During the time that the website was disabled whilst the exam was being undertaken at locations around the world, I received the following:
Quote:Hello Peter,
I suppose its quite OK to tell you about this morning's Module 2 layout as the exams in the UK must well be underway by now.
Station D was a station with four tracks of which two inner ones lead to a turnback siding offest to one side of the Main while the other two straddled the Up and Down Main. Coupling and Uncoupling of trains at Platforms 1 & 2 were required, so a must for call-ons since the depot was just before the station.
Near Station D was a depot with two sidings, a train wash track, headshunt and reception track. I suppose the way to treat the depot was to treat it like a Freight depot.
As I had expected, the layout had a level crossing. The level crossing was located just before Station D and it had 300 vehicles per peak hour so moderately busy I think. I decided to go for Manual Barrier Crossing which I think is the easiest to do, but forgot to mention monitored by CCTV remotely although the symbols correspond with the srtandards used by Network Rail. Put in a short justification for MCB.
For non stopping which was for trains every 10 minutes, two aspect with distant signals was OK but the determinant was really the stopping.
No contingency for headway required - so even with stopping three aspect will do the job although as usual four aspect would be more suitable given the numerous junctions there. Headway required was 3.5 mins.
I made an error which cost me some rework and time when computing the stopping; for the distance between signals I made the mistake of using the distance for the headway of 120 km/h (1115 metres) instead of the permitted of 140 km/h (of 1515 metres) but discovered it in time before I started putting down the signals.
So assumptions, non stopping and stopping were all there like in the practices posted on the forum.
I managed to put in the signals for one direction and was able to show transition from 4 to 3 aspect but did not have time to name the track circuits and put in the signals for the rest of the plain line layout. Most of my effort was concentrated around Station D, as well as trapping points for the reception track and putting the normal lie from the sidings so that any runaway was diverted from the mainline.
Would have liked to do and add in more but time did not permit.
But having said that I must still say that I enjoyed the layout and must say that in this attempt I was able to put in so much more than I have done so in the past.
It may however be still not good enough so we shall see.
Over the next few weeks may still submit for your comment an attempt on the 2004 layout, a comparison of ABCL, AOCL, AHBC distilled from RSPG 2E and GN 0642 (?) as well as reduced overlap/ROL distances extracted from one of the standards for posting on the Forum.
Cheers
Alex
PJW