Jake Neal and Jay K
Smithfield Street Bridge
LENGTH OF MAIN SPAN:
2 main spans, 360 ft each (344 ft clear)
TOTAL LENGTH (including longest elevated ramp):
HEIGHT OF DECK:
Emsworth Dam normal pool level 710 ft
Carries 4 lanes of roadway 2 pedestrian walkways.
TRUSS LENGTH: 34 Inches, 246 scale ft. (32 % reduction)
TRUSS HEIGHT: 6.5 Inches, 47 scale ft. (7% reduction)
The bridge connects Smithfield Street in Downtown
Pittsburgh with Station Square.
Cost: 16.3 million
PARTS COUNT: Estimated 8,000 - 9,000
WOOD TIES: 1,100 (rail side)
MAN HOURS: Estimated 2,000 minimum
RAW MATERIALS USED: C-V bridge girders, Plastruct Structural Shapes
and Cement, Evergreen strips and sheet stock, 36 ft. code 100 rail.
YEAR ERECTED / ENGINEER:
1881-83; Gustav Lindenthal, engineer
upstream side added 1889; widened to match downstream span 1911
The bridge has been designated a National Historic Civic
Engineering Landmark, a National Historic Landmark,
and has a Historic Landmark Plaque from the Pittsburgh
History and Landmarks Foundation.
The bridge also served the Pittsburgh Railways streetcar
system with a rail line
Thursday, January 24th, 2008
There was an icy spot on the Smithfield
Street Bridge and that people were falling
who crossed it.
From an office overlooks the bridge and a
few of us took a gander. Sure enough: we
saw a beautifully executed pratfall. As if we
were watching a circus performance, we
ohhed and ahhed as about one out of every
ten people who crossed the spot fell.
A suspension bridge is a type of bridge in which the deck is hung below suspension
cables on vertical suspenders.
In a lenticular truss, the top and bottom chords are curved in such a way
that the top chord functions as an arch, and the bottom chord
functions as a suspension cable.3 Vertical and diagonal web members
are necessary to divide the top and bottom chords into manageable
lengths and to transfer deck loads to the top chord and the bottom
chord. They also redistribute nonuniform loading, which cannot be
resisted by arch and cable action alone. The deck can be placed above
the top chord, supported by posts; below the bottom chord,
supported by hangers; or in between the two chords.
A holiday card featuring
Smithfield Street Bridge. The
inside greeting is "Wishing
you peace and joy this holiday
In 1845 half of
to the ground
The bridge also has the
The present bridge is distinction of being the
the third bridge at the most heavily walked
site and remains the pedestrian bridge
oldest steel bridge in
the United States.