OFFICIAL NAME:
Ninth Street Bridge
OTHER DESIGNATION:
LOCATION:
Pittsburgh
USGS 7.5" Topo Quad - UTM Coordinates:
Pittsburgh West - Zone 17; 0584 4477
CARRIES:
Ninth Street
BETWEEN:
-- Anderson St on right descending bank of Allegheny River
-- Ninth St and Fort Duquesne Blvd on left descending bank of Allegheny River
CROSSES:
-- Allegheny River at mile 0.7; Tenth Street Bypass
TYPE OF CONSTRUCTION / DESIGN:
Self-anchored Suspension
cables are steel eyebar chain
steel eyebar suspenders
steel plate girder deck
rusticated ashlar piers
LENGTH OF MAIN SPAN:
410 ft clear span
TOTAL LENGTH (including longest elevated ramp):
995 ft
HEIGHT OF DECK:
40.3 ft
Emsworth Dam normal pool level 710 ft
YEAR ERECTED / ENGINEER:
1925-28, County of Allegheny
Vernon R. Covell, T.J. Wilkerson, A.D. Nutter, and H.E. Dodge of the Allegheny County Department of Public Works, engineers; Stanley L. Roush, architect
Allegheny County, current owner
ADDITIONAL INFO:
One of the "Three Sisters." Municipal Art Commission mandated suspension as form of the bridges, but site conditions did not allow for typical anchorages. Bridges were built as cantilevers until catenaries were completed.
In a very unusual, self-anchored suspension design, instead of heavy anchorages to hold the cable ends, rigid towers hold the ends apart. First of this type in US.
Deck girders were previously painted green and remaining superstructure was painted aluminum grey. Most downtown Pittsburgh river bridges are currently painted golden yellow (the official city colors are Black and Gold).
Ninth St was formerly Hand St in Pittsburgh; it aligns with Anderson St in the former city of Allegheny (Northside).
Field Notes provide additional technical information.
view page - "Three Sisters" Bridges -- Historic American Engineering Record document
FIELD CHECKED:
09-Jul-1999
INFO SOURCES:
Comm. of PA, et. al.: "Historic Hwy Bridges"; Kidney: "Landmark Architecture"; USACE Allegheny River Nav. Charts
