Port Tobacco times, and Charles County advertiser. (Port Tobacco, Md.) 1845-1898, 1873-04-24

millions Of dollars. So many condi-
tions enter into the estimate that it is
almost impossible to arrive at any cor
rect result. One heavy item has been
the damage to buildings on Wilson
streets and the streets intersecting. AL
though the excavation did not come
near to the foundations of the houses,
yet it disturbed the normal condition
Fof the underlying ground, and many
cracked and sunken walls are to be seen
between Madison avenue and Pennsyl-
vania avenue. Another difficulty that
required much engineering skill toover
come was the drainage. Little streams,
of water came trickling down through,
the rocks at frequent intervals, and to
provide aqueducts for all these was no
inconsiderable matter. A city sewer
was tapped at the intersection of Nc
Culloh and Wilson streets, which for
a time presented most difficult prob
lem to the engineers, and the property
oweners of the neighborhood were
greatly alarmed lest the drainage.
should be interrupted. The joint Com
mittee on Highways of the City Coun-
Gil was also somewhat exercised over.
what seemed to be a "crisis," but hap
PLY the engineers solved the difficulty.
The diameter of the sewer was four
and a-half feet, and the fall nine in
ches in one hundred feet. The ques-
tion was how to get this sewer over or
under the tunnel, and still preserve e.
nough of fall to discharge the water.
A new section of sewer was construct
ed, six feet in diameter, which was car
ried along on the launches of the tun-
mel, with fall Of three inches to the
hundred feet (the diameter having
been increased, the fall could be pro-
portionately lessened) until it reached
the intersection of Morris alley and
Wilson street. At this point it had
reached an elevation which permitted
it to be carried across the top Of the:
tunnel, and thence eastward until the
sewer was reached at the intersection
Of McMechen street and Morris alley.
It will be seen from this that the rail-
road company did considerable sewer.
4O4 U11C C1Uts
In building the tunnel about four
teen millions of hard burned brick
were used ,inta rning the arch, and
lenty-fyet housand tons of CockeysvilIeo
limestone in putting up the side Walls.i
The transportation of stone from the
quarries, thirteen miles distant, was in
itself a heavy undertaking. The blocks
were lifted from the cars with derricks,,
and dressed ready for putting ZIP be-
fore they were taken into the tunnel.
The process of construction is too COM
plicated to admit of description in this
articleexceptin the most general terms
The work was divided into sections and
a shaft sunk to the proper depth at,
the beginning of each section. From
these starting points excavations were
made in both directions, the debris be-
| ing brought back to the shaft and lift
ed out by means Of elevators worked
by steam. Small cars were used which
were pushed back to the shaft on tenn
porary track, lifted to the surface by
the elevators, and then hauled away
on another track to whatever point on
the outside needed filing up. The ex-
cayation has cribbing of stout hick-
ory logs, which very probably would
have made the tunnel safe for some
years without any stone walls or brick
arch. AS soon as section sixteen feet
long was excavated, a sort of wooden
arch was constructed, the logs being
placed longitudinally, each section O.
verlapping the other four feet thewhole
being held up by strong props. Every
thing being made safe for the work.
men in this way, a section of twelve
feet of the tunnel was built, then the
props were knocked out, the forms O.
yer which the arch is turned, techni-
cally called 'centres," and the staging
were moved forward twelve feet, and
new section begun. This, of course, 7
only applies to that part of the tunnel
where the surface ground was not re-
moved. In some places the excavation
was carried down from the top, and in
these sections the work was of course
less complicated. ,5
The daily average of men employed
On the work is about nine hundred
We believe that only four men have
thus far been killed, and each of these
lost his life by an accident, the result
of his own Indifference to danger and
want of .forethought. Seventy-five
thousand cubic yards of rock were
blasted out, but no accident occurred
from this cause, nor from the falling
of any portion of the excavated earth
or rock. One fine day last week we
walked through the tunnel from the
intersection Of Madison avenue and
Wilson street to the entrance near
Charles street avenue. The walk is
not commended as particularly pleas
ant, on account of the active operations
now going on in breaking stone for bal
lasting and putting down the track,
but no one can take it without being
impressed with the magnitude of the
work, and the skill, energy and capital
expended in carrying it through. The
contractor, Mr.. Thomas Rutter, has
become famous as a builder of tunnels,
and this last one is not the least of the
subterraneap monuments of his genius.