New-York tribune., 1922-11-22
Concrete Pipes
For tunnel Put
I'm Hudson Bed
Engineers Score Triumph i'm
Underwater Work: Tubes
Filled and Cut Off IlOI
Feet Below River Level

The New York and New Jersey
vehicular tunnel engineers, under
Chief Engineer Clifford NJ Holland,
and experts under the direction OF
Booth & Finn, the contractors, have
scored an engineering triumph in
building large foundations under water
with concrete piles. They completed
yesterday the driving Of thirty-nsne
24-inch steel tubes ESQ feet through
silt to bedrock on the New Jersey side
of the Hudson, pumped the silt out OF
the tubes, filled many of them with re-
inforced concrete, cut them off 110 feet
below high water and capped them, so
that they are like tiles in floor, ready
for huge steel caissons which will be
part of the two ventilation shafts of
the twin tubes between Canal Street,
Manhattan, and Jersey City.
The 24-inch steel pipes were sunk
one by one in sections twenty feet long
through the silt to bedrock, each added
length being screwed on to the one be-
low. Many experts on subaqueous con-
struction predicted that the screw
threads never would stand the pound
ing necessary to jam the 24inch pipes
through the silt, but in this they were
mistaken, as the work went on without
= hitch and one foundation is nearly
completed The cutting Of the pipe 10
feet below the surface Of the river was
done with cutting tool working from
the inside of tie pipes.
Two Of these underwater founda-
tions are being built with forty-two of
the 24-inch steel-skin reinforced con-
crete piles for each Of them. Only
three more tubes are to be sunk to
bedrock in the hrst foundation.
Chief Engineer Holland announced
a.. u
for the ventilation shaft on the New
York side Of the river opposite Canal
Street will be finished by the Staten
Island Ship Building Company the
first week in December, and that its
launching and installation will take
place Immediately following. The
caisson is a steel box, with double
walls, 93 feet long, 65 feet high and
3D. feet wide. Mr.. Holland said that
at 8 o'clock yesterday the contractors
had completed seventeen and one-half
feet of actual tunnel. with the big
thirty-foot rings bolted together, and
everything as it will be at the time
three years hence when 10000 vehicles
will be passing through the twin tubes
every twenty-four hours. What is
more. the contractors have got the big
shield, from which they slowly drive
the tunnel work, through the most
ticklish spot of the construction on
the New York end, and all hands are
breathing easier on account of it.
In order TO get out into the made
ground off Canal Street. the 4oOton
shield, with It's hydraulic machinery,
WAS showed through fivcfoot thick
steel concrete caisson wall on the
Canal Street end, and on account of
the unprecedented weight of the
~ so5I a
lit struck the soft made ground on
the QUITE side of the caisson wall it
would drop down from it's own weight
and "hicIl up'' at the rea, end against
the casson wall. # this had oc-
Cured it would have destroyed the
caisson wall and the shield as we'll
The big shield stood up, and all is
we'll.
| In order TO make sure that there
shall be no leak, or variation, in air
pressure due to bad "roof," the con-
tractor has emptied into the slip run
! ming into the river at Canal Street
100000 cubic yards Of clay. This they
call protective blanket" The tun-
now is in made ground Of uncertain
| character. From one weeks end to
| another the workmen do not know what
! they will encounter. They are prepared
for anything, from old scows filled
with rock to forgotten wood piling.
| They struck some of the latter this
week.
The tunnel building is going forward
now at the rate of about two and n
half feet a day. They will soon make
it five feet day, and continue this
! gait until they strike the solid rock
next May, and they will continue in
| the rock for full year, with slow
l progress.