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