The Day Galloping Gertie Danced to Her Demise
Howard Clifford running off the Tacoma Narrows Bridge during collapse, Tacoma, Washington, November 7, 1940 – UW Digital Collections, No restrictions, via Wikimedia Commons

On a crisp November morning in 1940, the Tacoma Narrows Bridge, affectionately nicknamed Galloping Gertie, met a dramatic and untimely end. This suspension bridge, which spanned the Puget Sound in Washington State, was an engineering marvel of its time. However, it also became a cautionary tale that reshaped the field of bridge design forever.

The Tacoma Narrows Bridge was an ambitious project from the start. Designed by Leon Moisseiff, a renowned engineer who had worked on the Manhattan Bridge in New York City, it was intended to be a symbol of modern engineering prowess. The bridge stretched 5,939 feet and had a main span of 2,800 feet, making it the third-longest suspension bridge in the world at that time. Its sleek design and elegant lines were meant to convey both beauty and strength.

But beneath its graceful exterior lay a fatal flaw. Moisseiff’s design did not adequately account for aerodynamic stability. The bridge’s narrow deck and shallow girders made it susceptible to wind-induced vibrations. Engineers at the time were aware of the phenomenon known as aeroelastic flutter, but they did not fully understand its implications for large structures like suspension bridges.

From the moment it opened to traffic on July 1, 1940, Galloping Gertie exhibited unusual behavior. Motorists crossing the bridge reported feeling as though they were driving on a roller coaster. The deck would undulate and twist in response to even moderate winds, creating an unsettling experience for those brave enough to traverse it. Local residents quickly dubbed the bridge Galloping Gertie due to its wild movements.

Despite these early warning signs, engineers believed that the bridge was safe. They attributed its oscillations to minor design flaws that could be corrected over time. However, on November 7, 1940, Mother Nature had other plans.

That morning, winds gusting up to 42 miles per hour swept through the Tacoma Narrows. As the wind funneled through the narrow strait beneath the bridge, it set off a series of oscillations that grew increasingly violent. Eyewitnesses described how the bridge began to twist and turn like a living creature caught in a storm.

At around 10:00 AM, Leonard Coatsworth, a Tacoma News Tribune editor who happened to be driving across the bridge at that moment, found himself in a life-or-death situation. His car was thrown from side to side as he struggled to maintain control. Realizing that he was in grave danger, Coatsworth abandoned his vehicle and crawled on his hands and knees toward safety.

By 11:00 AM, Galloping Gertie had reached her breaking point. The twisting motion became so severe that sections of the roadway began to tear apart. Finally, with a deafening roar, the central span of the bridge collapsed into Puget Sound below.

Miraculously, no human lives were lost in the disaster—though Coatsworth’s dog Tubby tragically perished when he was unable to coax her out of his abandoned car before fleeing for his life.

The collapse of Galloping Gertie sent shockwaves through both engineering communities and the general public alike. How could such an advanced structure fail so catastrophically? In search of answers, engineers conducted extensive investigations into what went wrong.

They discovered that aeroelastic flutter—a complex interaction between aerodynamic forces and structural dynamics—was responsible for bringing down Galloping Gertie. When wind flows over an object like a suspension bridge deck at certain speeds and angles (known as critical velocity), it can create oscillating forces that amplify each other until they reach destructive levels.

This revelation prompted major advancements in understanding aerodynamics within civil engineering disciplines worldwide; new techniques such as wind tunnel testing became standard practice when designing large structures exposed directly or indirectly (through their surroundings)to high-speed winds or turbulent airflows.

In addition to improving our knowledge about aeroelasticity itself (including how different shapes affect airflow patterns), researchers also developed innovative solutions aimed specifically at mitigating these risks: adding stabilizing devices like dampers or tuned mass absorbers; redesigning components with more aerodynamic profiles; even altering entire layouts based upon computational fluid dynamics simulations predicting potential problem areas before construction begins!

Today’s modern suspension bridges owe much their success—and safety—to lessons learned from tragic events surrounding Tacoma Narrows Bridge collapse back then: better materials science combined with advanced computer modeling tools allow us build stronger yet lighter structures capable withstand forces nature throws way without compromising aesthetics functionality either!

So next time you drive across one those magnificent spans connecting distant shores remember story behind Galloping Gertie appreciate just how far we’ve come since those fateful days November 1940!

Don Leith

By Don Leith

Retired from the real world. A love of research left over from my days on the debate team in college long ago led me to work on this website. Granted, not all these stories are "fun" or even "trivial" But they all are either weird, unusual or even extraordinary. Working on this website is "fun" in any case. Hope you enjoy it!