26-09-2012, 11:24 PM
You correctly declared the railway's practice used for the plan.
It would have been better to have used the word "Notes" rather than "Assumptions" above your numbered items.
1. Suggest reword to: "AWS fitted to all running signals at 180m. Suppressors provided on bi-directional lines".
2. OK.
3. Suggest delete; this note makes no sense. A crossover between opposite direction running lines consists of a pair of facing points or alternatively a pair of trailing points, but you aren't going to call the two ends both A in the first case and both B in the second case!
4. You mean "electrically" rather than "electronically". Note sure really need this note (and if you follow Reuben's and my advice then you'd actually have some handpoints so it wouldn't be true.
5. You meant this to apply just to 4 aspects on the Main line; actually not sure really needed as you covered this in your calculation write up.
A few other things:
a) You have an overlap beyond the station D Down main platform starter (doesn't seem to be numbered) into the sidings. Suggest shouldn't be shown, or at least qualified with a note "only valid when forward route set",
b) You have drawn a ROL beyond 206 signal, but in this case this gives no advantage. One provides a ROL when it gives additional layout flexibility by not locking TRAILING points (which can then be used to route a different train). The full overlap that you have drawn on the Up Main is FOUL of 313 Reverse; you should have placed it further away so that it was clear, it would be a bit over 180m but that wouldn't be a problem- indeed you have placed the alternative leg of the swinging overlap sensibly at 240m
c) Given the signalling that you have provided in the Yard, you forgot that you needed a signal on the Arrival & Departure to protect 320 points, parallel to 239. at the AN / AO joint. This ought to be a main aspect Red with an associated PL for pulling ahead into the headshunt.
d) Similarly you'd need a similar signal protecting points 319 on the Run Round, opposite signal 209. Again there is a protecting signal missing at the other end of the Run Round protecting 312B at the AJ /AK joint. You probably would then not need signal 108.
e) 206 route box. Why doesn't the A route show Y/YY/G?
The PLJI for the B route is actually pos 4.
Although Reuben and I have between us pointed out quite a few things to learn from and the thread is not exhaustive, actually the overall impression is pretty reasonable. If you make sure that you don't throw marks away by missing trap points or signals protecting conflicts etc and make sure that you really read and understand the operational notes on the plan and provide the signalling to enable the operational moves, then I think you'll probably pass provided that you are fast enough to get a significant proportion of the layout broadly completed in the time available.
It would have been better to have used the word "Notes" rather than "Assumptions" above your numbered items.
1. Suggest reword to: "AWS fitted to all running signals at 180m. Suppressors provided on bi-directional lines".
2. OK.
3. Suggest delete; this note makes no sense. A crossover between opposite direction running lines consists of a pair of facing points or alternatively a pair of trailing points, but you aren't going to call the two ends both A in the first case and both B in the second case!
4. You mean "electrically" rather than "electronically". Note sure really need this note (and if you follow Reuben's and my advice then you'd actually have some handpoints so it wouldn't be true.
5. You meant this to apply just to 4 aspects on the Main line; actually not sure really needed as you covered this in your calculation write up.
A few other things:
a) You have an overlap beyond the station D Down main platform starter (doesn't seem to be numbered) into the sidings. Suggest shouldn't be shown, or at least qualified with a note "only valid when forward route set",
b) You have drawn a ROL beyond 206 signal, but in this case this gives no advantage. One provides a ROL when it gives additional layout flexibility by not locking TRAILING points (which can then be used to route a different train). The full overlap that you have drawn on the Up Main is FOUL of 313 Reverse; you should have placed it further away so that it was clear, it would be a bit over 180m but that wouldn't be a problem- indeed you have placed the alternative leg of the swinging overlap sensibly at 240m
c) Given the signalling that you have provided in the Yard, you forgot that you needed a signal on the Arrival & Departure to protect 320 points, parallel to 239. at the AN / AO joint. This ought to be a main aspect Red with an associated PL for pulling ahead into the headshunt.
d) Similarly you'd need a similar signal protecting points 319 on the Run Round, opposite signal 209. Again there is a protecting signal missing at the other end of the Run Round protecting 312B at the AJ /AK joint. You probably would then not need signal 108.
e) 206 route box. Why doesn't the A route show Y/YY/G?
The PLJI for the B route is actually pos 4.
Although Reuben and I have between us pointed out quite a few things to learn from and the thread is not exhaustive, actually the overall impression is pretty reasonable. If you make sure that you don't throw marks away by missing trap points or signals protecting conflicts etc and make sure that you really read and understand the operational notes on the plan and provide the signalling to enable the operational moves, then I think you'll probably pass provided that you are fast enough to get a significant proportion of the layout broadly completed in the time available.
PJW