3 Needs and problems The last section has established that engineering is about satisfying needs. In fact, with so many needs, it's a wonder that not everyone is an engineer! So, now that we have talked about both needs and problems, the logical progression is to examine the relationship between them. Take the water example as being a fundamental need. We can state it thus: This village needs a supply of clean water. 1.4 Routine solutions This is the last of our three categories, and possibly the most difficult to define because the approach is not as definite. Routine solutions involve configuration or reconfiguration of existing devices or components, without innovation, because something is broken or needs to be repositioned, or there is simply a better way to do it. If you change the locks in your house or car, you are reconfiguring them; if you tune the car, calibrate the central heating, set the coordinates for your sate 6.3 Tacoma Narrows suspension bridge failure Such over-design could not be sustained for long and bridge designers gradually pared back their margins of safety. There is elegance and economy in having the lightest structure compatible with function. But history has a habit of repeating itself. In 1940 a new suspension bridge with a central span of 2800 feet was built over the Tacoma Narrows in the United States. It was soon noticed the bridge deck was prone to oscillate in certain winds. The vertical amplitude of the oscillations 6.1 New Tay Bridge So the collapse of the bridge was probably caused by premature fracture of the lugs, perhaps aided by fatigue (Input 10). Once the wind braces had been lost, the stability of the piers was drastically reduced because each trio of columns became separated (Figure 47). It only needed a further small sway to ca 5.15 Further investigation is possible There are still many mysteries that surround the Tay Bridge disaster, largely because so little was recorded at the time of construction. For instance, questions remain about the details of reject rates for the castings, and modifications made to the first designs of the piers and their component parts. Although enlargement of the BoT set of pictures has helped clarify the various failure modes described by Henry Law and others at the enquiry, it has also revealed yet more mysteries. Wh 5.12 Pole and Stewart report Apparently prepared using the same methodology as Law, Pole and Stewart produced a report that calculated the loads at various points in the bridge under live locomotive loads and wind loading at various pressures. Stewart was employed by Bouch to perform the original design calculations for the bridge, while Pole was brought in as an independent expert. He had extensive experience of use of different materials in bridges, and indeed, had written a standard text book for engineers on the subj 5.10 Bridge stability Any fracture of the diagonal wind brace tie bars could allow substantial lateral movement at the top of the piers. If these tie bars had already been injured by the previous train to cross the bridge, it would have only taken a little extra effort to complete the process as the mail train arrived over each pier supporting the high girders. Once the wind braces had failed completely, and the struts fractured at their connections each pier would behave as two separate supporting structures. Bridge oscillations Testimony was taken from the many workers employed during construction and painting of the structure just after completion. Their evidence was more compelling, especially from painters working at the top of the high girders piers during passage of trains, as well as during windy weather. They were painting the cast iron of the piers during the summer of 1879. In the main, they reported feeling strong sideways as well as vertical motion: Disaster! The train receded into the darkness and the light of the three red tail lamps grew dimmer. Sparks flew from the wheels and merged into a continuous sheet that was dragged to the lee of the bridge parapet. Eyewitnesses would later recall at the inquiry that they saw a bright glow of light from the direction of the train just after it must have passed into the high girders section, and then all went dark. The train was timed to pass the Dundee signal box at 7.19 pm. When it failed to arri Construction of piers The dimensions and detailed construction of the cast-iron piers are shown in Figure 15. A single pier consisted of six columns of cast iron tied together by struts, bars and rods made from wrought iron. Each pier in the high girders section was built up by bolting together seven flanged cast-iron columns, g Acknowledgements The following material is Proprietary and is used under licence: Naughton, J. (1998) ‘Arts: Internet: It's free and it works. No wonder Bill Gates hates it’, Observer, 8 November 1998, © Guardian News and Media Ltd 2005; Wilkins, E. (1994) ‘Rescued from £1 a day for girl's upkeep’, The Times, 31 January 1994. Copyright © Times Newspapers Ltd 1994; ‘Agency demands 1p from father’, The Times, 22 December 1993. Copyright © Times Newspapers 6.1 Perspectives on managing My focus in this section is on the M ball being juggled by a systems practitioner. My purpose is to enable you to appreciate the diversity of activities that might constitute managing. More specifically, I am concerned with the type of managing a systems practitioner might undertake. When you began Part 3, Section 4, I asked you to complete an activity (Author(s): 5.10 Contextualising any particular systems approach The capacity to put any systems approach into context is based on the ability of a practitioner to appreciate their own traditions of understanding and to make connections with the history of particular systems methods or methodologies, or to formulate their own. Above all, there is a need to learn from using them and to achieve outcomes that are agreed by those involved as worthwhile. This is a level of systems practice to which you can aspire. At the beginning of Part 3, Section 5 I p Critical systems thinking Critical systems thinking (CST) is regarded as a systems approach to research and intervention in complex situations. The approach developed from the concerns held initially by C. Wes Churchman and his student Werner Ulrich. Later, Mike Jackson and Bob Flood, who were then professors at the University of Hull in the UK (e.g. Jackson, 1991, 2000; Flood and Jackson, 1991) developed their interpretations of the earlier work. Jackson and Flood were concerned that existing systems methods, includi 3.1 The state of ‘Being’ The structure of Section 3 is set out in Figure 25. Use this as a way of keeping track of the argument I am making. 9.2 Systems maps: searching for system A simple definition of a system is an assembly of components interconnected as if they had a purpose. I am going to use the idea of purpose to look at the situation as I understand it. Presented with the complexity of this situation it may be hard to know where to start. I have often found it helpful to start with the notion that somewhere in all this complexity there is, or was, some purpose. It is quite common in situations like this to find the mess has arisen because somewher 3.2 Learning by experience It's a familiar idea but it implies two activities: learning and experiencing. Both activities need to happen if I am to say that learning from experience has happened. Experiencing seems to have two components. The first is the quality of attention that allows me to notice the experience and its components. The second is memory. Calling experience to mind allows me to examine the experience and to think about it in ways that were not possible at the time. Learning is what I take away from th 18.2.1 Relative advantage In order to succeed, an innovation has to be perceived as offering advantages relative to existing comparable products or services. For example, it has more chance of selling if it is cheaper to make and buy, does the job better or does something previously not possible, offers more features, is easier to use, or is reliable and safe. Relative advantage is sometimes called competitive advantage. A good example is how the steady reduction in size and increase in efficiency of the electri 12.2 Technology push The technology push model is a simple linear model that suggests that the innovation process starts with an idea or a discovery – it is sometimes called ‘idea push’ (Figure 51). Sometimes this is by a creative individual who has the knowledge and imagination to realise its 11.5.5 Chance Another important source of inventions and scientific discoveries is chance, which is strongly associated with acts of insight. As well as the sort of painstaking work that either precedes an invention or goes into the steady improvement in performance, in the development of most inventions there's a moment when chance plays a part. Often people are looking for one thing but find another – perhaps working on one technology when they stumble on the principles behind another. The skill of the
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