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Virtual Study Group
#31
(24-06-2010, 08:16 PM)KonduriRaghavakumar Wrote: Thank you, Sir. I think I need to say need to say sorry. I am in a hurry mood to solve a difficult problem without actually seeing what values I am using. I will improve this and will come back with a good attempt sir.

No need to say sorry- easily done!
It is good to see such enthusiasm.
However there is an English expression "less haste, more speed" or alternatively "Make haste, slowly".
PJW
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#32
I had attempted nonstophead way calculation for M/Line layout 2000. Check it out Sir.


Attached Files
.doc   NonStop headway Calculation of 2000 mainline lay out.doc (Size: 85 KB / Downloads: 50)
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#33
(21-07-2010, 07:38 PM)KonduriRaghavakumar Wrote: I had attempted nonstophead way calculation for M/Line layout 2000. Check it out Sir.

I have entered comments and some alterations using Track Changes- see attached.

Overall along right lines and clearly set out but do explain and don't just quote formulae from nowhere; do define abbrieviations and terms and be consistent.

Also be careful to use the right speed values for braking and headway respectively.

Suggest you also look at this example of the same calculations


Attached Files
.doc   NonStop headway Calculation of 2000 mainline layout PJW.doc (Size: 90 KB / Downloads: 39)
PJW
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#34
Sir,
Contigency is generally to required to recover the service perturbations and the contigency will acts as a buffer. Contigency of 25% is taken in order to design the signaling which gives greater capacity. Sir, Is this value of contigency depends upon the timetable i.e., no.of services needed per hour? In the three aspect signaling i think the maximum distance is to compare with the SBD+33% to determine the over braking. In case of four aspect it is SBD+33%/2. If overbraking exists in a given headway my idea is it can be reduced by over providing MAS continuously with max. signal spacing.
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#35
(23-07-2010, 07:28 PM)KonduriRaghavakumar Wrote: Sir, Contigency is generally to required to recover the service perturbations and the contigency will acts as a buffer. Contigency of 25% is taken in order to design the signaling which gives greater capacity.

Sir, Is this value of contigency depends upon the timetable i.e., no.of services needed per hour?

Yes look at how many trains per hour as well as just the closest pair of trains requiring to be timetabled in order to determine a suitable level of contingency.
If there is a need for a train every 5 minutes, 12 trains per hour then there must be a decent level of contingency, otherwise if one train is delayed for just a couple of minutes, then many subsequent trains will be delayed. Designing signalling with plenty of contingency might mean for example designing to achieve a headway of 4 minutes. This would mean that the 2nd train would only be delayed by 1 minute and the third could be on time; if less contingency provided with the signalling achieving 4.5 minutes, then the 2nd train would be delayed by 90s, the 3rd by 60s, the 4th by 30s and it would be the 4th before the timetable could be recovered fully.

Conversely if there is an ocasional need for a train to follow another 5 minutes apart but then there is no other train for half an hour, then don't really need any contingency at all, since there would be no knock-on delay to a significant number of trains anyway. Train 1 would delay train 2 by the same amount but then there is plenty of spare time before train 3 is in the area.

Quote:In the three aspect signaling i think the maximum distance is to compare with the SBD+33% to determine the over braking. In case of four aspect it is SBD+33%/2.
Yes, you are right; however you need to be careful in your explanation and presentation that you do not confuse spacing between adjacent signals and spacing between alternate signals in the 4 aspect case.

Quote:If overbraking exists in a given headway my idea is it can be reduced by over providing MAS continuously with max. signal spacing.

Yes, again I believe you correctly understand. However I suggest you do not use the phrase "over providing MAS" as it is liable to be misunderstood; it would be better to say "Provision of MAS with the greatest signal spacing being limited by considerations of overbraking rather than the need to provide the required headway"
PJW
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#36
Hello,
I have just registered with the forum as i would like to sit Module 2 exam (and then the other 3 required).
I worked overseas for about 8 years in metro industry as singalling engineer and about an year ago i came to work in Australia, this time in heavy rail industry.
I have understood that the exam can only be booked by 30th of June and held early October so i am a bit late for this year so i'll take my chances next year.
In the mean time i would like to consolidate my knowledge in "signalling the layout" area and all it involves for this exam, so can you please let me know where i can find documentation, eventually past exam papers so i can practice and get prepared?
Thank you!
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#37
(28-09-2010, 05:29 AM)ivanutd Wrote: I have understood that the exam can only be booked by 30th of June and held early October so i am a bit late for this year so i'll take my chances next year.
In the mean time i would like to consolidate my knowledge in "signalling the layout" area and all it involves for this exam, so can you please let me know where i can find documentation, eventually past exam papers so i can practice and get prepared?
Thank you!

True.

MUCH too late; the exam is 4 days time!

Module 2 has a detailed Study Pack but much more content relevant to Main line than Metro. You will get this when registering for the exam, so the sooner the better.
However you do need to have been accepted into some form (usually Student) membership of IRSE when you apply, so if not already a member then this should b your first action.

Alex from Singapore has been submitting some module 2 layouts (to UK mainline practice) and several people have been attempting headway/braking calculations recently; these are filed in the relevant sub-forums under the Module 2 heading. These should give you the general idea of what the paper entails and the sort of responses expected from candidates together with my comments on their attempts.

This year for the first time on the Exam Forum we have had a Study Group in Australia active; it may well be that having done Module 1 this year that they may turn their attention to the Module 2 area next year so perhaps you might be able to link up with them virtully, even if you are great distance from Brisbane.
I think Australian practice is generally pretty similar to that of the UK so that in itself should not be too much of a problem; certainly practices do vary. Indeed the Study Pack does contain a real answer to an exam paper which depicts what are (to me somewhat foreign) Australian practices which scored highly in the exam, so that would provide a good comparison.

Note that whereas there is no harm learning a bit about more modules, to pass the exam you need to pass module 1 and then any other three of the remaining 6 modules and there is now no time limit imposed on how long you may take to do this.
PJW
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#38
Hello PJW,
Firstly, thank you for your prompt response and the explanations.
Few days ago i received my AMIRSE confirmation and only today i've found out the exam dates. Is it true that Module 1 is the first exam that i have to sit?
I was thinking that 2 and 3 are much better for me to start with but if it's 1 then i'll start taking care of that one.
Where that Study Pack can be found or bought please?
Best regards!
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#39
(28-09-2010, 07:56 AM)ivanutd Wrote: Hello PJW,
Firstly, thank you for your prompt response and the explanations.
Few days ago i received my AMIRSE confirmation and only today i've found out the exam dates. Is it true that Module 1 is the first exam that i have to sit?
I was thinking that 2 and 3 are much better for me to start with but if it's 1 then i'll start taking care of that one.
Where that Study Pack can be found or bought please?
Best regards!

No, you can do in any order. Indeed I would NOT recommend doing module 1 to a new comer until they have built up several years of experience. Perhaps your background may be different to many, but ven so I suggest that mod2/mod3 are the ones to start with- certainly more defined subjects and can largely be learnt from study material whereas module 1 cannot

PJW
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#40
(28-09-2010, 12:00 PM)PJW Wrote: [quote='ivanutd' pid='2189' dateline='1285656998']
Hello PJW,
Firstly, thank you for your prompt response and the explanations.
Few days ago i received my AMIRSE confirmation and only today i've found out the exam dates. Is it true that Module 1 is the first exam that i have to sit?
I was thinking that 2 and 3 are much better for me to start with but if it's 1 then i'll start taking care of that one.
Where that Study Pack can be found or bought please?
Best regards!

No, you can do in any order.
Indeed I would NOT recommend doing module 1 to a new comer until they have built up several years of experience. Perhaps your background may be different to many, but even so I suggest that mod2/mod3 are the ones to start with- certainly more defined subjects and can largely be learnt from study material whereas module 1 cannot.

Study Pack should be sent free when registering for the exam. Generally they issue them all on a DVD updated with the last year's exam questions added and that is not available until about Easter time. I would suggest that you register for exam earlier and specifically ask for a Study Pack to be sent so that you can start using it- explain that the previous year's pack delivered immediately would be appreciated (it generally doesn't change much year on year and the 2010 papers ought to bcome available separately by January's exam review anyway.



PJW
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