1998 paper - preset shunts

[Peter]

I have attempted the 1998 aspect sequence chart.

Where some of the main signals preset a shunt signal I thought this should somehow be shown on the chart (maybe just a note against the main signal). Looking at the model answer in the study pack there is no mention of the preset shunts at all. Can anyone explain why they are not shown/mentioned?

Thanks.

I'm not an expert in this, but from what I know of preset shunts, although the calling or setting of the shunt may be proved at the route level, I have never seen any aspect level proving. If the aspect shown by the shunt is not proved in the main aspect, putting it on the aspect sequence chart would have no value. Thinking about it, given that the aspect level controls for the main signal are likely to be more onerous that for the preset shunt element, if the preset shunt route has set, any aspect level controls that would hold the shunt signal would also hold the main signal at danger.

I'd be interested to learn more if someone else has something to add.

Peter