One of the popular (although not necessarily the best attempted) questions was this one regarding platform sharing. Since it was selected, it has become more topical with the publication of the RAIB Report into the collision at Plymouth.
On the Saturday afternoon at the event, we discussed many of the component parts from which to construct an answer (after having looked at some photographs and diagrams to trigger conversation) but had no time left actually to construct an answer from these. Hence I have taken one of the best pre-event answers (selected the typed on rather than handwritten just because made it easier for me to modify, tough both had their merits) and have rewritten certain bits to further improve. However I have left a few items in identified by changing to red strike-through text) to show that these items were not strictly relevant (e.g. asked for "special" and things listed were in no way special in the context of the question so would not have been scoring any marks); this answer is attached.
I think that anyone would be doing very well to achieve this sort of answer in exam conditions; in terms of quantity I suspect that would equate to nearly 4 pages of typical handwriting which puts at the upper limit of what can reasonably be achieved in terms of quantity. I think that this would "stake a good claim" to achieving the vast majority of the marks available; one can always further refine an answer but I'd like to think this would get in the high 90% if it had actually been produced in exam conditions. Therefore represents something to aspire to, rather than have a realistic chance of achieving in an exam; however it sets a benchmark for calibration- i.e. if your answer could get some 50% of this content distributed evenly across the question, then it wouldn't be far off from achieving a Pass.
Question 8
Describe TWO distinct circumstances which might give an operational need for a train to enter a platform line already occupied by another train. [4marks]
For a signalling system of your choice, explain the following, giving reasons and identifying any limitations:
On the Saturday afternoon at the event, we discussed many of the component parts from which to construct an answer (after having looked at some photographs and diagrams to trigger conversation) but had no time left actually to construct an answer from these. Hence I have taken one of the best pre-event answers (selected the typed on rather than handwritten just because made it easier for me to modify, tough both had their merits) and have rewritten certain bits to further improve. However I have left a few items in identified by changing to red strike-through text) to show that these items were not strictly relevant (e.g. asked for "special" and things listed were in no way special in the context of the question so would not have been scoring any marks); this answer is attached.
I think that anyone would be doing very well to achieve this sort of answer in exam conditions; in terms of quantity I suspect that would equate to nearly 4 pages of typical handwriting which puts at the upper limit of what can reasonably be achieved in terms of quantity. I think that this would "stake a good claim" to achieving the vast majority of the marks available; one can always further refine an answer but I'd like to think this would get in the high 90% if it had actually been produced in exam conditions. Therefore represents something to aspire to, rather than have a realistic chance of achieving in an exam; however it sets a benchmark for calibration- i.e. if your answer could get some 50% of this content distributed evenly across the question, then it wouldn't be far off from achieving a Pass.
Question 8
Describe TWO distinct circumstances which might give an operational need for a train to enter a platform line already occupied by another train. [4marks]
For a signalling system of your choice, explain the following, giving reasons and identifying any limitations:
- What action the signaller or automatic route setting system performs before initiating such an operational move. [4 marks]
- What special interlocking conditions are proved before for this type of route can be set. [5 marks]
- What information is given to the train driver and how is it conveyed. [4 marks]
- What protection exists to prevent collision [4 marks]
- What additional measures could be provided to minimise risk of collision. [4 marks]
PJW