Presentation on theme: "Hyatt Regency Walkway Collapse Presentation by William J. Frey."— Presentation transcript:
Hyatt Regency Walkway Collapse Presentation by William J. Frey
Agenda Case Narrative STS Table Case Chronology Key Decision Point Ethical IssueResponsible Design To Engineer is Human (Video by Petroski) Code of Ethics Issues
Case Narrative On July 17, 1981, the second and fourth story walkways of the Kansas City Hyatt Regency Hotel collapsed killing 114 people and seriously injuring an additional 200. Cause: – A deviation in the design in the way the rods connected the lower skywalk to the upper and the upper to the ceiling of the atrium was clearly described and zeroed in on as the ultimate cause of the accident. Petroski: 86
Case Narrative Warning Signs – The Atrium ceiling collapsed during construction; but a study carried out by an independent engineering firm found nothing wrong with the skywalk – Workers carrying loaded wheel barrows across the skywalk complained about excess vibration and swaying Petroski – After twenty months of investigation, the U.S. attorney and the Jackson County, Missouri, prosecutor announced jointly that they had found no evidence that either a federal or state crime was committed… (TAMU Instructor Manual) However in an investigation carried out by the attorney general of Missouri… – Duncan, Gillium, and GCE International Inc. were found guilty of gross negligence, misconduct and unprofessional conduct in the practice of engineering. (TAMU Instructor Manual)
Chronology (Adopted from TAMU Instructor Manual Chronology) DateEvent Early 1976 Crown Center Redevelopment Corporation begins project to build Hyatt Regency Hotel July 1976 Gillum-Colaco, Inc. selected as consulting structural engineer July 1976 Project enters schematic design stage Summe r 1977 GCE works with PBNDML architect to decide upon basic design Late 1977 Bid set of structural drawings and specifications Early 1978 Project prepared under regional building codes
Chronology DateEvent April 4, 1978Contract finalized between GCE and PBNDML Spring 1978Construction begins August 28, 1978 Project specifications issued for construction based on AISC standards (American Institute of Steel Construction) December 1978 Eldridge Construction Company, general contractor, finalizes subcontract with Havens Steel Company. Havens agrees to fabricate and erect the atrium steel for the Hyatt project. February 1979 Havens makes design change from a single to a double hanger rod box beam connection…. Havens claims GCE approved. GCE denies approving this. Oct 14, 1979Atrium roof collapse November 1979 Seiden-Page investigates collapse and carries out a thorough design check of all elements of atrium roof. Assures owners of overall safety of newly designed roof.
Chronology DateEvent July 1980Construction of hotel completed July 17, nd and 4 th story walkways collapse killing 114 and injuring 200. February 3, 1984 Missouri Board of Architects, Professional Engineers and Land Surveyors files complaint against Daniel M. Duncan, Jack D. Gillium and GCE International Inc., charginng gross negligence, incompetence, misconduct and unprofessional conduct in the practice of engineering in connection with their performance of engineering services in the design and construction of the Hyatt Regency Hotel in Kansas City, Missouri. November 1984 Duncan, Gillium, and GCE International Inc. found guilty of gross negligence, misconduct and unprofessional conduct in the practice of engineering. Subsequently, Duncan and Gillum lost their licenses to practice engineering in the State of Missouri, and GCE had its certificate of authority as an engineering firm revoked. American Society of Civil Engineering (ASCE) adopts report that states structural engineers have full responsibility for design projects. Duncan and Gillum now practicing engineers in states other than Missouri.
Component / Value Walkway Design Physical Surroundings People, Groups, and Roles ProceduresLaws, Codes, Statutes Information and Information Structures Statics Principles Experience with past designs Cement Floors Rods and bolts Box beams Atrium with 60 foot high ceiling. Three Walkways suspended from Roof Large space below walkways on first floor Hotel Owner Architecture, Engineering Design, Construction, and Engineering Investigating Firms Professional Societies Governmental Officials Hotel Design Process Engineers signing off on plans Contracting and subcont dividing responsibility Post Accident Investigation Engineering Codes Contract, Civil and Criminal Law Regulatory authority delegated to Professional Society Post accident investigation US attorney investigation Trial by Missouri attn gen Black Box: account of case in textbooks Ease of Construction Difficulty of constructing with original design Designers hand off to constructers Communication between designer and constructer SafetyStudying past failures and testing to failure Engineers approving design Investigating firm Signing and Signing plans (licensed engineer) Codes set stds Legal system punishes violations Elegance or Beauty Create a floating walkway Walkway to appear suspended
Concepts related to Safety and Risk Risk Assessment Risk Communication Risk Perception Risk Management
Safety A thing is safe if, were its risks fully known, those risks would be judged acceptable in light of settled value principles. (Martin/Schinzinger, Engineering Ethics, 108) Safety and risk are different sides of the same coin – One is defined in terms of the other Settled value principles makes safety a matter of public policy. Government plays a role. So does business. Most importantly, so do members of the public
Public those persons whose lack of information, technical knowledge, or time for deliberation renders them more or less vulnerable to the powers an engineer wields on behalf of his client or employer – Michael Davis. Thinking Like An Engineer The public is in an especially vulnerable position. They stand subject to the risk. But they do not participate in the project that generates the risk The public has the right to free and informed consent. – This right is vulnerable if risk information does not get to them, if the risk information is too complicated for them to appreciate, or no provisions have been taken to include them in the collective risk acceptability (=safety) decision.
Risk The other side of the coin – Risk and safety are correlative and defined in terms of one another A risk is the potential that something unwanted and harmful may occur. (MS 108) Risk has four dimensions (assessment, management, perception, and communication) Since risk is the probability of harm and probability implies uncertainty (lack of complete knowledge), the ethics of risk lies in how this uncertainty is communicated and distributed. – For example, does a government regulatory agency approve a product unless it is proven harmful…. – Or does it withhold approval from a product until it is proven completely safe. – In the first, the burden of uncertainty falls on the public exposed to risk, in the second on the manufacturer who cant reap benefits from selling the uncertainly risky product.
Risk Assessment The scientific and exact process of determining the degree of risk Animal Bioassays – Animals exposed to risk fact at intense level for short period of time – Projection from animal physiology to human physiology and from short term/intense exposure to long term/less intense exposure Epidemological Studies – Comparison between populations exposed to risk and populations not exposed to risk – Search for significantly higher risk ratio. Three-to-one not generally significant. Six-to-one is significant Ethics of Risk – Since there is uncertainty in risk assessment, an ethical issue arises as to how that uncertainty is distributed
Risk Assessment in Engineering Fault Tree – a diagram of the possible ways in which a malfunction or accident can occur. – enable an engineer to analyze systematically the various failure modes attendant to an engineering project – Determining why a car wont start by considering different failure modes Harris, E., Pritchard, M., and Rabins, M. (2005). Engineering Ethics: Concepts and Cases. Thompson: 156
Risk Assessment in Engineering Faiure Mode – way in which a structure, mechanism, or process can function. Event Tree Analysis – reason forward from hypothetical events to determine what might have led to the final event – Reasoning from pipe break in nuclear reactor to possible outcomes (release of radiation) – Harris, E., Pritchard, M., and Rabins, M. (2005). Engineering Ethics: Concepts and Cases. Thompson: 157
Limitations in Risk Assessment Cannot predict all possible failure modes Human error is also difficult to predict (See Reason in Human Error for a possible account) Probabilities assigned are largely a matter of guesswork We can never be sure we have all of the possible initiating events…. Harris, E., Pritchard, M., and Rabins, M. (2005). Engineering Ethics: Concepts and Cases. Thompson: 157-8
Different Kinds of Accident Normal Accidents (Perrow) – Happens in tightly coupled systems – Leads to non-linear causality – Small failure proves difficult to isolate; spreads out to create other failures; these cascade to produced catastrophe Complexity of system makes it difficult to predict accident and assess risk – Ladd calls these loss of control accidents John Ladd. Bhopal Article
Human Error Reason treats accidents as pathogens that are latent in a complex system When circumstances are right, a configuration of events creates an opportunity for the pathogen to emerge Reason argues that accidents come from human cognitive procedures that usually work for the best
Risk Communication Results of risk assessment are technical and subject to different interpretations Public has a right to informed consent vis a vis risk – To consent to take a risk (or withhold consent) they must understand the risk and be able to make a coherent consent decision This raises issues in risk communication – Clear communication – Comprehensive communication (not leaving out anything significant) – Communication that takes into account the perspective from which the public will perceive the risk
Risk Perception The public perceives risk according to a clear perspective This renders risk perception rational because predictable (to a certain extent) Factors which influence public perception of a risks acceptability – Voluntariness – Expected benefits – Control over risk – Minimal dread factor – Minimal unknown factor
Risk Management Political process of determining if a certain degree of risk is acceptable according to a communitys settled value principles Value principles are identified via a process of deliberative democracy which respect the meta- norms of reciprocity, publicity, and accountability Communitys identify small scale project for experimental analysis – These validate settled values – These also help to determine if larger scale action is acceptable
Resources Hyatt Regency Kansas City Walkway Collapse" Online Ethics Center for Engineering 11/24/2010 National Academy of Engineering Accessed: Thursday, December 16, 2010 Henry Petroski (1985). To Engineer is Human: The Role of Failure in Successful Design. St. Martins Press: – The Kansas City Hyatt Regency Walkways Collapse – Department of Philosophy and Department of Mechanical Engineering Texas A&M University NSF Grant Number DIR – Photos by Dr. Lee Lowry, Jr. at TAMU