TRANSCRIPTS
So the rails are designed to support a weight of 12.5 tons.
But when we look at a curve, we find that the load is different. Look at the diagram on the board. You can see that the centrifugal force pushes the wheel against the outside rail of a curve. Instead of a downward compression load, the load is against the corner of the rail. To restore the equilibrium at high speed, the track is tilted like a cycle racing track, resulting in an extra stress on the inner corner of the higher rail – which is called the gauge corner. Under lateral pressure, the rails crack on the corner, which is known as ‘gauge corner cracking’.
So where was I? Oh yes. The Hatfield accident
was caused by gauge corner cracking. Two months before the crash, Railtrack was warned again that there was a significant risk of derailment from a broken rail. In the crash, the rail cracked along 135 metres – 35 metres of which shattered into 300 pieces. Naturally, the train derailed.
By the way, according to a 2004 article entitled ‘Rolling contact fatigue on the British railway system’, this was a widespread and serious problem in the late 1990s. You can find the article online via the Science Direct database. I’ll write all the details on the board at the end of the lecture.
The point of this case is that it was an accident waiting to happen, but it could have been prevented. The system of safety and maintenance inspections was inadequate. When the damaged rail had been identified, no proper risk assessment was done and trains were allowed to continue travelling at dangerous speeds. Also, as responsibility for safety was divided between the rail company and the maintenance company, neither took full responsibility. You can read the official report of the incident on the Internet, if you want to note this down … go to the Office of Rail Regulation website and search for the Hatfield train derailment final report by the Independent Investigation Board, July 2006. I also have a hard copy, if anyone wants to borrow it.
Right, I’d like you to do some research please, to present in tutorials next week. I’d like you to work in groups of four on health and safety incidents from other industries – for example, chemical processing, biotechnology, construction and so on. For example, you could look at the 1974 Flixborough disaster. Each group should consider what happened, who was responsible, what health and safety principles were ignored, and what changes should be implemented to avoid repetition.
Unit 9, Lesson 9.3, Exercise D ≤2.14
Extract 1 Ah … I see some of you are using the Cornell note- taking system. That’s good. If you want to know more about this system, I suggest you look at How to Study in College by Walter Pauk, 9th edition, published 2007. It should be in the university library.
Extract 2
By the way, according to a 2004 article entitled ‘Rolling contact fatigue on the British railway system’, this was a widespread and serious problem in the late 1990s. You can find the article online via the Science Direct database. I’ll write all the details on the board at the end of the lecture.
Extract 3
You can read the official report of the incident on the Internet, if you want to note this down … go to the Office of Rail Regulation website and search for the Hatfield train derailment final report by the Independent Investigation Board, July 2006. I also have a hard copy, if anyone wants to borrow it.
Unit 9, Lesson 9.4, Exercise C ≤2.15
Extract 1 The Flixborough disaster was an explosion at a chemical plant. Twenty-eight people were killed and thirty-six seriously injured. It seems quite clearly to have been an engineering error. While a reactor was being repaired, engineers designed a temporary pipe between two other reactors, which ruptured. By the way, these engineers apparently had no experience in designing high-pressure pipework, and the pipe was not properly tested either.
Extract 2
Erm, I think one of the problems at Flixborough was poor management of the, uh, repair work. Um, this is very important. We can see why this is very important. I have a slide here – oh, sorry, that’s the wrong slide. How do you go backwards on PowerPoint? Right. Um, so you can see I think the issue, err, was a problem, um, with the repairs made to the reactor, uh ...
Extract 3
Flixborough was a chemical processing facility. We could ask the question ‘what did they produce’?
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