ON THIS DAY: February 8, 2008, Birmingham Bridge closed after deck drops 8 inches
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By Matt Simmons
PITTSBURGH — Hours before dawn on Friday, Feb. 8, 2008, an unidentified caller told 911 dispatchers that there was a problem with the Birmingham Bridge. First responders found the roadway had dropped 8 inches, prompting an emergency closure of the span.
Officials speculated that the warning call had come from a motorist that drove over or up to the uneven bridge deck. The emergency closure was soon extended to include pedestrians and bicyclists during the investigation.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge The Birmingham Bridge was closed for 6 months after a bearing failed underneath the approach span, which dropped the deck eight inches.
Birmingham Bridge Aerial view of Pittsburgh, Pennsylvania, with a focus on the 1976 Birmingham Bridge, a bowstring arch bridge over the Monongahela Rive that connects East Carson Street on the South Side with Fifth and Forbes Avenues going to Uptown, Oakland, and the Hill District. It is named in honor of the English city of Birmingham and also for the neighborhood it connects to, which was once called Birmingham, now a part of the South Side. (Photographer: Carol M. Highsmith)
Birmingham Bridge Aerial view of Pittsburgh, Pennsylvania, with a focus on the 1976 Birmingham Bridge, a bowstring arch bridge over the Monongahela Rive that connects East Carson Street on the South Side with Fifth and Forbes Avenues going to Uptown, Oakland, and the Hill District. It is named in honor of the English city of Birmingham and also for the neighborhood it connects to, which was once called Birmingham, now a part of the South Side. (Photographer: Carol M. Highsmith)
Birmingham Bridge Aerial view of Pittsburgh, Pennsylvania, with a focus on the 1976 Birmingham Bridge, a bowstring arch bridge over the Monongahela Rive that connects East Carson Street on the South Side with Fifth and Forbes Avenues going to Uptown, Oakland, and the Hill District. It is named in honor of the English city of Birmingham and also for the neighborhood it connects to, which was once called Birmingham, now a part of the South Side. (Photographer: Carol M. Highsmith)
PennDOT investigators concluded that the rocker bearings beneath the approach span had over-rotated and failed, which caused the girders to drop and damage the bridge pier. In normal operation, rocker bearings allow bridges to expand and contract with the weather, moving forward and backward. The over-rotation was blamed on debris that choked and corroded the bearings, likely washed down from the roadway above, that caused the bridge to ratchet farther in only one direction until it failed.
A retrofit team stabilized and repaired the bridge, reopening the southbound side on March 3, 2008. Northbound traffic shared that side until the bridge was fully reopened on Sept. 8, 2008.
The bridge’s vast six lanes were instead connected at T-intersections with much smaller roads at each end. Large highway interchange ramps were instead connected to East Carson Street, Forbes Avenue and Fifth Avenue, though the vestigial remains of an unfinished on-ramp can still be found on the bridge’s southern approach.