England, 1820. Brighton Chain Pier, 1830s Menai Strait Suspension Bridge, 1826

England, 1820

Brighton Chain Pier, 1830s

Menai Strait Suspension Bridge, 1826

Robert Stephenson

Britannia Tubular Bridge

John A.Roebling

“storms are unquestionably the greatest enemies of

suspension bridges.”

--John Roebling

1841

What made the Niagara Bridge work for railway traffic?

“Weight, Girders, Trusses, and Stays”

--John Roebling, Final Report (1855)

--Robert Stephenson to John Roebling

“If your bridge succeeds, mine is a magnificent blunder”

Cincinnati-Covington

(Ohio River)Bridge

Brooklyn Bridge,

1883

Williamsburg Bridge, 1903

Ben Franklin Bridge

Thousand Islands Bridge

Deer Isle Bridge

Bronx-Whitestone Bridge

Tacoma Narrows Bridge

Lessons Learned

• wind is the enemy of suspension bridges

• unstiffened decks are vulnerable to the wind

Tacoma Narrows Bridge

Mackinac Straits Bridge

Akashi Kaikyo Bridge

Severn Bridge

“Progress, far from consisting in change, depends on

retentiveness. . . .

“Those who cannot remember the past are

condemned to repeat it.”

--George Santayana

Dee Bridge, 1847

Tay Bridge, 1879

Quebec Bridge

Milford Haven Bridge

A major failure every 30 years

• 1847 - Dee Bridge, trussed girder • 1879 - Tay Bridge, truss • 1907 - Quebec Bridge, cantilever • 1940 - Tacoma Narrows Bridge, suspension• 1970 - Milford Haven Bridge, steel box girder • 2000 –London Millennium Bridge, pedestrian • 2030 - ?

Dong Ting Lake Bridge

Clearwater Bridge