Tacoma Narrows Bridge 1950

Tacoma Narrows Bridge 1950

© Washington State Dept of Transportation

The Bridge

The original bridge across the Tacoma Narrows collapsed four months after opening in 1940. It was studied by engineers across the world to gain understanding of the effects of wind on the flat plate deck that caused it to oscillate and tear itself apart in winds of only 42mph. Previously bridges had vast truss-strengthened decks and the new deflection theory proposed thin flat-plate decks that were discredited in dramatic fashion.

A new bridge was completed in 1950, with an open truss deck and stiffening struts. This is now the westbound bridge of a pair of crossings following the opening of another, the eastbound bridge, in 2007.

In 1996 the Severn Bridge opened linking England and Wales across the River Severn. The bridge deck was designed by Bill Brown with an innovative aerodynamic box girder that acts as an aerofoil to deflect the wind and remain stable. He had studied the effects on deck sections in wind tunnel tests, learnt from the American engineers at Tacoma, and set a new standard that has been adopted globally. Images of the original Tacoma design were compared with his designs for Severn in presentations by Bill at conferences across the world.

Tacoma Narrows Bridge

Replaced the original 1940 Tacoma Narrows Bridge

Key Facts

Westbound road bridge

Eastbound bridge opened in 2007


Washington, USA

Across the Tacoma Narrows

Consulting Engineers

Jackson Leland Durkee

Dexter R. Smith

Charles E. Andrew


Suspension bridge

853m main span

1,646m total length

Main contractors

Bethlehem Pacific Coast Steel Corp.

John A. Roebling’s Sons Company


Opened 14 October 1950

Other long-span bridges