Butler citizen. [volume] (Butler, Pa.) 1877-1922, 1904-09-01
A Great Exhibit.

The Pennsylvania delegation to the
Worlds Fair had four great days in st.
Louis. last week, and the delegates
were greatly interested III the Pennsyl-
vania railroad display. Seven govern
ors of States have visited this section Of
the Transportation building, aud a
number of representatives, have been
sent by governments abroad. Over 500
Pennsylvanians have called and per-
sonally asked to have the exhibit ex-
planned to them. Its two principal
features are testing plant for loco
motives, and plan and section of the
new tunnel which is being built from
Bergen Hill, N. j., under the Hudson
river, under New York city. East river
and Long Island sound-the greatest
piece of engineering ever attempted in
the United States. A cross section and a
plan at the fair show the exact con-
struction Sitting in the section one
can see how it would seem TO ride
underground The safety of the gi-
gantic enterprise appeals to engineers,
and to people who have never seen any
thing like this before. There is a walk
on either side of the train, and hand
rail There is hose protection in case
of fire, and little inches and iron stairs,
which one could use as refuge in an
emergency If the train should get off
the track it could not go far-ten inches
on either side
After seeing the section the first
question everybody asks is: How can
they possibly build it SO far under the
river bed? As the manager of the dis
play explains, it is built in sections by
what is known as the shield method
The shield is a steel ring little bit
larger than the tunnel and about 20
feet long. 1t is a circular wall with
doors in it about five feet from the cnt-
ting edge. This shield is forced right
through the mud or silt under the
river by about 30 or 40 hydraulic jacks
which react back against the tunnel
which has already been in the solid
ground. The mud is forced out OF the
way and in most cases follows the line
of least resistance. After the shield
has been pushed forward three or four
feet. ring of the tunnel is built inside
the back of it. This is done by means
of two big hydraulic arms which pick
up section at time and hold it in
place while the men bolt it on. These
sections are six feet long and weigh
ton.
The tunnel is made water-tight by
means of rust calking, which is com
posed of steel filings and chemical
mixture. 1t simply cements into the
iron iron and becomes part of it.
After the iron part Of the tunnel is
built. false caps are removed from the
bottom and screw piles are forced down
by hydraulic pressure until they rest on
solid-rock These screw piles are put
down and boited together by means of
flanges on the inside. They are Is feet
apart. with 13 feet steel girders be-
tween them. These run the full length
Of the tunnel and carry all of the load,
of the train, the tunnel simply acting al
a shield to keep the mud and water
out.
The iron is protected from rust on
the outside by means of cement
grCut, which is passed through small
holes, one of which each casting has for
tniS phIDCoc, ne IS DTOitCbtu
by concrete, which also acts as a protec-
lection to the tunnel in case the train
should get off the track From the
bottom of the tunnel tho concrete is
filled in until it reaches almost to the
winow sills of the car, making a wall
on either side of the track Along
these sidewalks for 80 they lock -one
may go the whole length Of the tunnel
This wall comes within ten inches of
the car. Along this wall or sidewalk is
hose protection which looks exictly
like a hand rail. 1t is threeinch
water pipe three feet above the wall
The tunnel is little over mile long.
and is part Of r system Of tunnels seven
miles long which will cost $4,000, 600.
and will give the road direct entrance
to New York city. The exhibit at the
fair gives u concise and accurate idea of
this biggest piece Of engineering in the
world.