The Tacoma Narrows Bridge, nicknamed Galloping Gertie, collapsed into Puget Sound on Nov. 7, 1940. Built using Leon Moisseiff’s deflection theory and slender solid plate girders, the span succumbed to wind-induced aeroelastic flutter. There were no human fatalities, though a dog named Tubby died. The failure transformed bridge aerodynamics and led to improved testing and design standards; a replacement opened in 1950.
85 Years Since 'Galloping Gertie': How the Tacoma Narrows Collapse Changed Bridge Design
The Tacoma Narrows Bridge, nicknamed Galloping Gertie, collapsed into Puget Sound on Nov. 7, 1940. Built using Leon Moisseiff’s deflection theory and slender solid plate girders, the span succumbed to wind-induced aeroelastic flutter. There were no human fatalities, though a dog named Tubby died. The failure transformed bridge aerodynamics and led to improved testing and design standards; a replacement opened in 1950.
06:57, 08.11.2025Technology
85 Years Since 'Galloping Gertie'
On Nov. 7, 1940, the Tacoma Narrows Bridge — nicknamed "Galloping Gertie" — catastrophically collapsed into Puget Sound. The dramatic failure, which caused no human fatalities but claimed the life of a three-legged dog named Tubby, reshaped the study of bridge aerodynamics and permanently changed how engineers design long-span suspension bridges.
Backstory: A Bold, Slender Design
Designed by Leon Moisseiff and opened on July 1, 1940, the Tacoma Narrows structure represented the era's push for lighter, more graceful suspension spans based on Moisseiff's deflection theory. Unlike earlier suspension bridges that used open-web lattice trusses, Tacoma Narrows employed solid, deep plate girders that gave the deck a very slender profile but also prevented wind from passing freely through the structure.
Early Warning Signs
Within weeks of opening, observers reported pronounced vertical, wave-like oscillations of the roadway — sensations that quickly earned the bridge the nickname Galloping Gertie. While some motorists found the motion thrilling, many were alarmed. Engineers, including University of Washington professor F.B. Farquharson and others, experimented with fixes such as anchoring cables and installing hydraulic dampers, but these measures proved inadequate.
The Collapse and the Cause
On Nov. 7, 1940, sustained winds induced a violent, self-reinforcing motion that tore the span apart. The failure was later attributed to aeroelastic flutter: a dynamic instability in which twisting motion changes the airflow around a structure, which then amplifies the twisting in a destructive feedback loop. Video of the collapse remains one of the most studied engineering case files in history.
Human and Engineering Aftermath
Remarkably, there were no human fatalities. One of the most poignant details from the incident was the death of Tubby, a three-legged dog left inside an abandoned car. The collapse tarnished Moisseiff's reputation; he died of a heart attack a few years later.
Legacy and Rebuilding
A permanent replacement span opened in 1950 and now carries westbound traffic from Tacoma to Gig Harbor. Continued regional growth prompted construction of a second, parallel span in the early 2000s to carry eastbound traffic. More broadly, the Tacoma Narrows disaster spurred new emphasis on wind-tunnel testing, aeroelastic analysis and dynamic design criteria — advances that make modern long-span bridges far safer.
Sources: WSDOT, HistoryLink, Live Science and original reporting from FOX 13.