Down in the Tunnel

And at long last, we now have a few images of the work taking place inside TBM Tunnel No. 1 (the west tunnel) under Second Avenue.

The quoted text under each image is the caption that was provided to me by the MTA.



Courtesy of the MTA
8/2010
Inside TBM Tunnel No. 1
"General view along the TBM catwalk of the bridge conveyor and spoils [muck] being removed from the heading."



Courtesy of the MTA
8/2010
Inside TBM Tunnel No. 1 - looking south
"General view of extended vent line and locomotive pulling muck cars from the starter tunnel."



Courtesy of the MTA
8/2010
Inside TBM Tunnel No. 1 - looking north
"General View of full muck cars being hauled out of the tunnel."



Courtesy of the MTA
8/2010
Inside TBM Tunnel No. 1 - looking south
"A view of the steel rib initial support installation."


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And here are a few images of the work taking place at street level on Second Avenue.



8/21/10
69th Street - looking N

The access shaft shown in this image is now complete and the the contractor, S3 Tunnel Constructors, has now removed all of their equipment from the work area. Its nice to see how neat the contractor has left this work site.

This shaft, and its twin up near 72nd Street, is now ready for a new contractor to start mining the cavern for the new 72nd Street station in the not to distant future.



8/21/10
btw. 83rd & 84th streets - looking N

This looks like a new gas main that is undergoing a pressure test. This is done by pressurizing the new section of pipe with a non-flammable a gas and then checking to see that the pressure in the pipe remains constant for a fixed period of time.

Note the orange tanks in the image are marked with HAZMAT Class 2 "non-flammable gas" placard. One could assume that these tanks contain the gas that is being used for the pressure test.



8/21/10
91st Street - looking S

Workers here are preparing the area between 90th and 92nd Street, on the east side of Second Avenue, that will be subject a "ground freezing" process.

The ground in this area must be frozen before the TBM starts mining tunnel No. 2 (the east tunnel) because this area contained fractured rock and soft ground - materials that cannot be mined by the main beam TBM that is being used on this job.

Before the ground can be frozen the surface must first be prepared and a network of freeze pipes must be installed. Before the TBM starts its run for the east tunnel the ground in this area will be frozen solid.

After the TBM passes through this area an interim liner will be installed through the frozen zone to seal the ground and the groundwater from entering the tunnel as the ground thaws out. This interim liner will be incorporated in the final cast-in-place liner after this tunnel has been excavated.



8/21/10
91st Street - looking N

Another view of the surface preparation work in the zone where the ground freeze will take place.



8/21/10
In front of 1867 Second Avenue (btw. 96th & 97th streets) - looking S

At this location the contractor is using a technique known as compaction grouting to improve the soil conditions under the buildings at 1867, 1869, and 1871 Second Avenue.

The image above shows one of the drills that is being used to install the grout pipe. The temporary pedestrian access way to the front door of 1867 Second Avenue can be seen on the right.



8/21/10
In front of 1871 Second Avenue - looking S

A close-up view of the 2nd drill unit, which is located in front of the McDonald's restaurant.


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The MTA recently announced (on their web site) that the following two contracts are to be advertised in the near future:

Contract C-26008
Mine 86th Street Station Cavern
Second Avenue Subway
This project is to mine the 86th Street Station cavern as well as shafts and adits for the entrances, elevator, electrical, ancillaries, cross passages, underpinning of existing structures and cut and cover excavation.

Contract C-26009
Construct Track, Signal, Power & Communications Systems
Second Avenue Subway
This project is to construct track, signal, traction power, and communication systems for the Second Avenue Subway which includes the 96th, 86th, 72nd and Lexington/63rd Street Stations.


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

"Bring on the MTA Machines"
By Kelli Gail
Our Town - 8/18/10

Committee Report (7 pages)
Hearing Testimony (39 pages)
Hearing Transcript (141 pages)
"The 2nd Avenue Subway and the East Side –
Is there light at the end of the tunnel"
Oversight Meeting
Joint Committees on Small Business and Transportation
New York City Council - June 14, 2010


Under Businesses that have Closed:


8/21/10
1830 Second Avenue (btw. 94th and 95th)
Chinese Mirch - a take away restaurant
Closed at this location in August 2010



8/21/10
1817 Second Avenue (btw. 94th and 95th)
Re-opened as Konomi Sushi
in early August 2010


Under Notices & Posters:


8/21/10