Wheeling register. [volume] (Wheeling, W. Va.) 1878-1935, 1890-08-27
GIGANTIC TUNNEL.
A REMARKABLE TRIUMPH OF ENGINEERING
AT PORT HURON.
Al Underground Passage Between the Dominion
and the United Sates-The Immense Value
Of tie Schsma-Ihe Wgkmen Meet
in Mid-River.

PORT HURON, MICH., August 26.-The
longest river tunnel In the world, and
the most daring piece OF engineering
in this country, was completed here yes
tCrdaY morning. For 10 months coo
men have been silently and ceaScleSsly
digging under the ST. Clair river, and
now the world sees the completion of an
underground passage through mud.
quic6sand and powders, between Can
ada and the United States, working al
most iuestimable value TO transconti-
mental shipping, and abolishing the
slow ferries and attendant annoyance
90 travellers between the Northwest and
the East
IL is built under the supervision of
the Canadian Government, IS owned by
private company, has no double i'm
the world, and, in many ways, is
marvel.
The length of the tunnel from the be-
ginning of one approach to the end of
the opposite side is =. 600 feet, G,OOO of
which are wholly underground, with
2.3l0 feet under the river, ., 800 under
Michigan land, and 2.16O under Cana
dian. 10 is entirely a unique conStruc-
ton, built exclusively of iron, without
stone or brick i'm il. IL is simply an
iron tube made of plates; 5000 feet
long and 30 feet in diameter. perfectly
round and water-tight; rs dry as a
street in summer time. lighted by cleo
tric light, ventilated by air engines,
aud kept at the right temperature with
steam pipes.
The method of construction Is simple.
Tho shield, SO called because il contains
the men who do the digging and con-
Stantly protects them from danger, is
entirely unique, and has but TWO prOtO-
types I'm the science of civil engineer
ing.
Its success has been marvellous beyond
expectation. aud two of them working
from opposite sides of the river toward
each other have completed 5000 feet
within little more than years time.
10 is am immense cylinder OF the dame
Ter OF the tunnel. In the present in
stance 90 feet and l6 feet I'm length. Ii
is built OF steel plates Stauuchly braccd
inside with great timberS.
The plates which form the tunnel are
of such curvature and length. that l3 of
them with % key piece. form the 20-foot
circle. They are about Is inches wide
and weigh 1850 pounds each. The ends
and sides OF the SegmcutS are turned
mp. each one is bolted % its neighbor,
making the tunnel practically one piece.
This simple method of blowing into
the clay and digging 10 out. handling it
with ears aud dcrrickS, as i'm all cNca-
vatiouS, was used until the 2,3lO-foOt
section was reached. Here the water
began 90 pour in upon men. But this
emergency had been anticipated. and
the compressed air was turned ON. a
solid brick wall eight feet thick having
been built across the tunnel 1000 feet
from the opening.
Through great tubes four immense
engines pumped air into tank, and
thence into the air-tight section of the
tunnel until the pressure was 30 pounds
90 the square inch. Il proved TO bc
deadly process. and three men died in
quick succession. The horses drawing
the ears died after two days service.
Finally the men We're put under mcdi-
cal examination, and only one i'm ten
was found who could work under such
an unnatural atmosphere, but mules
were found 90 thrive ON IT, With this
pressure the water and quic6saud were
driven ahead; and the work went ON as
rapidly as before.
The greatest deptho of the tunnel under
ground is - feet. and 10 comes within
ll feet of the river bottom at one point.
Occasionally rift extending To the
river would Doe struck. through which
-he compressed air would rush and
cause the water go boil as a geySer.
Only three men have been killed during
the construction of the work. Its COM
pletion will Dee largely celebrated. and
Sir Henry Tyler, President of the Com
pany. comes from London. England. To
witness the event.
The machinery necessary 90 the con-
Struction. covered several acres. \
complete electric light plant, machine
shop. air engines and pumping stations,
hosting engines and boilers, steam
heating apparatus and many other con-
tr'vauccS.
The effect on transportation between
Canada. the East aud the Northwest,
will Dee of immense value. IL will re-
.duce tine time enroute several hours and
does away with tine slow and cumber-
some method of ferry transp ortation ON
1.-The roads passing through this section
.of the country. Il will bee leased 20
.othcr lines. for consideration and even
ually will bc used by at least four great
railroads 10 means much to shippers,
who are watching with interest TINS
hold and trftrauffc experiment.