The Silver Bridge Disaster

Hunter Major

The Silver Bridge Disaster

      The Silver Bridge carried a U.S. Route 35 over the Ohio River connecting Point Pleasant, West Virginia, and Gallipolis Ohio. The Silver Bridge was designed by J.E Greiner Company as well as the U.S. Steel's American Bridge Company. The bridge was a two lane, 1760 foot long, long eyebar suspension bridge. The bridges constructions began being in May 1927 and was completed in one year, opening to traffic on Memorial Day 1928. The bridge was originally supposed to be built with conventional wire cables, the eyebar chain design was used to lower the price. The bridge at the time was called by Engineering Magazine “unique (in their) use of heat-treated eyebar chains, portions of which form parts of the top chords of the stiffening trusses.” Once the state bought the bridge was bought by the state, the inspections were done by the State Road Commissions. Inspections of the bridge took place every other year and after more than 25 years of inspections, only $30,000 of recommended repairs were completed.

      On December 15th, 1967, in less than 20 seconds the entire 1460 foot bridge collapsed killing 46 people. A thorough analysis was done in the years to come on why the bridge collapsed. The bridge failure was due to a defect in a single link, eye-bar 330, on the north of the Ohio subsidiary chain, the first link below the top of the Ohio tower. A small crack only about 0.1 inches, was formed through corrosion at the bearing. Eventually, it went critical and broke in a brittle fashion. After the lower side of the eyebar failed, all the load was transferred to the other side of the eyebar. This then led to a failure because, too much weight needed to be supported, causing the bridge to collapse.

     The aftermath of this incident was the increased number of bridge inspections, as well as how thorough the inspection now where. Many bridges were closed down and rebuilt if they were built similar to the way to the Silver Bridge was built. Engineering has come a long way and there are much better ways to build bridges without having the massive flaws that the Silver bridge had.

Full Article: http://www.transportation.wv.gov/highways/bridge_facts/Modern-Bridges/Pages/Silver.aspx