Shepherdstown register. [volume] (Shepherdstown, Va. [W. Va.]) 1849-1955, 1893-09-01
A BIG UNDERTAKING.
improvements by the 3. and o. Railroad at
Harpers Ferry.

ton. In few months the old Boil
man bridge over the Potomac, which
in its time was one of the most IA
nous bridges in the country, will be
abandoned and trains will skim over
the river on a new double-track
bridge Of modern construction, after
passing beneath Maryland Heights
through tunnel carved out Of the
solid rock. The work, which was be-
gun about var ago, when finished
will make great change in the APP
pearance OF the historic old place.
The Improvement vas made neces-
sary by the wearing out Of the old
bridge, which was built to carry
trains composed of loaded cars of ten
tons each with thirty ton locomotives.
When it was erected the most enthu-
siastic railroad man never dreamed
Of locomotives weighing 10000
pounds, fifty-ton Pullman coaches, or
of freight cars with capacity OF
90, 900 pounds, and bridges were not
constructed to bear such strains.
Trains composed of such tremendous
weights as these pass over the old
bridge every day, however, hardly
making it tremble. The structure
has been strengthened several times
in recent years by putting in massive
wooden trusses and by supports be-
meath its floor. Under ordinary cir
cumstauces these would hold for
years, but experience has shown that
the Potomac cannot be depended
upon.
Perhaps the greatest strain the
bridge ever underwent was in the
spring of 1889, when the Potomac rose
IS feet and wrecked the Chesapeake
and Ohio canal and almost everything
else that was in its way. The water
rose five feet above the bridge floor,
but number Of big consolidated en-
gines were run out on it to hold it
down and against the expectations OF
almost everybody the old structure
remained in place. 1t would hardly
stand another such strain, which
might come in any spring or winter,
and prudence dictated the building
Of the new bridge, at the same time
it was decided to improve tho ap
proach to the river from both east
and west This necessitated a tunnel
through Maryland Heights on the
east side Of the old bridge and the re-
moval of the tracks for about 200 feet
to the south on the west side.
Work was begun on the improve
ment according to plans made by Mr..
w. L. Sisson, of the engineering de-
partment of the Baltimore and Ohio
Railroad. The work started July Is
Of last year, and has been carried on
by Mr.. Sisson and his assistants,
Messrs Philip Aylett and Morris Nit
ten, under the supervision Of Chief
Engineer w. r. Manning and Assist
ant Chief Engineer p. II. Irwin. The
provements began at Sandy Hook,
a mile east of Harper'S Ferry, by ele-
waiting the track from that point to
the tunnel, at which the track is eight
feet above its old level. The drilling
Of the tunnel was begun at both ends
at the same time. The engineers met
with great deal Of difficulty in get
ting their lines for this work. The
mountain was inaccessible for that
purpose on the west side and they
had to triangulate half mile up the
river. In drilling the tunnel Il small
hole about seven feet in diameter was
first made. This was called heading.
These headings are made small as
matter of economy, it being necessa
to drive the drill into the rock hori-
zontally and blast out This is slow
work.
As soon as the headings were far
enough advanced, work on the bench
es Of the lower part of the rock which
had to be taken out was begun, the
headings having given room to drive
the drill horizontally, so that much
larger masses of rock could be blasted
out. The headings were begun De-
cember /, and blasting on the benches
began a month later. The headings
met on the Goth Of July last, being
just one-half an inch out of line.
This is considered something remark
able in the way OF engineering. The
benches were all out on the 10th of
this'month, and the blasting now go
ing on is only TO trim up the rough
places in the tunnel and to make
ready for the east and west portals,
which will be Of masonry, topped out
with brick arches. The tunnel will
be $50 feet long, % feet wide and 24t
feet high. Over %, 900 cubic yards Of
rock were taken out of the tunnel
and 10000 cubic yards were blasted
out in making the approaches.
Work on the bridge piers was be-
gun early in August, and these are
all now practically completed. There
are eight Of these piers and two abut-
ments. They are 30 feet high above
water and stand on four-foot founda-
tions laid on bed rock. In all there
are about $4,000 cubic yards of ma
sonny in the piers and ahutWents, all
OF which are Of Gettysburg granite,
laid in cement. The bridge when
completed will be 40 feet above the
bed Of the river, and the railroad
tracks will be feet higher than the
highest water eyer known in the Ro-
tomac.