19-09-2008, 02:25 PM
Hello YLP, Peter,
Thank you for your comments. I had another look at the answer and following review again I have decided to change the answers althogether which is now appended.
I will try to answer your questions to the best that I can. Like you I am sitting for the exams (not my first for Module 3 though) and my day job does not require me to work on control tables much less British practice. Do hope Peter can join in, clarify and comment on my answer especially the latest posted. The earlier submission of 9th July has not been answered but never mind it can be ignored.
With regards to your questions, you are correct that I have missed out routes from signal 138. So the entries are:
225 N > R Set by Routes/GF are 138 A(S), 138 B(S) with Sectional Route Locking Released by TCs Clear CN, CL, BN
225 R > N Set by Routes/GF are 138 C(S), 138 D(S) with Sectional Route Locking Released by TCs Clear CN, CL
and I have included them in my latest submission.
Looking again at 122A(M) with the exit signal at 134, Point 222 being a facing point is a swinging overlap. As long as the point is detected either in Normal or Reverse, the overlap for the 122A(M) can be in either lie - one AD, AE, the other BM, BN. However for the overlap on track circuit BN, 225 must be in a Normal position. It is reflected as a overlap locking timed to a stand on AC before exit signal 134.
With regards to Points 234, having looked at it again, I would make some changes to the entries for Requires TC Clear. Hence the entries should be:
Point Requires TC Clear
234 N>R CG, ED, CF, (BS or 233N)
234 R>N CG, (ED or 232N)
CG being the dead locking track circuit and BS a foul track circuit unless 233 is Normal. As for Point 233, it is for flank protection when Point 234 is Reverse. I have also assumed CF/BS and CF/CG are foul.
Assuming it is a six foot between the Up Main and the Down Main, I do not think there is sufficient clearance between. Based on previous comments on my other submissions to this forum, I understand the examiner will not penalise if assumptions are made unless they are way off.
So....
Thank you for your comments. I had another look at the answer and following review again I have decided to change the answers althogether which is now appended.
I will try to answer your questions to the best that I can. Like you I am sitting for the exams (not my first for Module 3 though) and my day job does not require me to work on control tables much less British practice. Do hope Peter can join in, clarify and comment on my answer especially the latest posted. The earlier submission of 9th July has not been answered but never mind it can be ignored.
With regards to your questions, you are correct that I have missed out routes from signal 138. So the entries are:
225 N > R Set by Routes/GF are 138 A(S), 138 B(S) with Sectional Route Locking Released by TCs Clear CN, CL, BN
225 R > N Set by Routes/GF are 138 C(S), 138 D(S) with Sectional Route Locking Released by TCs Clear CN, CL
and I have included them in my latest submission.
Looking again at 122A(M) with the exit signal at 134, Point 222 being a facing point is a swinging overlap. As long as the point is detected either in Normal or Reverse, the overlap for the 122A(M) can be in either lie - one AD, AE, the other BM, BN. However for the overlap on track circuit BN, 225 must be in a Normal position. It is reflected as a overlap locking timed to a stand on AC before exit signal 134.
With regards to Points 234, having looked at it again, I would make some changes to the entries for Requires TC Clear. Hence the entries should be:
Point Requires TC Clear
234 N>R CG, ED, CF, (BS or 233N)
234 R>N CG, (ED or 232N)
CG being the dead locking track circuit and BS a foul track circuit unless 233 is Normal. As for Point 233, it is for flank protection when Point 234 is Reverse. I have also assumed CF/BS and CF/CG are foul.
Assuming it is a six foot between the Up Main and the Down Main, I do not think there is sufficient clearance between. Based on previous comments on my other submissions to this forum, I understand the examiner will not penalise if assumptions are made unless they are way off.
So....