Tacoma Narrows Bridge
Encyclopedia
The Tacoma Narrows Bridge is a pair of twin
Twin bridges
Twin bridges are a set of two bridges running parallel to each other. A pair of twin bridges is often referred to collectively as a twin-span or dual-span bridge. Bridges of this type are often created by building a new bridge parallel to an existing one in order to increase the traffic capacity...

 suspension bridge
Suspension bridge
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century...

s in the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 state of Washington, which carry State Route 16 (known as Primary State Highway 14 until 1964) across the Tacoma Narrows
Tacoma Narrows
The Tacoma Narrows , a strait, is part of Puget Sound in the U.S. state of Washington. A navigable maritime waterway between glacial landforms, the Narrows separates the Kitsap Peninsula from the city of Tacoma....

 strait of Puget Sound
Puget Sound
Puget Sound is a sound in the U.S. state of Washington. It is a complex estuarine system of interconnected marine waterways and basins, with one major and one minor connection to the Strait of Juan de Fuca and the Pacific Ocean — Admiralty Inlet being the major connection and...

 between Tacoma
Tacoma, Washington
Tacoma is a mid-sized urban port city and the county seat of Pierce County, Washington, United States. The city is on Washington's Puget Sound, southwest of Seattle, northeast of the state capital, Olympia, and northwest of Mount Rainier National Park. The population was 198,397, according to...

 and the Kitsap Peninsula
Kitsap Peninsula
The Kitsap Peninsula is an arm of land that is part of the larger Olympic Peninsula in Washington state that lies west of Seattle across Puget Sound. Hood Canal separates Kitsap Peninsula from the rest of the Olympic Peninsula...

. Historically, the name "Tacoma Narrows Bridge" has applied to the original bridge
Tacoma Narrows Bridge (1940)
The 1940 Tacoma Narrows Bridge was the first incarnation of the Tacoma Narrows Bridge, a suspension bridge in the U.S. state of Washington that spanned the Tacoma Narrows strait of Puget Sound between Tacoma and the Kitsap Peninsula. It opened to traffic on July 1, 1940, and dramatically collapsed...

 nicknamed "Galloping Gertie" which opened in July 1940 and collapsed
Structural failure
Structural failure refers to loss of the load-carrying capacity of a component or member within a structure or of the structure itself. Structural failure is initiated when the material is stressed to its strength limit, thus causing fracture or excessive deformations...

 four months later, as well as the replacement of the original bridge
Tacoma Narrows Bridge (1950)
The 1950 Tacoma Narrows Bridge is a suspension bridge in the U.S. state of Washington that carries the westbound lanes of Washington State Route 16 across the Tacoma Narrows strait, between the city of Tacoma and the Kitsap Peninsula...

 which opened in 1950 and still stands today as the westbound lanes of the present-day twin bridge complex.

The original Tacoma Narrows Bridge opened on July 1, 1940. It received its nickname "Galloping Gertie" because of the vertical movement of the deck
Deck (bridge)
A bridge deck or road bed is the roadway, or the pedestrian walkway, surface of a bridge. It is not to be confused with any deck of a ship.The deck may be of concrete,wood which in turn may be covered with asphalt concrete or other pavement...

 observed by construction workers during windy conditions. 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
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 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 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 15, 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
Golden Gate Bridge
The Golden Gate Bridge is a suspension bridge spanning the Golden Gate, the opening of the San Francisco Bay into the Pacific Ocean. As part of both U.S. Route 101 and California State Route 1, the structure links the city of San Francisco, on the northern tip of the San Francisco Peninsula, to...

 and George Washington Bridge
George Washington Bridge
The George Washington Bridge is a suspension bridge spanning the Hudson River, connecting the Washington Heights neighborhood in the borough of Manhattan in New York City to Fort Lee, Bergen County, New Jersey. Interstate 95 and U.S. Route 1/9 cross the river via the bridge. U.S...

. The 1950 and 2007 bridges are now the fifth-longest suspension bridge spans in the United States, and the 31st-longest in the world.

Tolls
Toll bridge
A toll bridge is a bridge over which traffic may pass upon payment of a toll, or fee.- History :The practice of collecting tolls on bridges probably harks back to the days of ferry crossings where people paid a fee to be ferried across stretches of water. As boats became impractical to carry large...

 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

The desire for the construction of a bridge in this location dates back to 1889 with a Northern Pacific Railway
Northern Pacific Railway
The Northern Pacific Railway was a railway that operated in the west along the Canadian border of the United States. Construction began in 1870 and the main line opened all the way from the Great Lakes to the Pacific when former president Ulysses S. Grant drove in the final "golden spike" in...

 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
Pierce County, Washington
right|thumb|[[Tacoma, Washington|Tacoma]] - Seat of Pierce CountyPierce County is the second most populous county in the U.S. state of Washington. Formed out of Thurston County on December 22, 1852, by the legislature of Oregon Territory...

 for a bridge over the Narrows. The bridge was designed by Leon Moisseiff
Leon Moisseiff
Leon S. Moisseiff was a leading suspension bridge engineer in the United States of America in the 1920s and 1930s. He was awarded The Franklin Institute's Louis E...

.

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 AM (Pacific time) due to a physical phenomenon known as aeroelastic flutter caused by a 67 kilometres per hour (41.6 mph) 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 (even though the real cause of the bridge's failure was aeroelastic flutter). Its failure also boosted research in the field of bridge aerodynamics/aeroelastics which have themselves influenced the designs of all the world's great long-span bridges built since 1940.

No human life was lost in the collapse of the bridge. However, a small dog perished after it was abandoned in a car on the bridge by its owner, Leonard Coatsworth, and by another man, both of whom were bitten by the terrified dog when they attempted to remove it. The collapse of the bridge was recorded on 16 mm film
16 mm film
16 mm film refers to a popular, economical gauge of film used for motion pictures and non-theatrical film making. 16 mm refers to the width of the film...

 by Barney Elliott, owner of a local camera shop, and shows Leonard Coatsworth leaving the bridge after exiting his car. In 1998, The Tacoma Narrows Bridge Collapse was selected for preservation in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 National Film Registry
National Film Registry
The National Film Registry is the United States National Film Preservation Board's selection of films for preservation in the Library of Congress. The Board, established by the National Film Preservation Act of 1988, was reauthorized by acts of Congress in 1992, 1996, 2005, and again in October 2008...

 by the Library of Congress
Library of Congress
The Library of Congress is the research library of the United States Congress, de facto national library of the United States, and the oldest federal cultural institution in the United States. Located in three buildings in Washington, D.C., it is the largest library in the world by shelf space and...

 as being "culturally, historically, or aesthetically significant". This footage is still shown to engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

, architecture
Architecture
Architecture is both the process and product of planning, designing and construction. Architectural works, in the material form of buildings, are often perceived as cultural and political symbols and as works of art...

, and physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...

 students as a cautionary tale
Cautionary tale
A cautionary tale is a tale told in folklore, to warn its hearer of a danger. There are three essential parts to a cautionary tale, though they can be introduced in a large variety of ways. First, a taboo or prohibition is stated: some act, location, or thing is said to be dangerous. Then, the...

.

Dismantling of the towers and side spans—which survived the collapse of the main span but were damaged beyond repair—began shortly after the collapse and continued into May 1943. The United States' participation in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

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

Westbound bridge

The current westbound bridge was designed and rebuilt with open truss
Truss
In architecture and structural engineering, a truss is a structure comprising one or more triangular units constructed with straight members whose ends are connected at joints referred to as nodes. External forces and reactions to those forces are considered to act only at the nodes and result in...

es, stiffening strut
Strut
A strut is a structural component designed to resist longitudinal compression. Struts provide outwards-facing support in their lengthwise direction, which can be used to keep two other components separate, performing the opposite function of a tie...

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, Galloping Gertie. 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 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. 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
Suspension bridge
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century...

 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

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
Washington State Department of Transportation
The Washington State Department of Transportation , was established in 1905. The agency, led by a Secretary and overseen by the Governor, is a Washington governmental agency that constructs, maintains, and regulates the use of the state's transportation infrastructure...

 collects a toll before entering the eastbound span, at $2.75 for Good To Go!
Good To Go!
Good To Go! is the electronic toll collection system used by the Washington State Department of Transportation on all current and future toll projects in the state of Washington. Good To Go! customers prepay their tolls into an account, the tolls are then electronically deducted as the customer...

 account holders with in-vehicle transponder
Transponder
In telecommunication, the term transponder has the following meanings:...

s, and a $4.00 toll (a more than 45% upcharge) for cash/credit card
Credit card
A credit card is a small plastic card issued to users as a system of payment. It allows its holder to buy goods and services based on the holder's promise to pay for these goods and services...

 customers. The existing span had been toll-free since 1965. The new bridge marks the first installation of the new Good To Go! electronic toll collection
Electronic toll collection
Electronic toll collection , an adaptation of military "identification friend or foe" technology, aims to eliminate the delay on toll roads by collecting tolls electronically. It is thus a technological implementation of a road pricing concept...

 system.

External links



Historical

Second span project
  • Tacoma Narrows Bridge Project (continuing coverage of bridge construction from The News Tribune)
  • "Bridge Workers are Walking Tall Above the Narrows", Rob Carson (The News Tribune), Kitsap Sun
    Kitsap Sun
    The Kitsap Sun is a newspaper in Bremerton, Washington, that covers general news. It serves the West Sound, covering Kitsap, Jefferson and Mason counties, has a circulation of about 30,000 and reaches over 100,000 adult readers seven days a week....

    , September 25, 2005
  • Wire by wire, Tacoma Narrows bridge is built Mike Lindblom, The Seattle Times
    The Seattle Times
    The Seattle Times is a newspaper serving Seattle, Washington, US. It is the largest daily newspaper in the state of Washington. It has been, since the demise in 2009 of the printed version of the rival Seattle Post-Intelligencer, Seattle's only major daily print newspaper.-History:The Seattle Times...

    , October 15, 2005
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