Failure by Design Hyatt Regency

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Failure By Design(Two Case Studies of Bridge Design Failure)

by Granger MeadorPhysics Teacher, Bartlesville High School Bartlesville, OK

FAILURE BY DESIGN(Two Case Studies of Bridge Design Failure)

by Granger Meador Published by the Author Version 2.0 Contact information: Granger Meador Physics Instructor Bartlesville High School 1700 SE Hillcrest Drive Bartlesville, OK 74003-7299 1-918-336-3311 FAX 1-918-337-6226 Email: or WWW:

This work is licensed under the Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License. To view a copy of this license, visit or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA.

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Failure By Design by Granger Meador (

PURPOSEDisasters are inherently intriguing to students, and can motivate them to engage in high levels of analysis. My goals in having my own 11-12th grade physics students analyze the Hyatt Regency hotel walkways collapse and the failure of the Tacoma Narrows bridge include: develop students analytical and deductive skills in determining the possible and actual failure modes of a structure illustrate for students how engineers and architects must utilize physics in designing safe structures have students use their knowledge of force loading and vectors to explain the flaw in the design change of the Hyatt walkways introduce concepts of wave motion and aerodynamics to explain the vibrations and failure of the Tacoma Narrows bridge

I have attempted to include enough information in this document to allow other teachers to deal with each disaster at varying levels of sophistication. Teachers own instructional goals and knowledge of their students level of conceptual and mathematical development will dictate how much time and effort they wish to devote to these topics. The Hyatt disaster is introduced as a puzzle to be solved, to increase student interest and motivation. Evidence is presented for students to debate and analyze in small groups or as a class. Students can use the evidence to develop and evaluate speculative conceptual solutions, which are then judged against additional evidence gathered after the accident. I have also included any additional data I could find for optional quantitative analysis. Students are asked to suggest possible design improvements, and the societal aspects of the design failure and the repercussions of the accidents are also presented. The Tacoma disaster is too complex to expect most introductory physics students to analyze its failure. Instead, a qualitative description of its behavior is used to illustrate some aspects of wave motion and point out how a large structures aerodynamic behavior cannot be safely neglected. Students are again asked to suggest possible design improvements which are compared to the changes made when the bridge was reconstructed. Many physics texts identify resonance as a reason for the Tacoma disaster; in recent years some engineers have argued that resonance was not involved, but more complex modes of self-excitation. The reader is referred to the technical discussions on the CD-ROM for more information.

Failure By Design by Granger Meador (

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ONLINE PRESENTATIONIn addition to this handout, there is online presentation at with graphical images, animations, and movies. The online presentation is adapted from a PowerPoint presentation, and you can progress through it in your web browser.

TACOMA NARROWS VIDEOTAPEThe public domain and online clips of the Tacoma Narrows disaster are of limited quality and duration. For the greatest dramatic effect, teachers are urged to consider purchasing a high-quality color video from a respected source. The American Association of Physics Teachers offers a videotape with three segments: Tacoma Narrows Bridge Collapse by Franklin Miller, Jr. (1963), The Puzzle of the Tacoma Narrows Bridge Collapse by R.G. Fuller, D.A. Zollman, & T.C. Campbell (1982), and the combined footage (1998). As of March 2008 the videotape and accompanying users guide was available for $48.95 for AAPT members, $37.00 for student members, and $61.00 for non-members. The users guide includes a number of suggested activities where students analyze the videotape to obtain quantitative data. Catalog Number: Description: VT-20 Twin Views of the Tacoma Narrows Bridge Collapse

American Association of Physics Teachers One Physics Ellipse College Park, MD 20740-3845 PHONE 301-209-3311 The incredible footage of the Tacoma disaster used in the above videotape was shot by a Tacoma camera store owner. His shop is now run by his son-in-law, who also has a videotape and DVD for sale. As of March 2008 the DVD price was $65.00 and the videotape price was $49.00 from:

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Failure By Design by Granger Meador (

THE COLLAPSE OF THE HYATT REGENCY HOTEL WALKWAYS IN KANSAS CITYHallmark Cards, Inc. is headquartered in Kansas City, Missouri. By 1968, the area surrounding its headquarters south of downtown suffered from urban blight, and the company began the massive Crown Center 85-acre redevelopment project. As part of the project, a Hyatt Regency Hotel was designed and constructed from 1976 to 1980. Unfortunately, the hotel had design and construction problems which led to a horrific disaster one year after it opened. The hotel has three main sections: a 40-story tower, a function block, and a connecting atrium area. The atriums dimensions are 145 ft (44.2 m) by 117 ft (35.7 m), and 50 ft (15.2 m) high. For guest convenience, three walkways were constructed along the width of the atrium to connect the tower and function block on the second, third, and fourth floors of the structure. The walkways were suspended from the ceiling so that the main floor would not be obstructed by support columns. The third floor walkway, which connected to a ballroom, was wider than the others and suspended from the roof on its own set of rods. The fourth floor walkway, which led to the health club and sports area, was also suspended from the roof by rods. The second floor walkway was suspended by rods from the fourth floor walkway, as seen in the architectural rendering at right.

The Disaster:On July 17, 1981 the hotel had been open for a year and a local radio station was holding a dance competition. By 7 pm the atrium was crowded with between 1500 and 2000 people, with many spectators observing from the walkways. At 7:05 pm a loud crack echoed through the building and the second and fourth floor walkways collapsed, killing 114 people and injuring over 200 others.

Failure By Design by Granger Meador (

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Hyatt Puzzle What part(s) of the walkways failed? Given the overall design as constructed, what parts of the support structure could have failed to cause both the second and fourth-floor walkways to collapse? What evidence would you look for to decide which part actually failed?The fourth-floor walkway was suspended from the roof by three sets of hanger rods. The rods passed through longitudinally welded box beams and were capped with washers and nuts which held up the walkway by pressing on the underside of the box beams. The second-floor walkway was suspended from the fourth-floor walkway by another set of hanger rods. These rods were held up by washers and nuts pressing on the top surface of the 4th-floor box beams. The rods passed through box beams for the second-floor walkway and were again capped with washers and nuts pressing against the underside of the 2nd-floor box beams. Long I-beams running down the sides of each walkway were suspended from the box beams by angle brackets. At right is a closeup view of the construction of the 4th-floor walkway and its connections to the hanger rods.

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Failure By Design by Granger Meador (

Hyatt Structural DetailsWalkway length: Walkway width: Hanger rod diameter: Hanger rod length: Inset for 2nd-floor rods: I-beams: Box beams: 117 feet (35.7 m) approx. 18 feet (5.49 m); 4th and 2nd-floor walkways were 15.6 in (0.397 m) narrower than separate 3rd-floor walkway 1.26 in (32 mm) as built, each approx. 20-23 ft (6-7 m); 4th-floor connection was 6.1 m below roof 4 in (102 mm) inward along axis of box beam 16-inch (40.6 cm) deep (W16x26 steel: wide flange steel beam of 16-in depth, weighing 26 pounds per foot) two 8-in (20.3 cm) deep rectangular channels welded toeto-toe (MC8x8.5: flanged channel steel beams of 8-in depth, weighing 8.5 pounds per foot); Jensen (2000) assumed capacity of 115 kips or 115,000 pounds of force concrete, 3.25 in (8.26 cm) thick, approx. 150 lb/ft3

Walkway floor:

Hyatt Possible Conceptual Solutions/Failure ModesThese are presented to assist you in leading a student discussion. Likely failure modes: 1) The hanger rods from the roof to the fourth-floor walkway snapped or the roof connection failed.

Examination of the accident scene would show the upper rods broken off, most likely near the roof where the load in each rod would be maximized.


The nuts under the fourth-floor box beams stripped free.

The accident scene should reveal nuts stripped from the hanger rods, but few if any punctures of the nuts through the fourth-floor box beams.


The fourth-floor box beams gave way at the ends, allowing the washers and nuts underneath them to punch through.The accident scene should reveal washers and nuts still on the rods hanging from the roof, with punctures through the box beams.