22-09-2012, 06:47 AM
Hello,
Regarding the 2009 mod 2 layout, and similar layouts with mixed traffic - my approach was to use 4 aspect signalling purely because of the difference in braking distances of the traffic involved. The braking distance of one train type (say passenger) is twice that of the other train type (say freight). By using 4 aspect signalling, the passenger trains can start braking at the double yellow aspects while the freight trains can start braking at the single yellow aspects. Compared to a 3 aspect solution, the 4 aspect solution ensures a reasonable distance between the relevant yellow aspect and the red aspects for all traffic.
Having said this, I'd like to know whether this is a reasonable approach, or is this too simplistic?
Taking this further, whenever mixed traffic is present and the braking distances between passenger and freight differ by more than a factor of 1.5, would it be justifiable to use 4 aspect signalling (or should this be judged on a case by case basis)?
Many thanks,
Robbie
Regarding the 2009 mod 2 layout, and similar layouts with mixed traffic - my approach was to use 4 aspect signalling purely because of the difference in braking distances of the traffic involved. The braking distance of one train type (say passenger) is twice that of the other train type (say freight). By using 4 aspect signalling, the passenger trains can start braking at the double yellow aspects while the freight trains can start braking at the single yellow aspects. Compared to a 3 aspect solution, the 4 aspect solution ensures a reasonable distance between the relevant yellow aspect and the red aspects for all traffic.
Having said this, I'd like to know whether this is a reasonable approach, or is this too simplistic?
Taking this further, whenever mixed traffic is present and the braking distances between passenger and freight differ by more than a factor of 1.5, would it be justifiable to use 4 aspect signalling (or should this be judged on a case by case basis)?
Many thanks,
Robbie