The Caucasian. (Shreveport, La.) 1900-192?, 1910-08-16
TUNNEL PLANNED
ON CHANNEL BED
Novel Engineering Feat An
nOunCed In New York.
CONNECTS TWO ISLANDS.

Staten island and Brooklyn Residents
Will Have Not Only Tubes For Cars,
but Carriage Road as WeII--Year Re-
quired to Construct Novel and Pre-
tentious Marine Driveway.
New York's latest plan to tunnel I'M
der the Narrows by laying tube on
| instead of under it's bed and SO con-
meet Staten Island and Brooklyn has
surprised and interested tunnel ex-
perts 1t was new way of tunnel
building, but they admitted that it was
feasible, provided a sufficient depth of
water for navigation was left over the
| tunnel
At the point where the New Jersey
and Staten Island Junction Railway
company proposes to build the tunnel
| in the Narrows the de 9TH at mean low
tide is declared to be fifty-six feet. AS
the tunnel is not expected to rise
above the bed of the Narrows more
| than eleven feet at any point, this
would leave depth of at least forty
Eve feet.
There can be no possible interfer
ence with navigation" said Stephen
Nc. Hoye, president of the company.
Even if the depth over the tunnel at
mean low water was only forty feet it
would still be deep enough to allow
| the very largest ships that win be
built to pass over it in perfect safety.
There are to be larger ships f1oated
| than are now being navigated, it is
true, but they will not be built deeper
than they are. but longer and with a
| greater beam.
| Grade Too Much.
! "The franchise permits us to build
tunnel under the Narrows from Staple
ton, In Richmond county, to Eighty
sixth street, Brooklyn. On the Brook
| lyn side the bluffs rise some fifty feet
above the water. Now. the depth of
water at low tide off Eighty-sixth
street is ffty-six feet 1t can be seen
at what depth we would have to lay
the tunnel to place it under the bed of
the Narrows 1t would mean d grade
at the shore ends Of at least four de
grees, which would make the under
taking inpracticabIe.
Our franchise permits the building
| not only of a railroad but a post road
under the Narrows The value of
post road in tunnel would at first
glance appear absurd, but the man
who drew up the application for
franchise was farseeing. 1t needs lit
| tie thought now to see the value of
such road in view Of the vast mum
Der of autos in operation in New York
Our tunnel will not be entirely upon
the bed of the Narrows. In places the
level of the tunnel will sink below that
of the bed of the strait.
Tt is a well known fact that spiles
under water do not decay. 1t is where
they are exposed part of the time to
the air that they disintegrate Now,
we propose to build this tunnel by
first sinking double rows of spflcs for
the side foundation walls of our tun-
mel. The tops of these are then sawed
off under water and the spaces be-
tween filed with concrete
Building Tedious Work.
Next we build the upper halves of
the tunnel in sections. These upper
halves will consist Of inner and outer
frames Of steel filed IN between with
concrete, aud each section when com
pleted will be foated and with the
water end closed viii be sunk to its
position, the sides Of the upper sec
tons resting on the spiles and concrete
foundations.
Probably the shore ends of the up
per sections will be placed first The
water end of these upper sections will
be closed, and there viii be tempo
rary floor in each, so that the water
can be pumped out and allow workmen
to enter.
Then the water end OF the lower
part of the tunnel under the upper
section viii be closed and the water
pumped out This viii allow the work
men to cut through the temporary
floor Of the upper section and cut
down the floor foundation spiles to the
depth they wish.
When the under water part of the
tunnel is done, which it will be III
about year from the time work is
started, we will have tunnel with
approaches of less than one per cent
grade. IN Brooklyn the tunnel will
connect with the Fourth avenue sub
way now being built