2007 Q3 RISKS OF MIX OF TRAMS AND HEAVY FREIGHT

[Railway Sleeper]

PJW
Thanks once again for all the feedback ,It has given me the confidence to know that at least Iam in the right direction.
Here is 2007 , module1 , qestion 3.

Thanks
ZZZzzz.....

[PJW]

PJW
Thanks once again for all the feedback ,It has given me the confidence to know that at least Iam in the right direction.
Here is 2007 , module1 , qestion 3.

Thanks
ZZZzzz.....

For some reason I had difficulty downloading the attachment- doesn't seem to be recognised as a Word file which I assume it is. Got a form of text file with lots of superflous characters which makes it somewhat difficult to fathom.
May be worth you trying to upload again.
I am actually on leave until the middle of next week, so perhaps someone else will take the lead on this one in my absence

[Douglas]

I sat this exam last year and Q3 was one of the ones that I tackled - I passed, so I must have done something right. Like Peter I'm having difficulty reading your file, please try attaching it again...

[Railway Sleeper]

I sat this exam last year and Q3 was one of the ones that I tackled - I passed, so I must have done something right. Like Peter I'm having difficulty reading your file, please try attaching it again...

Hi Doug
I have reattached the answer, Unfortunatey I had saved the document as microsoft 2007, I hope it works this time.

thanks

ZZZzzz...

[Douglas]

Railway Sleeper - here is my opinion, for what it's worth:

Your answer is a little short of a page and a half in print, which suggests it is over two pages when handwritten on the exam manuscript. That is a good start as the examiner will be taking you seriously (I think). You rewrote the question - I assume for the ease of people like me who are reviewing your answer here, so that's helpful and good, keep it up. However you must never waste time doing this in the exam itself, you simply do not have the time.
This question made me think of Tyne & Weir Metro and the shared section there, which I seem to recall was on the Sunderland end??? Anyway my point is that it got me thinking of that railway, so if I'd known the railway better then I could of based my answer on that; I didn't so I guessed based on my knowledge. I note that when you typed out the question you omitted the marks given for each part: a, b, & c. Your answer to each of these parts is roughly the same length, so how does that match up to the distribution of marks? Well part a and c are worth 5 marks each, while part b is worth 15 marks, I'd guess that you should of been writting 2-3 times as much for part b. Not always the case, the marks could be based on your quality of answers and the demonstration of your reasoned understanding, but in terms of general guidance, I'd say that part b should be longer.

So to the answers themself:
A - It is difficult to know what the hazard is without defining the system boundary, the question doesn't say what this is, so I'd point this out to the examiner. Then I'd assume a system boundary and state the principal hazards, is SPAD with two categories: TRAM SPAD, and Freight SPAD.

You then assume that the railway uses track circuits (without stating that this is an assumption - it has to be as the question doesn't say so) as a means of train detection - it could equally be axle counters or GPS position reporting: the first two categories are challenged by differing wheelsets / axle loads. You also go on to further list contributing factors (causes), I'm not sure that the examiner actually asked for these. It doesn't neccessarily harm you to write these down, but you may be wasting your time as there may be no marks for these. The second last bullet is not a hazard. The last bullet is good, it certainly never occurred to me, just goes to prove how different different student's answers can be.

B - I'm sure that I mentioned time table management first - its the cheapest to implement. Run all freight at night when the trams' service is off. Or run freight in the quiter periods, as a minimum run freight in the off peaks. Fit the freight trains in amongst the non-stop service tram (my assumption). Reducing freight speed during mixed operation, your trapping at the limits is a good idea. You mention use of axle counters as mitigating poor shunt resistance, what about the risk of radically differing wheel sets not registering a count on the axle counter?
You provide no mitigation for the maintenance issue?

Your answer to part C looks pretty much stock, it's the kind of stuff we rely on for 4/5 marks.


Basically I think that you gave this a fair go. I hope that I've given some worthwhile comment on your approach, I suspect that I am better qualified to do this than to actually answer the question. For what it's worth I think that all that you wrote seemed well reasoned, and you didn't throw in any obvious clangers, I'd expect this to achieve a pass.

Good luck on Saturday.
D.

I sat this exam last year and Q3 was one of the ones that I tackled - I passed, so I must have done something right. Like Peter I'm having difficulty reading your file, please try attaching it again...

Hi Doug
I have reattached the answer, Unfortunatey I had saved the document as microsoft 2007, I hope it works this time.

thanks

ZZZzzz...

[Railway Sleeper]

Thanks very much to Douglas and Peter (PJW) for your honest critisism of my 2007 attempts. Your inputs have paid off, I just got myself a pass. I now have all 4, thanks once again.

ZZZzzzzzz.......

[admin]

Thanks very much to Douglas and Peter (PJW) for your honest critisism of my 2007 attempts. Your inputs have paid off, I just got myself a pass. I now have all 4, thanks once again.

ZZZzzzzzz.......

Well done. Thanks very much for taking the time to post positive feedback.

[PJW]

Thanks very much to Douglas and Peter (PJW) for your honest critisism of my 2007 attempts. Your inputs have paid off, I just got myself a pass. I now have all 4, thanks once again.

ZZZzzzzzz.......

Thanks!
Also you are the only person so far prepared to share their results with the world- others who have let me know have emailed, texted or PM'd me personally.
Happy New Year- loks like you for one wan't have to work for exams, but please feel free to share your experiences with others via this website or personally

[hiteshp]

Hi,

Please find attached our attempts at the Mod 1 2007 paper Questions 1 - 3. [Q1 and Q2 now filed 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.

[Douglas]

Hi Laura & Hitesh
Laura, long... time no see. I hope that the southern hemisphere is treating you well.

Last Wednesday I had a session with the London Study Group and we looked at 2005 Q6, which is uncannily similar to this one. Take a look at my answer to that which is here: http://irseexam.co.uk/showthread.php?tid=604 . Note that my answer is probably a little shorter than I'd want it to be for the exam. So I'll leave you to judge whether or not the length of yours were appropriate.

Some general thoughts having read what you wrote:

I noted that Laura's was presented in a table - a hazard log, this is a good idea.
You have stated no assumptions and for your answer to stack up I think it is important that you do.
I think that one of the key hazards is the relative crash worthiness of the stock, a freight train would crush a tram - is that a hazard or an escalated consequence? Depends on your system boundary, an assumption that a hazard is considered to be any precursor, escalating factor, or exposure of risk will allow you to include this and give the examiner confidence that you understand what you are writing about.
You could fairly assume that trams are as per Croydon/Nottingham with low platforms and a casual public approach to the 'secure off road sections', hence safety of the public who frequently tresspass.
Indeed passengers standing at platforms where every tram stops (my assumtion and it helps us to clarify another hazard so its worth making) being startled / struck by a freight at 100 km/h.

Ideally I'd run the freight in the night time out of tram operating times, and I'd state that. But the question says they have to run at the same time, so I'd note that it takes the freight 6 minutes to get through this shared section 10km long at 100km/h. The trams only run at one every ten minutes in the peak, so off peak you could run a freight train only when there are no trams in the shared section, (that may be too operationally restrictive) or more realistically split the shared section in half. This is more straight forward than asking a signaller to double block which exposes us to greater human error as your asking signaller to take decisions more often - higher workload and increased frequency.
I never thought of misrouting and its really relevant - imagine a freight being sent down the high street! Why no mitigation?
Can you guarantee axle counters will be activated by a 'flimsy' tram wheel?

Part iii which is only answered by Hitesh: A safety case is a good idea; but that is WHERE you demonstrate method of operation is acceptable - not HOW. You say " to demonstrate... that the risk associated with the operation has been managed and reduced to an acceptable level (ALARP)". I think this phrase is the one you should be concentrating on. You should write more about the ALARP principle which I discuss in the final part of the question I mention above (go to the Yellow Book for the real detail) - this is the perfect opportunity to draw an ALARP carrot and talk about tolerable risk, broadly acceptable risks etc. If you are sitting module 1 it would be exam suicide not to be able to produce half a page of A4 (diagram included) on this topic in less than 3 minutes.

Hope this helps???

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In addition it has just occured to me that there are footpath crossings on Croydon's off road secure sections, that may be tolerable with trams (good braking) at 80km/h, but freight trains brake relatively poorly. Should we close the footpath crossings or reduce the line speed to 80kmh over the foot path crossings which don't give the crossing user necessary sighting time of an approaching freight train?