Tacoma Narrows Bridge

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Tacoma Narrows Bridge
Tacoma Narrows Bridge (117561801).jpeg
The bridges in 2015, as seen from the Tacoma side. 1950 bridge on the right, 2007 bridge on the left.
Coordinates 47°16′5″N122°33′2″W / 47.26806°N 122.55056°W / 47.26806; -122.55056
Carries8 lanes of WA-16.svg SR 16, cyclists and pedestrians
Crosses Tacoma Narrows
Locale Tacoma to the Kitsap Peninsula United States
Maintained by Washington State Department of Transportation
Characteristics
Design Twin suspension
Total length5,400 ft (1,645.92 m) [1]
Longest span2,800 ft (853.44 m) [1]
Clearance below 187.5 ft (57.15 m)
History
Construction startApril 12, 1948 (westbound)
October 4, 2002 (eastbound)
OpenedOctober 14, 1950 (westbound)
July 15, 2007 (eastbound)
Statistics
TollEastbound only (passenger car) [2] :
$5.50 (cash/credit price)
$4.50 (transponder price)
$6.50 (pay by mail)
Location
Tacoma Narrows Bridge

The Tacoma Narrows Bridge is a pair of twin suspension bridges that span the Tacoma Narrows strait of Puget Sound in Pierce County, Washington. The bridges connect the city of Tacoma with the Kitsap Peninsula and carry State Route 16 (known as Primary State Highway 14 until 1964) over the strait. Historically, the name "Tacoma Narrows Bridge" has applied to the original bridge nicknamed "Galloping Gertie", which opened in July 1940, but collapsed possibly because of aeroelastic flutter four months later, as well as the replacement of the original bridge which opened in 1950 and still stands today as the westbound lanes of the present-day two-bridge complex.

Contents

The original Tacoma Narrows Bridge opened on July 1, 1940. The original bridge received its nickname "Galloping Gertie" due to of the vertical movement of the deck observed by construction workers during windy conditions. While engineers and engineering professor, F. B. Farquharson were hired to seek ways to stop the odd movements, months of experiments were unsuccessful. [3] The bridge became known for its pitching deck, and collapsed into Puget Sound the morning of November 7, 1940, under high wind conditions. Engineering issues, as well as the United States' involvement in World War II, postponed plans to replace the bridge for several years; the replacement bridge was opened on October 14, 1950.

By 1990, population growth and development on the Kitsap Peninsula had caused traffic on the bridge to exceed its design capacity; as a result, in 1998 Washington voters approved a measure to support building a parallel bridge. After a series of protests and court battles, construction began in 2002 and the new bridge opened to carry eastbound traffic on July 16, 2007, while the 1950 bridge was reconfigured to carry westbound traffic. [4]

At the time of their construction, both the 1940 and 1950 bridges were the third-longest suspension bridges in the world in terms of main span length, behind the Golden Gate Bridge and George Washington Bridge. The 1950 and 2007 bridges are as of 2017 the fifth-longest suspension bridge spans in the United States and the 43rd-longest in the world.

Tolls were charged on the bridge for the entire four-month service life of the original span, as well as the first 15 years of the 1950 bridge. In 1965, the bridge's construction bonds plus interest were paid off, and the state ceased toll collection on the bridge. Over 40 years later, tolls were reinstated as part of the financing of the twin span, and are presently collected only from vehicles traveling eastbound.

Original bridge (1940)

Opening day of the Tacoma Narrows Bridge, Tacoma, Washington.jpg
Opening day, July 1, 1940

The desire for the construction of a bridge in this location dates back to 1889 with a Northern Pacific Railway proposal for a trestle, but concerted efforts began in the mid-1920s. In 1937, the Washington State legislature created the Washington State Toll Bridge Authority and appropriated $5,000 to study the request by Tacoma and Pierce County for a bridge over the Narrows. The bridge was designed by Leon Moisseiff and cost $6.4 million. [5]

The collapse of the original bridge.

The first Tacoma Narrows Bridge opened to traffic on July 1, 1940. Its main span collapsed into the Tacoma Narrows four months later on November 7, 1940, at 11:00 a.m. (Pacific time) possibly as a result of aeroelastic flutter caused by a 42 mph (68 km/h) wind. The bridge collapse had lasting effects on science and engineering. In many undergraduate physics texts, the event is presented as an example of elementary forced resonance, with the wind providing an external periodic frequency that matched the natural structural frequency, [6] the cause is still debated by engineers today. A contributing factor was its solid sides, not allowing wind to pass through the bridge's deck. Thus, its design allowed the bridge to catch the wind and sway, which ultimately took it down. [6] It was the first suspension bridge to utilize these solid I-beams as a form of support for the road deck, as other bridges would incorporate trusses in their designs in order to catch the wind. [7] Its failure also boosted research in the field of bridge aerodynamic and aeroelastic fields which have influenced the designs of all the world's great long-span bridges built since 1940.

There were no human deaths in the collapse of the bridge. The only fatality was a Cocker Spaniel named Tubby, who perished after he was abandoned in a car on the bridge by his owner, Leonard Coatsworth. Professor Frederick Burt Farquharson, an engineer from the University of Washington who had been involved in the design of the bridge, tried to rescue Tubby but was bitten by the terrified dog when he attempted to remove him. The collapse of the bridge was recorded on Kodachrome 16 mm film by Barney Elliott and Harbine Monroe, owners of The Camera Shop in Tacoma, and shows Farquharson leaving the bridge after trying to rescue Tubby and making observations in the middle of the bridge. The film was subsequently sold to Paramount Studios, who then duplicated the footage for newsreels in black-and-white and distributed the film worldwide to movie theaters. Castle Films also received distribution rights for 8 mm home video. [8] [9]

Elliott and Monroe's original films of the construction and collapse of the bridge were shot on 16 mm Kodachrome color film, but most copies in circulation are in black and white because newsreels of the day copied the film onto 35 mm black-and-white stock. There were also film speed discrepancies between Monroe and Elliot's footage, with Monroe filming his footage in 24 fps while Elliott had filmed his footage at 16 fps. [10] As a result, most copies in circulation also show the bridge oscillating approximately 50% faster than real time, due to an assumption during conversion that the film was shot at 24 frames per second rather than the actual 16 fps. In 1998, The Tacoma Narrows Bridge Collapse was selected for preservation in the United States National Film Registry by the Library of Congress as being "culturally, historically, or aesthetically significant". [11] This footage is commonly shown to engineering, architecture, and physics students as a means to teach about engineering disaster.

The dismantling of the towers and side spans — having survived the collapse of the main span, but being damaged beyond repair — began shortly after the collapse and continued into May 1943. The United States' participation in World War II, as well as engineering and finance issues, delayed plans to replace the bridge.

Westbound bridge (1950)

The westbound span in 1988. Tacoma Bridge Puget.jpg
The westbound span in 1988.

After the infamous fall of the original bridge, Professor Farquharson was commissioned again to test new designs for the bridge at the University of Washington, the home of these models. Tests ensured the new design would have a different outcome than the first and construction began on April 12, 1948, following the completion of a financing and insurance plan. [3] [12] A major earthquake struck the construction site on April 13, 1949, but the only damage was to a cable that fell into the water and was recovered; a fire two months later on the west tower damaged equipment and tools but did not cause permanent damage. The 502-foot (153 m) towers were complete in July 1949 and the cables for the new bridge were finished on January 16, 1950. [12] The current westbound bridge was designed and rebuilt with open trusses, stiffening struts and openings in the roadway to let wind through.[ citation needed ] It opened on October 14, 1950, and is 5,979 feet (1822 m) long—40 feet (12 m) longer than the first bridge. The new bridge cost $18 million to construct. [13] Local residents nicknamed the new bridge Sturdy Gertie, as the oscillations that plagued the previous design had been eliminated. [14] This bridge and its new parallel eastbound bridge are currently the fifth-longest suspension bridges in the United States.

When built, the westbound bridge was the third longest suspension bridge span in the world. [15] Like other modern suspension bridges, the westbound bridge was built with steel plates that feature sharp entry edges rather than the flat plate sides used in the original Tacoma Narrows Bridge (see the suspension bridge article for an example).

The bridge was designed to handle 60,000 vehicles a day. It carried both westbound and eastbound traffic until the eastbound bridge opened on July 15, 2007. [16] [17] During the Hanukkah Eve windstorm of 2006, the bridge was closed for the first time in its operating existence due to heavy winds but reopened approximately 6 hours later. [18]

Eastbound bridge (2007)

The eastbound span in 2013. Tacoma Narrows Bridge-2.jpg
The eastbound span in 2013.

In 1998, voters in several Washington counties approved an advisory measure to create a second Narrows span. Construction of the new span, which carries eastbound traffic parallel to the current bridge, began on October 4, 2002, and was completed in July 2007. The Washington State Department of Transportation (WSDOT) signed a design-and-construction agreement with Bechtel and Kiewit Pacific Co., who then engaged in a joint venture to construct eastbound. It was estimated by WSDOT that the project would cost $849 million to complete, but ultimately finished under budget at $786 million due to not using the funds allocated to emergency scenarios. [19] [20] [21]

The eastbound bridge has an overall length of 1,646 m, and a main span of 853 m, making it the fifth largest suspension bridge in the United States. In comparison, the Golden Gate bridge in San Francisco has a total length of 2,372 m or 1.7 miles.

The bridge was dedicated in honor of State Representative Ruth Fisher and State Senator Robert "Bob" Oke, a South Kitsap resident, one of the main proponents of building the second span across Puget Sound between the Kitsap Peninsula and Tacoma.

WSDOT collects a toll before entering the eastbound span. Tolls currently are $4.50 for "Good to Go" account holders with in-vehicle transponders, $5.50 for cash/credit card customers, and $6.50 for those who choose Pay-By-Mail. [2] The existing span had been free of tolls since 1965. The new bridge marks the first installation of the new Good To Go electronic toll collection system.

Opening Day

On July 15, 2007 the eastbound section opened to a ceremonial 5K run across the newly constructed bridge. About 10,000 people participated in the event. After the run finished, a ceremonial ribbon cutting event took place on eastbound. WSDOT estimated 40,000 people would be in attendance for the opening, but 60,000 ultimately attended. [22] A select few Washington State government officials partook in the ribbon cutting, such as Washington State Treasurer; Michael Murphy, State Representative Pat Lantz, Chief of the Washington State Patrol; John Batiste, and State Speaker of the House; Frank Chopp.

Tacoma Narrows Bridge Panorama.jpg
~300° panorama from the deck of the new Tacoma Narrows Bridge at sunset.

See also

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References

Notes
  1. 1 2 Tacoma Narrows Bridge at Structurae
  2. 1 2 "Tacoma Narrows Bridge tolling". Wsdot. Washington State Department of Transportation. Retrieved 26 October 2022.
  3. 1 2 "Introduction — UW Libraries". www.lib.washington.edu. Retrieved 2021-12-07.
  4. ↑ "More Than a Bridge". Wsdot. Washington State Department of Transportation.
  5. ↑ "PCAD - State of Washington, Highway Department, Tacoma Narrows Bridge #1, Tacoma, WA". pcad.lib.washington.edu. Retrieved 2021-12-07.
  6. 1 2 Billah, K.; R. Scanlan (1991). "Resonance, Tacoma Narrows Bridge Failure, and Undergraduate Physics Textbooks" (PDF). American Journal of Physics . 59 (2): 118–124. Bibcode:1991AmJPh..59..118B. doi:10.1119/1.16590.
  7. ↑ von Kármán, Theodore (August 2005). "Collapse of the tacoma narrows bridge". Resonance. 10 (8): 97–102. doi:10.1007/bf02866750. ISSN   0971-8044. S2CID   120498720.
  8. ↑ "Tacoma Narrows Bridge: Art of the Bridges Continues". www.wsdot.wa.gov. Archived from the original on 1 June 2019. Retrieved 7 December 2020.
  9. ↑ "::: Tacoma Narrows Bridge Film Collection :::". content.lib.washington.edu. Retrieved 7 December 2020.
  10. ↑ Pasternack, Alex (14 December 2015). "The Strangest, Most Spectacular Bridge Collapse (And How We Got It Wrong)". Vice Magazine . Retrieved 7 December 2020.
  11. ↑ "Complete National Film Registry Listing – National Film Preservation Board". The Library of Congress. Retrieved 2016-11-21.
  12. 1 2 "Narrows Bridge Was Designed Like Plane". The News Tribune. October 14, 1950. p. C2. Retrieved November 22, 2022– via Newspapers.com.
  13. ↑ "Governor Dedicates New Tacoma Narrows Bridge". The Bellingham Herald . Associated Press. October 15, 1950. p. 1. Retrieved November 22, 2022– via Newspapers.com.
  14. ↑ Vogel, Elmer C. (October 14, 1950). "Narrows Bridge Is Result of Research". The News Tribune. Associated Press. p. C3. Retrieved November 22, 2022.
  15. ↑ Holstine, Craig E. (2005). Spanning Washington : historic highway bridges of the Evergreen State. Washington State University Press. pp. 61–62. ISBN   0-87422-281-8.
  16. ↑ Carson, Rob (July 15, 2007). "First to cross? Nah, just go with the flow". The News Tribune. p. A14. Retrieved November 22, 2022– via Newspapers.com.
  17. ↑ Beekman, Dan and Santos, Melissa; "First traffic crosses new bridge" [ permanent dead link ]; The News Tribune ; July 16, 2007
  18. ↑ Sistek, Scott (December 14, 2016). "Dec. 14-15, 2006: Historic Hanukkah Eve windstorm pummeled Western Washington". KOMO 4 News (Seattle, Washington). Retrieved November 14, 2023. Article contains a copy of a live blog during the storm and an original Associated Press article from December 15, 2006
  19. ↑ Pilling, Nathan. "Eying traffic decline on Tacoma Narrows Bridge, state commission floats possible toll hikes". Kitsap Sun. Retrieved December 7, 2021.
  20. ↑ "Parsons/HNTB Joint Venture to Proceed on Tacoma Narrows Bridge Project Design". Business Wire. Pasadena, California. October 8, 2002. Retrieved June 1, 2022.
  21. ↑ Staff (January 1, 2008). "New Narrows Bridge comes in $114M less than state expected". The Seattle Times. Retrieved December 7, 2021.
  22. ↑ "Smooth opening day for drivers on new Tacoma Narrows Bridge". The Seattle Times. July 16, 2007. Retrieved December 8, 2021.

Further reading

Historical
Second span project
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