Sunday, May 4, 2025

Montana Swinging Footbridges near Kootenai Falls near Libby, MT

(Archived Bridge Hunter has a broken link; Bridge Hunter; Historic Bridges; Satellite)

This photo confirms that there has been a couple of generations of this crossing. It shows that the new bridge was built by 2019. I don't know when the old bridge was removed.
2019 Photo by Jeff Hitchcock via BridgeHunter

usda [I don't understand why federal agencies don't provide higher resolution photos.]

Note that the new bridge has lateral stabilization cables. I wonder how much this bridge swings. It looks like the deck could still be rather "bouncy." The original bridge was built in 1937 to help firefighting efforts. The Forest Service is calling this a reconstruction, but it looks like a replacement to me.
Kelly Robbins, Oct 2022

I recently learned about "stressed ribbon" bridge designs where the suspension cables are built in the deck.
Tanweer Malik posted via Dennis DeBruler

The cables are not in the deck in these bridges, but they do follow the same arc as the deck. And the cables subject the abutments to huge lateral forces. Thus this design is very similar to a stressed ribbon. This shows the abutments are heavy-duty trusses to withstand the lateral force.
Kelly Robbins, Oct 2022

Another view of the heavy-duty design of the bridge abutments.
Umang Doshi, Jul 2019

This is a view of the old bridge.
Alexis Marie posted
Dennis DeBruler: This bridge has been replaced, https://maps.app.goo.gl/2JnrHWFtryVVNAVW7.

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