One of the greatest engineering failures of all time, the original Tacoma Narrows Bridge collapse, took place 70 years ago today on November 7, 1940.

One reason for its notoriety is that the entire collapse was meticulously filmed by Barney Elliot, the owner of a local camera shop, using 16mm Kodachrome film. The film documented the Tacoma Narrows collapse from several different angles and was spectacularly useful as a post mortem analysis tool, enabling failure analysis engineers to determine with great precision exactly how the bridge failed & collapsed. It is often used as a cautionary film for engineers and architects.

The film also documented an extraordinary act of bravery, wherein a Professor Farquhausen rescues a dog from the badly swaying bridge.
Farquhausen, a great fan of dogs, also attempted to rescue a second canine named Toby. That dog belonged to Leonard Coatsworth, a newspaper editor. Coatsworth later recounted that he had crawled on his hands and knees from the middle of the span to escape the bridge. During a lull in the bridge’s movement, Farquhausen and another rescuer reached the vehicle, but the terrified dog refused to go along, biting Farquhausen instead. Toby, who was paralyzed and had only three legs, stayed in the vehicle and eventually plunged into the water below, becoming the only fatality of the collapse.

Oddly enough, Prof. Farquhausen was a bridge engineer who had been hired to research a solution to the bridge’s swaying.

At the time of its opening on July 1, 1940, the Tacoma Narrows bridge was the third-longest suspension bridge in the world. Verticle movement was observed on the bridge even as the deck was being built, prompting construction workers to call her “Galloping Gertie.” People on the bridge at its opening day said they could feel it moving, and it was often observed to sway in oscillating waves on blustery days.
On the day of its collapse, the bridge was encountering 40 mph winds – strong, but not uncommon for the area.

The collapse, and the film which documented it, had a significant impact on science and engineering. The film is held up as a prime example of aerolastic flutter, in which aerodynamic forces couple with an object’s natural mode of vibration to create a periodic motion or resonance, which, if it is not dampened, results in increasing and destructive self-exciting oscilliation.

However the bridge was also doomed by cost cutting and poor design, including shallow and narrow supports towers, and a narrow roadway.
Since the bridge failure this has been identified as a common problem in aircraft, bridges, and other large-scale structures.

Incoming search terms:

• Galloping Gertie bridge
• tacoma narrows bridge collapse gallopin gertie
• galloping gertie
• gallopin gertie
• tacoma narrows bridge 1940
• Tacoma Narrows Bridge Collapse Gallopin\ Gertie
• Tacoma Narrows bridge failure analysis
• tacoma narrows bridge collapse
• galloping gertie stats
• swaying bridge 1940
• kodachrome
• tacoma narrows bridge disaster
• galloping gertie collapse
• swaying bridge collapse
• gertie bridge
• tacoma bridge failure analysis
• tacoma narrows bridge collapse analysis
• the tacoma narrows bridge collapse
• dog died on bridge swaying
• Tacoma Narrows Bridge today