[TalBlack]

“Terrible. I remember the Kansas City Skywalk collapse in ‘81, I believe.“

Wasn’t there some kind of harmonic convergence involved there or did it just let go?

[DIRTYSECRET]

All I remember about the incident was construction crews coming in the middle of the night to gut the rest of the inside of the building-lawyers. The Hyatt in SF had the same design.

[OldHarbor]

Kansas City was a bad design that was altered , that, along with shoddy practices by the tradesmen and the engineers , set up the disaster.

AI summary

Redesigned Hanger System: The original design called for a single set of rods to pass through both walkways, with each walkway supported independently.

The modified design changed this to two separate sets of rods, where the second-floor walkway was suspended from the fourth-floor walkway.

This design placed the entire weight of both walkways on the fourth-floor beams.

Failed Connection Detail: The fourth-floor beam was comprised of two steel box channels welded together, which were not strong enough to handle the increased load. The design lacked proper stiffeners or reinforcing steel plates, causing the nuts to pull through the box beams under the weight.

Failure of Review: The contractor suggested the rod change to ease construction, but the structural engineering firm approved the change without performing calculations or conducting a detailed review.

Neglected Safety Codes: The original design itself was already inadequate by industry standards, with a capacity only roughly 60% of what was required by building codes.

[Governor Dinwiddie]

Poor engineering. The suspension rods, bolts, and washers were not capable of supporting the
weight of the walkway. A design change without engineering review was the direct cause.

[ridesthemiles]

HARMONICS—MY THOUGHT ALSO...

[ridesthemiles]

HARMONICS—MY THOUGHT ALSO...

ALL DANCING TO A TUNE WITH STOMPING???

THAT IS WHY MILITARY ALWAYS BREAKS CADENCE WHEN CROSSING ANY BRIDGE........

[FreedomPoster]

IIRC there was a significant difference with the hanger connection detail to the walkway between the engineer’s design, and the contractor’s shop drawings and installation, that no one caught. That combined with the added force by the rhythmic dancing created the failure and disaster.

[catnipman]

“Wasn’t there some kind of harmonic convergence involved there or did it just let go”

the steel fabricator changed the original design to simplify construction without proper engineering load analysis on the changes ... this resulted in the load being doubled on part of the walkway, which caused the collapse ..

[MHT]

Poorly designed screw that was used in suspended balcony walkway...no structural support.