Monday, June 13, 2011

A Rock and Roll Gantry

Complete with your own gantry.
Excellent neighborhood. Steps away from great shopping and restaurants!
24/7 surveillance! All utilities included but sorry no heat.
Trade your pantry for a gantry today!

Images follow.

73rd Street, NW corner looking S

And here it is, the now-under-construction...
72nd Street Station Muck Conveyance System
a.k.a The Muck House.

Inside this superstructure will sit the machinery that will transport the excavated rock from the underground 72nd Street station cavern to the waiting trucks on the surface. According to the MTA, this innovative muck transport system will reduce noise, dust and emissions at this job site.

btw. 72nd & 73rd streets - looking NE

The yellow section of the structure is the gantry crane that will roll back and forth (north and south) along a set of tracks inside the structure.

72nd Street, SE corner - looking N


A closeup look at some of the steel I-beams inside the structure.



A closer view of the gantry crane. The cylindrical object in the middle is most likely the electric motor for the hoist.


73rd Street, NE corner - looking S

One last view.

I found this structure to be particularly fascinating because of its location in the middle (almost) of Second Avenue.

Clearly the city would never approve the construction of any kind of permanent structure in the middle of a busy avenue in Manhattan.


btw. 69th & 70th streets - looking E

This image shows the current mucking site just north of 69th Street. Rock from the underground work site is lifted to the surface using the diesel crane shown, and then it is dumped into the muck bin on the left.


A closer view of the muck bin.


This is a closer view of the rock and other material in the muck bin. This rock is often called "shot rock" by people in the construction trade. It's called "shot rock" simply because it is produced during a blasting operation. (i.e. after the "shot" goes off.)


This is a truck that this contractor uses to deliver special grades of oil to the machinery on the job site. (Note the nine different coils of hose in the back of the truck, probably one for each grade.)

Workers were oiling a set of generators at this particular location.

83rd Street, just East of 2nd Avenue - looking W

An update: 6/14/11:
I was wrong. The contractor isn't drilling piles for a secant wall at this location.

What they are actually doing is this:
The drill casings you see [in this image and the one below] were used for drilled shafts at this location. The subcontractor drilled cylindrical shafts down to the bedrock, installed steel beams in the center of the casing, and then filled the casing with low-strength concrete. As the contractor digs that shaft down, they will dig out the low-strength concrete to expose the steel beams and then lag between the beams with timber boards.


Another view, this time without the fence. The actual piles can be seen on the left on this image.


A view of a small landscaped area that currently sites just to the north of this work site.

88th Street, NE corner - looking W

A view of a section of cobblestones under the asphalt on Second Avenue.

These cobblestones were only recently exposed when the City of New York started resurfacing large sections of Second Avenue. They were exposed after a layer of asphalt was removed from the road's surface.

90th Street, SE corner - looking SW

Another patch of exposed cobblestone.

90th Street & Second Avenue - looking NW

At 91st Street, I came across this small hole in Second Avenue. The hole, which is between 3 and 4 inches in diameter, was exposed when the city removed the top layer of asphalt.

This isn't just any old hole. This is the hole that was produced when a rock drill attached to the Second Avenue subway TBM broke through the surface of Second Avenue in the early morning hours of July 8th, 2010. (My earlier report on this event can be found on this link: TBM Probe Breaks Ground on 2nd Ave.)


One could imagine that this hole could provide easy access to the east tunnel for any number of creatures...

Sources reported two weeks ago that the city has resurfaced this section of Second Avenue - so the hole is once again no longer visible.

91st Street

The former site of the ground freeze operation - recently cemented over.

97th Street, SW Corner - looking W

A large number of secant pile casings, set up like organ pipes, waiting to be put to use.

near 99th Street

This odd looking contraption appeared on the site a few weeks ago. It is a so-called Travelift gantry crane from the company Mi-Jack Products of Hazel Crest, Illinois. This crane will be used to help build and move slurry wall cages for the 96th Street Station project.


Here's a link to MTA Capital Construction's latest Quarterly Report on the Second Avenue subway. The report, which covers the the 1st quarter of 2011, was posted on the MTA's web site only last week.

Second Avenue Subway, Phase I Quarterly Report
Report Period: 1Q2011 (January, February, March 2011)
MTA Capital Construction
Released 6/7/11


Last Reported Location
of the Tunnel Boring Machine
just south of 81st Street
as of 5/31/11

TBM Run No. 2 (east tunnel)
Tunnel length: 7,789 linear feet (LF)
Starting point: just south of 92nd Street
Ending point: Lexington Av / 63rd St Station
2,842 LF mined as of 5/31/11
4,947 LF to run

May TBM Mining Data:
Distance mined: 1,726 linear feet (LF)
TBM mining days: 21
Avg. distance per day: 82.19 LF

Note in particular the average distance mined, 82.19 linear feet per day, in May. This is far above the planned 50 LF/day that the MTA has been using for scheduling this part of the project.


Anonymous said...


A few comments. First off, the shot showing the east side of 83rd and 2nd is not a secant pile wall as you indicate in the post. The drill casings you see were used for drilled shafts at that location. The subcontractor drilled cylindrical shafts to rock, installed steel beams in the center of the casing, and then filled the casing with low-strength concrete. As the contractor digs that shaft down, they will dig out the low-strength concrete to expose the steel beams and then lag between the beams with timber boards.

Also, the gantry crane at 99th Street will be used to help build and move slurry wall cages for the 96th Street Station project.

Ben Heckscher said...

Thank you very much for your comments. I've just corrected and updated the posting with this new information.

If you wish you can also reach me on the e-mail


Anonymous said...

ben, at that same corner of 83rd, right in front of that odd looking sculpture (in your picture) adjacent to the "Spacious Living" sign, there is a vertical black pipe popping up(visible in your picture) that looks to be a vent.

That vent pipe is coming up from a 30' deep open shaft. It is a disaster waiting to happen.

Take a look if you happen to be walking by.

Ben Heckscher said...

I just forwarded your concern onto Claudia Wilson who is the MTA's Community Liaison at the work site. I'm sure that she'll have someone take a look at this as soon as possible.

You can reach Claudia direction on 212-792-9716 or

I'll have a look next time I'm at 83rd Street.