2005 Layout - Part 1

[asrisaku]

A couple of things that could improve it:
You have shown that the headway can be met with three aspect signalling at minimum braking with a fair degree of contingency. You have not made a comment about what the maximum over braking allowance is for your practice nor calculated what the maximum is without breaking the headway requirement.

Having made the comparison with the four aspect signalling, you have not actually said which scheme you would adopt - this would probably be self evident from what you draw on your layout, but more importantly you have not said WHY. In the case of the three aspect signalling with the stopping headway, the margin for contingency is smaller than for the non stop and, taking account of the fact that you would probably not want to (or be able to) put all signals at minimum braking, the margin would be even smaller, so based on that constraint, you may decide that opting for four aspect signalling is better.

---

Thanks Peter! Next time I’ll aware of that and I’ll put the comment 3-aspect or 4-aspect signaling is adopted and also include maximum braking distance.(1.5BD Max tolerable from YY to R for 4-aspect and 1.5BD max tolerable from Y to R for 3-aspect)

It is the victim of a cut line, but I cannot see properly what you have done with the signal that 117 reads up to - at some point you have gone from a 4 to three aspect sequence and I am not sure that you have quite done this correctly. I assume the signal after 117 to be a three aspect signal since i can see your "Y>R" annotation. From the positions on the plan, the post to post distance here is about 700m so for a three aspect Y>R, this would be insufficient. I would expect to see a G,Y,YY signal somewhere in the transition.

Could you please check out my new attachment in this reply for transition zone from 4-aspect to 3-aspect?

You have put a ROL on 118 signal which is not the correct use of ROL - it is for a warner route up to a convergence, not for bringing a signal closer to a facing junction.

Yes I agree with you. If I understand well, I need to position the signal 118 at 2700 to have a full overlap 180m. Could you please explain me the function of ROL? As I understand, the benefit is to have another opposing route can be set when the point is not locked. Am I right?

I may have got this wrong, but the route boxes that you posted do not appear to match up - for instance, 110 signal is shown here with a SI, but you have JI1 and JI4 in the route box attachment. Similarly, 107 has no MI associated with it on the plan, but has an entry for MI in the route boxes.

I have changed the layout to become JI1 and JI4 and made the route box. The ones that I attached to you seem obsolete. There were a lot of things missing my 2005 layout against with my 2009 attempt.

I am afraid I will have to leave it there for now.
Peter

Sincerely I really appreciate it for your help and it does really help me to go forward in my plan.