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Fernbridge (bridge)

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Coordinates: 40°36′51″N 124°12′8″W / 40.61417°N 124.20222°W / 40.61417; -124.20222
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This article is about the bridge. For the town, see Fernbridge, California.
Fernbridge
Partial view of the west side of Fernbridge as seen from the south bank of the Eel River
Coordinates40°36′51″N 124°12′8″W / 40.61417°N 124.20222°W / 40.61417; -124.20222
Carries SR 211
CrossesEel River
LocaleFernbridge, California
Other name(s)originally Eel River Bridge
Maintained byCalifornia Department of Transportation
Characteristics
DesignArch bridge
MaterialReinforced concrete
Total length1,320 ft (402.3 m)
No. of spans7
Piers in water8 during periods of high water
No. of lanes2
History
DesignerJohn B. Leonard
Constructed byPacific Construction (of San Francisco)
Construction start1910
Construction costUS$245,967 (equivalent to $8,043,000 in 2023)
OpenedNovember 8, 1911 (1911-11-08)
Replacesan old ferry crossing
Fernbridge
Area1.4 acres (0.6 ha)
NRHP reference No.87000566[1]
Added to NRHPApril 2, 1987
Location
Map

Fernbridge, originally Eel River Bridge,[2] is a 1,320-foot-long (402.3 m) reinforced concrete arch bridge designed by American engineer John B. Leonard which opened on November 8, 1911[3][4] 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 referred to as the "Queen of Bridges" and is still the longest functional poured concrete bridge in operation in the world.[5]

Construction

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Fernbridge framing in 1911

"It was generally believed that Eel River could not be bridged because its course changed so often."[6] Nevertheless, in 1909 the decision was taken to build a bridge at the Singley ferry crossing.[6] After 17 years of petitioning by Eel River valley residents,[3][4] Humboldt County Supervisors accepted bids for construction in 1910, and work started March 20 of that year.[7] The bridge is constructed of reinforced concrete because studies after the 1906 San Francisco earthquake showed that reinforced concrete withstood earthquakes.[3][4] The nearly one-quarter-mile (0.4 km) span cost US$245,967 (equivalent to $8,043,000 in 2023) 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.[7][8] As completed, the bridge had wooden trestle approach spans 500 feet (150 m) and 551 feet (168 m) long. The reinforced concrete structure was 1,451 feet (442 m) long overall with a 24-foot (7.3 m) wide roadway carried on seven 180-foot (55 m) long arches.[6][7] The original wooden approaches were replaced with the current concrete ramps in 1920.[9]

Floods

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1915 Eel River flood at Fernbridge

The bridge survived floods in 1912, 1913, 1914, 1915, 1937, 1953, 1955, 1964 and 1986.[8] In the 1955 Christmas Week flood, the flood waters measured 27.7 feet (8.4 m) deep at Fernbridge. The south side abutment was washed out, and the approach damaged.[8] During repairs the first end span was removed and an earthen embankment was built which shortened the bridge by about 20 feet (6.1 m).[8]

Nine years later during the Christmas flood of 1964, every stream gauge on the Eel River was either inundated and useless or destroyed except the one at Fernbridge and nearly every bridge on the Eel River was badly damaged because the force of the water was aided by thousands of redwood logs stacked for winter mill production along the bank of the river as well as homes and barns swept away by the rapidly rising waters.[10] The flood peak at Fernbridge occurred at 4:00 a.m. on December 23 when the flood level was 29.5 feet (9.0 m).[10] The waters stayed high for 24 hours, and the discharge was estimated to be in excess of 800,000 cubic feet per second (20,000 m3/s).[10] A large island which had built itself upstream of the bridge was washed away in the wake of the 1964 floods.[8]

Historic designation

[edit]
Plaque on Side of Fernbridge
American Society of Civil Engineers Fernbridge plaque

On September 24, 1976, the American Society of Civil Engineers designated Fernbridge as an historic civil engineering landmark and installed a plaque on the northwest approach pylon to the bridge.[11]

In 1987, the California Department of Transportation (Caltrans) recommended studying the removal of Fernbridge and replacement with a more modern span, such as the many which have washed into the Eel River during floods which Fernbridge withstood.[12] The Eel River regularly floods Fernbridge to the tops of the lower ridge of the support. In some high flood years, photographs have been taken showing the water level over the upper cone-shaped tops of the support pillars[13] as well as valley-wide flooding in 1915.[14] Residents of Ferndale successfully campaigned to stop any changes to the historic bridge. Fernbridge was added to the National Register of Historic Places on April 2, 1987.[1][6]

Recent events

[edit]

In 1995, Fernbridge served as the set for scenes in the movie Outbreak, where a string of U.S. Army tanks rolls across the bridge accompanied by low-flying assault helicopters. In 2008, Caltrans initiated restoration of the railings of Fernbridge to their original appearance. Additional small improvements were made in 2008 and 2009, but Fernbridge's general appearance remains unchanged.

Fernbridge bridge circa 1912, showing all seven spans

For the 100th anniversary celebration on August 7, 2011, a ceremony was held, the bridge was closed to vehicular traffic,[15] a run over and back was held as was done on opening day in 1911, a parade of historic vehicles and local dignitaries crossed over, and a Ferndale resident borrowed construction lights and lit it at night.[16] The Ferndale Museum produced a video related to the bridge and continues to exhibit information about its history.

The United States Geological Survey maintains a live webcam at Fernbridge near their stream gauge to visually monitor stream conditions.[17]

Fernbridge repairs in 2023 following the earthquake of December 2022 included concrete reinforcement of bridge pier 2

On December 20, 2022, an earthquake damaged the bridge, and the California Highway Patrol temporarily closed it to all traffic for a few weeks. The bridge was repaired to allow two-way traffic by March 2023[18] however additional work occurred in summer through autumn 2023 to fill undermined areas at pier 2 and repair a vertical crack in the pier.[19] The total repair cost was estimated to have been $26 million in March 2024.[3]

By mid 2023, the possible future construction of a new bridge was being contemplated by Caltrans that would cost between $200 million and $500 million.[19] In March 2024, Caltrans announced that seismic gates would be installed at each end of the bridge in the summer of 2024 which would lower when an earthquake of magnitude 5.6 was detected at the bridge.[3]

The deaths of two dogs after going swimming in the river near Fernbridge occurred on September 5, 2024 due to cyanobacteria in blue-green algae which is known to happen during times of warm weather and low water flow.[20]

References

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  1. ^ a b "National Register Information System". National Register of Historic Places. National Park Service. March 13, 2009.
  2. ^ Ring, Ross (2023–2024). Titus, Caroline (ed.). "The Queen of Bridges welcomes visitors to The Victorian Village". The Ferndale Enterprise (Souvenir ed.). Ferndale, California: Cage Publishing, Incorporated. p. 15.
  3. ^ a b c d e Pence, Steven (March 21, 2024). Greenson, Thadeus (ed.). "Caltrans to Install Seismic Gates on Fernbridge". The Ferndale Enterprise. Eureka, California: North Coast Journal Incorporated. pp. 1, 2.
  4. ^ a b c Ferndale Enterprise Staff (November 28, 2024). Greenson, Thadeus (ed.). "Caltrans to Host Fourth Fernbridge Meeting". The Ferndale Enterprise. Eureka, California: North Coast Journal Incorporated. p. 3.
  5. ^ "California 211". AA Roads. Retrieved December 24, 2012.
  6. ^ a b c d "Ferries Served Early River Traffic". The Humboldt Historian. XVI (1). Eureka, California: Humboldt County Historical Society: 3. January–February 1968.
  7. ^ a b c "World's Biggest Concrete Bridge Opened at Weeott". San Francisco Call. Vol. 110, no. 174. 21 November 1911. Retrieved 31 August 2016.
  8. ^ a b c d e Tuttle, Donald C. (June 10, 2011). A brief history of Fernbridge (PDF) (Report). Eureka, California: Humboldt County, California. p. 8. Retrieved December 24, 2012.
  9. ^ Bess, Carol; Newman, Beryl; Roberts, Ann, eds. (2004). Images of America: Ferndale. Charleston, South Carolina: Arcadia Publishing (copyright by The Ferndale Museum). p. 128. ISBN 978-0-7385-2890-8. Retrieved 31 August 2016.
  10. ^ a b c Flood! December 1964–January 1965 (Report). State of California, Department of Water Resources. January 1965. Retrieved December 24, 2012. Bulletin No. 161, 43 pages plus appendices and charts
  11. ^ Myers, William A.; American Society of Civil Engineers. San Francisco Section. History and Heritage Committee (1977). Historic civil engineering landmarks. San Francisco: Pacific Gas and Electric Co. p. 52. OCLC 6807860.
  12. ^ Stein, Mark A. (March 13, 1987). "Pride of Ferndale: Townsfolk Fight to Save 75-Year-Old Bridge". Los Angeles Times. Retrieved December 24, 2012.
  13. ^ "Fernbridge, photos 98, 99 & 100". Sunny Fortuna. Retrieved December 24, 2012.
  14. ^ "Lynette's NorCal History Blog". 2012. Retrieved December 24, 2012.
  15. ^ "Resolution Authorizing Temporary Closure of Vehicle Traffic Across the Bridge in Fernbridge, CA on August 7th, 2011 for the 100th Anniversary Celebration of the Bridge". Minutes. Humboldt County Board of Supervisors. December 7, 2010. Retrieved December 24, 2012.
  16. ^ "Fernbridge". Local Gallery. Aesthetic Design. August 7, 2011. Retrieved December 24, 2012.
  17. ^ "Eel River At Fernbridge, California". USGS Webcam. United States Geological Survey. Retrieved December 24, 2012.
  18. ^ Pence, Steven (March 9, 2023). "Caltrans: Fernbridge Slated to Fully Reopen". The Ferndale Enterprise. pp. 1, 3.
  19. ^ a b Pence, Steven (June 29, 2023). Greenson, Thadeus (ed.). "Caltrans Discusses Future of Fernbridge at Packed Town Hall Meeting". The Ferndale Enterprise. Eureka, California: Melissa Sanderson, North Coast Journal Incorporated. p. 3.
  20. ^ Enterprise Staff (September 12, 2024). Greenson, Thadeus (ed.). "Officials Urge Caution After Dogs Die Following Swim Near Fernbridge". The Ferndale Enterprise. Eureka, California: North Coast Journal, Incorporated. pp. 1, 3.
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