Point Pleasant Bridge Disaster Group 19

Events and consequences 5PM December people killed, 9 injured Only major connection between West Virginia and Ohio

Background Ohio river US highway 35 Point Pleasant, West Virginia, Kanauga, Ohio Two lane, 670m American Society of Civil Engineers

Technical Background First of its kind Eye bars linked in pairs like a chain Pin passed through eye Heat treated carbon steel Load of 4 million kg Ultimate strength of 725MPa Elastic limit of 520MPa Max working stress of 350Mpa

….continued Bedrock foundation too costly Reinforced concrete trough 60m long and 10.2 m wide supported by piles Shifting loads and temp. variations 40 m high pinned rocker towers

Technical factors contributing to collapse Cleavage fracture of an eye Minute crack when casting Stress corrosion and corrosion fatigue Ductile fracture near pin South chain then snapped

Human and managerial factors Lack of knowledge in 1927 Vindicates designer? Not accessible for visual inspection Bridge seemed to be performing well for 40 years

….continued Average weight of motor car Should have been addressed

Lessons learnt Secretary for transport Critical flaw sizes in bridge building materials New inspection equipment Techniques for protection, repair and salvage Periodic inspection of all nation’s bridges

Any Questions ?