Hello,
I have a question about points .2 and .3 on turnout definitions.
I understand .2 relates to the 'Distance along main line' field when creating a definition, but what is this supposed to align with in reality? I've made the assumption in the past that this would indicate the last long bearer (LLB) position. Does .3 also relate to the LLB position (on the turnout route)?
Hi Andrew,
Are you based in the UK? This extract from Network Rail's RE/PW/1214 (also see 1204) may help decipher the Bentley terminology. Basically for Network Rail S&C the .2 is the intersection point (IP). For other countries it can vary - with UIC S&C I think the .2 is the crossing heel (rather than IP).
The LLB isn't included in the NR S&C library, but you can add it manually if you wish by editing the turnout xml file. The LLB will then displayed after you complete the Connection Editor. Though note there are few quirks as it places the LLB at an angle rather than the UK convention where it's perpendicular to the main line.
Yes I am Paul. There does seem to be some inconsistency in how the definitions are applied for different S&C designs. Turnout Heel is not a well defined position. For transitioned turnouts it makes sense that this is the end of the clothoid element (i.e. tangent to straight track), but for natural/circular turnouts, this appears to be an arbitrary point that doesn't have any relation to the alignment.
That's correct Paul. Points 2 and 3 are to the heel of frog / crossing. The point at which a stock rail can be connected.