Jump to content

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


Lance

Recommended Posts

Is anyone really surprised? That meeting was a complete farce and only served to paint the full-closure supporters as the opposition. As soon as it was announced earlier this month, the modified plan was always going to be the one that went forward. The only way it will not is if there is some significant structural deficiency found that completely prevents its use, like how the (N) was kicked off the Manhattan Bridge in late 1990 after it was determined that continued use of the south tracks would further damage the structure.

Link to comment
Share on other sites


  • Replies 1k
  • Created
  • Last Reply

 

From 

 Project Weekly #6: The L is already prepped for storms, faster J M Z trains, Broadway Junction Station progress

 

Hello. Thanks to those of you who tuned in to the MTA board meeting on Tuesday. For a recap, start with this press release.  

While we work through next steps, we're not slowing down on the work still in progress. Some of it is actually, quite literally, speeding up. Read more on that and why the L is already more fortified in case of a future storm. Have a great weekend.

ICYMI: The L is already better prepared for future storms

Superstorm Sandy happened in October 2012. So what's been going on in the last six years to make the L more resilient before the official tunnel rehabilitation gets going?

We posed the question to Steven Loehr, our Subways Recovery & Resiliency Manager to get the answers. Here's our conversation:

Q: So we were able to restore service on the L in 10 days after Superstorm Sandy. What else did you do below ground then to fortify it for the future?

A: Actually, after L service was restored below ground, our team turned their focus to work above ground. It's kind of common sense, but the primary way to address tunnel flooding is to keep water out of the tunnel in the first place.

Q: Okay, so maybe we should have done this as a special resiliency edition of Myth Busters.

A. Ha, well, one myth would be that there's still a long way to go to make the L more resilient. We definitely have more work planned, but we've already completed the most important part, which is installing flood mitigation measures at street-level.

We’ve addressed every opening along the L that's vulnerable to flooding in a Category 1 or 2 hurricane. This includes:

Installing flood protection measures at 60 different potential water entry points (for example, vents, hatches, manholes and emergency exits)

Reconstructing the above-grade fan plant on the Brooklyn-side to be watertight.

And we’re actually doing this kind of flood-risk prevention across the entire subway system. For example, you might see giant flood doors at certain stations. This is all part of keeping the subway network protected in case of future coastal storms.

Q. But there's more coming for the in-the-tunnel part of the resiliency equation, right?

A. Yes! We are building in multiple layers of flood protection. A few examples of this include installing larger pumps with backup power, elevating as much equipment as possible, and using more water-resistant cabling and other components.

Faster J/M/Z trains are here

Have you been on a J, M or Z train lately? If it seems like it's been moving a little faster, you're right.

We've been giving a fresh look at train speed limits as part of our "Save Safe Seconds" campaign. This includes key lines in the L corridor—yes, the J, M and Z. Here's what's changed:

15 MPH limit raised to 30 MPH between Essex Street and The Bowery

10 MPH limit raised to 20 MPH for express trains merging into local track between Hewes Street and Marcy Avenue

Behind the scenes: Broadway Junction Station work set to finish in February

Two stats for you. Broadway Junction Station in Brooklyn is:

  • The third busiest station in all of Brooklyn, and,
  • Takes the top spot in our whole system for being used more to transfer than to start a trip.

With those numbers in mind, we’re making improvements to reduce crowding and make it easier for people to get to and from the platform, which means you can make those connections and catch the train faster.

Here's what you'll see when the work is completed at the end of February 2019:

  • Built two new stairs to each J-Z platform up the mezzanine, which will increase stair capacity by 50 percent per platform
  • Reconstructed two existing stairs to widen them
  • Expanded the J-Z mezzanine area

@RR503

Customer Question
of the Week

Q: Won't the new plan take up a lot of work time setting and breaking down the worksite each time they close and reopen the tunnel? - B. Bertaccini

A: This is something we're looking at as we rework how we execute the L Project. The time between what you're calling set up and break down is something we call "wrench time"—or the time we have to get work done. We've actually increased our wrench time for projects in the past year by 20 to 30 percent per shift, and we're taking it into account as we do the revised design.

Link to comment
Share on other sites

Just now, Union Tpke said:

A: This is something we're looking at as we rework how we execute the L Project. The time between what you're calling set up and break down is something we call "wrench time"—or the time we have to get work done. We've actually increased our wrench time for projects in the past year by 20 to 30 percent per shift, and we're taking it into account as we do the revised design.

Make no mistake: this increase in wrench time has pretty much zero to do with actual work efficiency, and has pretty much everything to do with the fact that they start work earlier and give work trains very high priority (see recent 4th Ave changes). I would hate for them to imitate this on the (L), which sees good ridership into the night, and has a signal system that is just barely capable of dealing w/ non-CBTC (so all) work trains. 

Link to comment
Share on other sites

52 minutes ago, RR503 said:

Those of you who have not yet read @Stephen Bauman's report on single track operations through the Canarsie tube should do so.

http://www.subchat.com/read.asp?Id=1500391 

Damning of the plan; even more damning of our ops. 

The more I see stuff like this the more I hope emperor gives up and says:

images?q=tbn:ANd9GcTMau5CMt2o8IC-hSHKESj

Link to comment
Share on other sites

On 1/18/2019 at 12:59 AM, East New York said:

MTA plans to move forward with (L) Train upgrades without a full shutdown. This is the preliminary update documents with more to be discussed at next weeks committee meeting.

http://web.mta.info/mta/news/books/docs/Canarsie - Board Presentation 011519 1120 FINAL.pdf

Cuomo's plan on safety of passengers and structural integrity of the tunnel:

Bird-Box-in-boat.jpg?w=1000

Edited by Lawrence St
Link to comment
Share on other sites

Like I said before, will some group now go to court to try to block this and force the (MTA) back to the original plan?  I still some doing that if for no other reason than to force Cuomo to admit under oath the real reasons why he's doing this. 

Edited by Wallyhorse
Link to comment
Share on other sites

12 hours ago, RR503 said:

Those of you who have not yet read @Stephen Bauman's report on single track operations through the Canarsie tube should do so.

http://www.subchat.com/read.asp?Id=1500391 

Damning of the plan; even more damning of our ops. 

Subchat appears to be down. Here's the link to the spreadsheet that shows the performance of single track operations on Jan 15 - 18 of last week. It covers the time period from midnight to 5am.

The 3 columns for each trip are 

RT0 which is the initial schedule posted on the real time feed. It's usually posted approximately 30 minutes before departure. The post time is given above the RT0 identifier in the header. If the post time is much closer to the departure, it means the dispatcher re-arranged the schedule.

RTN - The schedule is displayed and possibly modified every 30 seconds until the trip is completed. Only the remaining stops are given in each update. The RTN data represents the last update for each station. This is the data that's used by the countdown clocks at each station.

POS - There's also vehicle position data that notes the status to the next station. The arrival time is given by the timestamp part of the position message for the first STOPPED_AT status. It generally corresponds to the time when the station countdown clock displays a steady orange 0 minute message. It's approximately 20 seconds before the train actually stops within the station. The departure time is sending time for the last STOPPED_AT status position message. It's generally when the doors close.

I've repeated the schedule showing only the RT0 columns below on each sheet, to make it easier to follow what was planned. 

The 15th and 16th show tunnel travel times of 7 and 10 minutes with Union Sq to Lorimer being the longer. That's a total of 17 minutes, leaving 3 minutes buffer time for a 20 minute headway. The 17th and 18th show tunnel travel times of 10 and 7 1/2 minutes with the Union Sq to Lorimer being the longer. This leaves a 2 1/2 minute buffer for 20 minute headways. If the buffer times are assessed equally between Brooklyn and Manhattan bound trips, each trip needs to be within 75 or 90 seconds of schedule to avoid single track delays. 

An inspection of the POS column for the Canarsie departures reveals this criterion was often violated. Further inspection of the late start trips from Canarsie to Lorimer reveals that the CBTC/ATO/ATS combo was not particularly good at gaining lost time during the trip to Lorimer. Good management would investigate the reason behind the late starts and missed connections at the Canarsie Tunnel. The investigation's aim should be to avoid repeats.

20 minute headways during the midnight hours would not impose a hardship because it roughly duplicates the current service levels. It's a different story for weekends. 15 tph operation is scheduled for weekends. NYCT is not known for operating too many trains, when demand does not exist. I'd assume these trains are packed, although I've not sampled them.

It should be possible to operate 12 tph, with single track operation through the Canarsie Tunnel under the existing CBTC and power constraints. It would take a lot more operational discipline than NYCT exhibited during the 3 tph operations this past week.

Link to comment
Share on other sites

1 hour ago, Stephen Bauman said:

It should be possible to operate 12 tph, with single track operation through the Canarsie Tunnel under the existing CBTC and power constraints. It would take a lot more operational discipline than NYCT exhibited during the 3 tph operations this past week.

Where are you getting the 12tph figure? Even if you got down to 7 min runtimes in both directions, you’d be left w/ 15 min gaps between same-direction departures, or 4tph. Are you assuming they fleet trains? 

Link to comment
Share on other sites

12 minutes ago, RR503 said:

Where are you getting the 12tph figure? Even if you got down to 7 min runtimes in both directions, you’d be left w/ 15 min gaps between same-direction departures, or 4tph. Are you assuming they fleet trains? 

This is why it should be considered to construct a crossover east of 1 Av Station so that the single tracking is limited to just between 1 Av and including Bedford Av. travel time from lorimer St to 1 Av is about 5 mins, so we could pull off a 10-12 minute headway on weekends (accounting for high load volumes at Bedford Av and Lorimer St).

Link to comment
Share on other sites

3 minutes ago, darkstar8983 said:

This is why it should be considered to construct a crossover east of 1 Av Station so that the single tracking is limited to just between 1 Av and including Bedford Av. travel time from lorimer St to 1 Av is about 5 mins, so we could pull off a 10-12 minute headway on weekends (accounting for high load volumes at Bedford Av and Lorimer St).

I wish they had done this. Can't do it now, though -- designing and installing a new crossover, especially in CBTC territory, is difficult. 

Link to comment
Share on other sites

10 minutes ago, RR503 said:

Where are you getting the 12tph figure? Even if you got down to 7 min runtimes in both directions, you’d be left w/ 15 min gaps between same-direction departures, or 4tph. Are you assuming they fleet trains? 

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. 

Link to comment
Share on other sites

29 minutes ago, Around the Horn said:

What's causing all the late starts from Canarsie? Did they arrive late? 

The only info I have is what's publicly available from the GTFS-RT feed. I'd assume looking into the causes for the late starts should be one topic for the management investigation I suggested.

All the information regarding scheduled and actual arrivals and departures for all the station is contained in the linked spreadsheet. I'd suggest anyone study it to gain insight into NYCT operations.

Link to comment
Share on other sites

The latest from Streetsblog, who got a hold of the draft plan (and it's bad) 

https://nyc.streetsblog.org/2019/01/23/exclusive-cuomos-l-train-plan-still-has-lots-of-pain/

Quote

But Streetsblog has obtained a draft MTA memo that reveals the nuts-and-bolts behind the Cuomo plan — and it isn’t as pretty as the tabloid headlines made it sound.

On weekends, as previously announced, there will be 20-minute gaps between trains, up from four minutes. But the memo — “Potential L Tunnel Weekend and Late Night Service Plan With One-Track Closure” — reveals additional pain as well:

Stations at First and Third avenues will likely be reconfigured to exit-only. (“That’s just abysmal for the East Village,” said Jon Orcutt, the spokesman for TransitCenter.)

There will be no new inter-borough bus route because such a bus will no longer be “time competitive” if the city eliminates the HOV-3 requirement on the Williamsburg Bridge, as it is expected to do.

There will be no additional ferry service.

The overnight plan includes the same 20-minute gaps in train service, plus the following difficulties for riders:

There will be no additional L shuttle service.

There will be no increase in normal G service.

There will be the aforementioned need for “metering” at L platforms at Union Square, Third Avenue, First Avenue and Bedford Avenue. If the monitoring of station crowds reveals a danger, the MTA would temporarily restrict access to the platforms.

There will be no new bus service along 14th Street, between the boroughs, or in Brooklyn.

Both there are some pluses for riders:

On weekends:

There will be service on the M line along the Second Avenue line on the Upper East Side. The train doesn’t currently go there, but can be sent along that route so that it can turn around without affecting other lines, a source said.

Service on the G train will run every eight minutes instead of every 10 minutes.

There will be out-of-station MetroCard transfers between the Broadway stop on the G and the Hewes Street and Lorimer Street stops on the J and M lines. There will be similar free transfers between the Junius Street stop on the 3 train and the Livonia Avenue stop on the L.

The MTA will provide additional service on the M14 bus to reduce waits from 12 minutes to 10 minutes. (Reminder: Under the original shutdown plan, 14th Street was slated to become a bus-only route.)

There will be a bus shuttle from the L station at Bedford Avenue to the J and M station at Marcy Avenue

Transit in this city is a complete joke with these two clowns in office, and this is no exception.

Link to comment
Share on other sites

1 hour ago, Around the Horn said:

The latest from Streetsblog, who got a hold of the draft plan (and it's bad) 

https://nyc.streetsblog.org/2019/01/23/exclusive-cuomos-l-train-plan-still-has-lots-of-pain/

Quote

But Streetsblog has obtained a draft MTA memo that reveals the nuts-and-bolts behind the Cuomo plan — and it isn’t as pretty as the tabloid headlines made it sound.

On weekends, as previously announced, there will be 20-minute gaps between trains, up from four minutes. But the memo — “Potential L Tunnel Weekend and Late Night Service Plan With One-Track Closure” — reveals additional pain as well:

Stations at First and Third avenues will likely be reconfigured to exit-only. (“That’s just abysmal for the East Village,” said Jon Orcutt, the spokesman for TransitCenter.)

There will be no new inter-borough bus route because such a bus will no longer be “time competitive” if the city eliminates the HOV-3 requirement on the Williamsburg Bridge, as it is expected to do.

There will be no additional ferry service.

The overnight plan includes the same 20-minute gaps in train service, plus the following difficulties for riders:

There will be no additional L shuttle service.

There will be no increase in normal G service.

There will be the aforementioned need for “metering” at L platforms at Union Square, Third Avenue, First Avenue and Bedford Avenue. If the monitoring of station crowds reveals a danger, the MTA would temporarily restrict access to the platforms.

There will be no new bus service along 14th Street, between the boroughs, or in Brooklyn.

Both there are some pluses for riders:

On weekends:

There will be service on the M line along the Second Avenue line on the Upper East Side. The train doesn’t currently go there, but can be sent along that route so that it can turn around without affecting other lines, a source said.

Service on the G train will run every eight minutes instead of every 10 minutes.

There will be out-of-station MetroCard transfers between the Broadway stop on the G and the Hewes Street and Lorimer Street stops on the J and M lines. There will be similar free transfers between the Junius Street stop on the 3 train and the Livonia Avenue stop on the L.

The MTA will provide additional service on the M14 bus to reduce waits from 12 minutes to 10 minutes. (Reminder: Under the original shutdown plan, 14th Street was slated to become a bus-only route.)

There will be a bus shuttle from the L station at Bedford Avenue to the J and M station at Marcy Avenue

Transit in this city is a complete joke with these two clowns in office, and this is no exception.

This is some heavy punishment for not picking the fast+quality option. Now they get not-so-fast+poor-quality. And they won’t even save money on the project in the long run given the overhead costs of staging the sites for construction work every night.

I’m going to LOL so hard when the very proponents of single-tracking just call for the MTA to get it over with and go with the original plan.

With this kind of service, the attractiveness of living along the (L) will still plummet.

Edited by CenSin
Link to comment
Share on other sites

7 minutes ago, Bay Ridge Express said:

Excuse me?? Why?

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.

Link to comment
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.