The Hyatt Regency
Walkway Collapse
Group No. 3:
Clare O Farrell
Declan Farrell
John Deenihan
John Duffin
Introduction:
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Hotel opened July 1980
3 connecting structures
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40 story tower
Function block
3 x 37m skywalks spanning an atrium
3rd and 4th floor walkways suspended
independently from roof
2nd floor bridge suspended from 4th floor bridge via
system of 32mm steel hanger rods
Proposed Design:
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2nd floor was originally
designed to be suspended
from 4th floor via single rod
Rod threaded through
welded box beam
supported by a washer
and nut
However, proposed design
not implemented
Actual Design:
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Original design
impractical
Contractors amended
design to double
hanger rod connection
4th floor box beam now
had to support load of
two walkways
3rd floor walkway kept
to original spec.
Failure:
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Friday evening 17th July 1981, over 1,600 people
attended a tea dance in the atrium
All 3 walkways were crowded with people dancing
The weight and vibration caused the 4th floor box
beam to split at the welds and hanger rods were
ripped through
Resulted in both the 2nd and 4th floor walkways
collapsing, killing 114 people, injuring over 200
intact hanger rods from 4th
floor walkway opening
Close-up of one of the 4th floor beams
Responsibilities:
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Walkways collapsed under less load than
specified building code
Box beam connections did not meet code
Fault found to be with the structural
engineers – no recalculations for revised
design, thus constructed walkway was both
uncertified and illegal
Engineering licences lost
Conclusions:
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Engineers have a responsibility to public
and clients for both construction and
service life of a structure
All aspects of design must achieve a
standard of adequate safety and reliability,
no compromise may be made
Major neglect on part of engineering firm
involved