The Tacoma Narrows Bridge is a pair of

twin Twins are two offspring produced by the same pregnancy.MedicineNet > Definition of TwinLast Editorial Review: 19 June 2000 Twins can be either ''monozygotic'' ('identical'), meaning that they develop from one zygote, which splits and forms two em ...

suspension bridge A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. The first modern examples of this type of bridge were built in the early 1800s. Simple suspension bridges, which lack vertical ...

s that span the Tacoma Narrows strait of

Puget Sound Puget Sound ( ) is a sound of the Pacific Northwest, an inlet of the Pacific Ocean, and part of the Salish Sea. It is located along the northwestern coast of the U.S. state of Washington. It is a complex estuarine system of interconnected m ...

in Pierce County,

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

. 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 Aeroelasticity is the branch of physics and engineering studying the interactions between the inertial, elastic, and aerodynamic forces occurring while an elastic body is exposed to a fluid flow. The study of aeroelasticity may be broadly classif ...

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. 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. 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 World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, 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. 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 The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean. The structure links the U.S. city of San Francisco, California—the northern tip of the San Francisco Pen ...

and

George Washington Bridge The George Washington Bridge is a double-decked suspension bridge spanning the Hudson River, connecting Fort Lee, New Jersey, with Manhattan in New York City. The bridge is named after George Washington, the first president of the United S ...

. 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)

The desire for the construction of a bridge in this location dates back to 1889 with a

Northern Pacific Railway The Northern Pacific Railway was a transcontinental railroad that operated across the northern tier of the western United States, from Minnesota to the Pacific Northwest. It was approved by Congress in 1864 and given nearly of land grants, wh ...

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. 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

caused by a 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, 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. 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. Its failure also boosted research in the field of bridge aerodynamics 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 Kodachrome is the brand name for a color reversal film introduced by Eastman Kodak in 1935. It was one of the first successful color materials and was used for both cinematography and still photography. For many years Kodachrome was widely used ...

16 mm film 16 mm film is a historically popular and economical gauge of film. 16 mm refers to the width of the film (about inch); other common film gauges include 8 and 35 mm. It is generally used for non-theatrical (e.g., industrial, edu ...

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. Elliott and Monroe's original films of the construction and collapse of the bridge were shot on 16 mm

color film, but most copies in circulation are in black and white because

newsreel A newsreel is a form of short documentary film, containing news stories and items of topical interest, that was prevalent between the 1910s and the mid 1970s. Typically presented in a cinema, newsreels were a source of current affairs, inform ...

s of the day copied the film onto 35 mm black-and-white

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. 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. 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 The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

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by the

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as being "culturally, historically, or aesthetically significant". This footage is commonly shown to

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architecture Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constructing buildings ...

, and

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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

, as well as engineering and finance issues, delayed plans to replace the bridge.

Westbound bridge (1950)

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 University of Washington (UW, simply Washington, or informally U-Dub) is a public research university in Seattle, Washington. Founded in 1861, Washington is one of the oldest universities on the West Coast; it was established in Seatt ...

, 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. 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 towers were complete in July 1949 and the cables for the new bridge were finished on January 16, 1950. The current westbound bridge was designed and rebuilt with open

truss A truss is an assembly of ''members'' such as beams, connected by ''nodes'', that creates a rigid structure. In engineering, a truss is a structure that "consists of two-force members only, where the members are organized so that the assembl ...

es, stiffening

strut A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension. Human anatomy Part of the functionality o ...

s and openings in the roadway to let wind through. 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. Local residents nicknamed the new bridge Sturdy Gertie, as the oscillations that plagued the previous design had been eliminated. This bridge along with its new parallel eastbound bridge is 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. 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

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.

Eastbound bridge (2007)

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 The Washington State Department of Transportation (WSDOT or WashDOT, both ) is a governmental agency that constructs, maintains, and regulates the use of transportation infrastructure in the U.S. state of Washington. Established in 1905, it is ...

(WSDOT) signed a design-and-construction agreement with

Bechtel Bechtel Corporation () is an American engineering, procurement, construction, and project management company founded in San Francisco, California, and headquartered in Reston, Virginia. , the '' Engineering News-Record'' ranked Bechtel as the se ...

and Kiewit Pacific Co., who then engaged in a

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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. The eastbound bridge has an overall length of 1,646 m, and a main span of 853 m, making it the fifth largest

in the United States. In comparison, the

Golden Gate bridge The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the strait connecting San Francisco Bay and the Pacific Ocean. The structure links the U.S. city of San Francisco, California—the northern tip of the San Francisco Pen ...

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

transponder In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight trans ...

s, $5.50 for cash/

credit card A credit card is a payment card issued to users (cardholders) to enable the cardholder to pay a merchant for goods and services based on the cardholder's accrued debt (i.e., promise to the card issuer to pay them for the amounts plus the ...

customers, and $6.50 for those who choose Pay-By-Mail. 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

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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. 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 Frank Vana Chopp (born May 13, 1953) is an American politician serving as a Democratic member of the Washington House of Representatives, representing the 43rd district since 1995. His district covers the neighborhoods of Montlake, Fremont, Wall ...

Gallery

File:Narrows Bridge Sections BA.JPG, New bridge sections used in construction of the new span. File:Tacoma Narrows.jpg, A

panorama A panorama (formed from Greek πᾶν "all" + ὅραμα "view") is any wide-angle view or representation of a physical space, whether in painting, drawing, photography, film, seismic images, or 3D modeling. The word was originally coined i ...

of Tacoma Narrows Bridge in 2007. This picture was taken at Titlow Hidden Beach. File:Tacoma Bridge Puget.jpg, The westbound bridge, in 1988, when it carried traffic in both directions File:Tacoma Narrows and Mt. Rainier.jpg, Tacoma Narrows Bridge eastbound span from the Kitsap Peninsula during construction in February 2007, with Tacoma and

Mount Rainier Mount Rainier (), indigenously known as Tahoma, Tacoma, Tacobet, or təqʷubəʔ, is a large active stratovolcano in the Cascade Range of the Pacific Northwest, located in Mount Rainier National Park about south-southeast of Seattle. With a ...

visible in the background. File:TopViewNarrows.jpg, Both bridges during the 2007 bridge's grand opening ceremony, as seen from the top of the westbound bridge. File:Tacoma Narrows Bridge 2009.jpg, The twin-span bridges seen from the Tacoma side in 2009. File:Tacoma Narrows Bridge aerial.jpg, Aerial view, 2016 File:Tacoma Narrows aerial.jpg, Aerial view, 2017

References

;Notes

External links

Photos of the bridge and the new span under construction

Photos of the bridge and contractor details
* * *
Video clips of aeroelastic flutter
{{Authority control Suspension bridges in Washington (state) Bridges in Tacoma, Washington Bridges completed in 1950 Bridges completed in 2007 North Tacoma, Washington Rebuilt buildings and structures in the United States Toll bridges in Washington (state) Road bridges in Washington (state) Steel bridges in the United States