Peter,
Whilst looking through your handout given at the Signet weekend re. 2003 Module 2 headway calcs I got a little confused.
I understand your working for the non-stopping headway and that you are using the calculated spacing as a guide to whether the stopping headway can be achieved, however in your diagram you have shown train 2 approaching a YY aspect, which has just stepped up from a Y, as train 1 clears the overlap of the platform exit signal. Should it not be the case that this train should be approaching a green aspect, just stepped up from YY when train 1 clears the overlap?
If my thinking is correct then train 2 must traverse another full signal section, 1000m @ 33.3m/s, so another 30s must be added to the time taken. The total time is still within the 300s specified but has a lot less contingency.
Forgive me if I am being a bit stupid here but I was of the impression that headways should be calculated from G to R and not from YY.
Neil
Whilst looking through your handout given at the Signet weekend re. 2003 Module 2 headway calcs I got a little confused.
I understand your working for the non-stopping headway and that you are using the calculated spacing as a guide to whether the stopping headway can be achieved, however in your diagram you have shown train 2 approaching a YY aspect, which has just stepped up from a Y, as train 1 clears the overlap of the platform exit signal. Should it not be the case that this train should be approaching a green aspect, just stepped up from YY when train 1 clears the overlap?
If my thinking is correct then train 2 must traverse another full signal section, 1000m @ 33.3m/s, so another 30s must be added to the time taken. The total time is still within the 300s specified but has a lot less contingency.
Forgive me if I am being a bit stupid here but I was of the impression that headways should be calculated from G to R and not from YY.
Neil