View toward North Side
Elevation drawing looking downstream
View toward North Side, Sixth St Bridge at left
Seventh Street Bridge
Irvine (Irwin) Street Bridge
USGS 7.5" Topo Quad - UTM Coordinates:
Pittsburgh West - Zone 17; 0584 4477
-- Sandusky St on right descending bank of Allegheny River
-- Seventh St [Irvine/Irwin St] on left descending bank of Allegheny River
-- Allegheny River at mile 0.6
TYPE OF CONSTRUCTION / DESIGN:
Suspension - - catenaries were steel eyebar chain arranged in concentric pairs connected by lattice girders
steel eyebar suspenders
LENGTH OF MAIN SPAN:
two main spans, 320 ft; two side spans, 165 ft
TOTAL LENGTH (including longest elevated ramp):
HEIGHT OF DECK:
YEAR ERECTED / ENGINEER:
1885, Gustav Lindenthal; replaced 1925
A two-span suspension bridge which had truss-bracing on catenaries holding two eyebar-chain cables in concentric arcs. This bridge was designed by Gustav Lindenthal three years after he built the Smithfield Street Bridge.
Declared a toll-free bridge 16 March 1911.
Seventh St was formerly Irvine St (or Irwin St) in Pittsburgh; it aligns with Sandusky St in the former city of Allegheny (Northside).
view page - "Three Sisters" Bridges -- Historic American Engineering Record document
HAER; Lorant, "Pittsburgh"; Smith, "Pittsburgh: Then and Now"
Submit info or inquiry - share some facts or ask a question.
View Larger Map