The morning news., 1891-12-12
A GREAT TUNNEL.
The One Just Completed Under the
St. Clair River

The One Just Completed Under the
st. Clair River.
TICoNDERoGA, N. Y, Dec. list. Clair
river is the connecting link between Lakes
Huron and Ontario and floats every year
tonnage equal to, if not in excess OF, that
entering the harbor on New York city: and
it Is also on this river that Detroit is located,
which is tho terminus of many extensive
lines OF railways from the north, west
and south. On the eastern shore of the st.
Clair river is the terminus Of the
many Canadian systems Of railways, and
for many years the presence of this large
body of water, interfering with the easy
trauspoI tetion IT heavy freight, has been a
great hindrance, and men became tired OF
using boats as a means of transferring the
loaded cars; hence some other means was
necessary, and as bridging was not prac-
ticable, tunneling was decided on and in
1886 the st. Clair Tunnel Company was
formed. Work was not begun for three
years, or until August, 1889, and in August
1880, or Just one year from the time work
was begun on the tunnel, connection was
made between Canada and the United
States under the ST. Clair river and at the
end OF the secocd year. or on
Sept. 49,, 1891, the entire WORK
was finished and trains were sent through
the tunnel, marking the completion of one
Of the greatest engineering feats OF this re-
markable age. All who now go from our
eastern cities Co Chicago by what is called
the North Shore Limited" pass through
this tunnel The master mind in charge of
the construction of the tunnel was Joseph
Ho6son Of Guelph. Ont, Canada; and
while engineers familiar with such work
advised against undertaking the
scheme, almost without all exception,
he stood out advocating the building
OF the tunnel, and 1t was eventually placed
In his hands and built after his own ideas
and under his full charge; and what is
more remarkable, for less money than 1t
was estimated to cost, and for such great
undertaking, in most remarkably short
time. The process used in the excavation
was the so-caIled Beach shield, an inven--
ton Of Alfred E. Beach OF
this case being modified by Mr.. Hobson 70
suit the work he had 10 do. This shield
wos formed Of steel plates 16 feet long, se-
curely fastened together, each plate being
one inch thick. The plates thus fastened
together formed, what might be termed.
large sharp edged pipe 81 feet inches IN
diameter. Two of these shields were
placed some fifty or more feet below the
surface Of the ground; one on the Cana
olan side Of the river and one on the
American side. 1t was then the active
these shields were placed at regular
intervals twenty-four hydraulic rams
eight inches in diameter, with
Z4-lnch stroke. Force was delivered
20 these rams by Worthington pump ca
paole or delivering o pressure OF 5,OO0
pounds per square inch, or 3 900 tons when
aA twenty-four rams were all used at once,
though in practice only one-third Of this
power was delivered on the work. The
rams were 80 connected that they could be
USED separately or all at once as the work
seemed to require. The entire work was
carried on without any openings to the
air except those at the ends
where the shields entered, and it
quite remarkable in this respect. The tun-
nel is 2,3lO feet under the river, and with
the approaches at each end, is over $4,000
ieet long; the entire length of the tunnel
oeing $3.50 feet; the balance Of the distance
nelng deep open cuts. Ventilation is OBJ
talned by two tubes, 20 inches in diameter,
through which air is forced by two large
blowing fans Lighting is by means OF
e,ec' c'rlclty, and trains are taken through by
sne eaviess and most powerful loco
motives ever built The lining
OF the tunnel is composed of seq
ssr-sge-T~ cast iron, securely fastened to.
%~sIer, which were placed in position as the
work progressed; the usual cir locks and
similar fixtures being dispensed with. The
work was estimated to cost So, 00C. 900, but
Is said to have been completed for $780,
wv The completion Of this work marke
hIs Joining OF TWO parts OF O railway sys'