Arpan,
For the branch line look at the thread reagarding the 2011 layout to see if that answers it for you; if not ask again.
Basically the headway requirement is low so that the stop-stop distance could be pretty large; in reality on a railway there may well be other reasons to have signals more frequently (protection of level crossings, pointwork etc). so one tends to place stop signal for each of these constraints (each with their own distant of course) and then just cross check that no block section is too long that it is incompatible with the capacity constraint- if it is then split section nominally in half by an intermediate signal (and its distant), but positioning sensibly (often to somewhere that makes operational sense, is easy for the technician to access etc)
For the branch line look at the thread reagarding the 2011 layout to see if that answers it for you; if not ask again.
Basically the headway requirement is low so that the stop-stop distance could be pretty large; in reality on a railway there may well be other reasons to have signals more frequently (protection of level crossings, pointwork etc). so one tends to place stop signal for each of these constraints (each with their own distant of course) and then just cross check that no block section is too long that it is incompatible with the capacity constraint- if it is then split section nominally in half by an intermediate signal (and its distant), but positioning sensibly (often to somewhere that makes operational sense, is easy for the technician to access etc)
(28-09-2012, 09:31 AM)arpan_singhania Wrote: Hi Peter,
My calculations on the layout worked out to be 4 aspect on the mainline with nominal average spacing of 1000 m.
Taking account of the derivations for Safety 0.5s<=D4<=0.75s and
Service based on D4<=(DGR/3).
I am a little confused on the branch line. Given statements points that the branch line require isolated 3 aspect signalling, but cant find the stop-stop distance. Please help me.
Thanks & Regards,
Arpan Singhania
PJW