Smith

Andrea Smith THE TACOMA NARROWS BRIDGE

__Background Information__ The Tacoma Narrows bridge was built in 1940 in Tacoma, Washington. The bridge was a roadway over the Puget Sound and took two years to build, while it cost the city $6.4 million. The new Tacoma Narrows took ten years to build. __Design__ The Tacoma Narrows was designed by Leon Moisseiff who was famous for his building of very narrow bridges, hence the Tacoma //Narrows//. It was a suspension bridge that measured 7,392 feet in length and had a 2,800 foot span. The bridge was made from steel and concrete and Moisseiff used a solid steel girder as his main tool of strength. __The Collapse__ On November 7, 1940, The Tacoma Narrows collapsed over the Puget Sound. The collapse was caused by violent forty-two mph winds that sent enormous waves across the bridge. Engineers later found out that the problem came from the steel girders. Instead of letting the wind blow through the bridge, the girders were blocking the wind, causing it to twist and twirl uncontrollably. In result, engineers used a truss to secure the bridge which did the exact opposite of what the steel girders did. The new and improved Tacoma Narrows was built in 1950 and has been standing ever since. [|Link to Footage of Collapse] __Fun Facts__ After the collapse of the bridge, the Tacoma Narrows was nicknamed "Galloping Gertie" because of its chaotic, twisting behavior. Some drivers even said they felt seasick when driving along the bridge. Also, daredevils at the time would do on the bridge to experience the twisting and rolling and said that driving on the Tacoma Narrows felt like riding a roller coaster. When the bridge collapsed, several parts fell into the Puget Sound. In 1992, remains of the bridge were collected and stored in the National Register of Historic Places to protect them from being stolen.