Aspect Sequence Charts- rules to follow

[PJW]

I produced the attached for the London Study Group

[jenni.joseph9]

Hi,

This forum is really helpful for those who want to develop their skills in Railway Signalling. Thanks alot for all of those who are guiding us in one way or the other...

Again my query is not related to the Exam point of view and query follows...

Regulation is applied on a signal when there are level crossings with in the route. In the aspect sequence chart, do we need to show the regulations as they are always required for the aspect clearance?

Also if there are interlocked gates with in a route, then do we need to show that the gates are closed to road traffic and the barriers detected down, as the aspect clearance always requires the barriers detected down.


Thanks again.

Regards

[PJW]

No aspect SEQUENCE charts do not show (most of the) controls in the Aspect (i.e. the change from the most restrictive to the next less restrictive- generally from red to yellow); they show
a) the controls applicable to the "better aspects" i.e the less restrictive aspects dependent upon the aspect displayed by the signal ahead,
b) those other special controls imposed applicable to the regulation of speed- such as a Warner route up to a ROL, the approach release for a speed restricted route through a junction, those relating to under-braking of a signal section etc.

So level crossing controls are not shown (although there could be an argument for showing any delayed clearance imposed on a signal- such as a platform starter needing to allow a staff barrow crossing light time to give warning for staff to get clear). Certainly not controls such as barriers detected down.

Hi,

This forum is really helpful for those who want to develop their skills in Railway Signalling. Thanks alot for all of those who are guiding us in one way or the other...

Again my query is not related to the Exam point of view and query follows...

Regulation is applied on a signal when there are level crossings with in the route. In the aspect sequence chart, do we need to show the regulations as they are always required for the aspect clearance?

Also if there are interlocked gates with in a route, then do we need to show that the gates are closed to road traffic and the barriers detected down, as the aspect clearance always requires the barriers detected down.


Thanks again.

Regards

[jenni.joseph9]

Hi,

We have not seen any controls related to Level crossings in the Aspect sequence chart(ASC). It could be client requirement to include such controls in the ASC. Now we are producing those charts with the level crossing controls as our client has given a comment and shall upload them here, once they get approved. That may be of some use.

Thanks & Regards.

[PJW]

Interested to see.

As a contractor then of course one has to take notice of client requirements; however also need to recognise that sometimes there are specific people in client organisations that actually have a very personal view of the world and start stipulating things that may not actually be their company policy and then implementing such can lead to inconsistency across sites.
Sometimes "less is more" and too much information that is not strictly necessary for a drawing just adds to the clutter and gives potential for getting out of date when the key defning document is updated and therefore becomes positively detrimental. It would be interesting to unerstand the ratonale lying behind what you interpret as a client requirement.

Hi,

We have not seen any controls related to Level crossings in the Aspect sequence chart(ASC). It could be client requirement to include such controls in the ASC. Now we are producing those charts with the level crossing controls as our client has given a comment and shall upload them here, once they get approved. That may be of some use.

Thanks & Regards.