Responsible Engineers

Responsible Engineers - Professional Practice ,...

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Unformatted text preview: Professional Practice , Occupational Health and safety Responsible Engineers Course MIME-221 Responsible Engineers 1 If the "Ethics Rope" Breaks, We all lose ! We all lose ! Most valuable attributes of an engineer Character: Honesty & Integrity Responsibility (reliability) Skills & knowledge: Technical knowledge Analytical skills Computation skills Communication skills 2 Responsible -- definition Responsible: 1) liable to be called on to answer; liable to legal review or in case of fault to penalties; 2) able to answer for one's conduct and obligations; able to choose for oneself between right and wrong... (Webster's Ninth New Collegiate Dictionary) Responsibilities of engineers Legal responsibilities: Cause no harm; Compensate when harm is caused; Practice in accord with Engineering Practices Act Moral responsibilities: Recognize & discharge our duties & obligations; Understand and adhere to a Code of Ethics 3 Ways in which harm is caused Intentionally acting with an intent, this is often a criminal act Recklessly -- acting in a way that we recognize might cause harm Negligently -- failing to exercise due care Legal Remedies for Harm Liability Applies to individual professionals & corporations Willful, negligent or reckless usually proven Strict Liability Usually applied to corporations No attribution of fault require Legal concept, not necessarily a moral concept Is this the basis for commercial insurance? 4 Three responsibility models Minimalist or Malpractice model Reasonable Care model Good Works model Minimalist responsibility model (or Malpractice) Engineers have a duty only to conform to accepted practice and fulfill only basic duties prescribed by terms of employment. Those who follow this model may be most concerned with not doing anything "wrong". "That's not my responsibility, someone else will take care of that." 5 Reasonable Care model of responsibility: Adhere to accepted standards of practice, and... Take reasonable care to ensure that mistakes are prevented and the public welfare is protected Exercise and apply skill, ability and judgement reasonably and without neglect keep abreast of evolving changes in knowledge and practice recognize when minimal standards of practice might be Insufficient to prevent a harm, and take additional actions to prevent such a harm in those cases Characteristics of the Reasonable Care model Attitude of concern or caring Concern for preventing harm, rather than trying to prevent causing harm Oriented towards the future, toward avoiding problems and protecting the public Example: Roger Boisjoly's actions before the launch of the Challenger 6 Good Works responsibility model "...above and beyond the call of duty." Examples: A local consulting engineer offers to design a parking lot for a church at her cost, with no charge for her own time. An engineer joins a consensus standards body and volunteers time and expenses to update standards of practice for his profession. Where do professional responsibilities lie? The reasonable care model is the best model for engineers. Codes demand it (...accept responsibility in making engineering decisions consistent with the safety, health and welfare of the public, and to disclose promptly factors that might endanger the public or the environment...as in the seen Code of Ethics) Public expects it Principle of Proportional Care: When people have a greater ability to harm, they have a greater obligation to prevent harm. 7 Some impediments or obstacles to responsibility Self-interest Fear Self-deception Ignorance Egocentric tendencies Microscopic vision Uncritical acceptance of authority Antagonism toward outside regulation "Groupthink" Cumbersome business organizations Which of these played a role in the Challenger case? Groupthink? Cumbersome business impediments? Self-interest? 8 Missouri City Antenna Tower Engineer designed Antenna & 1000 ft. tower Contractor (rigger) awarded erection contract During erection, rigger realizes lifting points on antenna sections can't be used without fouling antenna baskets (design error ?) Rigger asks to remove baskets and replace them after erection Antenna Tower Scenario, cont'd. Engineer denies riggers' request to remove baskets (last contractor who removed baskets caused expensive damage to antennas) Rigger develops plan to mount extension on antenna section to lift it Rigger asks engineer to review the plan 9 Scenario, cont'd. Engineer declines to review riggers' plan to mount extension on antenna, citing increased liability Rigger proceeds with lift of antenna Extension boom fails, antenna falls striking stay cable, tower falls, seven workers are killed Tower erection method Gin pole Tower (about 1000 ft) Tower sections (40 ft) Antenna Section 10 Antenna lifting method-riggers' modification Free body diagram of antenna section during lift, with rigger's extension boom 11 12 Missouri City Antenna Tower I. Case Statement A. Date and Time: 1985 Time: B. Place: Missouri City, TX (a southwestern suburb of Houston) Place: C. Characters: (names have been fictionalized) Characters: 1. Antenna Engineering, Inc.- designed and built the antenna Inc.William Harris - President. Harris recommended to Jordan that Antenna Engineering, Inc. not get Engineering, involved with Riggers problems regarding lifting the antenna tower, due to legal liability issues. tower, Harry Jordan - Head of Engineering Division. Jordan told Riggers that they could not authorize could removing the microwave baskets, yet he also told Riggers that the engineering firm signed off the responsibility once Riggers accepted their design plans. 2. Riggers, Inc. - contracted to assemble the antenna Frank Catch - President. Randall Porter - Vice President. Made initial call to Antenna Engineering, Inc., detailing the problems Riggers was having lifting the top antenna section with the microwave baskets on it. Bob Peters - Lead lift. One of the workers killed in the collapse. Kevin Chapp - Cable Operator. Talked to Peters before the catastrophe, asking about the safety of the operation. D. The Situation A Houston television station decided it needed to expand its antenna coverage area by erecting a antenna new, taller (1,000 foot) transmission antenna in Missouri City, TX. They hired Antenna Engineering, Inc. to design the antenna. The design called for twenty 50-ft sections to be twenty 50stacked onto one another, with the last two sections having microwave antenna baskets on microwave them. Riggers, Inc. was hired by the television station to assemble the tower. They would use a crawling the jib crane to lift the sections into place and then they would manually bolt them together. The manually crane was capable of crawling up the tower and thus would be able to place section after able section in place. Each 50-ft segment of the tower had a lifting lug in the middle of the section. This was used to lift 50section. the section of of the truck it was on. Riggers' Inc. decided to use this lug to lift the sections of lift the tower into place. They would lift it by the center and rotate it using additional wires so that rotate it would be vertically oriented. This method worked for 18 of the twenty sections. The last two the sections had microwave baskets along their length. The wire would hit these baskets if the would riggers tried to rotate the section around the lifting lug. Riggers, Inc. called Antenna Engineering and asked if they could take the baskets off during the lifting phase and then reattach them once the section was in place. Antenna Engineering, Inc. place. had let one set of riggers take the baskets off once, and they completely destroyed them in the completely process. They were not going to let that happen again. They told Riggers, Inc. that the baskets must stay on the sections. Riggers' Inc. asked how they were supposed to lift the section and supposed were told that that was their problem. The Riggers devised a solution for their problem. they decided to take some channel steel they had to and attach it to the section at a right angle. They would attach the cable to the end of the channel steel and rotate about that point. The cable now would not hit the baskets. They called not Antenna Engineering, Inc. and asked if they could come look at the solution they had devised the since Riggers, Inc. had no engineers on staff. Antenna Engineering, Inc. said that they could Engineering, not look at the solution since then they would be liable if anything went wrong. In fact, the anything president of Antenna Engineering, Inc. told his engineers to stay as far away from the site as stay possible, so they would not be linked to anything the riggers were doing. were Their solution had some problems that even a freshman engineering student could identify. But, engineering they had no engineers, so they were unable to perform an analysis like the one below. analysis 13 Model used by Riggers Model Riggers should have used Free body diagram of the lifting bar solution Sum(MA) = TL - FBd = 0 Sum(MA) Sum(MB) = T(L - d) - FAd = 0 Sum(MB) Solving the above equations for FA and FB, FA = (T(L - d))/d and FB = (TL)/d and the corresponding shear stress on each bolt is: sigA = FA/Abolt = (T(L - d))/(dAbolt) FA/Abolt d))/(dAbolt) sigB = FB/Abolt = (TL)/(dAbolt) FB/Abolt (TL)/(dAbolt) where: FA = Force on bolt A FB = Force on bolt B Abolt = Cross-sectional area of bolt Crossd = distance between the bolts R = (Shear stress with moment arm)/(Shear stress from Riggers) = Error Factor R = ((TL/d)Abolt)/((T/2)Abolt) = (2L)/d Assuming one set of bolts were used, placed one foot apart, and the steel channel was six feet long: Analysis of lifting bar solution Riggers, Inc. proceeded to lift the second to last section up to the top of the tower. Everything went smoothly. This was not to be the case with the last section. Its ascent was with captured on video by the television station. As the last section rose, physics caught up with the riggers. Near the top of the tower, their solution failed. The bolts holding their channel steel to bolts the section failed and the section fell. The falling section hit one of the tower's guy wires and the entire tower collapsed. All of the riggers on the tower and on the section were killed in the collapse (seven men total). R = 2(6[ft])/1[ft] = 12, or, in other words, the stress (for these assumed numbers) in the new the lug bolts is twelve times what the Riggers thought it would be, based on their erroneous analysis 14 Missouri City Antenna Tower Antenna section after collapse 15 Extension boom and failed u-bolts Wreckage of antenna and crane 16 Antenna Failure Some questions... Were the engineer's actions the right actions? No, seven workers died. 17 Should the engineer's moral responsibility take precedence over his legal responsibility? Was the engineer's responsibility for a safe and workable design met with lifting lugs that could not be used by the rigger? Were the riggers morally responsible for this accident? Did they ask an engineer for assistance? Did they recognize that the modification they attempted required engineering skills to accomplish? 18 What could the engineer have done differently? Agree to review the riggers' plans? Allowed riggers to remove antenna baskets? Offer to design a better extension boom? Decline to review the plans, but suggest to the riggers that they should hire an engineer to review their plans? Final Question re Antenna Tower What model of responsibility did the engineer follow? Minimalist model? Reasonable care model? Good works model? 19 More questions...new case Suppose an airline maintenance engineer contacts an airframe manufacturer with a question about a proposed maintenance procedure, believing that it can safely reduce maintenance time and costs. What are the responsibilities of the airframe manufacturer's engineer? How will the manufacturer respond if he adheres to the... minimalist model of responsibility? reasonable care model? good works model? A Case in point... In 1979, the design features of the DC-10 satisfied FAA regulations. Improper servicing procedures cracked the pylons securing the engines to the wings. During takeoff from Chicago on 25 May 1979, American Airlines Flight 191 lost an engine from the left wing, severing hydraulic control and power lines near that pylon, causing loss of control, crash, and 274 deaths. 20 IRAN SCENIC ROAD FROM THE CAPITAL TO THE CASPIAN SEA 21 SCENIC ROAD FROM THE CAPITAL TO THE CASPIAN SEA Major Rock formation and structures Major serious potential of failure SCENIC ROAD FROM THE CAPITAL TO THE CASPIAN SEA Major Rock formation and structures Major serious potential of failure. High Mountains Deep valleys 22 Major failure of the Kandevan tunnel North of Iran Increase in Travel distance and time Over the Mountains Maintenance Gas 23 The north side of the mountains Near the Caspian Sea TRAGEDY STRIKES MAY 2004 very strong earthquake Major slope failures Major land slides Large rocks toppling on the cars on the road Nearly 100 people lost their lives 24 TRAGEDY 25 Instrumentation and monitoring 26 ROCK BOLTING There are simple Geo-Technical Engineering Solutions 27 Ethical Questions: Kandovan Tunnel Case What one should HAVE DONE ? What the Government should have done? What should the engineers in charge should have done? If the "Ethics Rope" Breaks, We all lose ! We all lose ! 28 References 1. ENGINEERING RESPONSIBILITY presentation of James C. Rock, PhD, PE, Department of Nuclear Engineering .Texas A&M University Original lecture materials from Dr. Ray James, & John Poston PROFESSIONALISM AND ENGINEERING CODES OF ETHICS John W. Poston, Sr. presentation Department of Nuclear Nuclear Engineering Texas A&M University Harris, Prichard & Rabins, Engineering Ethics: Concepts and Cases, Cases, Chapter 5: "Responsible Engineers" This presentation is put together from, course books , other presentations as well as various websites in the forms of text, photos, audio and video clips. All the references will be given in the general reference section on the web Ct References 29 ...
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This note was uploaded on 03/03/2010 for the course MIME 221 taught by Professor Hassani during the Spring '10 term at MO Southern.

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