alexgoei Wrote:Hello Peter,
Please can you go through my answers for the 2002 paper.
It is quite an unusual paper as there are not many opposing routes and one of the aspect control and route entries involves the use of a ground frame.
Thank you once again for your time and attention. Look forward to your comments.
Thank you & Regards
Yes it is a bit unusual.
You are obviously not only doing a significant amount of practice (I wonder how many other candidates are; I see little evidence of it!) but also studying the Past papers for "form" to see what comes up regularly.
You also recognise that there is something unusual most years, be it level crossing or flashing sequence etc. Obviously having considered as wide a selection as possible should increase your chances of being able to deal with such things, but if something comes up that you don't actually know how to deal with DON'T PANIC. The majority of the marks will still be for the usual stuff. Just have a shot (proving both at route and aspect level would be a reasonable thing for things ranging from a shunters release to aircraft trip wire); don't deliberately ignore it- if you have absolutely no idea of what to do then just state that since at least the examiners will reaslise that you are aware that something needs to be done (and in the real world you'd ask someone or find out somehow). Don't agonise about how many marks you'd have lost because it won't be many; just carry on and concentrate on doing the bits that you can do.
Railway double track triangles as that shown are not very common and certainly stations split with platforms on two converging lines are also reasonably rare; the combination may be unique for the mainline railway. I have the feeling that I ought to know the place that inspired this layout. There was a model railway on the exhibition circuit some years back, definitely Midland Railway in the early 20th century, almost certainly Derbyshire / Peak District. It may have been Ambergate; however whereever it was I am sure that it was really quite close to the area of the country where I have been spending the last couple of weekends so that is a bit of a strange coincidence in timing.
You are right that there is no need for opposing route locking, usually such a component of the staple diet, in this area. Note however the routes in the terminal station area do give you enough to demonstrate that you know what you are doing in that department- indeed I think it is quite a good layout having a bit of many things rather than just being heavy with opposing routes as some are.
I am suprised that Ground Frames do not occur more frequently. This one seems peculiar though- I really don't see why it is a GF rather than hand points. Certainly the FPL on 1B is pretty redundant- the only thing that can take it in the facing direction is a light loco leaving the short spur. It is only a trailing point in the passenger line, yet it has been given an FPL which locks in both lies; I have to ask WHY? It could be a handpoint at such a position beyond the end of the platform and on many heritage lines in the UK it indeed is; if theere is a greater length of railways going off to a loco depot or more sidings then there would be a sign at the end of the platform stating "Passenger trains must not pass this notice" and from thereon points would be handpoints. It makes precious little more sense on the runround yard- any train running in will already have passed over set of handpoints. There is also no stop board etc to act as an end of movement authority prior to encountering the point 1A- I suppose the one advantage over handpoints is that it does prevent any train in the loop converging with a loco that may be just off the platform standing on points 1B.
For the exam I think it'd be wise just to prove "Ground Frame locked and detected Normal" at both route and aspect level for any signalled move into either the platorm or the Yard line. (Note that a handsignalled move from the sidings could be made whilst GF released and potentially its points reversed- presumably the fact that 1A is reversed means that any train occupying DM must be in the spur portion .......)
I am just glad that we were not asked to do 217's CT; I really don't know a sensible way of maintaining the locking adequately yet not excessively after 137A(S) or 303A(S) used. If I were drawing the plan and I had to have the GF (perhaps we postualate that the line used to continue and has since been cut short and the pre-existing GF retained) there would be another track cirsuit CL on the Run Round yard and probably a "STOP and Obtain Instructions" noticeboard at points 1A and opposite it at the end of the platform.
However time to consider the CTs you did for the examiners' layout....
