Thursday, September 22, 2011

Subway Infrastructure Milestone Achieved

Tunnel Boring Machine Arrives
at Lexington Ave/63rd Street Station

Major Milestone Reached in the Long
History of the Second Avenue Subway

At 11:28 a.m. today, September 22, 2011, the tunnel boring machine (TBM) that had been mining the east tunnel of Phase I of the Second Avenue Subway reached its final destination.

It successfully broke through a rock cavern wall -- into open air -- deep inside Manhattan's Lexington Avenue/63rd Street station.

The posting that follows chronicles today's historic event.

Update: 9/23/11
The MTA's official video of the TBM breakthough, and a selection of media pieces about the event, have been added near the end of the post.

This is a view of the solid rock wall at the eastern end of the so-called 63rd Street Stub Cavern. Built in the early 1980's as part of the Lexington Avenue/63rd Street station, this cavern has one purpose: to connect to the G4 (east) tunnel of the Second Avenue subway.

When this image was taken at 10:22 a.m., the cutterhead of the TBM was still about 1-2 feet behind the rock wall.

Here, a large delegation of invited guests begins to congregate - cameras in hand.

As the TBM mines behind the rock, two workers check the rock face to ensure that all is proceeding as planned.

The machine continues to mine. . . The crew boss, on the right, communicates by radio with the operators of the TBM which is located on the other side of the wall.

At 11:23 a.m., small cracks and fissures start to appear in the wall, and rock dust begins to billow out toward the workers and guests. Viewing this gave me the impression of a long-slumbering dragon breathing out smoke as he slowly awoke.

Workers also begin to spray water on the wall in an effort to minimize the dust that is produced by the TBM's approach.

The dust continues to accumulate, settling again afterwards as the TBM pauses.

Finally, as the dust clears we have our first view of the face of the TBM -- at last!

Loud cheers break out and the assembled crowd claps in appreciation.

Second Avenue Subway TBM Hole Through (0:23)
via YouTube
This short video was shot a few minutes after the TBM broke through the wall.

Here, the machine is fully stopped. A worker (with the yellow shirt) steps forward to assess the depth of the remaining rock. He determines that the machine still has about about one foot of rock to grind through.

The workers step back and the machine is restarted in order to mine the last foot of rock. The dust builds again, as clearly can be seen in the images above and below.

The dust settles on the guests as the machine continues to thrust forward.

The cavern walls are now totally obscured by a dense cloud of dust.

A decision is made to stop the machine at this point, since it became clear that the final foot of rock would require more time to mine.

The assembled press is then brought forward to inspect the scene and to interview various MTA officials.

Dr. Michael Horodniceanu, President of MTA Capital Construction, answers a question from NY1 reporter Tina Redwine. Jay Walder, Chairman and CEO of the MTA, is standing on the far left.

An S3 Tunnel Constructors worker inspects the face of the TBM.

S3 Tunnel Constructors, a joint venture of Skanska USA Civil, Schiavone Construction, and
J.F. Shea Construction, is the contractor responsible for mining the two running tunnels, and the construction of the launch box, in Phase I of the project.

Look closely and you can see that a small trap door (at about 12 o'clock) on the face of the cutterhead has been opened.

The Sandhogs can use this door to access the face of the cutterhead. During mining operations, this door would only be opened after first stopping the machine and then backing it up about 5 feet, to create a space between the rock and the face of the TBM.


Following the press briefing, many people stood together for photos in front the TBM; I did my best to capture some of the group photos.

Here is what I really like about the group shots below -- they show just how proud all of these men and women are of today's accomplishment. These people have been part of a great achievement in underground construction, and each of them wants the event recorded for posterity.

MTA Chairman Jay Walder (center-left), MTA Capital Construction President Dr. Michael Horodniceanu (center-right) and New York City Council Member Daniel Garodnick (right).

Pat Barr and two other Sandhogs standing with Julio Martinez of S3 Tunnel Constructors.

MTA Chairman Jay Walder on the right.

MTA Capital Construction President, Dr. Michael Horodniceanu and MTA Chairman, Jay Walder.

This group from S3 Tunnel Constructors poses with MTA Capital Construction Sr. Vice President William Goodrich (3rd from the right). Goodrich has overall responsibility for the Second Avenue Subway project. An MTA project engineer is the 4th person from the left.

Three MTA engineers (vests) pose with two workers from S3 Tunnel Constructors (T-shirts).

A group of engineers from Arup and AECOM (formerly DMJM+Harris) pose with an MTA project engineer.

An assembled group of Parsons Brinckerhoff employees. Parsons Brinckerhoff is providing construction management services for Phase I of the project.

Chris Smart (a surveyor), Tom Maxwell, Anthony Del Vescovo, Mike Goldstein, Alaeden Jlelaty, Julio Martinez and Bob Hamill - all with S3 Tunnel Constructors.

Some of the original Second Avenue Subway design team from Arup and AECOM.


After the photo session, everyone was asked to leave the cavern so the machine could be restarted to complete the last bit of tunneling.

On my way out, I took these three pictures of the Lexington Ave/63rd Street station.

looking west

This is an image of the existing track on the north side of the lower level of the station. The track was laid in the early 1980's. Note that the 3rd rail has been removed.

This track extends through an inactive tunnel under Central Park that eventually leads to the 57th Street/7th Avenue station. (A diagram for this section of track can be found on this link.)

looking west

looking east

Note the active signal. This section of track was being used to store out-of-service trains between runs, until recently.

I exited the station so that I could transmit the cell phone picture that was used in the previous posting.


When I returned to the station about an hour later, I found these four Sandhogs and Julio Martinez, a Tunneling Engineer for S3 Tunnel Constructors, relaxing in the Lexington Ave/63rd Street station.

Normally, these guys are working inside the TBM. However, they are now clearly thrilled to be outside the TBM, contemplating a job well done.

Alaeden Jlelaty, Skanska's head project manager on this job and Anthony Barrett, a Sandhog with the very special title of walking boss.

Barrett, a long time Sandhog, was involved with the construction of the Lexington Ave/63rd Street station between 1979 and 1982. As a stroke of good Irish luck, today's events coincided with his birthday.

I was subsequently invited back down into the tunnel, with two other photographers, to take this group photo. Clearly, this is a very proud group of men.

The Sandhogs have a closer look at their machine and then proceed to climb back into it via the hatch (just out of view) that is now positioned at about 6 o'clock.

A Sandhog heading back to the job.

The walking boss, Anthony Barrett, is visibly pleased with today's accomplishment.

The last two Sandhogs descend back into the TBM.

The TBM will be backed up all the way to the launch box at 92nd Street and partially disassembled.

It will then be shipped back to the contractor's yard in New Jersey where it will be refurbished for its probably next assignment - an 8-mile long Combined Sewer Overflow tunnel for the city of Indianapolis, Indiana.

MTA staff photographer, Patrick Cashin, takes his final pictures.

The sign that says it all.

And so there you have it. A major milestone in the 82 year history of the Second Avenue Subway.


Update - 9/23/11

Second Avenue Subway - 9/22/2011 Update
Metropolitan Transportation Authority via YouTube

A selection of media pieces about the event:

"Second Avenue Subway Reaches "Boring" Milestone"
By Tina Redwine
Video (1:59) - NY1 - 9/22/11

"New York MTA Completes Two-Mile Tunnel for Second Avenue Subway"
By Esmé E. Deprez and Andrea Riquier
Bloomberg News - 9/22/11

"TBM breakthrough in New York"
By Paula Wallis
TunnelTalk - 9/11

"At 63rd Street, Adi emerges"
By Benjamin Kabak
2nd. Ave. Sagas - 9/23/11


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

"Construction to Start on Second Avenue Subway 86th Street Station"
By Amy Zimmer - 9/15/11



Interesting Press coverage of precise engineering in a difficult geological and environmental context.

AR Elia said...

Great work. Very interesting. It would be great if you can give an overview of the next phase of construction now that the tunneling is done (if it is done.). What are the next major above ground impacts. When will construction take place primarily below grade. Still, it's great to see progress toward getting 2nd Ave back online. Thanks for your efforts.

Anonymous said...

Congrats Ben on being the single greatest source for SAS construction information and for being present for this milestone.

As a resident of the UES I thank you very much for keeping us informed.

I was wondering if you have any particular insight as to when we can expect most surface level construction to be complete. I.e. when our sidewalks are returned.

Will the 83rd street access shaft be a working construction site all the way 'til the 2016 completion date or will there be a sooner date at which most if not all of the work will be concentrated underground?

jmp said...

Now that the TBM run is complete, how will this impact the surface conditions around the Launch Box itself?

It's my understanding that the muck removal system in place at 93rd Street was suitable for the debris produced by the TBM, but not for the stuff produced by the cavern mining operations for the various stations. With the TBM done, does that mean that there's no more need for the tower that's now been there for a couple of years? Does that mean it'll be coming down soon? What about the other structures that were there mostly to support TBM operations?

Is the backfill of the top of the launch box part of the tunneling contract, or the 96th Street Station contract? At what point will the area about the launch box be handed over to the station construction crew?

The Launch Box said...

Let me try to answer a few of the questions in the comments:

Surface Level Construction:
The best source of information is the new MTA Long-Term "Construction Look Ahead Map" on this link:
e.g from this map one can see that the 83th Street access shaft will be there until at least 1Q2014.

Surface Conditions above the Launch Box:
There will most likely be a fair amount of surface activity for the next few months as they disassemble the Muck Tower (btw. 92nd & 93rd streets) and the remove the TBM from the site. Once this is done one could expect that there will be far less heavy construction activity - since "all" they have to [now] is built the station, from the bottom up.

Backfill over the Launch Box:
My understanding is that this is not part of the current tunneling contract. This will be done after they build the 96th Street station.

Handover of Launch Box Site to the next contractor:
The current contractor (S3 Tunnel Constructors) will handover the site to the next contractor early next year.

Hope this helps a bit.


rgp1121 said...

Thank you for this post. The work is amazing. It really puts this effort into perspective. The pride and the hard work of many really come through in the photos. I, for one, have a bigger and better appreciation of this project.