07-10-2008, 01:41 PM
Artur Wrote:4 aspect signalling seemed to me a natural choice for main lines due to high speed and short headway. However, if you wanted to apply 20% contingency onto required headway then you would end up with... 4 aspect being not sufficient to deliver the headway... WOW! Where to go from there???
The easiest way was to reduce the contingency which appeared to be not ideal but the only way out. Was there anything ealse you could do?
Artur
Mmmmmm!
I haven't seen the question paper but one person tells me that 3 aspects are sufficient, yet another that even 4 aspects barely achieve required headway. I don't know what the truth is, but I detect inconsistency, so it looks like ione of you got your numbers wrong ......
PJW