(22-04-2011, 09:40 PM)Sid G Wrote: I have been practising attempting past papers and have the following questions arising from attempting the 2009 Main Line layout:
1.Using distance from G to R calculations at service speed of 120km/h; I determined that 3 aspect at 140km/h permissible speed would be suitable.However,on signalling the layout;I noticed tight spacing generally.Especially between Station B and Junction D and out of the tunnel to the junction after the single line along the down branch.When I tried 4 aspect;the spacings seemed to suit all the layout generally well.Is there a way my calculations could have forewarned me as I would have run into into serious time constraints in the actual exam having started using 3 aspect?
2.For the run around move between F and G;considering the distance, is it ok to signal using shunt moves on the Up Goods considering the distance?
3.Is it ok to signal the line from Station C to Station B using 3 aspect in the C to B direction with a stop and distant signal before the fixed diamond junction and permanent stop signal train length beyond platform for terminating trains.From B to C;use the platform 4 aspect starter to signal all the way to the buffer stop at B.Assuming axle counters for track sections.
Thanks PJW and Jerry.Your replies have cleared most of my grey areas about how to signal this layout.