Fernbridge

Fernbridge is a 1,320-foot-long concrete arch bridge designed by American engineer John B. Leonard which opened in 1911 at the site of an earlier ferry crossing of the Eel River. Fernbridge is the last crossing before the Eel arrives at the Pacific Ocean, and anchors one end of California State Route 211 leading to Ferndale, California. When built, it was named the "Queen of Bridges" and is still the longest functional poured concrete bridge in operation in the world.
After 17 years of petitioning by residents of Ferndale and the Eel River valley, Humboldt County Supervisors accepted bids for construction in 1910, and work started March 20 of that year. Reinforced concrete was used because studies after the 1906 San Francisco earthquake along 296 miles of the San Andreas Fault from Ferndale south to San Jose, California showed that reinforced concrete withstood earthquakes. The nearly one-quarter-mile span cost US$245,967 to build, and consumed millions of board feet of local redwood timber for the framing. Construction was finished and the bridge put into operation on November 8, 1911. As completed, the bridge had wooden trestle approach spans 500 feet and 551 feet long. The reinforced concrete structure was 1,451 feet long overall with a 24-foot wide roadway carried on seven 180-foot long arches. The original wooden approaches were replaced with the current concrete ramps in 1920.

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