The true northerner. [volume] (Paw Paw, Mich.) 1855-1920, 1872-01-12
The Detroit River Tunnel.
From the Detroit Post.

InOugh out comparatively little men
ton has been concerning the progress of
the Detroit River tunnel, the work has
been going on as rapidly as circumstan-
ces would allow. What has been done
and will be done is this:
The water front adjoining the Ferry
Great Westerns slip was chosen. Then
commenced the process Of forming
land. a large coffer-dam, about forty
feet square, was constructed. Immense
piles were driven down, in double rows,
upon which were securely bolted six
inch planks also in double rows, thus
making an immense box, or sheathing,
Of wood, foot thick. Hard blue clay
was then filled in and a solid pier con-
structed. Through this newly-made
land the shaft is to be sunk.
The shaft itself is a massive one of
iron, weighing eight tons. It's diameter
is fifteen feet, its thickness nearly two
feet. The water was found to be about
fifty feet deep, and the shaft to be sunk
a distance of over fifty feet before the
drainage tunnel will be commenced. 1t
has been placed in position, and upon it
the brick work has been built TO a
height Of ten feet. The great weight
OF the iron base and the additional
weight of the brick work will gradually
sink it to the required depth. The real
difficulties commence when the bottom
is reached. The first movement then
is to eXcavate the drainage tunnel.
This will be % feet lower than the main
tunnels at their respective entrances,
and will lie between them. From both
the Detroit and Windsor sides this tun-
mel will approach gradual elevation to
the centre, at which point it will be
but slightly below the main tunnels. 1t
will have a diameter Of five feet and be
connected with the others by iron
pipes.
The construction of this drainage
tunnel will be comparatively easy,
though, of course, the surveys and cal.
culations must be made with great
accuracy. This part of the work will
be rapidly pushed forward, and will
doubles determine in great measure
the further progress of the undertak.
| ing.
The two sections of men at work un.
der Lake Michigan, while constructing
the famous lake tunnel at Chicago
came out within an inch or less of the
place calculated by the engineer. That
undertaking was, however, small and
easy compared with the present one
Here it is deemed necessary to con
struct two tunnels for the trains passing
both ways. There is also possibility
OF getting into a strata in which there
is quicksand. Then as the upper part
of the tunnel is to be within twelve
feet of the river bed, there will be an
enormous pressure as the excavations
are made.
These and other contingencies must
be provided for, and the magnitude oil
the work and difficulties in the way car
hardly be sufficiently appreciated.
The fame and well.known skill o
Mr.. Chesebrough as civil engineer
gives C nfdenc in the success of the
undertaking. Mr.. Chesebrough is also
City Engineer of Chicago, whose lake
and river tunnels are widely celebrated
The other engineers are Mr.. +. S
Chesebrough and Mr.. E. C. Clark, un
der whose direct charge will come tn,
details of the work upon the tunnel
and who are both men of ability anC
experience.