pa1778data.pdf

U.S. STEEL DUQUESNE WORKS
HAER No. PA-115
(Page 121)
equipped with a heater and power operated gates. It is located
on a 30 ( -0" square platform attached to the ore bridge on its
eastern end by a steel framework extending downward from the top
chord of the bridge span. The dumper, which delivers ore to the
stockhouse bins, is centered over the ore bins along the trestle
as it travels the length of the ore yard.
7. Anemometer Platform and Frame: The anemometer platform
is approximately 7 , -0" wide. It spans the northern and southern
top chords of the bridge span approximately 75'-0" from its pier
leg end. At the center of the platform are two 4'-0" high
triangular frames made up of steel bars which are spaced 10'-0"
apart about the centerline of the span. The frames were used to
support an anemometer which measured wind force and speed.
8. Ore Bridge Stairwells and Landings: Steel framed
stairwells and landings leading from the ground to the top of the
ore bridge span are located at the pier leg and shear leg ends of
the bridge.
B. Ore Bridge Number Four: Ore bridge number four was
designed and built by the American Bridge Company in 1962. It is
located south of ore bridge number three and laid out on a east-
west axis across the ore yard. Made out of riveted steel
construction, it consists of a set of pier and shear legs which
carry a 334'-3" long x 24'-0" wide Warren bridge span. The
height of the span is 29'-0" from the western or pier leg end of
the bridge for a distance of 108'-4 1/2" before becoming 26'-0"
for its remaining length. The northern and southern members of
the span's top and bottom chord are laid out on a east-west axis.
The eastern and western members of the top and bottom chord are
laid out on a north-south axis.
The 80'-6 ,f high pier leg is a three dimensional V shaped
structure made up of large steel column framing. The V shaped
legs of the structure are located on the northern and southern
side of the ore bridge at its western end. Each V leg rises at a
60 degree angle from the structure's 60'-0" long bottom chord to
its 34'-0 M long top chords. The top chords of the structure,
spaced approximately 40'-0" apart, run on a north-south axis
flush underneath the northern and southern members of the span's
top chord. The bottom chord of the structure runs on a north -
south axis just above the 8-wheel pier trucks. A pair of 10 1/4"
diameter clevis connections are hung, one each, from the eastern
and western side of the bottom chord at both of its ends. The
centerline of the clevis connections coincide with the centerline
of the pier trucks. The two approximately 40'-0" long x S'-O"
wide x 8'-0" high 8-wheel trucks are constructed of four linearly
designed sets of two steel rail wheels, laid out on a north -