Tacoma Narrows Bridge: 8-Foot Girders vs 33-Foot Trusses

Washington State built the Tacoma Narrows Bridge twice. The first, opened in July 1940 with steel girders only 8 feet deep, was torn apart by the wind four months later. Its replacement, opened in 1950 on the same piers, was designed after years of wind-tunnel tests, with open steel trusses 33 feet deep and grates in the roadway, the deep-truss idea that had been rejected as too expensive in 1938. This documentary tells both bridges' stories from the Historic American Engineering Record, the 1941 report of the Federal Works Agency's board of engineers and the Federal Highway Administration. Chapters: 0:00 Introduction 0:40 Twenty-Five Feet or Eight 2:32 Seasick on the Deck 3:59 Forty-Two Miles an Hour 5:28 Tested Before It Was Built 7:08 Back on the Old Piers 8:49 Never Closed for the Wind Sources: Historic American Engineering Record, Tacoma Narrows Bridge, HAER No. WA-99 (Robert W. Hadlow, historian, 1993), with photographs by Jet Lowe and measured drawings. National Park Service; Library of Congress Prints and Photographs Division. O. H. Ammann, Theodore von Karman and G. B. Woodruff, The Failure of the Tacoma Narrows Bridge: A Report to the Honorable John M. Carmody, Administrator, Federal Works Agency (March 28, 1941). Copy: https://authors.library.caltech.edu/r... Federal Highway Administration, America's Highways 1776-1976 (Washington: Government Printing Office, 1977), p. 431. https://en.wikisource.org/wiki/Americ... Federal Highway Administration, Aerodynamics Laboratory, Turner-Fairbank Highway Research Center (video, 2019).    • Aerodynamics Laboratory   U.S. Weather Bureau surface map, November 7, 1940, NOAA Central Library. Film of the first bridge's construction, opening and failure, 1940 (Prelinger Archives copy). Map data: Natural Earth (public domain). Image credits: 1940 film, Prelinger Archives copy (Check: public-domain status not documented): https://archive.org/details/Tacoma-Na... Federal Highway Administration: public-domain photographs and film:    • Aerodynamics Laboratory   Historic American Engineering Record (National Park Service): public-domain photographs and film, via Wikimedia Commons Jet Lowe: public-domain photographs and film, via Wikimedia Commons Library of Congress: public-domain photographs and film, via Wikimedia Commons Lowe, Jet, creator: public-domain photographs and film, via Wikimedia Commons Lowe, Jet: public-domain photographs and film, via Wikimedia Commons NOAA Central Library (U.S. Weather Bureau): public-domain photographs and film, via Wikimedia Commons