The Republican. [volume] (Oakland, Md.) 1877-current, 1906-03-29

| Greek and the other over Great
TonOlway. The grading as far as
Licking Creek bridge, about two
and one-half miles, IS earth and
loose rock work of ordinary char
acter. Beyond this some heavy
work was done, including a fill
just east Of Milestone 600 feet long,
containing upward of 1900 cubic
yards of earthwcrk.
IL the second division for about
two miles the road runs close to
the canal and is built on a bench
cut into solid rock hillside which
rises abruptly from the edge ofthe
canal. This bench is in many
places supported by fills held in
place by both masonry and con-
crete retaining walls. This side
hill, or canal work as it is called,
was the heaviest and most expen-
sive work done on the entire line,
its estimated cost in some places
being as high as $50, 900 per mile.
After leaving the two-mlle
stretch of sidehill work at the west
of Sideling Hill Creek, the line
passes through Indigo tunnel,
which is the first and longest tun-
mel on the line, being 1850 feet
from portal to portal. The meth
Cd of driving this tunnel was
novel. Instead Of removing the
advance drift or heading from the
top Of the section, as is usually
done, a bottom heading ten feet
wide was driven and then the re-
maiuder Of the tunnel, or the over
head bench, as it may be be called,
was removed.
The tunnel was worked from
both ends. The material met
with throughout the tunnel was
hard shale formation which was
easily blasted. 1t was found to
be self sustaining, and thus no
timbering was required. The total
time for driving the tunnel was
eighteen months. This, as in the
case Of time given for other tun-
nels, does not mean much, as no
particular effort was made to make
fast time on account of great
speed in most cases being unnec-
essary, for the reason that steel
bridge work, and especially right
Of way matters, could be regarded
as governing the length Of time re-
quired to build the road; there
fore, in most cases, the ContraC-
tors were allowed to drive the
heading entirely through before
attempting the bench excavations.
A short distance beyond Little
Orleans is the first Potomac River
and canal crossing. This bridge
consists of two 7Q-foot deck plate
girder spans, one at each end; two
I5o-foot deck truss shore spans
and two I52-foot channel spans.
The abutments, as we'll as the five
piers, are all of concrete on solid
rock foundation
From this section to the second
river crossing the line follows
along the side hill for from two to
three miles, and just before reach
ing the river it passes through a
fairly deep cut which required the
excavation of about $4,000 cubic
wards of rock. The second river
and canal crossing is made on a
bridge 1867 feet long composed of
plate girder span at each end, a
truss deck girder span over the
canal, five truss deck girder river
spans and viaduct composed of
four plate deck girders supported
on three thirty-foot steel towers
resting on concrete pedestals
Near Baird the third river and
canal crossing is made on bridge
about 500 feet long, composed of a
three-span deck girder viaduct
which spans the canal, two truss
girder shore spans and one truss
girder channel span with an aver
age length of about ISL feet. From
the west end Of this bridge the
line is carried Oh a single track
temporary pile trestle, II77 feet
1,,.14 I