How They Bridged the
dreen
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North Carolina’s highest ansi dizziest
river crossing is a sight to see for
future mountain travelers.
Bu leon m. sum
Sure-footed craftsmen working with
steel and concrete have tamed the
rugged Green River Gorge out in an
eastern corner of Henderson County,
and in the accomplishment have added
a new' showpiece to the pageantry of
the mountain country’s highway sys¬
tem.
The steelworkers and their concrete¬
pouring companions have pushed
across the gorge, as a link in Interstate
Route 26 from Asheville to Charleston,
twin bridges a fifth of a mile long,
higher than any other river crossings in
the State, and brand new to North
Carolina in design.
From the approximate center of the
side-by-side spans, travelers will look
down 220 feet to the rather modest
stream w'hich, over countless centuries
of grinding its way downward, brought
the gorge into existence. That’s about
like looking dowm from the top of a 20-
story building.
There will be 22 feet of open space
between the two roadways, so travelers
in all four lanes — two southbound,
two northbound — will have plenty of
opportunity to see what’s below.
Motorists crossing the southbound
bridge, say, may whistle when they
look across to the northbound roadway
and observe that long sections of the
steel superstructure and concrete floor
are supported by a single tall pier, with
four piers in all supporting the entire
1,050-foot span.
Each pier is topped by a steel-and-
concrete crosspiece the size of a box¬
car. On the crosspieces, which are
three feet wider than the roadways,
rest the main girders.
Almost, that is. The girders don't
quite sit on the crosspieces because
between them is a small steel device
which bridge builders call a “rocker.”
The rocker’s function is to permit the
bridge superstructure to move slight-
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Four piers support the entire span. Between the twin bridges, 22 feet of open space allow on exciting
view of the bridge superstructure and the depths below. Neorest the camera is the northbound span.
The bridge is a link in new 1-26, which is presently incomplete on both sides of the river. However,
until it is officially opened, sightseers can reoch the location over
о
dirt rood. (Photo by Leon Siler.)
Here is some of the oction while the work was
underway. These concrete -filled piers now sup¬
port portions of spectoculor twin bridges 1,050
feet long, 220 feet above the Green River down
there below. (Stote Highwoy Commission photo.)
ly, longitudinally, when temperature
changes cause the steel girders to
shrink or expand.
The girders, incidentally, are some¬
thing to behold. They resemble ordi¬
nary steel I-bcams, but whereas the
ordinary structural steel I-beam is per¬
haps 14 inches in height, the height of
Lhese bridge girders is not 14 inches
but 14 feet, and they are up to 86 feet
long.
It took some doing to string these
girders across the canyon.
First, the piers had to be built. Their
steel shells were filled with concrete.
A crane such as isn’t seen very often
then lifted the boxcar-size crosspieces
and deposited them very gently and
very accurately on the piers.
Fabricated steel towers a hundred
feet high or more now' w'ere raised on
each side of the gorge. The towers were
topped by huge pulleys, and across
these, from shore to shore, a husky
steel cable was strung.
Dollies ran along the cableway.
From the dollies, hooks were dropped
and fastened to the girders. Winches
on both sides of the gorge pulled the
dollies and their load back and forth.
As the great girders soared along
from the river’s north bank to the
south — • a fifth of a mile, as has been
said — lifeneis were strung just below
them.
( Continued on page 22)
THE STATE, April 15, 196B
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