Sunday, July 17, 2011

Progress North to South


On Saturday mid-day, I walked from 100th Street down to 63rd Street to see what new and interesting things were happening on the project. It's been about four weeks since my last posting so I expected, and did, find much to report.

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Update 7/18/11:
Additional information has been added to the posting, as noted below. All of this new information was provided to me in a comment that was left on the blog earlier today.

Update 8/9/11:
Additional information about the permits that were issued for the crane disassemble work at 97th Street has been added.



7/16/11
near 99th Street - looking N

The gantry crane shown here, which was made by Mi-Jack Products of Hazel Crest, Illinois, is being used to build and move slurry wall cages (shown in the foreground) for the current 96th Street Station contract.



7/16/11
btw. 99th & 100th streets - looking E

Another view of the gantry crane.



7/16/11

A closer look at a section of slurry wall cage. The cages are built using reinforced steel bar, which is commonly known as rebar.



7/16/11
97th Street - looking N

Note the wood timbers that have been laid on the surface of Second Avenue at this location. This is done to better distribute the load of the very heavy Liebherr crawler crane (shown in the image) across the surface of the roadway.



7/16/11
97th Street, SW corner - looking S

This is a view of the future location of Ancillary Building No. 2 for the 96th Street Station. This was the location of the former Century Lumber Yard.



7/16/11
96th Street - looking N

This is a view of the temporary slurry plant that has been set up just east of Second Avenue, between 96th & 97th streets. The plant will eventually be removed by the contractor when it is no longer needed.

Note in particular the new "urban canvas" that the MTA has placed on the fencing at this location (left-click image to zoom in). The design was prepared by the artist Corinne Ulmann.



7/16/11
96th Street - looking S

I'm not sure exactly what these large steel objects are.

Update 7/18/11:
I've been told that these object are steel end stops for the slurry wall panels. The end stops go on the sides of each slurry wall panel to stop the flow of concrete around the side of the panel and to provide a structural “key” (i.e. a notch).

The trapezoidal side goes against the side of the concrete pour. Once the concrete cures, the end stop is stripped away and there is an indentation in the side of the concrete panel. When the next panel is poured, the concrete flows into this notch to provide a structural key between the two panels.

The contractors for this work (E. E. Cruz and Tully Construction Co.) began excavation for the first slurry wall panels last Friday.



7/16/11



7/16/11
94th Street, NW corner - looking S

This is a temporary storage container for commercial and residential waste. The idea is that trash will be deposited inside the steel storage container instead of piled on the street.



7/16/11
btw. 94th & 95th Streets - looking S

This rather unremarkable image is actually sort of interesting. It shows a location on Second Avenue where the MTA's contractor has added an additional two feet to the width of walkway by moving the fence line slightly to the west - so the sidewalk in this block is now nine feet wide instead of just seven feet wide.

This is good news for people who use this sidewalk.



7/16/11
btw. 94th & 95th streets

Someone applied duct tape over part of this MTA sign, as you can see. The words that have been covered say "Work on this project is expected to be completed by Summer of 2011."



7/16/11
93rd Street

During my journey down Second Avenue, I found this large new sign posted at about a dozen different locations. (Left-click on the image if you wish to read what it says.)



7/16/11
87th Street - looking S

The contractor at this location has recently started to excavate the north construction shaft for the 86th Street station.



7/16/11
83rd Street - looking E

And at this location, the contractor is excavating the south construction shaft for the 86th Street station.



7/16/11
83rd Street - looking N

Another view of the future location of the south construction shaft.



7/16/11
72nd Street - looking N

The is a view of the nearly complete spoils conveyance structure at this location.



7/16/11
btw. 72nd & 73rd street - looking NE

On the Saturday of my visit, workers were testing the system by using the [yellow] gantry crane to move around the large white buckets. These buckets will will be used to lift spoils to the surface.



7/16/11



7/16/11
just north of 70th Street - looking S

Down near 70th Street, I was surprised to discover that the MTA was in the process of building a second spoils removal system for the 72nd Avenue station.

I say that I'm surprised because one would think that one spoils removal system would be enough to remove the material from the station cavern below.

One could assume that similar structures will be constructed for the excavation of the 86th Street station cavern, but I don't know for sure.

Nothing like this system was built to excavate the spoils that are being produced by the MTA's East Side Access project. For that project, the spoils are being taken to Queens via a conveyor system inside the tunnels. Why a similar system (to remove the spoils via the tunnels) is not being used for the 72nd Street (and 86th Street) station caverns, I do not know.

Update 7/18/11:
I've now been told that the volume of muck (rock) being generated at each shaft is what necessitated two complete spoils removal systems at 69th and 72nd streets.

One gantry system would not be able to keep up with the volume of material being produced by the 72nd Street station cavern, the cross-passages and the drill and blast tunnel construction in the west tube from 65th Street (where the TBM stopped) to the 63rd Street/Lexington Avenue station.

A reader of this blog pointed out to me that there are several material differences between the mucking operations on Second Avenue and the East Side Access (ESA) project.

First off, the rock being generated at the 86th and 72nd Street stations is “shot rock” (i.e. it is produced by blasting the rock) and it thus much larger than the rock from the TBM.

For the dump station (the vertical conveyor system) at 93rd Street to be used, it would necessitate the crushing of all rock below grade [like they do at ESA] before it could go on a conveyor system.

Also, at ESA, there was an existing conveyor system running back to Queens left from the TBM contract. There is no conveyor system as part of the 2nd Ave running tunnels, so one would have had to be built.

A final consideration is access. At ESA, one contractor is doing all of the TBM mining and cavern mining. At SAS, each station is a different contract and a conveyor system through different contractor’s work zones would raise issues of who would need to maintain the system and operate it - logistical/contractual nightmare.

The MTA is also looking to install concrete tunnel lining, signals, and track in the tunnel sections as the cavern mining is on-going, so a conveyor running through the tunnel would hamper these work items and push out the overall schedule.

Also, work in the launch box at 96th Street would need to wait until all mining was finished as the launch box currently holds the muck and all conveyor systems. The current schedule has the work in the launch box proceeding concurrently with the mining.



7/16/11
69th Street - looking E

At 69th Street, I came across a team of steel workers who were in the process of assembling the superstructure for the spoils conveyance system at this location.



7/16/11



7/16/11



7/16/11
Lexington Avenue/63rd Street Station
On the lower level (Queens bound) platform - looking E

At this location, you can see that the contractor has now removed most of the false ceiling and much of the decorative wall on the opposite side of the track.



7/16/11
Lexington Avenue/63rd Street station
On the lower level (Queens bound) platform - looking E



7/16/11
Lexington Avenue/63rd Street station

The upper level (Manhattan bound) platform at this station was closed for the weekend. When I was at the station, it was easy to hear that workers were actively performing demolition work on the upper level platform while I was in the station.


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The images that follow were provided to me by Mark Lyon who lives in the neighborhood.

The first three images show road resurfacing work that was recently performed by the NYC DOT in the work zone north of 95th Street. This newly resurfaced roadway looks great, but I suspect that it won't be long before the contractor rips it up so that work on the 96th Station can continue.



Courtesy of Mark Lyon
7/9/11
96th Street - looking S

The machine shown above is used to grind away the top layers of the roadway.


Removing old pavement
Courtesy of Mark Lyon
7/9/11
97th Street - looking NW



Courtesy of Mark Lyon
7/9/11
96th Street - looking S

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These two images, also provide by Mark Lyon, show workers who are disassembling a large crawler crane at this location. From what I've been told, this work took place into the early morning hours (i.e. until about 3 a.m.) on Sunday 7/17/11.

The crane that was taken down is shown still upright in the fifth image of this blog posting. The crane was situated at the work site where the Ancillary Building No. 2 for the 96th Street station will be built.

Why it was necessary to perform this work in the middle of the night was not clear at the time that I posted this entry. However, it is my understanding that a permit had been issued for this work.


Bay Crane
Courtesy of Mark Lyon
7/17/11
97th Street, SW corner


Bay Crane
Courtesy of Mark Lyon
7/17/11
97th Street, SW corner

Note in particular how the crane is boomed-down across 97th Street in this image.


Update 8/9/11:
The NYC DOT issued three separate but related Street Construction Permits for this work. The permits allowed, among other things, the complete closure of 97th Street between 2nd & 3rd avenues.

Of particular note, is the specific stipulation, in each permit, that the work must take place between 9 p.m. on Saturday 7/16 and 6 a.m. on Sunday 7/17. This would explain why this work was performed in the middle of the night.


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And finally... these two images, from the MTA's recent presentation to Community Board 8's Second Avenue Subway Task Force, show the progress that is being made below ground at the 72nd Street station cavern site.


Source: MTA Presentation to CB8 Second Avenue Subway Task Force, 6/22/11, p. 22



Source: MTA Presentation to CB8 Second Avenue Subway Task Force, 6/22/11, p. 23

Look carefully at the image above. In the lower left corner, you can see that they have now broken through the station cavern floor into the west TBM tunnel below.



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Last Reported Location of the
Tunnel Boring Machine
just south of 75th Street
as of 6/30/11

TBM Run No. 2 (east tunnel)
Tunnel length: 7,789 linear feet (LF)
Start: just south of 92nd Street
End: Lexington Av / 63rd St Station
4,488 LF mined as of 6/30/11
3,301 LF to run

TBM Run No. 1 (west tunnel)
92nd Street to 65th Street
7,162 linear feet mined with TBM
Run completed 2/5/2011

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June TBM Mining Data:
Distance mined: 1,646 linear feet (LF)
TBM mining days: 22
Avg. distance per day: 74.8 LF http://www.blogger.com/img/blank.gif


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The two images that follow were clearly not taken on Second Avenue! They were taken in Lübeck, a city on the Baltic Sea in the north of Germany, a few weeks ago while I was on vacation.

The images show trench construction in the middle of a city. I've included them here because I found it interesting to see how an urban trench is constructed in Germany - compared to the many trenches that have been built in support of Phase I of the Second Avenue subway.



7/2/11
Breite Str, Lübeck - near the Rathaus



7/2/11


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Here's a listing of the recent additions
to the right-hand column of The Launch Box

Construction Update and Fence Wrapping
Second Avenue Subway Project Project Update for Community Board 8
MTA Capital Construction
6/22/11

Manhattan Chamber of Commerce Construction Scrim Proposal (Concept Only)
6/22/11

"Dust and Odors at Second Avenue Subway Construction Site"
By Amy Zimmer
DNAInfo.com - 6/24/11


Notice of Proposed Buy America Waiver
to Allow Bidder to Certify Compliance

Federal Transit Administration
Department of Transportation
Docket No. FTA-2011-0031
7/7/11

The MTA has asked the Federal Transit Administration to waive its Buy America requirements on the basis of public interest to permit the low bidder for a contract to construct the 86th Street Station for the Second Avenue Subway project to certify compliance with Buy America. The bidder certified non-compliance based on a misunderstanding of how FTA would apply its rules to certain construction materials. In fact, the low bidder is willing and able to comply with the Buy America rules. Without a waiver, MTA may spend an additional $32.9 million on the 86th Street Station without furthering the goals of Buy America.


Light Rail for Second Ave.: An idea almost gone
By Benjamin Kabak
2nd. Ave. Sagas - 7/8/11

"MTA close to awarding contract for Second Avenue subway tracks, signals and communications"
By Pete Donoghue
NY Daily News - 7/12/11

Underneath 2nd Ave., inching closer to a subway
By Benjamin Kabak
2nd. Ave. Sagas - 7/13/11

"Second Avenue Subway Construction Creates Many Realty Steals" (2:00)
By Jill Urban
NY1 - 7/15/11

Less than Picture Perfect:
The Legal Relationship between Photographers' Rights and Law Enforcement
By Morgan Leigh Manning
Tennessee Law Review
Vol. 78, p. 105, 2010

5 comments:

Anonymous said...

Ben,

Great post. In answer to some of the questions that you raised in the post:

The objects that you could not identify at 96th Street are end stops for the slurry wall panels. These steel objects go on the sides of each slurry wall panel to stop the flow of concrete around the side of the panel and to provide a structural “key” (notch). The trapezoidal side goes against the side of the concrete pour. Once the concrete cures, the end stop is stripped and there is an indentation in the side of the concrete panel. When the next panel is poured, the concrete flows into this notch to provide a structural key between the 2 panels. The contractor for this work (Cruz-Tully) began excavation for the first slurry wall panels on Friday 7/15/11.

The reason the crane up at 97th Street was disassembled overnight was in fact due to permits. The DOT only grants permits for oversize loads on off-hours so the trucks can only travel on certain hours. Also, it looks like from the photo that the crane was boomed-down across 97th Street, requiring a street closure. DOT only grants these on off-peak hours. In order to maintain traffic flow on 97th during daytime hours, the crane disassembly was done overnight.

In regards to the mucking systems that are being assembled at 72nd Street, the volume of muck being generated at each shaft is what necessitated 2 systems. Don’t forget that there is not only muck being generated for the 72nd Street station cavern, but also from cross-passages and the drill and blast tunnel construction in the west tube from 65th Street (where the TBM stopped) to the 63rd Street station. One gantry system would not be able to keep up with the volume of material, making the contractor “muck-bound.”

You allude to the East Side Access setup, but there are several material differences with this project. First off, the rock being generated at the 86th and 72nd Street stations is “shot rock”, much larger than the rock from the TBM. For the dump station at 93rd Street to be used, it would necessitate the crushing of all rock below grade [like they do at ESA] before it could go on a conveyor system—the logistics of building such a system are very difficult. Also, at ESA, there was an existing conveyor system running back to Queens left from the TBM contract. There is no conveyor system as part of the 2nd Ave running tunnels, so one would have to be built. A final consideration is access. At ESA, one contractor is doing all of the TBM mining and cavern mining. At SAS, each station is a different contract and a conveyor system through different contractor’s work zones would raise issues of who would need to maintain the system and operate it—a logistical/contractual nightmare. The MTA is also looking to install concrete tunnel lining, signals, and track in the tunnel sections as the cavern mining is on-going, so a conveyor running through the tunnel would hamper these work items and push out the overall schedule. Also, work in the launch box at 96th Street would need to wait until all mining was finished as the LB currently holds the muck and all conveyor systems. The current schedule has the work in the LB proceeding concurrently with the mining.

Ben Heckscher said...

Thanks for the detailed information and explanations.

I'll update the posting later today - as soon as I have time.

Ben

Mark said...

Why does the MTA and DOT value cars (which can choose a different route) over a nearly 12-hour overnight disturbance of residents?

Also, why didn't the MTA or DOT bother to notify the residents of the planned crane removal?

Anonymous said...

Anonymous @ 1, great response to a great post by Ben.

One question: How are they moving dirt out at the 86th station starter shafts at this early point? It looks like they are just digging down.
-Hank

Anonymous said...

Anonymous @4--right now, the soil and rock being removed from the starter shafts is just being excavated and stockpiled on site, then loading into trucks with an excavator. This operation has generated very little muck so there is no need for a mucking assembly, yet. When the next contract begins production mining [the contract right now only takes the shafts down 30'], that is when the capacity constraint arises and they need some sort of muck removal system.