The Weston Democrat. [volume] (Weston, W. Va.) 1875-current, 1875-02-15
TuSSEIISG THE HUDSON.
Tue EuEinesrs' Plan for Overcoming OBJ
acknowledgements Air Put TO n New
and Valuable Use.

Tue RuEineerS Plan for Overcoming OBJ
rtacles--Cenpresse Air Put TO n New
and Valuable Use.
The recent sdundings OF the North
river on the proposed line OF the Hudson
Tunnel Railroad Company, and the tests
made TO ascertain the material through
which ii will BIO necessary 10 work, great
ly encourage Mr. HaSEin, the originator
OF theischeme and president OF the com.
pany. Tha bed Of the river is composed
Of deposits Of river mud, mixed with
gravel, forming n compound which is
known As silt, This deposit forms Il
stratum varying from fifty to seventy
feet in depth, and Is, Mr.. Haskin thinks,
sufficiently cohesive to hold together
without clying while the tunnel isin pro-
cess Of construction. But, nevertheless,
nil precautions will be taken 10 prevent
{ any break-frst, by following the exca-
yation closely with q heavy circular brick
lining, so that at no time will the roof
OF the tunnel bO without a substantial
support OF solid masonry, except for the
four or five feet where the diggers are
actively at work; md, secondly, by stis-
tanning this space Of four ar five feet by
n volume " compressed air enclosed in
the tunnel, aud aiTording q pressure of
from twenty to thirty pounds per square
inch, according to the necessities OF the
Eituation. Utilizing compressed air in
its application to tunnoling is original
with Mr.. Hnskin, and he claims that the
saving in expense will DO enormous.
The old plRn-the ono on which the
Thames funnel in London was con-
atructed-was. to have n heavy, strong
Homework and lining exactly fitting the
excavation, which was pushed forward
2 by screwincks at the very instant that
tho removal Of the earth in front Of It
allowed It TO advance. All this neces-
STATED elaborate andintricate machinery,
which could only be worked ut immense
cost, and also greatly disconnected the
workmen, Consequently the Thames
tunnel cost over $1,000 n lineal foot,
while tho estimated cost of the Hudson
river tunnel is only fraction Of that
sum. The method Of applying the force
of compressed air is also Mr.. HRslin's
device.
After the tunnel has been excavntcd,
arched, and finished for ono hundred
feet, tho opening will be closed again at
the shore end by filling it with bank
OF earth, through tho length Of which
will run mn iron tunnel about five feet in
diameter. This iron tunnel will have ut
each end o strong, close.ftting door, air
tight. Through this tunnel will pass
pipes for the conducting Of the COM
pressed air to the pocketed tunnel, and
also return pipes through which tho ma
terinl excaylted will be forced by the
compressed mir 10 tho surface OF the earth
above. The iron tunnel will also afford
ingress and egress to the workmen en-
plOyed, and also passage for the bricks
and mortar needed for the permanent
arch. OF course this stoppage, or air.
lock, is only temporary, TO be removed
on the completion Of the tunnel. The
brick arch, or rather lining, for it com.
pletely enyelops the tunnel, will average
three feet in thickness, varying accord
ing TO the distance from the roof Of the
tunnel TO the bed Of tho river, which
distance is sometimes fifty feet, and
never less than twenty-five feet. The
line Of tho tunnel runs through layer
OF silt or clayey mud its whole length,
except ut one point about three hundred
feet from tho New York shore, where II
strikes n sand bank. There extra pre-
cautions will be taken, either by con.
strIicting caisson over the weak portion
md pumping the water ont Of It, or else
by using for little while machine
similar to that invented by Sir NJ. T.
Brunei for the Thames tunnel. A little
knob Of ruck is also found near New
York.
The dimensions of tho tunnel will DO
81 feet iii height by 90 feet in width,
sufficient to accommodate double track
railroad, and the length from shore TO
shore will be about 5000 feet. In nddi.
ton tho approaches will on each end be
about half milo long, the one in Jersey
City eomingto the surface somewhere on
Fifteenth street, while tho one in New
York will terminate about twenty feet
underground in the vicinity OF Washing
ton square. On tho New York shore the
tunnel will pass under tho space between
Piers 90 md 81.