19-04-2017, 01:05 PM
Hi all,
I am looking at 2016 Q10 and I just want you guys to confirm my assumptions are correct, because the assumptions I think I'm using are creating an ungodly complicated aspect sequence diagram, and I havn't come across such a complicated one in any study materials so far which is making me think my assumptions are incorrect.
I have gotten all my info from the modern signalling handbook 5th edition or from the IRSE mod3 study guide.
Assumption 1: all signals capable of showing stop, therefore no distant signals
Assumption 2: using standard overlap of 180m, i.e. there are no reduced overlaps
Assumption 3: Signal sighting is all OK, i.e. reading times are all above 8 seconds, there are no obstructions to this, as such I don't need any banner/splitting banner repeater signals.
Assumption 4: The signals are spaced too close for 3-aspect so it must be 4 aspect signalling (modern signalling handbook page 62 says 3 aspect ones are between 1600 and 2400 m apart)
Assumption 5: Signal 23, the turnout is 130kmph down to 80kmph, this delta is >16kmph so I need approach control, the initial speed is >96kmph so it can't be "Approach control from yellow preceeded by a double yellow" type, and Approach control from Red seems too restrictive for this so I'm thinking Approach control from yellow with flashing yellows.
Assumption 6: it says this layout has stopping and non-stopping trains on the up fast so that means Signal 27 turnout has the same approach control as assumption 5
Assumption 7: Signal 29 the turnout is 80kmph down to 65kmph, as this delta is <16kmph I do not need approach control,
I guess the fact that I think 23 and 27 both need approach control with flashing yellows is making my aspect sequence diagram huge and complicated. What do you think of these assumptions?
Oliver
I am looking at 2016 Q10 and I just want you guys to confirm my assumptions are correct, because the assumptions I think I'm using are creating an ungodly complicated aspect sequence diagram, and I havn't come across such a complicated one in any study materials so far which is making me think my assumptions are incorrect.
I have gotten all my info from the modern signalling handbook 5th edition or from the IRSE mod3 study guide.
Assumption 1: all signals capable of showing stop, therefore no distant signals
Assumption 2: using standard overlap of 180m, i.e. there are no reduced overlaps
Assumption 3: Signal sighting is all OK, i.e. reading times are all above 8 seconds, there are no obstructions to this, as such I don't need any banner/splitting banner repeater signals.
Assumption 4: The signals are spaced too close for 3-aspect so it must be 4 aspect signalling (modern signalling handbook page 62 says 3 aspect ones are between 1600 and 2400 m apart)
Assumption 5: Signal 23, the turnout is 130kmph down to 80kmph, this delta is >16kmph so I need approach control, the initial speed is >96kmph so it can't be "Approach control from yellow preceeded by a double yellow" type, and Approach control from Red seems too restrictive for this so I'm thinking Approach control from yellow with flashing yellows.
Assumption 6: it says this layout has stopping and non-stopping trains on the up fast so that means Signal 27 turnout has the same approach control as assumption 5
Assumption 7: Signal 29 the turnout is 80kmph down to 65kmph, as this delta is <16kmph I do not need approach control,
I guess the fact that I think 23 and 27 both need approach control with flashing yellows is making my aspect sequence diagram huge and complicated. What do you think of these assumptions?
Oliver