At 4:58 p.m. on December 15, 1967, the Silver Bridge spanning the Ohio River between Point Pleasant, West Virginia and Kanauga, Ohio collapsed without warning.  At the time of the failure the bridge was packed with rush hour and holiday season traffic.  Forty-six lives were tragically lost and two bodies were never recovered.   Investigation of the wreckage determined that the collapse was the result of a small crack in one of the suspension linkage eyebars.  There was no structural redundancy, so this small failure spread across the section and led to the collapse of the entire bridge.  

This incident had a profound impact on the approach used by civil engineers to assess the integrity of bridge structures.  The Federal-Aid Highway Act of 1968 initiated the first national bridge safety inspection program in the United States as a direct result of the collapse of the Silver Bridge. This legislation directed the Secretary of Transportation to develop National Bridge Inspection Standards (NBIS) and directed each state to establish an inventory of all bridges on the federal aid highway system (the National Bridge Inventory). Two years later, the Federal-Aid Highway Act of 1970 mandated that all bridges on the Federal-aid highway system routinely undergo a bridge safety inspection in accordance with the bridge inspection standards that had been developed.  In 1978 the mandate was expanded to all bridges longer than 20 feet on any public road.

Prior to the collapse, the Silver Bridge was not generally thought of as an unsafe bridge. Up until that time bridge inspections had been performed mostly from a maintenance perspective by individuals with no proper training and of various work backgrounds. These individuals were mostly looking for maintenance items that needed to be addressed to keep a bridge in good physical condition rather than deficiencies that might compromise the structural integrity of a bridge. 

The National Bridge Inspection Standards that were developed in response to this tragedy have resulted in the training and development of highly qualified bridge safety inspection professionals throughout the country that possess the necessary knowledge, skills, and experience to properly quantify and document deficiencies that might jeopardize public safety if left unaddressed. The collapse of the Silver Bridge was a tremendous disaster with significant loss that caused many to question the safety of our highway bridges. However, the aftermath of this tragedy brought about a very robust national bridge safety inspection program that has resulted in much safer highway structures throughout our nation.

In addition to the national inspection program, designs with greater redundancy became standard so that one small failure could be absorbed by other structural members and designs that ensured that key components were not hidden, but could be visually inspected also became part of engineering standard procedures.

References:
• The Silver Bridge Disaster of 1967 (Images of America) - Stephan G. Bullard, Bridget J. Gromek, 2012
• From Disaster to Prevention: The Silver Bridge (Civil Engineering Magazine, American Society of
• Civil Engineers) - T.R. Witcher, December 2017
• To Forgive Design: Understanding Failure (Harvard University Press) - Henry Petroski, 2012
• After-Action Report, Silver Bridge Collapse - U.S. Army Corps of Engineers, March 1968

 

Visiting the Landmark

Little evidence of the original Silver Bridge remains.  A memorial marker at the intersection of Main and 6th Streets in downtown Point Pleasant cites a few facts about the bridge and its collapse.  A flood wall obstructs the view of the river in this area.  A four-lane highway approaches the site on the Ohio side of the river to end at a tee intersection where a grassed field faces the river at the former bridge site.  No sign marks the location.  A replacement bridge is located eight tenths of a mile downstream, outside of downtown and the developed area.