The Point Pleasant
Bridge Disaster
The Collapse of “Silver
Bridge”
Group 19
Introduction
 Designed
by American Society of
Civil Engineers.
 Built by General Corporation and the
American Bridge Company, 1928.
 Linked Point Pleasant, West Virginia
and Kanauga, Ohio.
 682m long, 6.7m wide
Details of Bridge
 Revolutionary
eye bar chain
suspension bridge.
 High strength heat treated steel but
only 2 bars in each link.
 Low redundancy chains: cost
effective but safety dependant on
accuracy of manufacture and
materials
The Towers
 40m
tall “rocker” towers.
 Towers not connected rigidly to the
bases to allow the bridge to respond
to live loads and deflections.
 Anchorage to bed rock too costly so
a reinforced concrete trough filled
with soil and reinforced concrete was
used.
The Collapse
Collapsed on 15th
December 1967 at
5pm after standing
for 39 years.
 46 killed, 9 injured
 Important bridge
connecting West
Virginia and Ohio
completely
destroyed.

Wreckage Analysis
Failure of entire bridge due to a defect in a
single link in one eye bar.
 Fretting wear at the bearing caused a
small crack to form which led to stress
corrosion cracking.
 The lower side of the eye bar failed and all
the load was transferred to the other side
of the eye bar, which then failed by ductile
overload.
 The south chain then snapped and the
bridge collapsed.

Causes of Collapse
 Bridge
designed for loading of Ford
Model T (680kg) in 1928, average
car in 1967 weighed 1800kg.
 Traffic loads increased dramatically
between 1928-1967.
 Technology then did not exist to
detect minute cracks.
Aftermath
 The
collapse of the Silver Bridge led
to increased maintenance and
inspection of other older bridges.
 New inspection protocols were
developed and many bridges were
replaced.
Thanks