pa1778data.pdf

mk U.S. STEEL DUQUESNE WORKS
W HAER No. PA-115
(Page 119)
height of the span is 26'-0" from the pier leg end of the bridge
for a distance of 126*-10" before becoming 24'-0" for its
remaining length. The pier legs are made up of inverted
pyramidal shaped steel framed trusses and are located, one each,
on the north and south sides of the western end of the ore
bridge. The base of each inverted pyramid is 54*-0" long x 2'-0"
wide. Each leg rises at an approximate 60 degree angle from a
bolted connection on top of its respective 8-wheel pier truck for
a distance of 1Z*-0 W where it is riveted to a steel frame which
runs flush underneath the top chord of the bridge span. The 8
wheel pier trucks provide motive power for the pier leg end of
the bridge. Each is 39 f -2" long x 4'-6" wide x 7'-9 7/8" high
and is constructed of four linearly designed sets of two steel
rail wheels which are connected to a connecting rod arrangement
that is powered and driven by a motor and gear drive assembly.
The motor, manufactured by Crocker-Wheeler Company, is a 65 hp
mill type D.C. motor running at 440 rpm. The Michigan Tool
Company worm and gear set has a ratio of 2 5 to 1. Covering the
motor and gear drive assembly is a 28*-0" long x 4'-6" wide x 4'-
5" enclosure constructed of an irregularly shaped steel I-beam
^^ frame with a 1 1/4" thick steel plate welded to its top. A
^P clevis for bolting the apex of each inverted pyramidal leg to the
8-wheel truck is located on the east and west side of the truck
about its centerline.
The centerline of the shear legs is located 226'-0" east of
the centerline of the pier legs. They are made up of inverted
pyramidal shaped steel framed trusses and are located, one each,
on the north and south side of the eastern end of the ore bridge.
The base of each inverted pyramid is approximately 4'-0" square.
Each leg rises at a approximate 60 degree angle from a bolted
connection on top of its respective 8-wheel shear truck for a
distance of approximately 60*-0" where it is riveted to a steel
frame which runs flush underneath the top chord of the bridge
span. The 8-wheel shear trucks, which provide the motive power
for the shear leg end of the bridge, are constructed, powered,
and driven in much the same manner as the 8-wheel pier trucks.
Located 3*-8 1/4" west of the centerline of the pier leg
rail and running the length of the ore yard is a set of electric
rails spaced 13 1/2" apart. Bus work from the ore bridge
connecting to the rails provides the electrical energy needed to
power the ore bridge man trolley and dumping system.
1. Man Trolley: The man trolley sits on top of a set of
steel rails which run nearly the entire length of the bridge
•span. The rails, spaced ll'-6" apart about the span's
centerline, are carried by I-beams welded to the east and west
members of the span's bottom chord. The trolley is constructed