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** MEMBER #1439 of the CANADIAN PAPER MONEY SOCIETY **
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THE GREATEST DISASTER IN NORTH AMERICAN HISTORY! Is it Hurricane Katrina?? HECK, NO!!! Those were TERRIBLE disasters, with many lives shattered and lost amid chaos that paralyzed North American society for a long time afterwards. I'm talking about GREAT disasters, the kinds that cause destruction and financial loss only to those who can afford it. The kind of disasters that did not cause widespread devastation nor loss of life. The kinds of disasters that are just as likely to make people grin and chuckle as well as shake their heads in disbelief. To that end, there is one great disaster that wins hands down... Give-a-buck.com dedicates the month of November to the anniversary of the fall of the Tacoma Narrow Bridge. Everyone has, at some point in their lives, seen a picture or footage of the collapse of the famed suspension bridge. That's what makes this disaster so great... it was the most well-documented structural disaster of its time, and even to this day, every student of physics and structural engineering in Canada and the United States will be mesmerized by seeing a mile-long piece of concrete, steel and asphalt swaying and twisting like a playground swing. Tacoma Narrows is located in Puget Sound in the state of Washington. After years of planning and hand-wringing by people who wanted a bridge but did not want to spend a lot of money for one, construction of the first Tacoma Narrows bridge started in 1938. The official opening was on July 1st, 1940 and the total cost of construction was estimated at $6.4 million. The bridge quickly developed a reputation for being unstable and was nicknamed "Galloping Gertie". When the wind blew, the bridge would oscillate and form a series of transverse waves, meaning it would form a series of peaks and valleys along its length such that if you were driving along it, oncoming traffic in front of you would appear and disappear behind the roadway as it rose and fell. The thought of driving on a moving object makes my head spin! This sort of thing would never be allowed in today's society where half the people could not imagine riding a bicycle down a country road without wearing a helmet. Unfortunately, politics and financing got in the way of common sense back in 1940, and the Tacoma Narrows bridge proved to be a tourist draw, thus putting aside any safety concerns due to the bridge's eccentric behaviour.  Just 4 months after the bridge's opening, on the morning of November 7th, 1940, a stiff wind of up to 42 miles per hour (about 70kmph) blowing through Puget Sound caused the bridge's oscillations to become violent. Instead of rising and falling, the pavement began to twist along the center span. If you were standing in the middle of the two lanes looking down the road, the lane on your right would rise while the lane on your left fell, and they would oscillate back and forth to almost 45° past horizontal. Unfortunately, the two halves of the bridge's center span did not rise and fall together in synch. While the western half would rotate clockwise, the eastern half would rotate counter-clockwise, then vice-versa, creating the twisting motion you see in the animation above. The bridge's center span acted essentially like an airplane's wing because the wind was forced around it instead of through it, creating a sense of lift that increased the bridge's attack angle, hence generating a positive feedback response (i.e., it made the oscillations worse and worse as the bridge could not dissipate the energy as quickly as the wind provided more energy to it). The bridge essentially "fluttered" in the wind like an item of clothing on a clothesline. The wind, though brisk and constant, was not that strong, but it was enough to reach the bridge's resonant frequency. Fortunately, many man-made structures like office towers are built to withstand winds of several hundred kms per hour, the kind of winds produced by tornados and hurricanes.The Tacoma Narrows bridge started to become violent around 10 A.M. The last person to drive onto the bridge was a reporter named Leonard Coatsworth. He was forced to abandon his car and his dog, a cocker spaniel named "Tubby", and crawl along the twisting center span on his hands and knees for a distance of over 400 yards. News of the bridge's impending collapse spread through Tacoma quickly and brought many people to the scene to witness history. Among them was the owner of the local camera shop, Barney Elliot, and his friend Harbine Monroe. The two men were amateur newsreel photographers and they brought with them equipment to record the bridge's final moments from several angles on colour film. The son of the camera shop's owner, Ed Elliot, maintains a website where you can buy copies of the original movie made from the footage captured. Though Mr. Elliot maintains copyright of the movie, footage of the disaster has been archived in public institutions and disseminated in many forms across the world such that there's just no way of knowing who owns what. The movie file shown below is supposedly derived from the Camera Shop movie, but it is half as long as the supposed original film, and it is a copy of a copy of a copy... So the picture quality is not great, but you can download and view it unlike the clips on websites like YouTube. Other people immortalized by the bridge's collapse include Professor Burt Farquharson, the man seen walking along it in the newsreel footage. He realized that the bridge twisted along the center line which remained almost completely stable, so he walked down the centerline and attempted to rescue the reporter's dog from the stranded car. Tubby was too frightened and bit the professor, it was reported. So much for foolish heroism! Shortly after 11 A.M., the bridge fell into Puget Sound, along with the car and Tubby, the only victims of the Fall of the First Tacoma Narrows Bridge. The debris of the fallen bridge remain underwater and have been declared a national heritage site. A second bridge was built in the 1950s with greater stability features. It remains standing to this day. A second span was added alongside in 2007. Other suspension bridges in the U.S. were made more aerodynamic following the first Tacoma Narrows bridge's collapse. Thanks to the Internet, the legend of the Tacoma Narrows bridge lives on! Good technology combined with bad engineering have combined to make the collapse of the Tacoma Narrows bridge the Greatest Disaster in American History. 1938-1940
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