo for cancelling the shutdown because his panel of experts said that the tunnel can be repaired without impacting service. Instead, they're going to go after the MTA when the inevitable sea of riders crowds the (L) stations during the service reduction periods.

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On 1/20/2019 at 12:56 PM, Stephen Bauman said:

I had worked this out with travel times of 7 minutes from Union Sq to Lorimer and 7.5 minutes the other way. These were the minimum scheduled GTFS running times, when I figured this strategy out back in 2016. I can re-work it with the scheduled travel times from the Jan 15-18 midnight hours. It should not make much of a difference.

The nominal intermediate station service level capacity is 40 tph, including 30 sec dwell time per station. That's independent of signal system and has been achieved in practice by both Moscow and the BOT. The service level capacity is usually limited by the terminal stations. This is true with the 14th St Line. 

If trains are operated 6 at a time in each direction @ 40 tph the time interval between the first and last train will be 5 x 1.5 min or 7.5 min. The total travel time for 6 trains through the tunnel Brooklyn bound would be 14.5 minutes and 15 minutes Manhattan bound. This adds up to 29.5 minutes for 6 trains in each direction 12 tph.

This still leaves the terminals to be considered. Neither 8th Ave nor Rockaway Pkwy can handle 90 sec headways nor direction reversals without delaying followers. The solution is that not all trains would terminate at their respective terminals. Let's assume the Manhattan bound tunnel is operational. On the Manhattan side the first train would terminate at 8th Ave; the second at 6th Ave and the third at Union Sq. The next 3 would do the same but wrong rail to 8th Ave, 6th Ave and Union Sq. respectively. The Brooklyn bound train would be the third train which had terminated at Union Sq. It would be followed by the second, first, sixth, fifth and fourth arriving trains. Each had adequate time to recharge brakes to turn around.

Rockaway Parkway is a bit more complicated because the closest crossover to the Manhattan bound track (Q1 to Q2) is between Bushwick and Bway Jct. There are trailing crossovers north (Q2 to Q1) north of Livonia and Sutter, in addition to the diamond crossovers north of Rockaway Pkwy and Bway Jct. The no construction cost option would be to have the first two trains terminate at Rockaway Pkwy, and the next terminate at E 105, New Lots, Livonia and Sutter on the Brooklyn bound track. The return trip would have the first two Rockaway Pkwy trains depart onto the Manhattan bound track, followed by the train that terminated at Sutter using the trailing  point switch north of Sutter, followed by the trains that terminated at Livonia, New Lots and E 105 using the trailing point switch north of Livonia.

CBTC makes such an out of the box operation feasible because it should be able to wrong rail at maximum service levels. Substantial modification would be needed with a block system which wasn't built with this capability.

This would mean 40 tph operation through the Canarsie Tunnels which the MTA claims it can handle only 20 tph without additional substations. However, the 40 tph operation is in only 1 direction whereas the existing 20 tph operation is in both directions. This would require the same amount of peak amperage that the existing substations currently supply.

As noted above the cycle time is 29.5 minutes. However, it takes 7.5 minutes for the 6 trains to travel past a single station. Therefore, the worst case wait time scenario would be 22 minutes. 

To be honest the only real problem I can see with this plan is the crowding delays on that first train in each direction. 

After that 22 minute wait, the platform crowding would be whatever it would be under the current plan. Despite the fact that 5 more trains are coming down the pipe, I feel like everyone's gonna act like the first train is the last lifeboat on the titanic and pandemonium will ensue to board it. 

Yes the staggered starts from the terminals would help a little bit, but I'm not sure if it would be enough. 

Honestly, I think this is a use case for agent-based-modeling passenger rates and behavior of these situations. (you'd program the agents to basically have a random probability [within range] of trying to board visibly full train and then random [within range] time before giving up and waiting for next, and you could get a more clear picture of what's going on. 

 

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21 hours ago, Stephen Bauman said:

Both 1 Av and 3 Av are narrower side platform stations, whereas Bedford is a wider island platform. With 20 instead of 4 minute headways, the MTA rightly feels that overcrowding on the narrower platforms will be dangerous. It will be just as dangerous at Bedford.

20 minute headways during weekend days should be a non-starter. There are options, that NYCT isn't considering.

If so, I'd be demanding the (MTA) supplements the 20-minute headways with short-turn shuttles in Manhattan between 1st and 8th Avenues (operating every 6-9 minutes, incorporating the full-line trains onto the route) and short-turn trains in Brooklyn turning at Bedford (alternating with through trains).  That would at least solve some of the problems. 

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1 hour ago, itmaybeokay said:

To be honest the only real problem I can see with this plan is the crowding delays on that first train in each direction. 

After that 22 minute wait, the platform crowding would be whatever it would be under the current plan. Despite the fact that 5 more trains are coming down the pipe, I feel like everyone's gonna act like the first train is the last lifeboat on the titanic and pandemonium will ensue to board it. 

Yes the staggered starts from the terminals would help a little bit, but I'm not sure if it would be enough. 

Honestly, I think this is a use case for agent-based-modeling passenger rates and behavior of these situations. (you'd program the agents to basically have a random probability [within range] of trying to board visibly full train and then random [within range] time before giving up and waiting for next, and you could get a more clear picture of what's going on. 

 

Actually there's another problem. The scheduled times during single track operation were 10 and 8 minutes. The extra 3 minutes over the 7.5/8.0 means that only 10 tph operation is possible. The dead time for each direction would be raised to 24 minutes. I'd have to check the real time tunnel crossings to see if there were 3 minutes padding over the best times to get to 12 tph.

The stations have to be monitored to prevent overcrowding. I'd lock the turnstiles, to prevent more people from entering an already crowded platform. Maybe Paris could lend us some of the portillions automatique, if they still exist. There are electronic people counters, so personnel can be used for more important work. The major effort is to prevent dangerous situations on the platforms.

I have a couple of ideas to add safety and capacity to the platforms.

I would use an empty train on the unused track at Bedford to extend the platform width by 10 feet. It's vital to separate exiting and entering passengers from each other. It might be possible to rope off exiting and entering corridors on the platform. The entering passengers would be waiting on the empty train across the platform for exiting passengers to leave the train.

The side platforms at 1 Ave and 3 Ave are easier. CBTC under ATO is supposed to be able to stop within 1/8 inch of its mark. I'd put it to the test but I can relax the tolerance a bit. I'd park a train on the unused track. The train would be equipped with a gangplank on the side opposite the station. The gangplank would extend to the running track and be used to load passengers. (On second thought, the gangplanks would remain in the station between the rails. Their length would be such that it would extend to each track as an extra platform. They would not interfere with trains entering or leaving.)Trains would enter these stations and open their doors on the station side for exiting passengers. The train would then open the opposite side for incoming passengers. The doors opposite the platform on the "waiting room" train would be used as platform doors. Both 1 Ave and 3 Ave are straight platforms, so there should not be clearance problems. There would be no need for the moving platforms used at Union Sq (IRT) or South Ferry Loop.

I think the strategic placement of these empty trains should solve safety concerns, as well as permit 30 second dwell times. 

Edited by Stephen Bauman
slightly better solution having gangplanks semi-permanent in stations
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1 hour ago, Stephen Bauman said:

Actually there's another problem. The scheduled times during single track operation were 10 and 8 minutes. The extra 3 minutes over the 7.5/8.0 means that only 10 tph operation is possible. The dead time for each direction would be raised to 24 minutes. I'd have to check the real time tunnel crossings to see if there were 3 minutes padding over the best times to get to 12 tph.

The stations have to be monitored to prevent overcrowding. I'd lock the turnstiles, to prevent more people from entering an already crowded platform. Maybe Paris could lend us some of the portillions automatique, if they still exist. There are electronic people counters, so personnel can be used for more important work. The major effort is to prevent dangerous situations on the platforms.

 I have a couple of ideas to add safety and capacity to the platforms.

I would use an empty train on the unused track at Bedford to extend the platform width by 10 feet. It's vital to separate exiting and entering passengers from each other. It might be possible to rope off exiting and entering corridors on the platform. The entering passengers would be waiting on the empty train across the platform for exiting passengers to leave the train.

 The side platforms at 1 Ave and 3 Ave are easier. CBTC under ATO is supposed to be able to stop within 1/8 inch of its mark. I'd put it to the test but I can relax the tolerance a bit. I'd park a train on the unused track. The train would be equipped with a gangplank on the side opposite the station. The gangplank would extend to the running track and be used to load passengers. (On second thought, the gangplanks would remain in the station between the rails. Their length would be such that it would extend to each track as an extra platform. They would not interfere with trains entering or leaving.)Trains would enter these stations and open their doors on the station side for exiting passengers. The train would then open the opposite side for incoming passengers. The doors opposite the platform on the "waiting room" train would be used as platform doors. Both 1 Ave and 3 Ave are straight platforms, so there should not be clearance problems. There would be no need for the moving platforms used at Union Sq (IRT) or South Ferry Loop.

 I think the strategic placement of these empty trains should solve safety concerns, as well as permit 30 second dwell times. 

Issue with Bedford is unless you're willing to nix the possibility of running more than just these fleeted trains over the full (L) route, that's where you'd be turning supplemental trains -- either as relay from Lorimer, or as a turnback at the platform. There isn't enough space between the crossover and Bedford, IIRC, to hold a train clear of the switch. 

At 1st and 3rd, wouldn't it be simpler just to do a temporary overbuild of the OOS track, a la Smith-9th? Makes the door alignment issue easier to handle. 

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How bout this: 

Let's just go with the original plan! Problem solved!

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8 minutes ago, RR503 said:

Issue with Bedford is unless you're willing to nix the possibility of running more than just these fleeted trains over the full (L) route, that's where you'd be turning supplemental trains -- either as relay from Lorimer, or as a turnback at the platform. There isn't enough space between the crossover and Bedford, IIRC, to hold a train clear of the switch. 

At 1st and 3rd, wouldn't it be simpler just to do a temporary overbuild of the OOS track, a la Smith-9th? Makes the door alignment issue easier to handle. 

I'm nixing the possibility of running a shuttle between Bedford and points east. The switch will see trains crossing it every 90 seconds in one direction or the other. That leaves not time to sneak in a shuttle.

This is not a 24/7 operation. It's temporary for midnight and weekend hours. At other times its normal operation. Therefore any temporary overbuild at 1st and 3rd would have to be removed and set up within a few minutes. If you have a low cost implementation in mind - great. I haven't.

 

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14 minutes ago, RR503 said:

At 1st and 3rd, wouldn't it be simpler just to do a temporary overbuild of the OOS track, a la Smith-9th? Makes the door alignment issue easier to handle. 

I don't know if that would be practical to set up every evening and tear down every morning. I assumed that the train-of-trains singletrack concept was still only and overnights/weekends thing.

I had a thought that you could make a consist of flatcars specially configured to be a "platform train" that could rapidly be put in place and moved, but I thought this would be overly complex. 

1 hour ago, Stephen Bauman said:

I would use an empty train on the unused track at Bedford to extend the platform width by 10 feet. It's vital to separate exiting and entering passengers from each other. It might be possible to rope off exiting and entering corridors on the platform. The entering passengers would be waiting on the empty train across the platform for exiting passengers to leave the train.

Not the worst plan in theory - I'd say even better with the "platform-train" - but I would imagine, in practice, getting the masses to perform that shuffle would be like herding cats. In theory people would get used to it, but we can't even get people not to stand in the doorway. 

Could you send 5 trains over, terminting the first at 8th, 2nd at 6th,  and so on so on so you have trains at 1st, 3rd, Union, 6th and 8th, and then start them all back simultaneously not making any additional stops in manhattan? You'd still have the problem at bedford though. 

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3 minutes ago, Lawrence St said:

How bout this: 

Let's just go with the original plan! Problem solved!

I'm starting to see the merit of this idea. 

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2 minutes ago, Stephen Bauman said:

I'm nixing the possibility of running a shuttle between Bedford and points east. The switch will see trains crossing it every 90 seconds in one direction or the other. That leaves not time to sneak in a shuttle.

This is not a 24/7 operation. It's temporary for midnight and weekend hours. At other times its normal operation. Therefore any temporary overbuild at 1st and 3rd would have to be removed and set up within a few minutes. If you have a low cost implementation in mind - great. I haven't.

Bridge plates, as used on LIRR/MNR, offer interesting precedent. 

As for the shuttle, that switch will be occupied when the fleets come through. In the 15 or so minutes between each fleet's passage, though, there would be nothing there. I'd imagine it'd help with crowding elsewhere on the line if you ran some Lorimer-RPY trips. Whether or not that positive impact outweighs the loss of potential platform space at Bedford is an open, and completely valid, question. 

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Is the track at Bedford that leads to the portion of tunnel closed off used to store work equipment? If not, you could terminate every other train there, and at least have trains every 10 minutes in Brooklyn....

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9 hours ago, RR503 said:

Bridge plates, as used on LIRR/MNR, offer interesting precedent. 

As for the shuttle, that switch will be occupied when the fleets come through. In the 15 or so minutes between each fleet's passage, though, there would be nothing there. I'd imagine it'd help with crowding elsewhere on the line if you ran some Lorimer-RPY trips. Whether or not that positive impact outweighs the loss of potential platform space at Bedford is an open, and completely valid, question. 

You're right regarding the 15 minute gap at the Lorimer switch. My mistake.

I did try to estimate the accumulation of incoming passengers during the 24 minute gap at each of the stations. I used the turnstile data that's available on the MTA's website. It's reported in 4 hour segments. I just divided the entry count by 8 to guess what a 30 minute accumulation might be. The counts at Bedford are between 543 and 691 from 11am to 7pm on Saturday and Sunday. I'd prefer to have the extra platform space to avoid any mishaps. 

None of the single line stations between Bedford and Canarsie approach these figures. Graham is the next closest with an accumulation around 150 during these hours. I wonder whether a shuttle is worth the effort, given the sharp drop.

The next busiest single line station is 1st Ave, with accumulations around 300 from 11am to 11pm. It's a mistake to make the second busiest station on the line exit only.

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10 hours ago, Lawrence St said:

How bout this: 

Let's just go with the original plan! Problem solved!

The operational problems on the Canarsie Line might be "solved". However, it's been shoved onto the public. Weekday ridership is much greater. The proposed surface transportation enhancements would not have been sufficient. It would have been worse than the proposed 3 tph for weekends with no surface transportation enhancements.

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Quote

On Tuesday afternoon, the MTA shut down L train service between Manhattan and Brooklyn for several hours to determine the source of noxious chemical odors that caused several riders to faint and vomit. On Wednesday morning, L train riders said the smells were still lingering. 

Rebecca Pedroza says she got on the train at Grand Street in Brooklyn around 8:45 a.m., and smelled the fumes on the train all the way to Union Square. Pedroza described the smell as "exhaust and chemicals that feel like it can destroy your lungs—or like you’re standing behind a really, really old car that skipped 30 years of smog checks."

...

UPDATE 1:35 p.m. Both commuters and transit workers were still dealing with the L train odor as of 1 p.m. on Wednesday. "It's like my fourth time coming through, and I'm feeling a little lightheaded," a train operator at Lorimer told us. "We had to turn on the A.C."

A different operator passing through the station added: "I am not OK. The whole train smells like an oil dump. It has to do with some construction, they broke some pipes." He then gestured above ground and pulled out of the station.

http://gothamist.com/2019/02/06/the_l_still_smells.php

So theres been a strong fuel smell in the (L) train tunnels in Williamsburg for days now and I'm supposed to believe that the MTA can properly mitigate silica dust in time for morning rush hour? <_<

Please for the love of god, go back to the old plan.

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27 minutes ago, Around the Horn said:

http://gothamist.com/2019/02/06/the_l_still_smells.php

So theres been a strong fuel smell in the (L) train tunnels in Williamsburg for days now and I'm supposed to believe that the MTA can properly mitigate silica dust in time for morning rush hour? <_<

Please for the love of god, go back to the old plan.

If they dont clean up that silica dust...I can hear the lawsuits already coming...

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How about someone forward this to the emperor so he can still tell you off and say his plan is superior?

This will either be a wake up call to most or we will still be dense enough to just let politics continue to run everything.

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On 2/6/2019 at 6:03 PM, MysteriousBtrain said:

How about someone forward this to the emperor so he can still tell you off and say his plan is superior?

This will either be a wake up call to most or we will still be dense enough to just let politics continue to run everything.

Yeah.  Maybe Cuomo can be convinced this can be fixed or he more likely writes it off.

Maybe once Cuomo realizes he has no chance of being the Democratic nominee in 2020 he'll change. 

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6 hours ago, Wallyhorse said:

Yeah.  Maybe Cuomo can be convinced this can be fixed or he more likely writes it off.

Maybe once Cuomo realizes he has no chance of being the Democratic nominee in 2020 he'll change. 

I'm yelling you, the reason why he even did this in the first place is to win votes for the next election, while making (MTA) look like the bad guy.

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8 hours ago, Lawrence St said:

I'm yelling you, the reason why he even did this in the first place is to win votes for the next election, while making (MTA) look like the bad guy.

The (MTA) in media is the bad guy no matter what, although that's not without reason

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On 1/24/2019 at 8:46 PM, Lawrence St said:

How bout this: 

Let's just go with the original plan! Problem solved!

Our Infinite Master Cuomo has already taken the reigns of totalitarian control and he shall not let a peasant touch his astonishing accomplishment {F*CKED UP FAILURE AND NATURAL DISASTER} But shall we give him the blame once someone gets Lung Cancer because of Silica dust, may he not see himself re elected.

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On 2/9/2019 at 12:37 AM, WestFarms36 said:

Our Infinite Master Cuomo has already taken the reigns of totalitarian control and he shall not let a peasant touch his astonishing accomplishment {F*CKED UP FAILURE AND NATURAL DISASTER} But shall we give him the blame once someone gets Lung Cancer because of Silica dust, may he not see himself re elected.

They do that and then Cuomo, who in this scenario is somehow actually leading the delegate count in the Democratic primary when New York votes somehow loses New York narrowly, he blames it on being forced to do the original (L) shutdown as he is "shown" "some" voters went to other candidates solely because of that and it was just enough to cost him New York. 

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On 2/6/2019 at 4:22 PM, Around the Horn said:

http://gothamist.com/2019/02/06/the_l_still_smells.php

So theres been a strong fuel smell in the (L) train tunnels in Williamsburg for days now and I'm supposed to believe that the MTA can properly mitigate silica dust in time for morning rush hour? <_<

Please for the love of god, go back to the old plan.

Wait though, it's not really a valid comparison to say "they couldn't eliminate the fuel oil smell so silica dust will be a problem if they do work on the weekends"

I'm not offering tacit support for the hammered-through cuomo plan in rejecting that logic but, notes: 

  1. Dust is inherently easier to mitigate than oil.
    • You're talking about near-macroscopic airborne particles for dust, versus literally molecules for diesel vapour.
    • Due to the larger particle size the dust is less likely to even enter vehicles travelling the tunnel. 
  2. The dust is easier to control since the point and time of emission will be known. 
    • Not for nothing, I 3d printed a vaccum attachment for my drill that completely eliminates drywall dust when I drill into the wall. It's not rocket science (actually it's fluid dynamics) 
    • Water jet systems alone can control silica dust whereas water inherently can't effectively mitigate hydrocarbons. 
  3. The concentration of silica dust required to be suspended in the air to pose a substantial risk is remarkably high. 
    • Health concerns of silica dust are generally confined to workers exposed for entire shifts for extended periods of time. The concentrations required for point-exposure implications are generally like, volcanic. 

(source: osha guidelines for silica dust. google it i'm not dredging up the link)

I really think that "the dust" ought not to be the boogieman in this boondoggle. The unsustainable off hours service should be the issue. As you were. 

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Yeah dust may be easier to clean than oil.

 

But that same counterargument can be proven invalid especially since it definitely proven that MTA management sucks ass right now. 

Not to even explain that the MTA should already be trained to handle oil during emergencies like this.

Edited by MysteriousBtrain

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yes, mta management sucks. I don't think that invalidates my points. 

And I'm not certain that a single transit system has a contingency plan beyond "clean up the oil and seal the leak" with regard to seepage of underground oil plume into existing subway tunnel. Maybe they should but cursory research seems to suggest that this has never happened prior, other than plumes encountered during initial tunnel construction. Diesel smell is pervasive and persistent, merely cleaning up and sealing the leak will not immediately remove the aroma. 

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Shifting gears, we have the finalized plan for the partial shutdown. If you're familiar with the recent nights and weekends closures, you're more than well prepared for the actual shutdown, which still begins on the weekend of April 27th. During these off-hours closures, service will be reduced to 20 minute intervals across the river and possible across the entire line, especially during overnight hours to facilitate the closure of one tunnel. The shuttle buses loop connecting the Canarsie line to the Crosstown and Jamaica lines will be in effect, but all other shuttle bus options offered during the original planned shutdown will not run. Also under consideration is turning both 1 Avenue and 3 Avenue into exit only stations during the closure periods to avoid a massive overcrowding situation.

WNBC has the full story.

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