(
Bridge Hunter;
Historic Bridges;
HAER;
Satellite)
BLE = Bessemer & Lake Erie
Andrew Carnegie built the predecessor of this railroad to provide a better connection between the iron ore docks on Lake Erie and his steel mills in the Pittsburgh area. This bridge became part of US Steel when it was formed. The piers are wider than the truss because they were made wider so that this double-track truss could be built next to the single-track truss that was to be replaced. After the old truss was removed, the new one was moved sideways to center it on the piers. The continuous truss spans showcased a new high-strength silicon steel developed by US Steel. [
HAER-data] According to a satellite view, the bridge now carries only one track.
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HAER PA,2-OAK.V,1--1
Oblique of bridge, looking west from south bank of Allegheny River at lock and dam no. 3. - Bessemer & Lake Erie Railroad, Allegheny River Bridge, Spanning Allegheny River, East of Pennsylvania Turnpike (I-76), Oakmont, Allegheny County, PA |
This close up of the piers show the rails on top of the pier that were used to move the new truss from the side to the center after the old truss was removed.
Kenneth Nielsen posted five images with the comment:
I am reposting this to make it more understandable "In order to grasp the size and scale of the engineering that went into this bridge I have included a map image next to the interstate. The white spot below the “76” in that picture is a tractor trailer. Also I have included a picture with a train. I drive past this frequently for work. Bessemer & Lake Erie Railroad Bridge.
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This photo not only shows the cantilevered technique used to construct the spans, it shows the existing single-track span that is being replaced.
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