19-03-2009, 04:17 AM
Hello Peter,
You are absolutely correct. It was supposed to have been the non stopping calculations for the G23 Activity Calculations. Please have a look as the train separation for headway, Green to Red and N values are very different from those given in Appendix W, Activity 1B Headways and Braking Calculations.
Thank you for your clarifications. In the interest of facilitating the review, I have decided to resubmit the graphs, one from C to Station D and the other from Junction B to Station D. Salient points to highlight in these graphs are:
1 Takes on board your earlier comments about the Speed Limit for turnouts as applying to the divergence or convergence only. So you will find that in the graph from C to Station D, it is a simple straight line deceleration although the impact on the signal at braking distance to the platfrom at Station D is minimal.
2 When the rear of the train clears chainage 4090 leaving Station D platform, the total distance is 450 metres. This includes 25 metres from the platform stopping position to the signal at the end of the platform (assumed), the length of the train, 200 metres, and the overlap of 225 metres.
3 Sorry for the typo - there is indeed no platform at chainage 2551. Based on the braking distance of 1115 metres, this would be the protecting signal (if using 3 aspect signalling) for entering into the platform at Station D.
4 The more onerous Stopping Requirement is from Junction B (Branch) to the platform at Station D.
Finally is there any need to work out if the Branch (which is single line operation) can support a stopping headway of 4 minutes?
Look forward to your comments.
Thank you and Regards
You are absolutely correct. It was supposed to have been the non stopping calculations for the G23 Activity Calculations. Please have a look as the train separation for headway, Green to Red and N values are very different from those given in Appendix W, Activity 1B Headways and Braking Calculations.
Thank you for your clarifications. In the interest of facilitating the review, I have decided to resubmit the graphs, one from C to Station D and the other from Junction B to Station D. Salient points to highlight in these graphs are:
1 Takes on board your earlier comments about the Speed Limit for turnouts as applying to the divergence or convergence only. So you will find that in the graph from C to Station D, it is a simple straight line deceleration although the impact on the signal at braking distance to the platfrom at Station D is minimal.
2 When the rear of the train clears chainage 4090 leaving Station D platform, the total distance is 450 metres. This includes 25 metres from the platform stopping position to the signal at the end of the platform (assumed), the length of the train, 200 metres, and the overlap of 225 metres.
3 Sorry for the typo - there is indeed no platform at chainage 2551. Based on the braking distance of 1115 metres, this would be the protecting signal (if using 3 aspect signalling) for entering into the platform at Station D.
4 The more onerous Stopping Requirement is from Junction B (Branch) to the platform at Station D.
Finally is there any need to work out if the Branch (which is single line operation) can support a stopping headway of 4 minutes?
Look forward to your comments.
Thank you and Regards