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2007 Q1 MARGINS & TOLERANCES IN CONTROL SYSTEMS
#1
Ladies and gents
Can you pease look at this attempt, digest it and may I have your honest feedback please

thanks

The faithful Sleeper ZZZzzzz.....


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.doc   2007 question 1 Module 1.doc (Size: 27 KB / Downloads: 273)
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#2
Railway Sleeper Wrote:Ladies and gents
Can you pease look at this attempt, digest it and may I have your honest feedback please

thanks

The faithful Sleeper ZZZzzzz.....

Good as far as it goes but one side of A4 is nothing like enough; I'd aim for 3 at minimum, generally 4. Some questions when really get going and stuff flows could well be 6 sides or even more. Beware quantity at the expense of quality though; that's why 5 mins thought before leaping in, 5 minutes a side and then 5 mins just to cast a reflective eye over what you have written whilst re-reading the question so that you can inject / tag on a few bullets at the end anything you missed is what I'd recommend.

You need to expand on what you have written and in particular give more explicit condideration to "margins and tolerances" that may be implied by your answer but you have not driven the point home.

In such questions a good approach is often to take each word/phrase, muse to yourself what it means and try to expand it. What do you understand by "train control"?- does it mean ATO, ATP, TCB signals controlled via interlocking from panel, in-cab signalling, mechanical semaphore signalling with absolute block, RETB, hand signalling in degraded mode; which of these are obviously included in the question and which , with a little bit of justification to the examiner, can you reasonably also relate the question to and include in your answer.

Similarly: what margins? what tolerances?- are we talking time, distance, overlapping technical solutions, combination of rules and procedures; so forth throughout the wording.....

Have a look at the presentation re "ticking as many as possible of the boxes within the matrix" that I have put under the Signet weekend in YM Events for more ideas to widen the question. You also need to deepen it and give some specific detail for certain elements to show your understanding is not only high level superficial.

So it seemed to be a good start but then STOPPED just when I had hoped we'd be treated to a really good answer!
PJW
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#3
Sir,

I am enclosing my answer to this question. I have answered for the IRSE 2007 q1 Part 1 (i.e associated risks in the system during normal operation).

IRSE 2007 q1 Part 2: I have not enclosed. Since it is related to Part 1.

Please clarify whether my understanding and response are in the right direction. Please guide me if I need to expalin more about each risks.

Thank you.

Sincerely,
Jegadeesh K

Enclosed: Pdf (2 Pages)


Attached Files
.pdf   IRSE Sample answer 2007 Q1.pdf (Size: 673.39 KB / Downloads: 183)
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#4
PWJ
Thanks for the response, that was an eye opener it then brought to mind issues like-
Margins and tolerances- includes safety intergrity levels in safety critical and safety related equipment eg in electronic interlcking.

RAMS -reliability availability mantainaiblity and safety
Random failures(MTBF, MTTF,MTBWSF, and component failure rate calculations for hardware and systematic failures for software )

System design archtectures eg redundancy (triplicatere dundancy and standby), duplication for availability.
Include ergonomics during design of man machine interface eg control room designs
During risk assessment zero risk can not be achieved so use of ALARP
principle which has margins and tolerances
All these design measures can reduce the risks identified in part one of the question.
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#5
KrishJ Wrote:Sir,

I am enclosing my answer to this question. I have answered for the IRSE 2007 q1 Part 1 (i.e associated risks in the system during normal operation).

IRSE 2007 q1 Part 2: I have not enclosed. Since it is related to Part 1.

Please clarify whether my understanding and response are in the right direction. Please guide me if I need to expalin more about each risks.

Thank you.

Sincerely,
Jegadeesh K

Enclosed: Pdf (2 Pages)

Although you clearly have some understanding of the situation, I am afraid that you'd not have scored well. The type written portion is really pure introduction; yes it does help to set the scene of the context of your answer but you spent too long doing so, giving too much detail much of which was not relevant to your actual answer for part 1. If you felt you needed this then a tabular form with ticks for option 1 & 2 would have been both quicker and also give a better comparison of simularities / differences. One small thing- whereas an option 1 could be a pure protection system with no visibility in normal operation to the driver (and this is certainly something that you could have majored upon later) you seem to be describing ETCS levels 1 & 2 and there is a Driver machine Interface for both, albeit displaying different info.

Looking at your handwritten part which should be concentrating on RISKS it lists a range of FAULTS and FAILURES but does not actually attribut these to risks. Should be thinking of derailment at points, head-on collision, rear-end collision, entering an area that should be reserved for trackside workers under possession etc- in other words you need to identify the precursor to some form of accident- loss or damage to human life, property, environment etc.......
The question even uses the phrase "unsafe event"- your answer does not explicitly say what event follows "vehicle MMI fails to display" for example- you need to explain what is inherently UNSAFE about this or how something unsafe may happen as a consequence for which this might have been the root cause of the scenario leading toi accident.

Almost the only reference you have made is "degraded modes relying on human can lead to accidents due to misunderstandings, inaattention etc" and in truth you never actually even said that explicitly.

You did not pick up on the various other "hooks" in the question:
"absolute safety / ALARP"
"margins and tolerances"
"likelihood"

So I am afraid that you'd actually get few marks for what you had written- sorry if that sounds harsh but better I tell you now than the examiners in October....
PJW
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#6
Hi,

Please find attached our attempts at the Mod 1 2007 paper Questions 1 - 3. [Q2 and Q3 filed now separately PJW]

This was done under time pressure and therefore may be lacking in content!

Cheers,
Hitesh & Laura

ps: thanks for your comments on our previous attempts. They are very helpful! We hope to keep practising until the exam.


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.doc   2007 Q1.doc (Size: 41.5 KB / Downloads: 42)
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#7
(18-08-2010, 06:15 AM)hiteshp Wrote: Hi,

Please find attached our attempts at the Mod 1 2007 paper Questions 1 - 3. [Q2 and Q3 filed now separately PJW]

This was done under time pressure and therefore may be lacking in content!

Cheers,
Hitesh & Laura

ps: thanks for your comments on our previous attempts.  They are very helpful!  We hope to keep practising until the exam.

Like the attempts at this question earlier in this thread, you struggled a bit with this one.  Many of the same comments apply particularly to HP's answer; you need to be clear what you consider to be a risk and choose carefully with a thought to the mitigations related in the second part of the question.  The majority of the marks were for this second portion and whereas there the bare bones of the answer it was really just a skeleton.

I much preferred LO's answer; again there was not enough there but that which was included was good.  The tabular presentation worked well and the risks were generally true risks, adequately explained and covered a fair range; similarly the mitigations were suitable and described in a sensible level of detail.  If only the answer had been twice as long and had carried on in the same vein, then we might well have had the first good answer to this question.  

Actually if you'd done this question together in a study group session and Hitesh's skeleton had been given the Laura treatment then I think you'd have submitted a very worthy attempt; in the exam of course you are time limited and on your own.  For now though, take advantage of being able to look at the various attempts posted here and reflect how you could have done better and hopefully some of this will stick with you when confronting the exam.


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.doc   2007 Mod 1 Q1 Aus.doc (Size: 55.5 KB / Downloads: 52)
.pdf   2007 Mod 1 Q1 Aus.pdf (Size: 113.63 KB / Downloads: 16)
PJW
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#8
Question paper FYI


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.pdf   2007Module1Exam.pdf (Size: 75.23 KB / Downloads: 13)
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