1. Daire McCormack Natasha Brady Peadar Barrett

2.  Constructed in 1928 and spanned the Ohio River between Point Pleasant, West Virginia and Kanauga, Ohio.  Known as silver bridge due to aluminium paint.  The bridge spanned 608m and had a width of 8.2m.  Renovations in 1951 after it was purchased by the State of West Virginia.

3.  Rocker Towers Allowed movement of the bridge due to live loads, vibrations to temperature changes Curved fitting next to a flat one at the bottom of the piers Dowel rods to keep the structure from shifting horizontally

4.  Reinforced concrete trough 60.96m long and 10.36m wide filled with soil and reinforced concrete.  Supported on 406 0.4m octagonal reinforced concrete piles in which the cable pull is resisted by the weight of the anchorage and by sharing the halves of the piles

5.  The bridge's eye-bars were linked together in pairs like a chain while a large pin passed through the eye and linked each piece to the next.  Each chain link consisted of a pair of 2" x 12" bars and was connected by an 11" pin.

6.  December 15 th 1967 @ 5pm, 39 years in service  46 people died, 9 injured  Major transportation route destroyed

7.  Single Link  Eyebar 330 @ joint C13N  Cleavage fracture  Heat treated Carbon steel prone to cracking  Reached Critical depth of 1/8 th “  Ductile overload

8. Stress Corrosion -Tensile stress -Corrosive Environment - unexpected failure in normally ductile material Corrosion Fatigue -Cyclic Loading -Corrosive Environment -Fatigue damages protective film on steel

9.  Two concepts unknown in 1928  Inspection impossible without disassembly  Engineers did not anticipate design loads x3  Based on Model-T traffic  1928 average car weighed 680kg

10. Stress Corrosion + Corrosion Fatigue +Minute Crack +Increased Loads = Complete Structural Failure

11.  Similar bridges were closed  1 Destroyed  1 still standing  NBIS  Regular inspections

12.  Inspection Procedures  Design bridge material standards  Expand knowledge of bridge behaviour

14. Thank you