Where does the dimension of the different AREMA turnout come from? I'm using a number 8 straight Arema standard turnout and I dont understand from where the dimension come from. Number 8 switch are around 28.8m long for Arema but in Openrail they are more around 23m long. So where does this number come from? The angle ratio is good but not the lenght.
Should I check ALL the other switch?
Please provide from where you got those numbers or verify them.
Regards
These definitions are from old Bentley Rail Track definitions, which would need some digging to find where they came in the first place. But they are the same definitions used for many years. If you can share a schematic with dimensions of the turnout (28.8m long one) we can compare it to see if there is something wrong in the OpenRail definition, or maybe it is not the same dimension or the original definitions are updated in the recent years. You can find the schematic definitions in OpenRail Designer below;
https://docs.bentley.com/LiveContent/web/OpenRail%20Designer%20CONNECT-v5/en/GUID-C4B945E3-686A-4321-BF7F-3809A2C54C7C.html
You should refer to A.R.E.M.A. Standard Plans #901-03, 910-13 and 920-12 for the answers to the questions regarding dimensions. Curved or Straight A.R.E.M.A. Split Switch Turnouts will have different lengths for the same frog angle.
I will send you the different AREMA standard diagram so you can check your turnout, I was really upset when I found out afterward that my geometry was not good, or not compliant because I did not doublecheck Bentley's work. Partly my fault, but it won't happen again.
AREMA plans present with various switches and frogs. However, the overall dimensions are standard across North America, with an exception of some random exceptions (smaller older railroads) of shorter leads and PS-PITO.
I am not surprised ORLD might have it incorrect, since it was developed overseas with apparent lack of familiarity with US standards, definitions, and our rail terminology
Here is a quick cheat sheet.
I would highly advise against any design engineer using the above chart.
While I do not have a current copy of AREMA standard plans, based on industry knowledge and pulling out an AREA copy of Standard Track Plans from 1996, the PS to PITO in the above chart is incorrect (at least for a #10)
AREMA (Formerly AREA) has the PS to PITO of 31.25', not 32.80'. Possibly the #11 and #10 are switched?
I would also advise any design engineer to ask the host railroad what their standards are, as turnouts can vary from AREMA in the US. As an example, Amtrak's standard #10 has a PS to PITO length of 29.90'.