Bismarck daily tribune. [volume] (Bismarck, Dakota [N.D.]) 1881-1916, 1910-08-18
Tunnel PLANNED.
ON CHANNEL BED
t'o;e| Engineering Feat An
nounced N New York.
CONNECTS TWO ISLANDS.

Staten Island and Brooklyn Residents
Will Have Not Only Tubes For Cars,
but Carriage Road 40 WsII-Ysar Re-
quired to Construct Novel and Pro-
tsntious Marine Driveway.
New York's latest plan to tunnel I'M
der the Narrows by laying tube on
instead Of under its bed and so con-
meet Staten Island and Brooklyn has
surprised and interested tunnel ex-
perts. 1t was a new way Of tunnel
building, but they admitted that it was
feasible. provided 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 depth at mean low
tide is declared to be fifty.si1 feet. Az
the tunnel is not expected to rise
above the bed of the Narrows more
than eleven feet at any point, this
would leave a depth of at least forty
FIVE feet.
There can be no possible interior
ence with navigation" said Stephen
M. 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 will bs
built to pass over it in perfect safety.
There are to be larger ships doated
than are now being navigated, 1t IL
true, but they will not be built deeper
than they are, but longer and with .
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
Ign side the bluffs rise some fifty feet
above the water. Now, the depth Of
water at low tide of Eighty-sixth
street is fifty-six feet. 1t can be seen
at what a depth we would have to lay
the tunnel to place it under the bed Of
the Narrows. 1t would mean a grade
at the shore ends of at least four de-
grees, which would make the under
taking impracticable. u.s. -,
"Our franchise perm... I. building
not only of a railroad but d post road
under the Narows. The value Of q
post road In a tunnel would at first
glance appear absurd. but the man
who drew up the application for q
franchise was farseeing. 1t needs lit
tie thought now to see the value OF
such a road in view Of the vast num-
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.
1T Is a well known fact that Spiles
under water do not decay. It 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 spiles for
the side foundation walls Of our tun-
mel The tops Of these are then sawed
of 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 filled in between with
concrete, and each section when COM
pleted will be floated and with the
water end closed will be sunk to its
position, the sides Of the upper sec.
lions 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 viii
be closed, and there will be tempo
rary floor in each, 20 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 will be closed and the water
pumped out. This will allow the work
men to cut through the temporary
floor Of the upper section and cut
down the floor foundation spiles to tho
depth they wish.
when the under water part Of tho
tunnel is done, which it will be In
about a year from the time work u
started, we will have a tunnel with
approaches Of less than one per cent
grade. In Brooklyn the tunnel viii
connect with the Fourth avenue sub
way now being built"