New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1903-10-18
PENNSYLVANIA TUNNEL.
Details Regarding Work To Be
Done Under the North RiUer.

some interesting details OF the Pennsylvania
fNallroads proposed tunnel under the Hudson are
supplied in the latest issue OF Engineering News q"
Including the extension eastward to Long Island
Cry. the whole work viii be five and three-ouarter
miles long. and viii probably cost about $50 600 900
he North River division extends from the west
err soe OF Ninth-aNe, this city, TO point on the
west side Of Hoboken heights at North Bergen.
Its total length between these two points is Ii sS1
feet or pa miles. The tunnel structure varies in
character several times in its length. From Ninth
ave west for 65 feet it is four-track subway I'M
Ger q single broad arch The next section, 10eS feet
long. is divided into three pats. the central
being big enough 10 take two tracks. and each
Of the side ones a single track. somewhat Ike
the New-York Central tunnel above Forty second
81 However. there is great difference The
central passage descends more rapidly than the
other two. and its floor is ten feet lower than
theirs at its western end. The side passages ter
inmate there. and are largely for storage pur
poses Only the two tracks in the middle go all
the way across These are first led through q
short bit Of tunnel under a single arch and then
through separate single track tunnels 10 the river
section proper. At the beginning Of this there is
20 be an enlargement for a short distance to ad-
NIT the shields employed in driving the tubes
under the river.
The North River tunnel is considered here TO
comprise all the tunnel coming between the shield
chambers on the Manhattan shore and those on
the Jersey shore Il is all twin tube tunnel. and
is all subaqueous work Two styles of structure
are employed one with screw pile foundations and
one without special foundation
The amount Of tube tunnel without foundation
Is conparatively small Il comprises a section
81 feet on the Manhattan side and section
,eo feet long on the New-Jersey side. Each tube
has an interior diameter OF nearly ten feet, and
provides for a single track and the two tubes are
located or the same level and thirty-seven feet
a-a-t centre to centre The construction differs
from that Of previous cast iron lined tube tunnels
--nciDsIlv in the great thickness and strength OF
the concrete lining
TIE greater portion a the North River tunnel
some 55o feet consists OF parallel cast iron and
concrete tubes carried on a foundation consisting
% i--b e-ev niles SPACED Is feet apart This is
by all ODDS the most novel feature OF the entire
tunnel structure. IN substance each tunnel con-
sists Of a cast iron tube made very sim by means
o. a heavy lining Of concrete. which Is carried on
q row OF piers. each composed OF single sore"
nile OF large size The structure is very simple its
construction however involves some difficult feat
ures The following paragraphs relate to the tun-
neI structure alone
The cast iron lining for tubes proper is Of the
ordinary r,pe except that where the screw piles
occur 4 special segment is inserted Each ring OF
lining IS 30 inches long and is made Up OF twelve
ee--,e--s one being crown Or key segment with
an arc ~ inches long. and eleven being body seq
-,erts with arcs feet 5.64S3 inches long
The New-Jersey land section Of the tunnel be
rms a. the shield chambers on the Jersey shore
80 ev-e-ds 20 the portal at North Bergen This
section Of the tunnel is $50 feet long. and Il
rfe-oes the rock formations OF Bergen Hill Par
a1Iel single track twin tunnels are planned These
tunnels are spaced thrty-seven feet apart, centre
10 centre with q rock core about eleven feet thlch
l..-,.oo- -ba-n Al intervals Of about three hun
z-.7 feet q cross passage correcting the TWO tun-
- ts ,.,- through the rock core. and at these
f.s -re cross passes are enlarged TO form circuit
broken chambers. -,
TIE tunnel has concrete sidewalks and orlcA
fed on
-, .-,,7 concrete is used for the front walls OF
-. -,a,boles. The construction Of these tunneis
s r-r,-.-ned by the same requirements as tHo'e u
:, -. of The Manhattan land section