(30-09-2009, 07:27 PM)Peter Wrote: In general, you have also not consistently either included or excluded the dead locking track from the route locking release. I have heard arguments both ways on this one, so would welcome some comments from people cleverer than me on this topic - should deadlocking tracks be shown to be required clear in the route locking release?
IT DEPENDS ON YOUR STANDARDS!
Basically in RRI I'd expect tracks up to but EXCLUDING dead locking tracks. If the point is locked by the track anyway, the route locking (even if it actually exists) is not shown on CTs as it adds nothing.
In SSI there is (almost always) track bob protection; i.e. if track becomes clear unexpectedly (e.g. rusty rails) then the route locking holds for 15 seconds since it does mitigate risk of loss of train shunt. Particularly important where Automatic Route Setting is provided, since computer would take advantage of apparent route availability whereas the human would hopefully stop and think: "where is that other train?"
Hence in this case there is ADDITIONAL locking after the track becomes clear after route has been set, as compared to just the track itself without any route being set. Hence for SSI then show route lockig INCLUDING the dead track. However even in SSI only provide such locking for the "post-to-post" route but not the overlap portion, so therefore for the overlap then again it is route locking EXCLUDING the dead track.
It really does not matter what standards you adopt, BUT DO BE CONSISTENT. Also be consistent within your group of Control Tables- for example if you decide to give shunt routes overlaps when doing the "route and signal", do make sure that when doing the point CTs that you also give shunt routes overlaps.
A real big give-away that you don't know what you are doing is where you produce CTs of two elements which interlock each other and you do the two inconsistantly- e.g. decide a particular set of points is called flank by a specific route when writing the point CT, yet failing to call that very set of points when writing the CT for that specific route!
This either demonstrates "carelessness" or "complete lack of comprehension", neither of which is a good impression to create on the examiner
PJW