Monday, February 7, 2011



Updated (10:00 p.m.)

Second Avenue Subway TBM Run No. 1 (the west tunnel) was completed on Saturday morning, February 5th at 4:30 a.m.

Workers are now in the process of partially disassembling the TBM so that it can be backed out of the tunnel over the next 4 - 5 weeks.

Once the 485-ton machine is backed out of the tunnel, it will be jacked from the west side of the launch box to the east side of the launch box. Then it will start Run No. 2 (the east tunnel).

The plan calls for the TBM to mine the east tunnel all the way to the existing 63rd Street / Lexington Avenue station - a distance of 7,840 feet. When it reaches this station, sometime in late 2011, we should expect a dramatic arrival at 63rd Street, when it breaks through the rock into the open air.

The contractor was not able to use the TBM to mine the west tunnel all the way to the 63rd Street / Lexington Avenue station because the radius of the turn at the end of the run would have been too tight for the machine to handle. This curve in the west tunnel will instead be mined using traditional methods, i.e. with explosives.


The MTA issued this press release on
Monday, February 7th with the news:

Excavation of West Tunnel for Second Avenue Subway Complete

The Metropolitan Transportation Authority (MTA) today announced the completion of the excavation of the west tunnel for Phase I of the Second Avenue Subway. To achieve this major milestone, a tunnel boring machine (TBM) mined 7,612 7,162 feet. The 485-ton, 450-foot-long machine began mining in May 2010 from 92nd Street and will now be disassembled and pulled back to 92nd Street where it will start its second run this spring to mine the east tunnel. The subway line is on schedule to be completed by December 2016.

“Construction of this much-needed subway continues to move forward and this week marks another major accomplishment to transform New York as we know it,” said MTA Capital Construction President Michael Horodniceanu. “These are tangible results that will not only expand our capacity but will also bring new economic activity and growth to Manhattan’s Upper East Side and points beyond.”

Phase I of the Second Avenue Subway will serve more than 200,000 people per day, reducing overcrowding on the Lexington Avenue Line and restoring a transit link to a neighborhood that lost the Second Avenue Elevated in 1940.

When Phase I is complete, it will decrease crowding on the adjacent Lexington Avenue Line by as much as 13%, or 23,500 fewer riders on an average weekday. It will also reduce travel times by up to 10 minutes or more (up to 27%) for those on the far east side or those traveling from the east side to west midtown.

The line is being built in phases, with the Phase I of the Second Avenue Subway providing service from 96th Street to 63rd Street as an extension of the Q train, three new ADA-accessible stations along Second Avenue at 96th, 86th and 72nd Streets, and new entrances to the existing Lexington Av/63 Street Station at 63rd Street and Third Avenue. Further phases of the project will extend the line from 125th Street in Harlem to Hanover Square in the Financial District. The configuration of the tracks will allow for possible future extensions into Brooklyn, Queens, and the Bronx.

The Second Avenue Subway is one of four large-scale projects being built as the MTA undertakes the largest expansion of New York's public transportation system in two generations. The MTA is also connecting the Long Island Rail Road to Grand Central Terminal, extending the 7 subway line to the far west side, and building the Fulton Street Transit Center in Lower Manhattan.


Congresswoman Carolyn B. Maloney followed
later in the day with this News Release:

Maloney Cheers Completion of 1st Second Avenue Subway Tunnel

New York, NY – Congresswoman Carolyn B. Maloney (D-NY) celebrated the news that the Metropolitan Transportation Authority’s (MTA) 485-ton, 450-foot-long tunnel boring machine (TBM) had reached 63rd Street, completing the first tunnel for the Second Avenue Subway. On May 14, 2010, the MTA launched the TBM at 92nd Street. The TBM will now be disassembled, brought back to 92nd Street, reassembled and relaunched to dig the subway’s second tunnel.

“We’re starting to see real progress now that the tunnel boring machine has completed the first tunnel for the Second Avenue Subway. There’s still a lot of work to do, but that light at the end of the tunnel is growing ever-brighter now that this milestone has been reached. I congratulate the MTA and the construction team for getting us this far, and I look forward to celebrating the completion of the second tunnel,” said Maloney.


A recent set of images from inside the
west tunnel can be found on this link:

"A View Down Below - January 23, 2011"


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

(link no longer available)
"NYC Tunnel Tour - Part 1" (4:40)
By Aileen Cho and Luke Abaffy
Engineering News-Record - 1/11

"Freeze Ground, Thaw Hearts"
Engineering News-Record - 2/2/11

"Cavernous Crusades"
By Aileen Cho
Engineering News-Record - 2/2/11

ADI completes her western run under Second Ave.
By Benjamin Kabak
2nd. Ave Sagas - 2/7/11

Notice of Limitation on Claims
Against Proposed Public Transportation Projects

Federal Transit Administration (FTA), DOT
Federal Register / Vol. 76, No. 11 - 1/18/11
This notice announces final environmental actions taken by the Federal Transit Administration (FTA) for Second Avenue Subway Project. The purpose of this notice is to announce publicly the environmental decisions by FTA on the subject projects and to activate the limitation on any claims that may challenge these final environmental actions.


jmp said...

How does this compare to the various schedules, or did they not specify the breakdown between the first and second TBM runs?

Does the process of mining the caverns for the 72nd street and 86th street stations have to wait until the TBM has passed those stations for the second time, will the mining start ahead of the TBM and leave space for the TBM to still tunnel through rock, or will the TBM just pass through the station caverns in progress?

Anonymous said...

"This curve in the west tunnel will instead be mined using traditional methods, i.e. with explosives."

Did the MTA verify this? I ask because a chart presented by the MTA at the CB8's Second Avenue Subway Task Force meeting on 2/15 states:
"The West TBM ended its run just south of 65th St at 2nd Ave.
The first TBM run (West) does not connect to the existing 63rd St station. That will be accomplished by East TBM run which will start later this spring."

Awesome pictures!

The Launch Box said...


Mining of the 72nd Street station cavern has started.

For the moment the contractor (SSK Constructors JV) will only be blasting out the top portion of the 72st station cavern -- so the TBM can mine through solid rock when it passes the area (again) later this year.

SSK Constructors will mine the 72st Street station cavern down to the floor level of the track tunnels after the TBM has completed the east tunnel.

The Launch Box said...

It is still my understanding that the west tunnel will be extended from 65th Street to the 63rd Street/Lexington Avenue station by the 72nd Street station cavern contractors (SSK Constructors) using traditional drill and blast methods. i.e. not with the TBM.

If/when I confirm a change in this plan I will post the news on the blog.