Sunday, July 5, 2009

July 5, 2009

93rd, looking south
These signs have been setup in preparation for the "controlled blasting" that is planned for the southern end of the work zone (between a point just south of 92nd and a point just north of 93rd.)

The blasting, which will be supervised by the New York City Fire Department's Explosives Unit, is necessary so that bedrock that is currently inside the launch box can be removed. (For those interested, the regulations that govern blasting in New York City can be found in NYC Fire Code Local Law No. 26, Chapter 33.)

btw. 91st and 92nd streets, east side of street
This generator was setup about 3 weeks ago to provide power for lighting and other equipment that is being installed under the road decking.

near the SE corner of 92nd
I've heard that this square hole, in the deck of the launch box, is technically called a glory hole. (In this image the hole has temporarily been covered with two large steel plates.)

There will be 3 glory holes (1 at this location, a 2nd between 92nd and 93rd, and a 3rd [I assume] just north of 93rd]) in the decking over the launch box. The contractor will use these holes to remove the dirt, muck, rocks and other material from the launch box below -- and I assume that the tunnel boring machine (TBM) will be lowered into the launch box, in parts, through these holes.

By the way -- the project manager for S3 Tunnel Constructors announced at the last Community Board 8 Second Avenue Subway Task Force meeting that he expects that the TBM will be drilling it's way south to 63rd Street by the end of the year -- and that the planned rate of progress for the TBM, once it starts working, should be about 1 linear block per week.

92nd, looking N
An example of an access hole through the street decking. Note the protective steel cage that has been erected over the hole, to keep people and objects from falling into it.

btw. 92nd and 93rd streets
I believe that the tall object in this image is an exhaust fan. It will be used to provide air circulation in the cavern, under the street decking, that will become the launch box.

near the SE corner of 93rd
Work on the road decking continues on the east side of the work zone. The contractor has only about 100 linear feet of decking left to install, between a point just south of 93rd and a point just north of 93rd. At the rate they are going, the entire surface of the launch box will be decked over in just a few weeks.

btw. 93rd and 94th streets
Since this picture was taken, about a week ago, all of the decking has been installed in this area.

95th, SE corner - looking W
Here the contractor is working at the north bulkhead of the launch box.

96th Street, SE corner - looking N
And here you can see that the slurry mixing silos, that were across the street here, have now been removed. This location, at the moment, is being used to store various pieces of construction equipment.

97th street, SE corner - looking W
Century Lumber is still in operation at this location -- but as the sign suggests, they will be moving soon - to make room for the ancillary building that will be built on this site.

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

"A Review of Entrances and Ancillary Buildings of the Second Avenue Subway: a presentation prepared by BJF Planning"
CIVITAS presentation to the
Community Board 8 Second Avenue Subway Task Force
on 6/29/09

"Second Avenue Subway - A Status Report"
DMJM Harris | AECOM - 17 pages - 6/13/08

Contact Details for the MTA's Second Avenue Subway Project Team
(i.e. if you want to call the Second Avenue Subway Hotline, get on the mailing list, or send the Project Team an e-mail.)


jmp said...

I'm curious about the generator on site. Is it really more efficient and/or cost effective to run a generator at the construction site than to get the power directly from the grid? With all the utility work that's been going on around the project, I would assume that getting access to power lines would be trivial, or is there some safety reason to have a generator rather than a tap from the grid?

Ben said...

It could be that the generator, btw. 91st and 92nd, has been setup to temporarily supply power to the site -- until a fixed connection to ConEd's network is established.

I remember that for the longest time a generator was used to supply the power to the 32 story building on the NE corner of 1st and 92nd that was put up a few years ago -- even after most of the construction was completed.

I'll see if I can find out the answer.


Ben said...

Here's what the MTA told me about the generator:

The generator at this location is only expected to be there for about a month or so. ConEd supplied electrical power will be used just as soon as the excavation under the deck goes deep enough so that there is space for the permanent power panels.

Also, the generator will only be in operation during normal work hours, when work is on-going under the deck.