The Anderson intelligencer. [volume] (Anderson Court House, S.C.) 1860-1914, 1880-07-29
BeiRrNo THE TUNNEL.
How the worlfnen Dig their Way Through
the Mud and are Protected from Danger
Wonders OF Compressed Air.
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IEVHt Wc 1sttV 1OTS 3sWtS.
Piles of hoiler-iron plates,oa Heap OF
bricks and masons' materials, and a col.
lection of low sheds with an ifsnaeusc
| smoke-stack towering above them, mark
the spot at the foot Of Fifteenth street,
Jersey City, where the Hudson Tunnel
Railroad Company have lcomnelced the
mighty work of tuanelling the North
River. The work is we'll under way, and
is being pushed forward day and night,
| with no let-u2 on Sundays or holidays.
already 800 feet Of the tunnel have been
completed, 200 Of which are under the
the river itself, and within C months
time the, workmens will be adding
to It's length ats tie nate of between
four and five feet every twenty.four
hours.
The. method of building the tnnhel is
/ different, it is claimed, from anything
ever tsfore attempted. Thelprfnciple
is adopted of using compressed air
to exclude the water, eyaporate the
moisture of the ALT, so that tha lat
ter, BY being thus dried, can be easily
handled at the heading, and is rendered
less liable to cave in, and TO aid in up.
holding the iron and brick work after
they are placedi in positions. Col. Hnskins
has secnred.a patent ia connection with
the application of this principle, under
which the tunnelling Is beingdo The
land in this yioitiity is largely of einders.,
which have been IflIed ID, fand 10 isssos
porous that when the tunnel was first
commenced there syas q lcopstapt escape
of the air which was forced into the eT.
cavation. This was remedieI by Uufyihg
large sheets of canvas several feet below
The surface ofitliei grouhd. Il TkeI ioWer
the tunnel s'eps, however, the more
compact the filling became, and the less
annoyance wes experienced from this
source. Now that the silt has been pen-
etrated, this difficulty no longer exists.
Tile pressure of. the compressed air now
used In the tunnel about twenty pounds
TO the square inch. The two air com:
pressors are kept running day and night.
They pump the sir into the air-reservoir.
which is Of tough boileT.iron. cylindrical
IN shape and has a, diameter Of five feet
eleven inches. j A'gsnge ct its side ALWAYS
indicates'the pressure Of the air In the
tunhel.i Frons theTe5ervoir the air is
pumped into the tunnel through the air
lock. Upon this supply Of pure air and
a careful regulation of it's pressure the
lives Of the workgn len sand the &ncceas of
the work depend, and d constant eve is
kept upon the movements of the gauge.
fiuger as it balances itseIfunsteadiiy over
the sdial, The tunnel was gradually
pushed downward from the air-iock until
the if6psr ls29l vas reached, instead of
;being commenceS iat the bottom of tive
shaft and continued on tie required level.
This was O Temporary device, and after5
abe work had been thus prose11Sked for az
distance of300 feet the heading Ssas buIk-t
headed, and the workmen, turning in
their trackgyT began toEdig toward the
shatt and to clear away Instructions in
this direction. Heie the grand arch at
the mouth of the tunnel will be built.
Its width will be 80 feet and its height
Sp feet. UponStbis work the men are
now engaged.
There will be, two tuunels thrown,
acroSs the river, each being Is feet wide
and l6 feet in the clear when completed.
They tadjoinione another, but will lie sep
arate and distinct pieces of workmanships
uniting, how ever, under the grand arches
at the working-shaft on either side OF the
river Asingle track will be laid in each,
fspd, sas one of thelnEyilli alwdSs Ssa het slsSd5
IN going iiiand the eotheEin colhia kont Ok
the New York depot, collisions can mover
occur. The approaches to the tunnel
on both sides of the river, .f::ll ba 26 feet
wide and 26feet high in, the clear, and
their Yails are to be of the best hard
buried brick laid in hydraulic cement.
Intkis citytth tracks will not be less
than 10 feet below the surface, and at no
point, when the tunnel is completed will
the anFfdce be- disturbed in the streets
except 'iofientFance to and egress from
the underground depot.
In shape these twin tunnels will be
nearly rouhds Hhns Z Ahai biara cylinders
made of boiler.irona about. % feet ii1 height
and 20 feet in breadth. They are made 4
in sections which are welded together,
and the completed shells are pushed
ahead as faat as the excavations are made.
1helron of one 0fthese cylinders ia. 3-inch
IN fhlcle sss ,..e:.s "A ii.ss s;s arc
2 feet 9 inches in width. Some of them
are 3 feet and othere feet in length.
On eaeir.o of their four sidesare flankes
q inches in width, through which the
plate Is Dolted to every one Of the pIateS
around 1t. The joints are broken as the
: ':.ts. g &c <, sire sire , -
tional ,st1,ength' 70 the cylinder. AS fiat
90 the cylinder Ia advanced The maaon5
follow, nnd line it with a wall of hard..H
y z =, iest nafd cefnents
Az this yRll extends. completely around
the interior It presents the form of an
arch againat any outside pressure, wheth-
er vertical or lateral. -Four classes of
men are ep1pleyed, in building tlie tunnel
--mihers. Seiaets, laborers aud ihasons.
at tho heading the miners advance with
pick and shovel, the yelders bring to.
gether she iron sections, the laborers dis.
pose, of, the diggings. and tho masopa
throw up their Wtiiii. 81 yFs g E !