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Unit 4 Safety, Maintenance,and Quality ControlLessons Team Project Review Additional Resources EXIT Unit 4 Safety, Maintenance,and Quality ControlLesson 1. What caused the explosionLesson 2. The prevention of accidentsLesson 3. Wearing special clothesLesson 4. The amplitude of motionLesson 5. Quality and a finished itemLesson 6. A “ total quality control” approach EXIT Unit 4 Safety, Maintenance,and Quality ControlAdditional ActivitiesReading ResourcesWriting ResourcesUnit TestG rammar ResourcesAdditional Resources EXIT Look at the photograph below and, in pairs, answer the questions.n Lesson 1 What caused the explosiona1. What accident does the photograph show?2. When and where did this incident take place?3. What caused the accident?4. How many lives were lost in the accident? Skim through the text quickly to check your answers.b NASA space shuttle consists of three major components: a winged orbiter that carries both crew and cargo, an external tank containing liquid hydrogen (fuel) and liquid oxygen (oxidizer) for the orbiters three main rocket engines, and a pair of large solid-propellant rocket boosters (SRBs). On January 28, 1986, the Challenger shuttle and its crew of seven (including teacher Christa McAuliffe, who had been selected to be the first private citizen in space) were destroyed shortly after launch from Cape Canaveral, Florida. The primary cause of the loss of the Challenger was the failure of an O-ring seal of a joint on one of the solid rocketboosters. The SRBs are constructed in four cylindrical sections. These have to be sealed together completely to prevent the escape of the extremely hot by-products of the burning fuel during a launch. The O-rings are rubber rings that play a vital part in sealing the joints.A On the day of the launch, the weather was unusually cold and this caused the rubber of one of the O-rings on the joint between the bottom two segments of the right SRB to become brittle. This, combined with the faulty design of the joint, allowed hot gases from the burning solid rocket fuel to escape. The gases and flames burned through the metal that held the SRB in position. When the SRB broke off, it ruptured the side of the external fuel tank. This allowed the liquid hydrogen and oxygen to mix prematurely and this is what caused the explosion. Read the first paragraph of the text and, in the diagram, label the three main components of the space shuttle.cHistory capsule Another tragic accident occurred on February 1, 2003, when the Columbia space shuttle broke up over north-central Texas at an altitude of about 40 miles (60 kilometers) as it was returning from an orbital mission. All seven crew members died in the accident.a. _b. _c. _ _ Read through the text again and complete the sentences with because or so.d1. The O-ring was brittle _the weather was cold.2. The O-ring was brittle, _this allowed hot gases to escape from the SRB.3. The metal holding the rocket was damaged, _ the rocket broke loose.4. The hydrogen and oxygen mixed and exploded _ the rocket ruptured the fuel tank. becauseso so because Key In your notebook, write four conditional sentences about the causes of the accident.e Draw a series of diagrams to explain exactly what caused the Challenger accident.feg.If the weather had not been cold, the O-ring would not have become brittle.In pairs or small groups, discuss your reactions to what you read in the text.g Listen to an interview with a NASA spokesperson and answer the questions.h1. When was the Presidential Commission on the Space Shuttle Challenger Accident created? _2. Who was named chairman of the commission? _3. Who set up the Challenger Data and Design Analysis Task Force? _4. How long did the commissions investigation take? _5. How many people were involved in the investigation? _6. When was the commissions report published? _Early February 1986.William P. Rogers.NASA.Four months.More than 6,000.Early June 1986. KeyScript Listen to the next part of the interview and complete the notes.i1. SRBs: _2. A new joint design: _3. Main space shuttle engines: _ _4. Office of Safety, Reliability, Maintainability, and Quality Assurance: _ _completely redesignedsubjected to stringent examination and review put through most thorough ground-testing program in their history, equivalent to more than 36 real missionsestablished in 1986 KeyScript Research and prepare a report about another accident. Describe what caused the accident (mechanical failure, electrical failure, materials failure, human error, etc. ), how the accident could have been avoided, and what happened as a consequence of the accident.j Interviewer: What happened in the immediate aftermath of the Challenger accident?Spokesperson: In early February 1986, President Ronald Reagan announced the creation of a Presidential Commission on the Space Shuttle Challenger Accident.Interviewer: Known to most people as the Rogers Commission, right?Spokesperson: Thats right. The chairman of the commission was William P. Rogers. At the same time, NASA established the Challenger Data and Design Analysis Task Force to support the work of the Commission.Interviewer: How long did the investigation take?Spokesperson: It took four months to complete and required the involvement of more than 6,000 people. The report was published and delivered to the president early June 1986. Interviewer: So what changes were made as a result of the commissions report?Spokesman: Well, modifications were made both to shuttle hardware and to NASAs safety and quality assurance procedures. While the space shuttle fleet was grounded, hundreds of modifications were incorporated into the shuttle system. The SRBs were completely redesigned and a new joint design was subjected to stringent examination and review. NASA put the main space shuttle engines through the most thorough ground-testing program in their history. This was the equivalent in operational time to more than 36 real missions. All engine improvements were certified to demonstrate improved reliability and operating safety margins.Interviewer: I see.Spokesman: And, as I mentioned, apart from making changes to hardware, NASA completely reorganized its safety programs. The Office of Safety, Reliability, Maintainability, and Quality Assurance was established in 1986. This has direct authority for safety and quality control for all NASA operations. n Lesson 2 The prevention of accidentsLook at the four types of engineers and, in pairs, discuss the questions.a1. What differences are there between these types of engineers?2. What do these fields of engineering have in common?safety engineer operating engineer maintenance engineer control engineer Listen to check and compare your answers.b Script Read the interview and write the questions that you think the interviewer asked.c KeyQ: 1. _?A: Many large industrial and construction firms employ safety engineers. Also nowadays, insurance companies working in the field of employee compensation maintain safety engineering departments.Q: 2. _?A: In most cases, safety engineering is a specialty adopted by engineers who received their initial training in some other branch of engineering.Where do safety engineers usually workHow do people become safety engineers KeyQ: 3. _?A: Well, the principal objective of engineers working in this field is preventing accidents. Safety engineers work on ways of safeguarding all types of worker but particularly the ones who work in occupations that can be hazardous.Q: 4. _?A: No, not all of them. You see, some safety engineers also help in the design of machinery, factories, ships, and roads. They suggest modifications and improvements to try to reduce the likelihood of an accident.What do safety engineers doDo all safety engineers work in the field Match each word from the interview with the correct definition. The first one has been done for you.d Keydafbc Read through the text and, for each phrasal verb in parentheses, suggest a more formal replacement from the box, in the correct form. There are four extra verbs. The first one has been done for you.eAs we have seen, safety engineers can offer help at the design stage by (1) proposing (put forward) improvements that can (2) _ (cut down) the risk of accidents. For example, when some new machinery is being designed, a safety engineer tries to find ways to (3) _ (get rid of) any dangerous projecting parts that might hurt someone. The safety engineer tries to (4) _ (cover up) the moving parts of a machine to minimize the chance of accidental contact with the operator. conceal eliminate ensure initiate maintain modify prevent propose reduce seekreduceeliminateconceal Key The safety engineer will also (5) _ (make sure) that any emergency cutoff switches are within reach of the operator. As for the design of safer roads, when a new road system is being designed, safety engineers (6) _ (look for) ways of avoiding hazards like sharp turns or blind intersectionsthings that have been known to cause traffic accidents. ensureseek Key responsible, thorough, methodical, . . .Write a list of adjectives that describe the personal and professional qualities that you think are required in the field of safety engineering.f In pairs, compare and discuss your ideas. Then discuss with other pairs the personal and professional qualities that are required in your particular field of study or work.g In my field, you need a lot ofpatience and you have to be able to concentrate. In small groups, conduct a physical inspection of your school or place of work and fill out a chart like the one below.hi Write an account of an accident that you or someone you know had at school or work. Describe what happened, what caused the accident, and how, if at all, it could have been avoided.location potential danger recommendation for improvement Engineer 1: I work as a maintenance engineer. I am responsible for the continued safe and dependable operation of the equipment in the plant where I work and for carrying out timely and efficient repairs.Engineer 2: I work in the field of safety engineering. Basically, our main objective is the prevention of accidents. We develop methods and procedures to safeguard workers, especially those who work in hazardous occupations.Engineer 3: As an operating engineer, I oversee and control a number of different areas at this factory: machinery, power, transportation, communications. I have to set up procedures and supervise personnel to ensure that the operation runs in a reliable and economic way.Engineer 4: Im a quality control engineer. It is my job to carry out on- site inspections to check that all parts and systems meet various technical and other requirements. Of course, these may also cover safety issues. n Lesson 3 Wearing special clothesLook at the photographs below and, in pairs, discuss the questions.a1. What do you observe in the photograph?2. What sort of work do you think is being carried out here?3. Why do you think the people are wearing special clothing? Listen to the speakers and complete the notes with the correct information. Then listen again and circle the statements True or False.b KeyName: StephanieOccupation: _Current job/ project: _Name: GregOccupation: _Current job/ project: _ _Name: CarolOccupation: _Current job/ project: _civil engineera large tunnel projectradiologistresearch into the use of X-rays and gamma rays in the diagnosis and treatment of diseaseelectronic engineermanufactures LEDs Script KeyName: TomasOccupation: _Current job/ project: _ _production engineerinstallation of heavy machinery at a new car manufacturing plant Key 1. Something that is prohibited _2. Something that is obligatory _3. Something that is not obligatory _4. Something that is permitted _Give examples of the following concepts.c Keybeing exposed to radiation for long periodswearing a hard hat at all timesnot having to wear a tiewearing normal clothes when not in the clean room 1. allowed to _ a. this is prohibited 2. Must _ b. this is obligatory3. mustnt _ c. this is not obligatory4. dont have to _ d. this is permittedMatch the expressions with the concepts.d Keydbac 1. Our boss is very strict about punctuality. We _ arrive on time.2. The dress code here is quite informal. For example, men _ wear a tie.3. You _ eat or drink near the computers. This is forbidden.4. This is a smoke-free area. If you want to smoke, you _ go outside.5. You _ eat in the canteen, but you can if you like.6. One piece of adviceyou _ park in the bosss parking space!Complete the sentences with an appropriate expression. Use must, mustn t, have to, or don t / doesn t have to.e must/have todont have tomustnt must/have todont have to mustnt Key In small groups, discuss the rules that people have to follow in your school or place of work. Use the suggestions in thebox plus your own ideas.fsafety rules safety equipment dress code punctualityeating and drinking smoking ways of addressing peopleDo you have to wear formal clothes to work? In your notebook, write three sentences about rules at your school or place of work. Write two statements that are true and one that is false.gI have to arrive at work at eight oclock. Men dont have to wear suits.Take turns reading aloud your statements from Exercise g and have your classmates guess which statement is the false one.h Stephanie: Hi. Im Stephanie. Im a civil engineer. Im currently working on a large tunnel project in the north of the country. We dont have to wear any special clothes but strong boots are recommended. Im often working close to cranes and other big machines so I have to wear a hard hat at all times. When we work at night, I have to wear a special vest with reflective material so that people can see me.Greg: My name is Greg. Im a radiologist. At the moment I am doing some research into the use of X-rays and gamma rays in the diagnosis and treatment of disease. In my work I handle radioactive material. To avoid exposure to harmful radiation, we have to wear protective clothing and, sometimes we work behind a protective screen. We must not be exposed to radiation for long periods and so there are strict time controls. Carol: My name is Carol. Im an electronic engineer. In my present job, I manufacture LEDs. The components are very small and delicate. They can be damaged by just one speck of dust. Everything in my workplace must be extremely clean. So I have to work in a clean room, which is a space where the particles in the air and the humidity are strictly controlled. We mustnt let any dust or moisture come into contact with the components. So I have to wear a special suit with a mask over my mouth and vinyl gloves. When were not in the clean room, we can wear our normal clothes.Tomas: My names Tomas. Im a production engineer. At the moment Im coordinating the installation of heavy machinery at a new car manufacturing plant. Factories are very noisy places so one thing that is essential in this place is earplugs, which you must use to prevent serious damage to your hearing. Oh, and your hard hat. You have to wear a hard hat at all times. There is no real dress code where I work. I mean, you dont have to wear a tie. Of course, you can if you want to but I normally dont bother. n Lesson 4 The amplitude of motiona Look at the photographs below and, in pairs, discuss the questions.1. What is happening in the photographs?2. What happened to this bridge?3. What do you think was the cause of the problem? 1. Year of construction: _2. Location: _3. Number of months in operation: _4. Length of span: _Listen to check your answers. Complete the notes.b KeyScriptTacoma Narrows Bridge1940Puget Sound, Washington statefour2,800 feet c Using models, drawings, or any other visual aid, demonstrate the following three different types of movement that the Tacoma Narrows Bridge exhibited before it collapsed.1. The bridge buckles along its whole length.2. The bridge twists with one side going down as the other side lifts up.3. The midpoint of the bridge stays still while the two halves of the bridge twist in opposite directions. d Complete the text using the words below. The first one has been done for you. Limit state design is a design (1) _used by structural and civil engineers. Structures and buildings are usually designed to (2) _ with codes that are based on limit state theory. A limit state is a set of performance (3) _covering, for example, strength, tendency to (4) _, stability, tendency to buckle or twist, etc. These are the criteria that must be met when a structure is subjected to various types of (5) _. A structure or a building has to satisfy two main criteria: the ultimate limit state (ULS) and the serviceability limit state (SLS). To satisfy ULS criteria, all the types of (6) _ (bending, shearing, compression, etc. ) that a particular element (a column or a beam, for example) could be subjected to must be below an established (7) _.criteria vibrate load stresses comply limit methodologycomplycriteriavibrate loadstresses limit Keymethodology e Using a dictionary, write a definition for each of the following verbs in the context of structural movement and damage.1. bend: _2. buckle: _ _3. twist: _4. shear: _ _to force into a curved, angled, or sloping positionto become bent, wavy, or warped through pressure, heat, etc.to change shape or form by turning, rotating, etc.to break by way of a sideways or twisting sideways force Key f Read the interview and then discuss the questions in pairs or small groups.Q: You mentioned two main criteria: the ultimate limit state and the serviceability limit state. Tell us more about the serviceability limit state.A: Well, the purpose of SLS requirements is to make sure that people inside a structure are not upset or alarmed by large deflections or vibrations in the floor when they walk. SLS criteria also require the beam deflections in a roof to be low enough to ensure that the plaster or the paint on the ceiling does not crack or fall off. SLS requirements limit the excessive swaying from side to side of a building or of a bridge in high windssomething that might make people feel sick. 1. Have you ever been inside a building that made you feel physically unsafe in some way?2. What characteristics of a building or a structure might make a person feel nervous or uneasy?3. What other aspects of a building or a structure do you think should be covered by SLS criteria?Q: So, are SLS requirements less stringent than ULS criteria?A: Yes, they are. A structure that may fail to satisfy certain SLS criteria is not necessarily unsafe or likely to fall down! g In groups, look for information about the standards, codes, and specifications that govern structural engineering and civil engineering projects in your country. Present your findings in an oral report.h You have been asked to carry out an inspection of a bridge, a tower, or some other public building to check that it is structurally sound. In small groups, discuss what aspects of the structure you will examine, what measurements youwill take, what tests you will apply, etc. i Find out about the regulations governing the construction of the building (s) that you study or work in and present your findings in a report.The design of this building has to comply with standards established by the Department of . . . Narrator: The Tacoma Narrows Bridge was built in July 1940 across the Narrows of Puget Sound in the state of Washington. Its 2,800-foot span made it the worlds third longest bridge at that time. But the bridge would only be in operation for four months. Soon after its opening, it was discovered that the bridge swayed and buckled dangerously in windy conditions. The bridge buckled along its length, i.e., one half of the central span would rise as the other half went down. Then engineers noticed a different type of twisting that they had never seen before. The left side of the bridge would go down as the right side would lift up, while the centerline of the road woul
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