3 votes

Fern Hollow Bridge (1973)


AISC Prize Bridge, 1974

AISC Prize Bridge Photo


BH Photo #516411

Street Views 


Lost Batter-Post steel rigid frame bridge over Fern Hollow Creek on Forbes Avenue
Pittsburgh, Allegheny County, Pennsylvania
Built 1970 to replace a steel arch bridge; collapsed January 28, 2022
- Conn Construction Co. of New Castle, Pennsylvania (General Contractor and Erector, Conn Fabrication & Engineering Co. was division that did fabrication)
- Richardson, Gordon, & Associates of Pittsburgh, Pennsylvania (Design)
Batter-Post steel rigid frame, constructed from weathering steel (also known as Cor-Ten steel)
Length of largest span: 166.0 ft.
Total length: 446.9 ft.
Deck width: 49.9 ft.
Approximate latitude, longitude
+40.43950, -79.90025   (decimal degrees)
40°26'22" N, 79°54'01" W   (degrees°minutes'seconds")
Approximate UTM coordinates
17/593270/4477119 (zone/easting/northing)
Average daily traffic (as of 2005)
Inventory numbers
PANBI 02410 (Pennsylvania BRKEY bridge number on the 2011 NBI)
BH 96087 (Bridgehunter.com ID)
Inspection report (as of September 2017)
Overall condition: Poor
Superstructure condition rating: Poor (4 out of 9)
Substructure condition rating: Satisfactory (6 out of 9)
Deck condition rating: Fair (5 out of 9)
Sufficiency rating: 18.7 (out of 100)
View more at BridgeReports.com

Update Log 

  • January 31, 2022: Updated by Nathan Holth: Added AISC award info and photos, engineer, contractor, and similar bridge in West Virginia.
  • January 28, 2022: Updated by Luke: Clarified type of rigid frame
  • January 28, 2022: Updated by Nathan Holth: Added design details to note the bridge was built from weathering Cor-Ten type steel.
  • January 28, 2022: Updated by Brian Powell: rename to differentiate from predecessor
  • January 28, 2022: Updated by Paul Plassman: COLLAPSED

Related Bridges 


Fern Hollow Bridge (1973)
Posted February 1, 2022, by George Oakley (georgeoakley49 [at] yahoo [dot] com)

Just read in today's paper that PennDOT said even though there was deterioration during a September inspection it wasn't enough to warrant it's closure.During the inspection the weight limit was 26 tons and the steel was rated a 4 on a scale from 0 to 9 which is poor.Citing the ongoing investigation into the collapse PennDOT will not release the full inspection report.

Fern Hollow Bridge (1973)
Posted January 31, 2022, by George Oakley (georgeoakley49 [at] yahoo [dot] com)

I just saw a video with president Biden talking about the infrastructure bill being passed.Thanks to him and the Democrats along with the Republicans couldn't pass this bill months earlier which might have made a difference in getting this bridge either repaired or replaced.That's what i think but i might be wrong.Hopefully we don't see more bridges collapsing with deadly results.Just wondering how far this infrastructure money will go concerning bridges.I'm also keeping politics off of this site as a favor to all Bridgehunter enthusiasts.

Fern Hollow Bridge (1970-2022)
Posted January 28, 2022, by Jesse Belfast (jbellafesta [at] gmail [dot] com)

Bridge named "best in AISC's category for medium-span, high-clearance structures, 1974.

Fern Hollow Bridge (1970-2022)
Posted January 28, 2022, by Jay Kitsap (jay [dot] prodesign [at] gmail [dot] com)

It looks like the section just beyond the bus rose as it rotated about the foundation. This dragged the section the bus is sitting on down the slope a long ways. The balance of the deck dropped basically straight down with hinging not breaks, as the deck still looks connected.

So true how the media does a horrible job on bridge collapses. CORTEN and road salt is a bad combination. Interesting how many years it has been in poor condition with little maintenance performed.

Fern Hollow Bridge (1970-2022)
Posted January 28, 2022, by Nathan Holth (webmaster [at] historicbridges [dot] org)

News media and the White House is typically useless when evaluating bridge collapses. Those of us in the industry will need to wait a long time for science based facts about this from the NTSB, who has started a file for this collapse, see official page here:


I will be interested to learn if the bridge's weathering steel played any role in the collapse. Weathering steel has shown to underperform in winter climates especially if salt is used. In Michigan some weathering steel bridges have required painting in fact!

Fern Hollow Bridge (1970)
Posted January 28, 2022, by Paul Plassman