2013 Aspect Sequence

[YENDRI]

Thanks Peter for the Valuable guidance.

If the aspect displayed only gives information about the aspect ahead and does not convey any information about the speed then it solved my query.

Kind regards,
Yendri Lismana

[asrisaku]

This is new one. Could any one of you have comments?

Thanks
Arnut

[BastowM]

Hello moderators,

Please find attached my attempt at this question. Your comments would be very much appreciated.

Thanks in anticipation.
Mike

[PJW]

Hello moderators,

Please find attached my attempt at this question. Your comments would be very much appreciated.

Thanks in anticipation.
Mike

Looks pretty good to me as far as the chart is concerned; however you did NOT answer all the question.
There would have been marks for listing the aspects / indicators / combinations thereof and particularly for giving the meaning for the train driver and unless there was a sheet I missed you just didn't do this.  Also very light on assumptions.

I think you were right to introduce the "non-red" signal.
The MAY-FA for the diverging route to the branch does not seem appropriate for the facing points that seem to me only to be 50km/h; however I have annotated your chart on this basis.
It may not be obvious to those brought up on Computer Based Interlockings, but Aspect Sequence traditionally depicts logic generally implemented outside of the interlocking by lineside circuits between the aspect relays of the various signals housed physically close to the signal they controlled and therefore normally had to be tested with staff distributed along the lineside towards the end of the testing process (whereas the interlocking and aspect controls within an interlocking would have been done rather earlier). 

It isn't 100% but I think of each line between signals as representing a line circuit from the fuse at the "exit" signal back to the aspect relay at the "entrance" signal.  Of course the various types of approach release, including the
Delayed Yellow associated with a ROL beyond the next signal, are implemented within the interlocking which is one reason why I tend to like to show them dashed (as indeed you have).  Note that for MAY-FA, just as for MAR, it is the junction signal which is approach released and the FY (and FYY) on the approach arise as a CONSEQUENCE of the approach release, so your dashed line for this at 13 signal is incorrect.  Yes there is a feedback to the junction signal that the signal in rear has actually started to flash (or else the MAY-FA attempt is quickly aborted) and there is a minimum distance that the train must be on the approach of the FY when it starts, but these are interlocking controls in the diverging route of the junction signal and do not get shown on the Aspect Sequence chart (but actually a # note on the diagram at the junction signal is a good idea).  Even where there is MAY-FA, then also need to show MAR as the fall-back alternative.

Don't leave aspects "hanging" as for 11; best to mark the chart / diagram as "single yellow not shown"

[PJW]

Another last minute attempt that I may not have the chance to comment upon.....

[PJW]

Another last minute attempt that I may not have the chance to comment upon.....

Only the time to make some comments on the first bit, but that seemed the most valuable anyway- see attached