Kansas City Hyatt Regency Walkway Collapse Packet This packet is intended for use in an introductory mechanical engineering course. An overview of the Kansas City Hyatt Regency Walkway collapse is presented, and construction safety issues are emphasized. A homework assignment is included, as are sample exam problems. Time for presentation is estimated as 30 minutes. Objectives: 1. 2.

To introduce mechanical engineering students to concerns present in engineering. To increase awareness of construction safety.

This packet includes the following items: • • • •

Lecture material for the instructor Overheads for use during the lecture Lecture handouts for the students Homework problem

Kansas City Hyatt Regency Walkway Collapse Lecture Outline I. An Engineer’s Responsibility (OVERHEAD 1) A. Engineers have a tremendous responsibility to insure the safety, health, and welfare of the public. B. The public well-being can be maintained only if engineers follow all codes and standards, and uphold their professional obligations. C. Safety during the construction phase of projects will help to insure the ultimate safety of the completed structure. D. The Kansas City Hyatt Regency Walkway Collapse is an incident where construction safety was compromised, leading to the eventual collapse of the walkway. II. Kansas City Hyatt Regency Walkway Collapse (OVERHEAD 2) A. On July 17, 1981, the Hyatt Regency Hotel in Kansas City, Missouri held a videotaped teadance party in their atrium lobby. The hotel had only been open for approximately one year. 1. Many people were standing and dancing on the suspended walkways. 2. The connections supporting the ceiling rods that held up the second and fourth-floor walkways across the atrium failed, and both walkways collapsed onto the crowded first-floor atrium below. 3. The fourth-floor walkway collapsed onto the second-floor walkway, while the offset third-floor walkway remained intact. 4. 114 people were killed, and over 200 injured. Millions of dollars in costs resulted from the collapse. B. Basic Walkway Design (OVERHEAD 3) 1. Three walkways, on the second, third, and fourth floors, span the atrium. 2. The third floor walkway was designed for higher traffic than the other walkways, and was consequently wider and offset from the other walkways. 3. The third and fourth floor walkways were suspended from the atrium roof, with the second floor walkway connected to the fourth floor walkway. C. A Collapse During Construction (OVERHEAD 4) 1. A collapse occurred on October 14, 1979 while the hotel was under construction. 2. Over 2700 square feet of the atrium roof collapsed because a roof connection failed. 3. After this collapse, the engineering firm in charge promised to review all steel connections and requested on-site representation during construction. 4. The owner rejected the request, due to the additional cost involved. D. While the hotel was under construction, changes were made in the design of the hanger rod connections. 1. The fabricator changed the design from a one-rod to a two-rod system to simplify the assembly task, doubling the load on the connector, which ultimately resulted in the walkway collapse. (OVERHEADS 5, 6. Discuss as desired.) 2. (OVERHEAD 7) The fabricator did not want to have to thread the entire rod in order to install the washer and the nut. The revised design consisted of: a. The top ends of the third and fourth floor support rods were attached to the atrium roof.

b.

The bottom ends went through the box beam where a washer and nut were threaded on. c. A second rod was attached to the box beam four inches from the first rod. d. The second floor walkway was suspended from the fourth floor walkway in a similar fashion. 3. (OVERHEAD 8) The fabricator, while in sworn testimony, claimed that his company had telephoned the engineering firm for change approval. The engineering firm declared they had not received the phone call. 4. Even as originally designed, the walkways were barely capable of holding up the expected load, and would have failed to meet Kansas City building requirements. 5. The Kansas City Building Code requires a minimum support value of 151 kN. The original design was capable of supporting 90 kN. With the design changes made during construction, the walkways would be supporting double that amount, or 180 kN, assuming the walkways were loaded at the maximum recommended weight limit. E. Who was responsible? (OVERHEAD 9) 1. A lack of communication between the designer and the fabricator is one of the contributors to the failure of the walkways. 2. The engineering firm did receive revised drawings during construction and stamped them with their engineering review seal, authorizing construction. 3. The revised design was significantly less capable of holding up the required forces, and was not designed in accordance with the Kansas City building code. F. Consequences (OVERHEAD 10) 1. 114 people were killed and over 200 injured. 2. Many principals involved lost engineering licenses. 3. Engineers were found guilty of gross negligence, misconduct, and unprofessional conduct in the practice of engineering. 4. Expensive legal suits were settled out of court. 5. Several firms involved went bankrupt. III. Conclusion (OVERHEAD 11) A. From the Kansas City example, the importance of an engineer’s responsibility can be seen in aspects ranging from design to construction. B. The collapse of the atrium roof during construction was indicative of problems with the overall design. C. Engineers should thoroughly review all designs and modifications made during the construction phase to insure the safety of the project. Adapted from: http://www.eos.uoguelph.ca/webfiles/james/homepage/Teaching/210/WebShare/WWWROOT/Home/ Background_/background_.htm http://lowery.tamu.edu/ethics/ethics/hyatt/hyatt1.htm http://www.people.virginia.edu/~jtt3e/hyatt/paper.htm http://www.sgh.com/kchyatt.htm http://www.uoguelph.ca/~ajenney/webpage.htm

Kansas City Hyatt Regency Walkway Collapse

An Engineer’s Responsibility • Engineers have a tremendous responsibility to insure the safety, health, and welfare of the public. • The public well-being can be maintained only if engineers follow all codes and standards, and uphold their professional obligations. • Safety during the construction phase of projects will help to insure the ultimate safety of the completed structure. • The Kansas City Hyatt Regency Walkway Collapse is an incident where construction safety was compromised, leading to the eventual collapse of the walkway.

1

Kansas City Hyatt Regency Walkway Collapse On July 17, 1981, the Hyatt Regency Hotel in Kansas City, Missouri held a videotaped teadance party in their atrium lobby. The hotel had only been open for approximately one year. • Many people were standing and dancing on the suspended walkways. • The connections supporting the ceiling rods that held up the second and fourth-floor walkways across the atrium failed, and both walkways collapsed onto the crowded firstfloor atrium below. • The fourth-floor walkway collapsed onto the second-floor walkway, while the offset third-floor walkway remained intact. • 114 people were killed, and over 200 injured. Millions of dollars in costs resulted from the collapse.

2

Basic Walkway Design • Three walkways, on the second, third, and fourth floors, span the atrium. • The third floor walkway was designed for higher traffic than the other walkways, and was consequently wider and offset from the other walkways. • The third and fourth floor walkways were suspended from the atrium roof, with the second floor walkway connected to the fourth floor walkway.

3

A Collapse During Construction • • •

•

A collapse occurred on October 14, 1979 while the hotel was under construction. Over 2700 square feet of the atrium roof collapsed because a roof connection failed. After this collapse, the engineering firm in charge promised to review all steel connections and requested on-site representation during construction. The owner rejected the request, due to the additional cost involved.

4

ORIGINAL DESIGN

Connector supports the weight of one walkway

Taken from http://www.uoguelph.ca/~ajenney/webpage.htm

5

DESIGN, AS BUILT

Connector supports the weight of two walkways Taken from http://www.uoguelph.ca/~ajenney/webpage.htm

6

The fabricator did not want to have to thread the entire rod in order to install the washer and the nut. The revised design consisted of: • The top ends of the third and fourth floor support rods were attached to the atrium roof. • The bottom ends went through the box beam where a washer and nut were threaded on. • A second rod was attached to the box beam four inches from the first rod. • The second floor walkway was suspended from the fourth floor walkway in a similar fashion.

7

• The fabricator, while in sworn testimony, claimed that his company had telephoned the engineering firm for change approval. The engineering firm declared they had not received the phone call. • Even as originally designed, the walkways were barely capable of holding up the expected load, and would have failed to meet Kansas City building requirements. • The Kansas City Building Code requires a minimum support value of 151 kN. The original design was capable of supporting 90 kN. With the design changes made during construction, the walkways would be supporting double that amount, or 180 kN, assuming the walkways were loaded at the maximum recommended weight limit.

8

Who was responsible? • A lack of communication between the designer and the fabricator is one of the contributors to the failure of the walkways. • The engineering firm did receive revised drawings during construction and stamped them with their engineering review seal, authorizing construction. • The revised design was significantly less capable of holding up the required forces, and was not designed in accordance with the Kansas City building code.

9

Consequences • • •

• •

114 people were killed and over 200 injured. Many principals involved lost engineering licenses. Engineers were found guilty of gross negligence, misconduct, and unprofessional conduct in the practice of engineering. Expensive legal suits were settled out of court. Several firms involved went bankrupt.

10

Conclusion • From the Kansas City example, the importance of an engineer’s responsibility can be seen in aspects ranging from design to construction. • The collapse of the atrium roof during construction was indicative of problems with the overall design. • Engineers should thoroughly review all designs and modifications made during the construction phase to insure the safety of the project.

11

Kansas City Hyatt Regency Walkway Collapse Lecture Handout I. An Engineer’s Responsibility A. Engineers have a tremendous responsibility to insure the safety, health, and welfare of the public. B. The public well-being can be maintained only if engineers follow all codes and standards, and uphold their professional obligations. C. Safety during the construction phase of projects will help to insure the ultimate safety of the completed structure. D. The Kansas City Hyatt Regency Walkway Collapse is an incident where construction safety was compromised, leading to the eventual collapse of the walkway. II. Kansas City Hyatt Regency Walkway Collapse A. On July 17, 1981, the Hyatt Regency Hotel in Kansas City, Missouri held a videotaped tea-dance party in their atrium lobby. The hotel had only been open for approximately one year. 1. Many people were standing and dancing on the suspended walkways. 2. The connections supporting the ceiling rods that held up the second and fourth-floor walkways across the atrium failed, and both walkways collapsed onto the crowded first-floor atrium below. 3. The fourth-floor walkway collapsed onto the second-floor walkway, while the offset third-floor walkway remained intact. 4. 114 people were killed, and over 200 injured. Millions of dollars in costs resulted from the collapse. B. Basic Walkway Design 1. Three walkways, on the second, third, and fourth floors, span the atrium. 2. The third floor walkway was designed for higher traffic than the other walkways, and was consequently wider and offset from the other walkways. 3. The third and fourth floor walkways were suspended from the atrium roof, with the second floor walkway connected to the fourth floor walkway. C. A Collapse During Construction 1. A collapse occurred on October 14, 1979 while the hotel was under construction. 2. Over 2700 square feet of the atrium roof collapsed because a roof connection failed. 3. After this collapse, the engineering firm in charge promised to review all steel connections and requested on-site representation during construction. 4. The owner rejected the request, due to the additional cost involved. D. While the hotel was under construction, changes were made in the design of the hanger rod connections. 1. The fabricator changed the design from a one-rod to a two-rod system to simplify the assembly task, doubling the load on the connector, which ultimately resulted in the walkway collapse.

ORIGINAL DESIGN Connector supports the weight of one walkway

DESIGN, AS BUILT Connector supports the weight of two walkways

2.

E.

F.

The fabricator did not want to have to thread the entire rod in order to install the washer and the nut. The revised design consisted of: a. The top ends of the third and fourth floor support rods were attached to the atrium roof. b. The bottom ends went through the box beam where a washer and nut were threaded on. c. A second rod was attached to the box beam four inches from the first rod. d. The second floor walkway was suspended from the fourth floor walkway in a similar fashion. 3. The fabricator, while in sworn testimony, claimed that his company had telephoned the engineering firm for change approval. The engineering firm declared they had not received the phone call. 4. Even as originally designed, the walkways were barely capable of holding up the expected load, and would have failed to meet Kansas City building requirements. 5. The Kansas City Building Code requires a minimum support value of 151 kN. The original design was capable of supporting 90 kN. With the design changes made during construction, the walkways would be supporting double that amount, or 180 kN, assuming the walkways were loaded at the maximum recommended weight limit. Who was responsible? 1. A lack of communication between the designer and the fabricator is one of the contributors to the failure of the walkways. 2. The engineering firm did receive revised drawings during construction and stamped them with their engineering review seal, authorizing construction. 3. The revised design was significantly less capable of holding up the required forces, and was not designed in accordance with the Kansas City building code. Consequences 1. 114 people were killed and over 200 injured.

2. 3.

Many principals involved lost engineering licenses. Engineers were found guilty of gross negligence, misconduct, and unprofessional conduct in the practice of engineering. Expensive legal suits were settled out of court. Several firms involved went bankrupt.

4. 5. III. Conclusion A. From the Kansas City example, the importance of an engineer’s responsibility can be seen in aspects ranging from design to construction. B. The collapse of the atrium roof during construction was indicative of problems with the overall design. C. Engineers should thoroughly review all designs and modifications made during the construction phase to insure the safety of the project. Adapted from: http://www.eos.uoguelph.ca/webfiles/james/homepage/Teaching/210/WebShare/WWWROOT/Home/ Background_/background_.htm http://lowery.tamu.edu/ethics/ethics/hyatt/hyatt1.htm http://www.people.virginia.edu/~jtt3e/hyatt/paper.htm http://www.sgh.com/kchyatt.htm http://www.uoguelph.ca/~ajenney/webpage.htm

Kansas City Hyatt Regency Walkway Collapse Homework Assignment Write a one page paper discussing the following: 1. What was the loading problem in the walkway collapse? 2. Why should the problem have been detected? 3. What design issues were partial causes of the collapse?