Transcript Presentation on tacoma.pptx


Opened to traffic July 1st 1940

Third largest suspension bridge in the world

Bridge nicknamed Galloping Gertie

3 Span Suspension Bridge

Length 1810m -Mid span 853m


Engineers valued lightness, flexibility and
slenderness
I beam used to support deck instead of truss
Why did it collapse



I beams caught the wind
Wind Forced above and below
Vortex caused vertical forces on bridge


Aerodynamics not fully understood at the
time
Led to further research

Longitudinal resonance

Torsional Resonance

Determine and design for possible “freak”
conditions

Understanding of aerodynamics

Using wind tunnel analysis

Testing models in “in-situ” conditions