Sunday, December 31, 2023

1926,1940 Bridge of the Gods over Columbia River at Cascade Locks, OR

(Bridge Huntger broke Mar 22, 2023; Historic BridgesSatellite 5,259 photos)

The rehabilitation date of 1940 surprised me. Normally big truss bridge lasted into the second half of the twentieth century before it needed major rehabilitation. But HistoricBridges explains that the bridge was raised 40' (12m) when the 1938 Bonneville Dam was built. The steel girder approach spans were added when the bridge was raised.
Street View, Sep 2021

Terrence Fenton posted four photos with the comment: "Bridge of the Gods in Cascade Locks, OR. One of many bridges across the Columbia River."
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2

3

4

HistoricBridges says that "The project [to raise the bridge 40' (12m)] included constructing enormous riveted lifting girders on the piers, at the base of the bridge's main posts. These lifting girders were not removed after the bridge was raised and can still be seen today." I presume the lifting girder is the deep girder at the base of the truss just above the pier.
Jennifer Kimchi, Jun 2022

HisjtoricBridges, Source: Washington State Archives
Before the bridge was raised.

HisjtoricBridges, Source: Washington State Archives
After the bridge was raised.

nps_1
The 1,858' (566m) long bridge has a main span of 1,131' (345m) and a width of 35 (10.7m)'. It was raised 44' in 1938.
"Strange trivia fact: In September 1927, Charles Lindbergh flew up the gorge from Portland in the "Spirit of St. Louis," passing low over the newly-built Bridge of the Gods. He then turned around and flew under the bridge, before heading back to Portland."

nps_2, Photo: Table Mountain. Creative Commons, BY-SA 4.0, Eric Prado.
There used to be a natural bridge here. "Geologists believe that about 600 to 1,000 years ago a giant landslide from nearby Table Mountain on the north shore of the Columbia River blocked the Gorge and stopped the river’s flow. This natural dam created an inland sea in eastern Oregon, Washington, and into Idaho. Over time, water eroded the dam and created an awesome natural stone bridge. Eventually, this bridge fell, creating the Cascade rapids."

"The Bridge of the Gods collapsed around the 1690s — which coincides with the date of the last Great Cascadia Subduction Zone earthquakes — creating the rocky Cascade Rapids." [CascadeLocks]

This video of the construction also has scenes showing how the river used to flow over the rapids before the Bonneville Dam was built.
9:15 video @ 8:18
The link was from CorbettOregon, which explains the Native American legend that motivated the name of the bridge.

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