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‘Galloping Gertie’ The Tacoma Narrows Bridge Failure. November 21, 2006 Max Walker Robby Poshusta Jan Kubica Aaron Aslin. History. Started November 23, 1938 Opened to the Public July 1, 1940 Designed by Clark Eldridge Altered by Leon Moisseiff
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‘Galloping Gertie’The Tacoma Narrows Bridge Failure November 21, 2006 Max Walker Robby Poshusta Jan Kubica Aaron Aslin
History • Started November 23, 1938 • Opened to the Public July 1, 1940 • Designed by Clark Eldridge • Altered by Leon Moisseiff • Pacific Bridge Company, General Construction Company, Columbia Construction Company
Random Facts • Greatest Span 2,800ft • Total Length 5,979ft • Cost – $8 million • 17.25” Diameter Cables • 6,308 wires spun one at a time to make the large cables. • Third largest suspension span in the world at the time.
Engineering Design Included: • Suspension bridge • Two Towers • Two Main Cables • Two Anchorages • One Lane Highway
Engineering Anchorages
Engineering • False Bottom Caisson • 600 ton blocks of concrete were used to anchor the caisson
Collapse • 11am on November 7, 1940 • 42 M.P.H. wind • No one died in the collapse • Several cars were thrown into the water
Collapse Mechanical Resonance • A • B • C • D
Outcome • “The consulting designer, Leon Moisseiff felt the fall occurred because engineers did not know enough about aerodynamics, and that lack of funds had forced the building of a bridge unprecedently narrow for its length. (University of Washington- Special Collections)”
Bibliography • University of Washington Special Collections- Tacoma Narrows Bridge. November 16, 2006. <http://www.lib.washington.edu/specialcoll/exhibits/tnb/default.html> • WSDOT- Tacoma Narrows Bridge: Extreme History. November 16, 2006. <http://www.wsdot.wa.gov/TNBhistory/>