Structural Integrity: Silver Bridge - for iPod/iPhone: Recent Episodes
The Open University
The 1967 collapse of the Silver Bridge over the Ohio River was an engineering mystery and a human tragedy - 46 people died. Why did a suspension bridge built to last a century not make 40 years? Built in 1928, it was a slimmer version of similar bridges built in nearby Pittsburgh. The slimming down was deemed to be safe because of the use of a tougher steel and ‘silver coloured anticorrosion paint’. The tracks in this album look at the factors which led to the catastrophic failure of one of the eyebars which supported the deck, and the subsequent forensic investigation which led to the creation of the National Bridge Inspection Standards to inspect the 1 million bridges of the USA. This material forms part of the course T357, Structural integrity: designing against failure.
How the Silver Bridge and the Hi-Carpenter Bridge differed from other suspension bridges in one crucial aspect.
Transcript -- How the Silver Bridge and the Hi-Carpenter Bridge differed from other suspension bridges in one crucial aspect.
Why it's safer to incorporate more eyebars than are actually needed, to bear the weight of the bridge.
Transcript -- Why it's safer to incorporate more eyebars than are actually needed, to bear the weight of the bridge.
Transcript -- How the use of a new high-strength steel led to mistaken assumptions about safety.
How an investigation identified where the failure had occurred. A recovered eyebar is examined up close.
Transcript -- How an investigation identified where the failure had occurred. A recovered eyebar is examined up close.
How increasing traffic and freezing temperatures triggered the failure. An eye-witness account of the collapse.
Transcript -- How increasing traffic and freezing temperatures triggered the failure. An eye-witness account of the collapse.
How an undetected 3mm crack formed over 39 years weakened the eyebar, and a forensic deconstruction of what happened during the accident.
Transcript -- How an undetected 3mm crack formed over 39 years weakened the eyebar, and a forensic deconstruction of what happened during the accident.