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Mock 2018 exam
#1
Hi all,
I have just done a time mock exam using 2018 layout- I have attached the calculations below, please could someone check these over.

I have a few burning questions.
So I am planning on doing an ETCS layout, I spent an unnecessary amount of time writing the design rules on the paper - as there are no GB design rules for ETCS released yet. I have been basing the design on rules that were written by the transpennine team for the route upgrade to ETCS west of Leeds.

I'm trying to find the best way to arm myself for the exam as I ran out of time this year (why did they make the 2018 paper so busy Sad ). Should I just state some hard and fast rules on the paper, which will apply to the layout, or would referencing a project specific design rules paper be sufficient (I don't think this would).

Im happy to write out the rules for the examiners understanding, but want to make sure that this doesn't take too much time. Help here would be really great if anyone can offer.

I spent about 30 mins on the calcs too which im thinking is probably a bit too long.
Didn't get all my TCs and Points labelled, and neither did I label all entrance/exit points for MA.

Some layout guidance would be really good if anyone has any to offer, I know what I need to do, its just applying it fast enough, that's the downfall.


TF


Attached Files
.pdf   2018 Mod 2 calcs.pdf (Size: 1.08 MB / Downloads: 14)
.pdf   2018-mod2-Paper.pdf (Size: 10.23 KB / Downloads: 8)
.pdf   2Mod 2 2018 layout.pdf (Size: 798.97 KB / Downloads: 14)
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#2
Your calcs look along the right lines (I haven't checked the details). I got the core part a/b section down from around 30 min to less that 10 min by practice and memorising the conversions from km/h to m/s, and the resulting v^2 values, which are the braking distances at a=0.5 m/s/s, which is common (for each 10 km/h interval from about 50 to 200). They follow enough of a pattern and are distinct enough to remember generally. I would usually leave the last part of the calcs until I had some of the basic work on the layout (I think it suggests you need to plot a signal or two first anyway).
Can we see your layout? You're brave doing ETCS, though if you have the knowledge, go for it! See if you can summarise the principles where you have applied them (annotate) and state that you are following the principles of a certain implementation of ETCS - just like for a colour light layout stating GB mainline practice, but with some help to the examiner working out how you have applied it to the layout. I don't think you should have to list every principle!

Daniel
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#3
Morning,

Good to see the table, your answers for part a) look correct. Another thing to add might be a primer for the Newtonian calcs for the examiner's benefit.

Your part b) HT3 and HT4 calcs use the headway minimum braking distance rather than the maximum PSR 160km/h braking distance. I calculated 85 seconds for 3 aspect and 69 seconds for 4 aspect using a braking distance of 1235m.

The calculation principles and diagrams are good as ever so well done.

The poster above offers good advice about calculating part c after some layout details.

The best way (in my view) to reduce your calculation time is just practice and knowing your answer structure.

With regard to the design rules, standard practice seems to be stating high level assumptions on the paper (for example- "assume all train detection is axle counters, treadles not shown", etc). If you were applying ETCS principles which require long explanation on the paper this may be a big constraint in the exam. You could denote specific areas requiring clarification or practices used on the paper next to the effected area with a brief note.
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#4
REMBrum Wrote:Morning,

Good to see the table, your answers for part a) look correct. Another thing to add might be a primer for the Newtonian calcs for the examiner's benefit.

Your part b) HT3 and HT4 calcs use the headway minimum braking distance rather than the maximum PSR 160km/h braking distance. I calculated 85 seconds for 3 aspect and 69 seconds for 4 aspect using a braking distance of 1235m.

The calculation principles and diagrams are good as ever so well done.

The poster above offers good advice about calculating part c after some layout details.

The best way (in my view) to reduce your calculation time is just practice and knowing your answer structure.

With regard to the design rules, standard practice seems to be stating high level assumptions on the paper (for example- "assume all train detection is axle counters, treadles not shown", etc). If you were applying ETCS principles which require long explanation on the paper this may be a big constraint in the exam. You could denote specific areas requiring clarification or practices used on the paper next to the effected area with a brief note.
Thanks everyone for the replies,
The advice is great, and will come in handy for cutting these times down. Next two weeks is all about that, getting those exams skills nailed down.
For the design rules, I think I will reference ETCS reference designs,  transpennine design- but also state (max 10) key design rules. These will be prepared beforehand, and might just be the first thing I do before starting the layout. This should help the examiner, and also myself whilst doing the layout to make sure I stick to principles, and don't miss anything out.

Thanks again.

TF
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