Silver Bridge

Silver Bridge
The Silver Bridge upon completion in 1928
Coordinates	38°50′42″N 82°08′28″W / 38.84500°N 82.14111°W / 38.84500; -82.14111Coordinates: 38°50′42″N 82°08′28″W / 38.84500°N 82.14111°W / 38.84500; -82.14111
Crosses	Ohio River
Locale	Point Pleasant, Mason County, West Virginia, United States Kanauga, Gallia County, Ohio, United States
Followed by	Silver Memorial Bridge
Characteristics
Material	Steel
Total length	681.2 m
Longest span	213.5 m
Design life	39 years
History
Constructed by	American Bridge Company
Opened	1928
Collapsed	December 15, 1967
References

The Silver Bridge was an eyebar-chain suspension bridge built in 1928 and named for the color of its aluminum paint. The bridge carried U.S. Route 35 over the Ohio River, connecting Point Pleasant, West Virginia, and Gallipolis, Ohio,

On December 15, 1967, the Silver Bridge collapsed while it was full of rush-hour traffic, resulting in the deaths of 46 people. Two of the victims were never found. Investigation of the wreckage pointed to the cause of the collapse being the failure of a single eyebar in a suspension chain, due to a small defect 0.1 inch (2.5 mm) deep. Analysis showed that the bridge was carrying much heavier loads than it had originally been designed for and had been poorly maintained.

The collapsed bridge was replaced by the Silver Memorial Bridge, which was completed in 1969.

At the time of the Silver Bridge construction, eyebar bridges had been built for about 100 years. Such bridges had usually been constructed from redundant bar links, using rows of four to six bars, sometimes using several such chains in parallel. An example can be seen in the Clifton Suspension Bridge, designed by Isambard Kingdom Brunel. The chain eyebars are redundant in two dimensions. This is an early suspension bridge still in service. Other bridges of similar design include the earlier road bridge over the Menai Strait built by Thomas Telford in 1826; the Széchenyi Chain Bridge in Budapest, built in 1839–1849, destroyed in the closing days of World War II by retreating Germans in 1945, and rebuilt identically by 1949, with redundant chains and hangers; and the Three Sisters, self-anchored suspension bridges of similar design in Pittsburgh.