1. Point Pleasant Bridge Disaster Group 19

2. Events and consequences 5PM December 1967 46 people killed, 9 injured Only major connection between West Virginia and Ohio

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

4. 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

5. ….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

6. 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

7. 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

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

9. 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

10. Any Questions ?